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<front>
<journal-meta>
<journal-id journal-id-type="publisher-id">LV</journal-id>
<journal-id journal-id-type="nlm-ta">Lijec Vjesn</journal-id>
<journal-title-group>
<journal-title>Lijecnicki Vjesnik</journal-title>
<abbrev-journal-title abbrev-type="pubmed">Lijec. Vjesn.</abbrev-journal-title>
</journal-title-group>
<issn pub-type="ppub">0024-3477</issn>
<issn pub-type="epub">1849-2177</issn>
<publisher><publisher-name>Croatian Medical Association</publisher-name></publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="publisher-id">LV-142-148</article-id>
<article-id pub-id-type="doi">10.26800/LV-142-5-6-27</article-id>
<article-categories><subj-group subj-group-type="heading"><subject>Drugs and procedures</subject></subj-group>
</article-categories>
<title-group>
<article-title>Hemodinamski monitoring: od invazivnog nadzora do personaliziranog pristupa</article-title>
<trans-title-group xml:lang="en">
<trans-title>Haemodynamic monitoring: from invasive monitoring to personalised medicine</trans-title>
</trans-title-group>
</title-group>
<contrib-group>
<contrib contrib-type="author" corresp="yes"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0002-6883-2108</contrib-id><name><surname>Bari&#x0161;in</surname><given-names>Stjepan</given-names></name><xref ref-type="aff" rid="aff1"><sup>1</sup></xref><xref ref-type="aff" rid="aff2"><sup>2</sup></xref></contrib><contrib contrib-type="author"><name><surname>Ostovi&#x0107;</surname><given-names>Helena</given-names></name><xref ref-type="aff" rid="aff1"><sup>1</sup></xref><xref ref-type="aff" rid="aff2"><sup>2</sup></xref></contrib><contrib contrib-type="author"><name><surname>Gospi&#x0107;</surname><given-names>Ivan</given-names></name><xref ref-type="aff" rid="aff1"><sup>1</sup></xref></contrib><contrib contrib-type="author"><name><surname>&#x0110;uzel</surname><given-names>Viktor</given-names></name><xref ref-type="aff" rid="aff3"><sup>3</sup></xref></contrib><contrib contrib-type="author"><name><surname>Bari&#x0161;in</surname><given-names>Ana</given-names></name><xref ref-type="aff" rid="aff4"><sup>4</sup></xref></contrib><contrib contrib-type="author"><name><surname>Grubje&#x0161;i&#x0107;</surname><given-names>Igor</given-names></name><xref ref-type="aff" rid="aff5"><sup>5</sup></xref></contrib><contrib contrib-type="author"><name><surname>&#x017D;up&#x010D;i&#x0107;</surname><given-names>Miroslav</given-names></name><xref ref-type="aff" rid="aff5"><sup>5</sup></xref></contrib>
<aff id="aff1"><label>1</label>Klinika za anesteziologiju, reanimatologiju i intenzivnu medicinu Stomatolo&#x0161;kog fakulteta u Zagrebu, Klini&#x010D;ka bolnica Dubrava, Referentni centar Ministarstva zdravstva za hemodinamski nadzor u intenzivnom lije&#x010D;enju kirur&#x0161;kih bolesnika</aff>
<aff id="aff2"><label>2</label>Medicinski fakultet Sveu&#x010D;ili&#x0161;ta Josipa Jurja Strossmayera u Osijeku, <addr-line>Osijek</addr-line></aff>
<aff id="aff3"><label>3</label>Sveu&#x010D;ili&#x0161;ne bolnice Barking, Havering i Redbridge, NHS Trust, London, Ujedinjeno Kraljevstvo</aff>
<aff id="aff4"><label>4</label>Poliklinika Medikol, <addr-line>Zagreb</addr-line></aff>
<aff id="aff5"><label>5</label>Klinika za anesteziologiju, intenzivnu medicinu i lije&#x010D;enje boli, Medicinski fakultet Sveu&#x010D;ili&#x0161;ta u Rijeci, <institution>KBC Rijeka</institution>, <addr-line>Rijeka</addr-line></aff>
</contrib-group>
<author-notes>
<corresp id="cor1">Adresa za dopisivanje: Doc. dr. sc. Stjepan Bari&#x0161;in, dr. med., <ext-link ext-link-type="uri" xlink:href="https://orcid.org/0000-0002-6883-2108">https://orcid.org/0000-0002-6883-2108</ext-link> Bulvanova 20, 10000 Zagreb; e-po&#x0161;ta: <email xlink:href="sbarisin@gmail.com">sbarisin@gmail.com</email></corresp></author-notes>
<pub-date pub-type="epub-ppub"><month>06</month><year>2020</year></pub-date>
<volume>142</volume>
<issue>5-6</issue>
<fpage>148</fpage>
<lpage>154</lpage>
<permissions>
<copyright-year>2020</copyright-year>
<copyright-holder>Croatian Medical Association</copyright-holder>
<license xlink:href="http://creativecommons.org/licenses/by-nc-nd/4.0/" specific-use="CC BY-NC-ND 4.0"><license-p>This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives (CC BY-NC-ND) 4.0 License.</license-p></license>
</permissions>
<abstract>
<title>SA&#x017D;ETAK</title>
<p>Kontinuirano pra&#x0107;enje sr&#x010D;anoga minutnog volumena (CO) i odr&#x017E;avanje normovolemije primarni su ciljevi optimizacije hemodinamskog (HD) statusa svakoga kriti&#x010D;nog bolesnika. Za razliku od samo invazivnog nadzora i intermitentne termodilucijske procjene CO-a s pomo&#x0107;u plu&#x0107;nog arterijskog katetera, danas se puno vi&#x0161;e primjenjuju minimalno invazivne i potpuno neinvazivne metode. Minimalno invazivne metode koje se s pomo&#x0107;u transpulmonalne termodilucije (TD) pri procjeni CO-a slu&#x017E;e analizom krivulje tlaka pulsa dijele se na starije, kalibrirane i novije, nekalibrirane. Dinami&#x010D;ki parametri kao &#x0161;to su varijacija udarnog volumena (SVV) i varijacija pulsnog tlaka (PPV), koji se kontinuirano prate ovim metodama, puno preciznije odra&#x017E;avaju potrebu za ciljanom optimalnom volumnom nadoknadom (GDVT) u odnosu prema tradicionalnim, stati&#x010D;kim parametrima (CVP i PCWP). Suvremenije neinvazivne kontinuirane metode koje jo&#x0161; nisu dovoljno validirane u klini&#x010D;kim uvjetima jesu aplanacijska tonometrija, pletizmografija, metoda djelomi&#x010D;noga ponovnog udaha parcijalnog CO<sub>2</sub> i procjena CO-a temeljena na tranzicijskom vremenu pulsnog vala. Torakalna elektri&#x010D;na bioimpedancija i bioreaktancija koriste se slabom naizmjeni&#x010D;nom strujom koja prolaskom kroz prsni ko&#x0161; kontinuirano u sistoli prati fazne pomake napona i analizira krivulju udarnog volumena (SV). Poznato je da primjenom volumena u oko 50% kriti&#x010D;nih bolesnika ne&#x0107;e do&#x0107;i do pove&#x0107;anja SV-a, stoga je va&#x017E;no prije primjene volumena kontinuiranim pra&#x0107;enjem SV-a/CO-a procijeniti ho&#x0107;e li biti prikladnoga HD odgovora na volumen. Danas postoji vi&#x0161;e metoda kojima se mo&#x017E;e procijeniti odgovor na volumnu nadoknadu poput mjerenja varijacije dijametra donje i gornje &#x0161;uplje vene, okluzijskog testa na kraju ekspirija, testa respiratorne sistoli&#x010D;ke varijacije, SVV-a i PPV-a. Pasivno podizanje nogu (PLR) ima najve&#x0107;u prediktivnu vrijednost u dinami&#x010D;koj procjeni volumnog statusa kod hemodinamski nestabilnog bolesnika.</p>
</abstract>
<trans-abstract xml:lang="en">
<title>SUMMARY</title>
<p>Continuous monitoring of cardiac output (CO) and maintenance of normovolaemia are the primary aims of haemodynamic (HD) optimization in every critical care patient. Previously, invasive monitoring and intermittent thermodilution with pulmonary artery catheterization were the main methods for determining CO. However, the methods more commonly used today are either minimally invasive or non-invasive. Minimally invasive methods of transpulmonary thermodilution (TD) in CO monitoring analyze the pulse pressure curve and are divided into older, calibrated and newer, non-calibrated systems. Dynamic parameters such as stroke volume variation (SVV) and pulse pressure variation (PPV) which can be continuously monitored, are far more precise in determining the optimal goal-directed volume therapy (GDVT) in comparison to the traditional static parameters such as CVP and PCWP. Modern non-invasive continuous methods, that are still not fully validated in clinical circumstances are: applanation tonometry, plethysmography, partial CO2 rebreathing technique, and pulse wave transit time measurements of CO. Thoracic electrical bioimpedance and bioreactance uses a weak alternating current, and through the phasic variations in the charge of the current during a systolic cycle, enables continuous analysis of the stroke volume (SV) curve. It is known that volume administration will not increase SV in roughly 50% of critically ill patients (<italic>fluid non-responders</italic>), therefore, prior to volume administration, through continuous SV/CO monitoring, it is important to assess whether a patient will have an adequate haemodynamic response to fluid administration (<italic>responders</italic>). There are some methods available for predicting the response to fluid administration, like measurement of variation in the diameter of the superior and inferior vena cava, the end-expiratory occlusion test, respiratory systolic variation test, SVV and PPV. The passive leg raising (PLR) test has the highest predictive score in dynamic assessment of the volume status in a haemodynamically unstable patient.</p>
</trans-abstract>
<kwd-group kwd-group-type="author"><kwd>Deskriptori HEMODINAMSKI NADZOR &#x2013; metode</kwd><kwd>HEMODINAMIKA &#x2013; fiziologija</kwd><kwd>SR&#x010C;ANI MINUTNI VOLUMEN &#x2013; fiziologija</kwd><kwd>UDARNI VOLUMEN &#x2013; fiziologija</kwd><kwd>INTRAOPERACIJSKI NADZOR &#x2013; metode</kwd><kwd>TERMODILUCIJA &#x2013; metode</kwd><kwd>KRITI&#x010C;AN BOLESNIK &#x2013; lije&#x010D;enje</kwd><kwd>LIJE&#x010C;ENJE TEKU&#x0106;INOM</kwd><kwd>KRVNI VOLUMEN</kwd><kwd>ARTERIJSKI TLAK</kwd></kwd-group>
<kwd-group kwd-group-type="translator" xml:lang="en"><title>Descriptors </title><kwd>HEMODYNAMIC MONITORING &#x2013; methods</kwd><kwd>HEMODYNAMICS &#x2013; physiology</kwd><kwd>CARDIAC OUTPUT &#x2013; physiology</kwd><kwd>STROKE VOLUME &#x2013; physiology</kwd><kwd>MONITORING, INTRAOPERATIVE &#x2013; methods</kwd><kwd>THERMODILUTION &#x2013; methods</kwd><kwd>CRITICAL ILLNESS &#x2013; therapy</kwd><kwd>BLOOD VOLUME</kwd><kwd>FLUID THERAPY</kwd><kwd>ARTERIAL PRESSSURE</kwd></kwd-group>
</article-meta>
</front>
<body>
<p>Suvremeni hemodinamski (HD) monitoring u intenzivnoj medicini vezan je za kontinuirano pra&#x0107;enje fiziolo&#x0161;kih varijabla u realnom vremenu uz procjenu odgovora na terapijsku intervenciju. Ispravnost na&#x0161;ih postupaka vezana je ponajprije za razumijevanje fiziolo&#x0161;kih procesa. (<xref ref-type="bibr" rid="r1"><italic>1</italic></xref>) Stoga se od monitoringa <italic>per se</italic> ne mo&#x017E;e o&#x010D;ekivati pobolj&#x0161;ani ishod bolesnika, ve&#x0107; precizno pra&#x0107;enje terapijskih odluka u kriti&#x010D;nih bolesnika. (<xref ref-type="bibr" rid="r2"><italic>2</italic></xref>) Sr&#x010D;ani minutni volumen (CO, skr. od engl. <italic>cardiac output</italic>) temeljna je hemodinamska varijabla koja utje&#x010D;e na optimizaciju perfuzijskog tlaka i dostavu kisika (DO<sub>2</sub>) radi obnove prikladnoga stani&#x010D;nog metabolizma. Pra&#x0107;enje CO-a i odr&#x017E;avanje normovolemije primarni su ciljevi optimizacije HD statusa uz po&#x0161;tovanje jasnih klini&#x010D;kih protokola. No, pra&#x0107;enje CO-a ponajprije je vezano uz procjenu makrocirkulacije, ali nikako i mikrocirkulacije koje su u me&#x0111;usobnoj prirodnoj koherenciji. U patofiziolo&#x0161;kim klini&#x010D;kim stanjima (npr., te&#x0161;ka sepsa, politrauma, sindrom malenoga sr&#x010D;anog minutnog volumena) dolazi do disbalansa mikrocirkulacije kao kriti&#x010D;ne odrednice perfuzije tkiva. (<xref ref-type="bibr" rid="r3"><italic>3</italic></xref>) U takvim stanjima pri volumnoj nadoknadi dolazi do gubitka makro-mikrocirkulacijske koherencije, &#x0161;to dovodi do prekida korelacije izme&#x0111;u CO-a i tlaka pulsa (PP). (<xref ref-type="bibr" rid="r4"><italic>4</italic></xref>, <xref ref-type="bibr" rid="r5"><italic>5</italic></xref>)</p>
<p>Svjedoci smo brze evolucije tehnolo&#x0161;kog razvoja u primjeni HD monitoringa: od invazivnoga, preko minimalno invazivnog do potpuno neinvazivnoga. (<xref ref-type="bibr" rid="r6"><italic>6</italic></xref>) Konceptualno je do&#x0161;lo i do promjena u pristupu pra&#x0107;enju i razumijevanju hemodinamskih varijabla: od stati&#x010D;kih (CVP i PCWP)* prema dinami&#x010D;kim parametrima kao &#x0161;to su varijacija udarnog volumena (SVV) i varijacija pulsnog tlaka (PPV), od apsolutnih broj&#x010D;anih vrijednosti do kontinuiranog pra&#x0107;enja trendova u realnom vremenu i od razli&#x010D;itih klini&#x010D;kih algoritama i protokola prema personaliziranom pristupu. (<xref ref-type="bibr" rid="r7"><italic>7</italic></xref>)</p>
<sec sec-type="other1">
<title>Hemodinamski monitoring: gdje smo danas i kamo idemo?</title>
<sec>
<title>Od invazivnog intermitentnog nadzora prema neinvazivnomu kontinuiranom pra&#x0107;enju</title>
<p>Intermitentna termodilucijska metoda procjene CO-a srca temelji se na plu&#x0107;nom arterijskom kateteru (PAK) na &#x010D;ijem se vrhu nalazi napuhani balon koji flotiraju&#x0107;i dospijeva u distalni ogranak plu&#x0107;ne arterije. Ako je vrh katetera zaglavljen u ogranku arterije podru&#x010D;ja Westove zone 1, tad plu&#x0107;ni tlak odra&#x017E;ava alveolarni tlak, a ako je, primjerice, u Westovoj zoni 3, tad je to tlak lijevog atrija ili teledijastoli&#x010D;ki tlak lijeve klijetke. (<xref ref-type="bibr" rid="r8"><italic>8</italic></xref>, <xref ref-type="bibr" rid="r9"><italic>9</italic></xref>) Glavne varijable koje se ovom metodom dobivaju jesu minutni volumen, plu&#x0107;ni arterijski tlakovi, vaskularni otpori i mije&#x0161;ana venska saturacija. Modernija, kontinuirana termodilucija rabi filament ugra&#x0111;en u kateter (<italic>Vigilance</italic> ili <italic>OptiQ</italic>) koji povremeno oda&#x0161;ilje temperaturu zagrijavaju&#x0107;i krv u desnom srcu. Razliku temperature prepoznaje termistor na vrhu plu&#x0107;nog katetera koji svakih 30 &#x2013; 60 min skuplja podatke i nakon 5 &#x2013; 15 min revidira vrijednosti CO-a desnog srca. Od 1970-ih godina pa sve do danas termodilucija ostaje i dalje zlatni standard pri procjeni hemodinamskog profila kriti&#x010D;nog bolesnika, kao i u usporedbi i validaciji s naprednijim i manje invazivnim tehnologijama. Danas je njezina uporaba ograni&#x010D;ena na rizi&#x010D;ne kardiokirur&#x0161;ke bolesnike i kompleksne hemodinamske situacije. (<xref ref-type="bibr" rid="r10"><italic>10</italic></xref>)</p>
<p>Novije, manje invazivne metode u procjeni CO-a temelje se na analizi krivulje tlaka pulsa koju su prvi opisali Erlanger i Hooker jo&#x0161; 1904. godine. (<xref ref-type="bibr" rid="r11"><italic>11</italic></xref>) Wesseling i suradnici (<xref ref-type="bibr" rid="r12"><italic>12</italic></xref>) tek su 80 godina poslije razvili algoritam izra&#x010D;una udarnog volumena integriraju&#x0107;i povr&#x0161;inu ispod krivulje arterijskog tlaka pulsa u fazi sistole. Manje invazivne metode koje su danas dostupne na klini&#x010D;kom tr&#x017E;i&#x0161;tu, a slu&#x017E;e se analizom krivulje tlaka pulsa temelje se na transpulmonalnoj termodiluciji (TD) te se mogu podijeliti na starije, kalibrirane metode (<italic>PiCCOplus</italic>, <italic>VolumeView, LidCOplus</italic>) i novije, nekalibrirane metode (<italic>FloTrack/Vigileo</italic>, <italic>LiDCOrapid</italic>, <italic>ProAQT/Pulsioflex</italic>). Analiza krivulje invazivnog arterijskog tlaka temelji se na na&#x010D;elu ventrikuloarterijskog <italic>couplinga</italic>, &#x0161;to zna&#x010D;i da je krivulja tlaka pulsa odre&#x0111;ena udarnim volumenom (SV) lijeve klijetke i obrnuto proporcionalna arterijskom otporu. Transpulmonalna termodilucija kao indikator rabi hladni injektat ili litij koji se injicira kroz centralni venski kateter. Indikator prolazi desnim srcem, plu&#x0107;nom cirkulacijom, lijevim srcem sve do ogranka descendentne aorte gdje je smje&#x0161;ten termistor na vrhu arterijskog katetera u femoralnoj arteriji. Prema modificiranoj Stewart-Hamiltonovoj jednad&#x017E;bi, krivulja transpulmonalne termodilucije druga&#x010D;ijeg je oblika, polo&#x017E;enija je i s kasnijom vr&#x0161;nom to&#x010D;kom u odnosu prema transkardijalnoj termodiluciji. Iz krivulje TD-a u manje invazivnim kalibriranim metodama dobivaju se volumetrijski parametri intratorakalnog volumena (ITBVI i GEDV), koji su objektivniji parametri procjene cirkuliraju&#x0107;eg volumena venskog bazena od CVP-a, te parametri procjene ekstravaskularne vode u plu&#x0107;ima (EVLW i PVPI). Dodatni parametri koje dobivamo analizom krivulje arterijskog tlaka jesu SVV, PVV i GEF kao parametar kontraktilnosti.</p>
<p>Druga skupina minimalno invazivnih monitora kojima nije potrebna vanjska kalibracija, odnosno koji se slu&#x017E;e autokalibracijom pri izra&#x010D;unu SV-a imaju integrirane algoritme &#x0161;to u obzir uzimaju antropometrijske, demografske podatke i parametre: impedanciju, popustljivost arterijskog bazena te sustavnu vaskularnu rezistenciju. (<xref ref-type="bibr" rid="r13"><italic>13</italic></xref>) Od nekalibriranih minimalno invazivnih monitora najvi&#x0161;e je validirana preciznost <italic>FloTraca</italic> u odnosu prema metodi TD-a. Pregledna studija Slagta i suradnika (<xref ref-type="bibr" rid="r14"><italic>14</italic></xref>) iz 2014. godine, koja je obuhvatila 65 radova na 2234 bolesnika i 44.592 opservacije, pokazala je da tre&#x0107;a generacija metode <italic>FloTraca</italic> ima veliku preciznost u uvjetima HD stabilnosti i hipodinamskim uvjetima (npr., nakon kardijalne kirurgije), ali ne i u hiperdinamskim uvjetima (npr., pri kirurgiji jetre ili u uvjetima sepse) te da je pra&#x0107;enje SVV-a u 85% kirur&#x0161;kih bolesnika dobar navje&#x0161;&#x0107;iva&#x010D; (prediktor) odgovora na volumen. S druge strane, Monnet i suradnici (<xref ref-type="bibr" rid="r15"><italic>15</italic></xref>) utvrdili su da ista metoda nije precizno mjerila HD parametre u uvjetima hipotenzije uz primjenu vi&#x0161;ih doza noradrenalina, a &#x0161;to je SVR bio vi&#x0161;i, to su i odstupanja u mjerenjima izme&#x0111;u <italic>FloTraca</italic> i transpulmonalne termodilucije bila ve&#x0107;a.</p>
<p>Ezofagealni dopler metoda je minimalno invazivnog monitoringa opisana jo&#x0161; 70-ih koja postaje popularna 90-ih godina, posebice u operacijskim uvjetima, a &#x010D;ija je validnost pri mjerenju CO-a u kriti&#x010D;no oboljelih i kirur&#x0161;kih bolesnika jasno potvr&#x0111;ena pa je stoga ta metoda uvr&#x0161;tena u smjernice NICE-a iz 2011. godine. Temelji se na procjeni brzine protoka krvi kroz descendentnu aortu i analizama oblika krivulja protoka. Metoda nije tako precizna kod abnormalne distribucije krvi izme&#x0111;u donjih i gornjih ekstremiteta te pri velikim varijacijama u volumnom statusu za vrijeme uporabe katekolamina. (<xref ref-type="bibr" rid="r16"><italic>16</italic></xref>)</p>
<p>Neinvazivne metode u procjeni sr&#x010D;ane funkcije koje se ne rabe kontinuirano jesu transtorakalna ehokardiografija (TTE) i transezofagealna ehokardiografija (TEE). Kao rutinska intraoperativna metoda kojom kardijalni anesteziolog prati tijek kardiokirur&#x0161;kog zahvata, 2D-TEE i novije ehokardiografske tehnologije (RT-3D, TDI) imaju va&#x017E;nu ulogu i u pra&#x0107;enju hemodinamski nestabilnih bolesnika u nekardijalnoj kirurgiji te kriti&#x010D;nih bolesnika u jedinicama intenzivnog lije&#x010D;enja. (<xref ref-type="bibr" rid="r17"><italic>17</italic></xref>&#x2013;<xref ref-type="bibr" rid="r19"><italic>19</italic></xref>) Iako se mogu rabiti u procjeni SV-a lijevog i desnog srca, te metode nisu prikladne u analizi CO-a srca. (<xref ref-type="bibr" rid="r20"><italic>20</italic></xref>) Neinvazivne kontinuirane metode pokazale su prednosti u procjeni HD statusa bolesnika neposredno prije indukcije anestezije, pri optimizaciji volumnog statusa danima prije po&#x010D;etka kirur&#x0161;kog zahvata, kao i u pra&#x0107;enju bolesnika s niskim do umjerenim rizikom u perioperativnim uvjetima kad nije potrebno invazivno mjerenje.</p>
<p>Od suvremenijih neinvazivnih kontinuiranih metoda koje pri pra&#x0107;enju CO-a rabe analizu krivulje tlaka pulsa metode su aplanacijske tonometrije (<italic>T-line</italic>) i pletizmografije (<italic>Clearsight</italic>, <italic>CNAP</italic>). Aplanacijska tonometrija koristi se senzorom postavljenim iznad radijalne arterije koji mehani&#x010D;kom kompresijom i kratkotrajnim prekidom protoka kroz arteriju mjeri pulsni tlak od trenutka kada transmuralni tlak postane jednak nuli. Nakon prigu&#x0161;enja krivulje pulsnog tlaka pa sve do trenutka maksimalizacije pulsnog vala na temelju autokalibracije dobiva se vrijednost CO-a s granicom pogre&#x0161;ke od 15 do 17% u odnosu prema invazivnom mjerenju tlaka radijalne arterije. (<xref ref-type="bibr" rid="r21"><italic>21</italic></xref>, <xref ref-type="bibr" rid="r22"><italic>22</italic></xref>) Pletizmografska procjena rabi LED tehnologiju s napuhanim tlakom <italic>cuffa</italic> oko prsta ruke gdje dolazi do korelacijskog izra&#x010D;una arterijskog tlaka na prstu ruke. Iz idealnoga kontinuiranog oblika krivulje tlaka pulsa mogu se izra&#x010D;unati SVV, PPV i CO, dok u uvjetima hipotermije, edema prstiju ruke i slabosti srca ovaj izra&#x010D;un nije prikladan. (<xref ref-type="bibr" rid="r23"><italic>23</italic></xref>) Metoda djelomi&#x010D;noga ponovnog udaha parcijalnog CO<sub>2</sub> temelji se na Fickovu na&#x010D;elu gdje se prati eliminacija CO<sub>2</sub> i ETCO<sub>2</sub>. S pomo&#x0107;u monitora NICO sa senzorom postavljenim na jednokratnoj petlji intubiranog bolesnika izra&#x010D;una se CO tijekom ponovnog udaha parcijalnog CO<sub>2</sub> kroz tu petlju. Ponovni udah smanjuje potro&#x0161;nju CO<sub>2</sub>, a pove&#x0107;ava ETCO<sub>2</sub>, odnosno CaCO<sub>2</sub> iz &#x010D;ega se izra&#x010D;una CO. Nedostatci ove respiratorne neinvazivne metode jesu postojanje intrapulmonalnog <italic>shunta</italic>, HD nestabilnost, trauma prsnog ko&#x0161;a i neadekvatna minutna ventilacija. (<xref ref-type="bibr" rid="r24"><italic>24</italic></xref>)</p>
<p>Za procjenu CO-a temeljenu na tranzicijskom vremenu pulsnog vala &#x2013; PWTT (<italic>esCCO</italic>, <italic>Nihon Kohden</italic>) potrebni su simultano mjerenje EKG-a, periferne saturacije i neinvazivno mjerenje krvnog tlaka na podlaktici. PWTT je tranzicijsko vrijeme od po&#x010D;etka vrha R-zupca na EKG-u do to&#x010D;ke porasta pulsnog vala u kojoj pulsni val dose&#x017E;e 30% svoje vr&#x0161;ne amplitude. Neke klini&#x010D;ke studije govore o 30 &#x2013; 80%-tnim odstupanjima u validaciji esCCO-a u odnosu prema CO-u mjerenom PAK-om, dok druge govore o preciznoj linearnoj korelaciji. (<xref ref-type="bibr" rid="r25"><italic>25</italic></xref>, <xref ref-type="bibr" rid="r26"><italic>26</italic></xref>) Metoda torakalne elektri&#x010D;ne bioimpedancije &#x2013; TEB (<italic>BioZ</italic>, <italic>Aesculon</italic>) kontinuiranog mjerenja CO-a zasniva se na prolazu slabe naizmjeni&#x010D;ne struje sinkrono sa sr&#x010D;anim ciklusom analiziraju&#x0107;i pulsatilnost vala kroz aortu u sistoli i mjere&#x0107;i vrijeme izba&#x010D;aja lijeve klijetke. Vrijednosti bioimpedancije ovise o sadr&#x017E;aju teku&#x0107;ine u prsnom ko&#x0161;u i respiraciji, a procjena je puno slabija kod HD nestabilnih bolesnika i u aritmijama. U&#x010D;injena validacija procjene CO-a TEB-om s metodom pra&#x0107;enja CO-a TD-om u 30 hemodinamski nestabilnih bolesnika nakon ve&#x0107;ih kirur&#x0161;kih zahvata pokazala je velika odstupanja. (<xref ref-type="bibr" rid="r27"><italic>27</italic></xref>, <xref ref-type="bibr" rid="r28"><italic>28</italic></xref>) Bioreaktancija (<italic>NICOM</italic>, <italic>Starling SV</italic>), kao modificirana metoda torakalne elektri&#x010D;ne bioimpedancije, jednostavna je i vrlo prakti&#x010D;na neinvazivna metoda mjerenja SV-a/CO-a. Prolaskom slabe naizmjeni&#x010D;ne struje kroz prsni ko&#x0161; kontinuirano prati fazne pomake napona ura&#x010D;unavaju&#x0107;i elektri&#x010D;ni otpor tkiva te kapacitivna i induktivna svojstva krvi. Izbacivanjem krvi iz srca u aortu tijekom sistole javlja se fazni pomak napona koji je gotovo linearan pulzacijskom protoku krvi u aorti gdje je ukupna teku&#x0107;ina u prsi&#x0161;tu stati&#x010D;na (engl. <italic>thoracic fluid content</italic> &#x2013; TFC) i ne pridonosi ukupnoj analizi krivulje SV-a. Metoda je validirana s mjerenjem CO-a termodilucijom s pomo&#x0107;u plu&#x0107;nog katetera na 110 kardiokirur&#x0161;kih bolesnika uz srednji bias od 0,06 L/min<sup>-1</sup> i prihvatljivi postotak gre&#x0161;ke od 30%, a objavljena je i visoka korelacija s mjerenjem CO-a TD-om i ezofagealnim doplerom. (<xref ref-type="bibr" rid="r29"><italic>29</italic></xref>, <xref ref-type="bibr" rid="r30"><italic>30</italic></xref>) Pasivnim dizanjem nogu (PLR) ili bolusnom tehnikom mo&#x017E;e se dinami&#x010D;ki vrlo precizno procijeniti volumni status (&#x2206;SVI) tijekom kirur&#x0161;kog zahvata, kao i u hemodinamski nestabilnih bolesnika u septi&#x010D;kom &#x0161;oku. (<xref ref-type="bibr" rid="r31"><italic>31</italic></xref>) Spomenuti na&#x010D;ini i metode hemodinamskog pra&#x0107;enja prikazani su na <xref ref-type="fig" rid="f1">Figure 1</xref>.</p>
<fig id="f1" position="float" fig-type="figure"><label>Figure 1</label><caption><p>Modes and types of haemodynamic monitoring</p></caption><graphic xlink:href="LV-142-148-f1"></graphic></fig>
</sec>
<sec>
<title>Procjena odgovora na optimalnu primjenu volumena i strategije optimizacije</title>
<p>Kod hemodinamski nestabilnog bolesnika va&#x017E;no je prvo u&#x010D;initi optimizaciju venskog priljeva. Tradicionalno, stati&#x010D;ki parametri CVP i PCWP dugo su godina u uporabi radi procjene cirkuliraju&#x0107;eg volumena venskog priljeva desnog i lijevog srca na terapiju volumenom. CVP zapravo reflektira volumen povi&#x0161;enja tlaka desnog atrija ili smanjenja kontraktilnosti desne klijetke ili oboje. Ovi stati&#x010D;ki parametri vrlo slabo koreliraju s odgovorom na primjenu volumena u odnosu prema dinami&#x010D;kim parametrima SVV-om i PPV-om. (<xref ref-type="bibr" rid="r32"><italic>32</italic></xref>) Canneson i suradnici (<xref ref-type="bibr" rid="r33"><italic>33</italic></xref>) u mehani&#x010D;ki su ventiliranih bolesnika podvrgnutih koronarnoj kirurgiji primjenom 500 mL 6%-tne otopine HES-a utvrdili vrlo visoku specifi&#x010D;nost i senzitivnost PPV-a (87 &#x2013; 88%) i SVV-a (82 &#x2013; 88%) u razlikovanju <italic>fluid respondera</italic> od onih koji to nisu, a u odnosu prema stati&#x010D;kim parametrima (CVP, PCWP, CI). Prema Frank-Starlingovu zakonu, s pomo&#x0107;u primjene intravenskih teku&#x0107;ina uz o&#x010D;uvanu kontraktilnost srca porastom venskog priljeva dolazi i do porasta SV-a. (<xref ref-type="bibr" rid="r34"><italic>34</italic></xref>) No ovaj se mehanizam odnosi samo na polovicu bolesnika kod kojih primjena volumena rezultira porastom udarnog volumena (engl. <italic>fluid responsiveness</italic>). Poznato je da u oko 50% kriti&#x010D;nih bolesnika primjena volumena ne&#x0107;e dovesti do pove&#x0107;anja SV-a (engl. <italic>fluid non-responders</italic>). (<xref ref-type="bibr" rid="r35"><italic>35</italic></xref>) Stoga je preporuka da se prije o&#x010D;ekivane ve&#x0107;e nadoknade volumena kontinuiranim pra&#x0107;enjem CO-a ili SV-a prvo procijeni radi li se o bolesniku koji je <italic>fluid responder</italic> ili nije. (<xref ref-type="bibr" rid="r36"><italic>36</italic></xref>) Rivers i suradnici (<xref ref-type="bibr" rid="r37"><italic>37</italic></xref>) utvrdili su da je kod hemodinamski nestabilnih bolesnika s te&#x0161;kom sepsom i u septi&#x010D;kom &#x0161;oku potrebno radi boljeg ishoda ekscesivno primijeniti volumen u prvih 6 sati. S druge strane, poznato je da prekomjerna primjena volumena rezultira pove&#x0107;anjem morbiditeta i mortaliteta u kriti&#x010D;nih bolesnika. (<xref ref-type="bibr" rid="r38"><italic>38</italic></xref>, <xref ref-type="bibr" rid="r39"><italic>39</italic></xref>) Stoga je kontinuirano pra&#x0107;enje dinami&#x010D;kih parametara nu&#x017E;no pri nadoknadi volumena, posebice u brzoj nadoknadi. Danas postoji vi&#x0161;e metoda kojima se mogu procijeniti odgovor na volumnu nadoknadu i prag te procjene. Kod minimalno invazivnih tehnologija naj&#x010D;e&#x0161;&#x0107;e su u uporabi pra&#x0107;enje SVV-a ili PPV-a uz zna&#x010D;ajnost praga od 12%, ali i uz dosta limitacija. Bolesnik mora biti anesteziran i priklju&#x010D;en na mehani&#x010D;ku ventilaciju uz volumen udisaja V<sub>T</sub> &gt; 8 mL/kg te u sinusnom ritmu. Otvaranje prsnog ko&#x0161;a, visok intraabdominalni tlak i zatajenje desnog srca te visoka frekvencija disanja tako&#x0111;er limitiraju uporabu ove metode. Ostale metode jesu mjerenje varijacije dijametra donje &#x0161;uplje vene transtorakalnom ehokardiografijom uz prag procjene od 12%, varijacije dijametra gornje &#x0161;uplje vene primjenom ezofagealnog doplera uz prag od 36%, okluzijski test na kraju ekspirija uz prag od 5% pri kojemu bolesnik mora biti intubiran te test respiratorno sistoli&#x010D;ke varijacije koji nije ovisan o volumenu udisaja. (<xref ref-type="bibr" rid="r40"><italic>40</italic></xref>&#x2013;<xref ref-type="bibr" rid="r42"><italic>42</italic></xref>) Pasivno podizanje nogu (PLR) kao provokativni test koji se po&#x010D;etno primjenjivao u hitnim stanjima sinkope i u stanju &#x0161;okiranog bolesnika ima potvr&#x0111;eno vrlo visoku prediktivnu vrijednost (senzitivnost i specifi&#x010D;nost do 92%) u procjeni hipovolemije kod HD nestabilnog bolesnika. Ovim jednostavnim testom ve&#x0107; inkorporiranim u metodu bioreaktancije (<italic>NICOM</italic>, <italic>Starling SV</italic>) mo&#x017E;e se pratiti porast SV-a za vi&#x0161;e od 10% u bolesnika <italic>fluid respondera</italic> koji pri ovoj metodi ne moraju biti ovisni o mehani&#x010D;koj ventilaciji niti su im ograni&#x010D;enje sr&#x010D;ane aritmije ili manja rastegljivost plu&#x0107;a. (<xref ref-type="bibr" rid="r43"><italic>43</italic></xref>&#x2013;<xref ref-type="bibr" rid="r45"><italic>45</italic></xref>)</p>
</sec>
<sec>
<title>Strategije hemodinamske optimizacije: vi&#x0161;e ili manje volumena?</title>
<p>Uporaba kontinuiranoga HD monitoringa CO-a uz prikladnu primjenu intravenske teku&#x0107;ine i inotropne potpore temeljni je algoritam hemodinamske optimizacije. (<xref ref-type="bibr" rid="r46"><italic>46</italic></xref>) Politrauma, veliki i dugotrajni kirur&#x0161;ki zahvati i te&#x0161;ka sepsa povezani su sa znatnom hipovolemijom, redukcijom kontraktilnosti i promjenama reaktibilnosti vaskularnog tonusa. Optimizacija hemodinamike primjenom prikladnog volumena i u pro&#x0161;losti i danas ostaje nerazja&#x0161;njena i prijeporna. Koncept optimizacije prvi spominje Clowes, (<xref ref-type="bibr" rid="r47"><italic>47</italic></xref>) a zatim i Shoemaker. (<xref ref-type="bibr" rid="r48"><italic>48</italic></xref>) Njihove su studije prve pratile pojedina&#x010D;ne hemodinamske i oksigenacijske parametre bolesnika koji su pre&#x017E;ivjeli stanje te&#x0161;ke sepse i &#x0161;oka. Pre&#x017E;ivjeli su imali znatno ve&#x0107;e CO, DO<sub>2</sub> i potro&#x0161;nju kisika (VO<sub>2</sub>) u odnosu prema onima koji su umrli. Otad se u klini&#x010D;ku praksu pri primjeni intravaskularne teku&#x0107;ine uvode algoritmi za procjenu SV-a ili CO-a, dok manjina intenzivista po&#x010D;inje primjenjivati i inotropnu potporu smatraju&#x0107;i da supranormalno pove&#x0107;anje CO-a &gt; 4,5 L/min/m<sup>2</sup> i DO<sub>2</sub> &gt; 600 mL/min/m<sup>2</sup> utje&#x010D;e na bolje pre&#x017E;ivljenje. (<xref ref-type="bibr" rid="r49"><italic>49</italic></xref>, <xref ref-type="bibr" rid="r50"><italic>50</italic></xref>) U perioperativnom periodu tako&#x0111;er je pomalo prijeporna primjena ukupne koli&#x010D;ine intravaskularne teku&#x0107;ine. Naime, liberalniji pristup s vi&#x0161;e primijenjene teku&#x0107;ine, kao i restriktivniji pristup s manje teku&#x0107;ine u odnosu prema masi bolesnika rezultirali su ve&#x0107;im mortalitetom. (<xref ref-type="bibr" rid="r50"><italic>50</italic></xref>, <xref ref-type="bibr" rid="r51"><italic>51</italic></xref>) Prekomjerna nadoknada intravaskularnog volumena mo&#x017E;e biti opasna u stanju hipervolemije (edem, ileus, plu&#x0107;ne komplikacije, smanjeni DO<sub>2</sub>), kao i restrikcija u stanju hipovolemije (hipoperfuzija organa, SIRS, zatajenje bubrega). U oba slu&#x010D;aja zbog patolo&#x0161;kog utjecaja na perifernu mikrovaskulaturu mo&#x017E;e do&#x0107;i do te&#x0161;kog disbalansa mikrocirkulacije, tj. dolazi do razaranja endotelnog glikokaliksa i izlaska teku&#x0107;ine u tre&#x0107;i prostor. (<xref ref-type="bibr" rid="r52"><italic>52</italic></xref>) Studija ANZICS, (<xref ref-type="bibr" rid="r53"><italic>53</italic></xref>) provedena na 3000 bolesnika, utvrdila je da restriktivni na&#x010D;in u primjeni intravaskularne teku&#x0107;ine nema prednosti pred liberalnim te da pravodobno odr&#x017E;avanje centralne normovolemije iziskuje dublje razumijevanje hemodinamske optimizacije uz primjenu sofisticiranoga HD monitoringa. Visokorizi&#x010D;ni bolesnici koji su podvrgnuti velikoj i dugotrajnoj kirurgiji i u neposrednom poslijeoperacijskom razdoblju nala&#x017E;u ozbiljniji i konceptualniji protokol za optimizaciju CO-a/SV-a, tj. ciljanije vo&#x0111;enu terapiju &#x2013; GDT. Njezin su cilj osiguranje odgovaraju&#x0107;ega cirkulacijskog statusa normovolemi&#x010D;nim bolesnicima, smanjenje upalnog odgovora organizma i prikladna dostava kisika u sva tkiva. (<xref ref-type="bibr" rid="r54"><italic>54</italic></xref>) Brojne studije u kojima je za optimizaciju CO-a primjenjivan GDT nisu dovele do skra&#x0107;enja boravka u bolnici, manjeg morbiditeta i mortaliteta, a osobito dvije posljednje studije OPTIMISE i POEMAS koje su provedene u visokorizi&#x010D;nih bolesnika podvrgnutih velikoj abdominalnoj kirurgiji. (<xref ref-type="bibr" rid="r55"><italic>55</italic></xref>, <xref ref-type="bibr" rid="r56"><italic>56</italic></xref>) Individualni poku&#x0161;aji u optimalnoj primjeni volumena vezani su samo za bolesnike koji pripadaju skupini onih &#x0161;to &#x0107;e bilo na bolusni volumen ili na PLR-test odgovoriti pove&#x0107;anjem SV-a &gt; 10%. Prosje&#x010D;an volumen kristaloidne otopine od 500 mL jest onaj provociraju&#x0107;i volumen koji mo&#x017E;e izazvati &#x017E;eljeno pove&#x0107;anje SV-a ili je to, pak, primjena volumena od 4 mL/kg tijekom 5 min u neposrednome poslijeoperacijskom razdoblju. (<xref ref-type="bibr" rid="r57"><italic>57</italic></xref>, <xref ref-type="bibr" rid="r58"><italic>58</italic></xref>) Nakon svega jasno je da jo&#x0161; nema univerzalnih i jednostavnih protokola koji bi u klini&#x010D;kim uvjetima mogli biti vezani za rizike bolesnik&#x00E2; i vrstu kirur&#x0161;kog zahvata, a ni za na&#x010D;ine ili vrste HD monitoringa.</p>
</sec>
</sec>
<sec sec-type="other2">
<title>Zaklju&#x010D;ak</title>
<p>Posljednjih 20 godina HD monitoring razvija se od invazivnih i intermitentnih metoda, koje su nudile manji broj ciljanih parametara, prema manje invazivnim i neinvazivnim metodama &#x0161;to kontinuirano i u stvarnom vremenu prate ve&#x0107;i broj varijabla, a to prati i velik broj novih sofisticiranih ure&#x0111;aja i softvera. Prema istra&#x017E;ivanju globalnog tr&#x017E;i&#x0161;ta, u budu&#x0107;nosti se predvi&#x0111;aju rast manje invazivnih metoda i stagnacija invazivnih. Kada se radi o brzoj procjeni terapijskih ili dijagnosti&#x010D;kih intervencija u kriti&#x010D;nih bolesnika kao &#x0161;to su primjena volumena ili brzi odgovor na vazoaktivne lijekove, kontinuirano pra&#x0107;enje SV-a ili CO-a puno je korisnije i informativnije nego intermitentno, iako je manje precizno.</p>
<p>Idealni HD monitoring trebao bi biti neinvazivan, kontinuiran, precizan, reproducibilan, jednostavan za primjenu i lije&#x010D;nicima i bolesnicima, jeftin, uz &#x0161;to manje nuspojava. Novije, minimalno invazivne i neinvazivne tehnologije koje kontinuirano prate CO i druge HD varijable tom se idealu iz dana u dan pribli&#x017E;avaju. Cilj novih tehnologija jesu pronalazak individualne procjene za svakog bolesnika te mogu&#x0107;nost optimalnog lije&#x010D;enja s obzirom na njegovo stanje i klini&#x010D;ki scenarij. Funkcionalnost novih tehnologija jest u tome &#x0161;to su one sve manje vezane samo za operacijsku salu ili jedinicu intenzivnog lije&#x010D;enja radi personaliziranog pristupa svakom kriti&#x010D;nom bolesniku. (<xref ref-type="bibr" rid="r59"><italic>59</italic></xref>)</p>
<sec>
<title>Skra&#x0107;enice/Abbreviations</title>
<list id="L1" list-type="simple"><list-item><p>CO &#x2013; minutni volumen srca</p></list-item>
<list-item><p>CI &#x2013; indeks srca</p></list-item>
<list-item><p>SV &#x2013; udarni volumen srca</p></list-item>
<list-item><p>CVP &#x2013; centralni venski tlak</p></list-item>
<list-item><p>PCWP &#x2013; plu&#x0107;ni kapilarni okluzivni tlak</p></list-item>
<list-item><p>SVR &#x2013; sistemska vaskularna rezistencija</p></list-item>
<list-item><p>PAK &#x2013; plu&#x0107;ni arterijski kateter</p></list-item>
<list-item><p>TD &#x2013; transpulmonalna termodilucija</p></list-item>
<list-item><p>SVV &#x2013; varijacija udarnog volumena</p></list-item>
<list-item><p>PPV &#x2013; varijacija pulsnog tlaka</p></list-item>
<list-item><p>GDVT &#x2013; ciljna optimalna volumna nadoknada</p></list-item>
<list-item><p>PLR test &#x2013; test pasivnog podizanja nogu</p></list-item>
<list-item><p>DO<sub>2</sub> &#x2013; dostava kisika u tkiva</p></list-item>
<list-item><p>VO<sub>2</sub> &#x2013; potro&#x0161;nja kisika u tkivima</p></list-item>
<list-item><p>CaCO<sub>2</sub> &#x2013; sadr&#x017E;aj CO<sub>2</sub> u arterijskoj krvi</p></list-item>
<list-item><p>PP &#x2013; tlak pulsa</p></list-item>
<list-item><p>ITBVI &#x2013; indeks intratorakalnog volumena krvi</p></list-item>
<list-item><p>GEDV &#x2013; globalni end-dijastoli&#x010D;ki volumen</p></list-item>
<list-item><p>EVLW &#x2013; ekstravaskularna voda u plu&#x0107;ima</p></list-item>
<list-item><p>PVPI &#x2013; indeks plu&#x0107;ne vaskularne permeabilnosti</p></list-item>
<list-item><p>GEF &#x2013; globalna istisna frakcija</p></list-item>
<list-item><p>TEE &#x2013; transezofagealna ehokardiografija</p></list-item>
<list-item><p>RT-3D &#x2013; 3D ehokardiografija u realnom vremenu</p></list-item>
<list-item><p>TDI &#x2013; tkivni Doppler</p></list-item>
<list-item><p>ETCO<sub>2</sub> &#x2013; CO<sub>2</sub> na kraju ekspirija</p></list-item>
<list-item><p>PWTT &#x2013; vrijeme tranzicije pulsnog vala</p></list-item>
<list-item><p>esCCO &#x2013; neinvazivna procjena kontinuiranog minutnog volumena srca</p></list-item>
<list-item><p>TEB &#x2013; torakalna elektri&#x010D;na bioimpendanca</p></list-item>
<list-item><p>TFC &#x2013; sadr&#x017E;aj teku&#x0107;ine u prsi&#x0161;tu</p></list-item></list>
</sec>
</sec>
</body>
<back>
<ref-list>
<title>LITERATURA</title>
<ref id="r1"><label>1</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Guyton</surname><given-names>AC</given-names></name></person-group>. <article-title>Physiologic regulation of arterial pressure.</article-title> <source>Am J Cardiol</source>. <year>1961</year>;<volume>8</volume>:<fpage>401</fpage>&#x2013;<lpage>7</lpage>. <pub-id pub-id-type="doi">10.1016/0002-9149(61)90159-X</pub-id><pub-id pub-id-type="pmid">13710076</pub-id></mixed-citation></ref>
<ref id="r2"><label>2</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Takala</surname><given-names>J</given-names></name></person-group>. <article-title>The pulmonary artery catheter: the tool versus treatments based on the tool.</article-title> <source>Crit Care</source>. <year>2006</year>;<volume>10</volume>:<fpage>162</fpage>. <pub-id pub-id-type="doi">10.1186/cc5021</pub-id><pub-id pub-id-type="pmid">16953899</pub-id></mixed-citation></ref>
<ref id="r3"><label>3</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>De Backer</surname><given-names>D</given-names></name><name><surname>Donadello</surname><given-names>K</given-names></name></person-group>. <article-title>Sakr Y i sur. Microcirculatory alterations in patients with severe sepsis: impact of time of assessment and relationship with outcome.</article-title> <source>Crit Care Med</source>. <year>2013</year>;<volume>41</volume>:<fpage>791</fpage>&#x2013;<lpage>9</lpage>. <pub-id pub-id-type="doi">10.1097/CCM.0b013e3182742e8b</pub-id><pub-id pub-id-type="pmid">23318492</pub-id></mixed-citation></ref>
<ref id="r4"><label>4</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Monnet</surname><given-names>X</given-names></name><name><surname>Teboul</surname><given-names>JL</given-names></name></person-group>. <article-title>Cardiac output monitoring: throw it out&#x2026; or keep it?</article-title> <source>Crit Care</source>. <year>2018</year>;<volume>22</volume>:<fpage>35</fpage>. <pub-id pub-id-type="doi">10.1186/s13054-018-1957-5</pub-id><pub-id pub-id-type="pmid">29422074</pub-id></mixed-citation></ref>
<ref id="r5"><label>5</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>De Backer</surname><given-names>D</given-names></name><name><surname>Donadello</surname><given-names>K</given-names></name><name><surname>Taccone</surname><given-names>FS</given-names></name><name><surname>Ospina-Tascon</surname><given-names>G</given-names></name><name><surname>Salgado</surname><given-names>D</given-names></name><name><surname>Vincent</surname><given-names>JL</given-names></name></person-group>. <article-title>Microcirculation alterations: potential mechanisms and implications for therapy.</article-title> <source>Ann Intensive Care</source>. <year>2011</year>;<volume>1</volume>:<fpage>27</fpage>. <pub-id pub-id-type="doi">10.1186/2110-5820-1-27</pub-id><pub-id pub-id-type="pmid">21906380</pub-id></mixed-citation></ref>
<ref id="r6"><label>6</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Alhashemi</surname><given-names>JA</given-names></name><name><surname>Cecconi</surname><given-names>M</given-names></name><name><surname>Hofer</surname><given-names>CK</given-names></name></person-group>. <article-title>Cardiac output monitoring: an integrative perspective.</article-title> <source>Crit Care</source>. <year>2011</year>;<volume>15</volume>:<fpage>214</fpage>. <pub-id pub-id-type="doi">10.1186/cc9996</pub-id><pub-id pub-id-type="pmid">21457508</pub-id></mixed-citation></ref>
<ref id="r7"><label>7</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Hadian</surname><given-names>M</given-names></name><name><surname>Pinsky</surname><given-names>MR</given-names></name></person-group>. <article-title>Functional hemodynamic monitoring.</article-title> <source>Curr Opin Crit Care</source>. <year>2007</year>;<volume>13</volume>:<fpage>318</fpage>&#x2013;<lpage>23</lpage>. <pub-id pub-id-type="doi">10.1097/MCC.0b013e32811e14dd</pub-id><pub-id pub-id-type="pmid">17468565</pub-id></mixed-citation></ref>
<ref id="r8"><label>8</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Swan</surname><given-names>HJ</given-names></name><name><surname>Ganz</surname><given-names>W</given-names></name><name><surname>Forrester</surname><given-names>J</given-names></name><name><surname>Marcus</surname><given-names>H</given-names></name><name><surname>Diamond</surname><given-names>G</given-names></name><name><surname>Chonette</surname><given-names>D</given-names></name></person-group>. <article-title>Catheterization of the heart in man with use of a flow-directed balloon-tipped catheter.</article-title> <source>N Engl J Med</source>. <year>1970</year>;<volume>283</volume>:<fpage>447</fpage>&#x2013;<lpage>51</lpage>. <pub-id pub-id-type="doi">10.1056/NEJM197008272830902</pub-id><pub-id pub-id-type="pmid">5434111</pub-id></mixed-citation></ref>
<ref id="r9"><label>9</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>West</surname><given-names>JB</given-names></name></person-group>. <article-title>The beginnings of cardiac catheterization and the resulting impact on pulmonary medicine.</article-title> <source>Am J Physiol Lung Cell Mol Physiol</source>. <year>2017</year>;<volume>313</volume>:<fpage>L651</fpage>&#x2013;<lpage>8</lpage>. <pub-id pub-id-type="doi">10.1152/ajplung.00133.2017</pub-id><pub-id pub-id-type="pmid">28839102</pub-id></mixed-citation></ref>
<ref id="r10"><label>10</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Cannesson</surname><given-names>M</given-names></name><name><surname>Pestel</surname><given-names>G</given-names></name><name><surname>Ricks</surname><given-names>C</given-names></name><name><surname>Hoeft</surname><given-names>A</given-names></name><name><surname>Perel</surname><given-names>A</given-names></name></person-group>. <article-title>Hemodynamic monitoring and management in patients undergoing high risk surgery: a survey among the American and European anesthesiologists.</article-title> <source>Crit Care</source>. <year>2011</year>;<volume>15</volume>:<fpage>R197</fpage>&#x2013;<lpage>233</lpage>. <pub-id pub-id-type="doi">10.1186/cc10364</pub-id><pub-id pub-id-type="pmid">21843353</pub-id></mixed-citation></ref>
<ref id="r11"><label>11</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Erlanger</surname><given-names>J</given-names></name><name><surname>Hooker</surname><given-names>DR</given-names></name></person-group>. <article-title>Experimental study of blood-pressure and of pulse-pressure in man.</article-title> <source>John Hopkins Hosp Rep</source>. <year>1904</year>;<volume>12</volume>:<fpage>145</fpage>&#x2013;<lpage>378</lpage>.</mixed-citation></ref>
<ref id="r12"><label>12</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Wesseling</surname><given-names>KH</given-names></name><name><surname>de Wit</surname><given-names>B</given-names></name><name><surname>Weber</surname><given-names>JAP</given-names></name><name><surname>Ty</surname><given-names>SN</given-names></name></person-group>. <article-title>A simple device for the continuous measurement of cardiac output.</article-title> <source>Adv Cardiovasc Phys</source>. <year>1983</year>;<volume>2</volume>:<fpage>16</fpage>&#x2013;<lpage>52</lpage>.</mixed-citation></ref>
<ref id="r13"><label>13</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Monge Garc&#x00ED;a</surname><given-names>MI</given-names></name><name><surname>Saludes Ordu&#x00F1;a</surname><given-names>P</given-names></name><name><surname>Cecconi</surname><given-names>M</given-names></name></person-group>. <article-title>Understanding arterial load.</article-title> <source>Intensive Care Med</source>. <year>2016</year>;<volume>42</volume>:<fpage>1625</fpage>&#x2013;<lpage>7</lpage>. <pub-id pub-id-type="doi">10.1007/s00134-016-4212-z</pub-id><pub-id pub-id-type="pmid">26801663</pub-id></mixed-citation></ref>
<ref id="r14"><label>14</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Slagt</surname><given-names>C</given-names></name><name><surname>Malagon</surname><given-names>I</given-names></name><name><surname>Groeneveld</surname><given-names>AB</given-names></name></person-group>. <article-title>Systematic review of uncalibrated arterial pressure waveform analysis to determine cardiac output and stroke volume variation.</article-title> <source>Br J Anaesth</source>. <year>2014</year>;<volume>112</volume>:<fpage>626</fpage>&#x2013;<lpage>37</lpage>. <pub-id pub-id-type="doi">10.1093/bja/aet429</pub-id><pub-id pub-id-type="pmid">24431387</pub-id></mixed-citation></ref>
<ref id="r15"><label>15</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Monnet</surname><given-names>X</given-names></name><name><surname>Anguel</surname><given-names>N</given-names></name><name><surname>Jozwiak</surname><given-names>M</given-names></name><name><surname>Richard</surname><given-names>C</given-names></name><name><surname>Teboul</surname><given-names>JL</given-names></name></person-group>. <article-title>Third-generation FloTrac/Vigileo does not reliably track changes in cardiac output induced by norepinephrine in critically ill patients.</article-title> <source>Br J Anaesth</source>. <year>2012</year>;<volume>108</volume>:<fpage>615</fpage>&#x2013;<lpage>22</lpage>. <pub-id pub-id-type="doi">10.1093/bja/aer491</pub-id><pub-id pub-id-type="pmid">22265900</pub-id></mixed-citation></ref>
<ref id="r16"><label>16</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Dark</surname><given-names>PM</given-names></name><name><surname>Singer</surname><given-names>M</given-names></name></person-group>. <article-title>The validity of trans-esophageal Doppler ultrasonography as a measure of cardiac output in critically ill adults.</article-title> <source>Intensive Care Med</source>. <year>2004</year>;<volume>30</volume>:<fpage>2060</fpage>&#x2013;<lpage>6</lpage>. <pub-id pub-id-type="doi">10.1007/s00134-004-2430-2</pub-id><pub-id pub-id-type="pmid">15368037</pub-id></mixed-citation></ref>
<ref id="r17"><label>17</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Shanewise</surname><given-names>JS</given-names></name><name><surname>Cheung</surname><given-names>AT</given-names></name></person-group>. <article-title>Aronson S i sur. ASE/SCA guidelines for performing a comprehensive intraoperative multiplane transesophageal echocardiography examination: recommendation of the American Society of Echocardiography Council for Intraoperative Echocardiography and the Society of Cardiovascular Anesthesiologists Task Force for Certification in Perioperative Transesophageal Echocardiography.</article-title> <source>J Am Soc Echocardiogr</source>. <year>1999</year>;<volume>12</volume>:<fpage>884</fpage>&#x2013;<lpage>900</lpage>. <pub-id pub-id-type="doi">10.1016/S0894-7317(99)70199-9</pub-id><pub-id pub-id-type="pmid">10511663</pub-id></mixed-citation></ref>
<ref id="r18"><label>18</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Barisin</surname><given-names>S</given-names></name><name><surname>Sakic-Zdravcevic</surname><given-names>K</given-names></name><name><surname>Barisin</surname><given-names>A</given-names></name><name><surname>Gulam</surname><given-names>D</given-names></name></person-group>. <article-title>Three-dimensional transoesophageal echocardiography: a new intraoperative perspective in follow-up of cardiac patients.</article-title> <source>Med Vjesn (Osijek)</source>. <year>2011</year>;<volume>43</volume>:<fpage>61</fpage>&#x2013;<lpage>71</lpage>.</mixed-citation></ref>
<ref id="r19"><label>19</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Barisin</surname><given-names>S</given-names></name></person-group>. <article-title>Real-time 3-dimensional transesophageal echocardiography assessment of left ventricular shape and function after surgical remodeling.</article-title> <source>Signa Vitae</source>. <year>2017</year>;<volume>13</volume> <supplement>Suppl 1</supplement>:<fpage>20</fpage>&#x2013;<lpage>3</lpage>. <pub-id pub-id-type="doi">10.22514/SV131.032017.2</pub-id></mixed-citation></ref>
<ref id="r20"><label>20</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Wetterslev</surname><given-names>M</given-names></name><name><surname>M&#x00F8;ller-S&#x00F8;rensen</surname><given-names>H</given-names></name><name><surname>Johansen</surname><given-names>RR</given-names></name><name><surname>Perner</surname><given-names>A</given-names></name></person-group>. <article-title>Systematic review of cardiac output measurements by echocardiography vs. thermodilution: the techniques are not interchangeable.</article-title> <source>Intensive Care Med</source>. <year>2016</year>;<volume>42</volume>:<fpage>1223</fpage>&#x2013;<lpage>33</lpage>. <pub-id pub-id-type="doi">10.1007/s00134-016-4258-y</pub-id><pub-id pub-id-type="pmid">26932349</pub-id></mixed-citation></ref>
<ref id="r21"><label>21</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Langwieser</surname><given-names>N</given-names></name><name><surname>Prechtl</surname><given-names>L</given-names></name></person-group>. <article-title>Meidert AS i sur. Radial artery applanation tonometry for continuous noninvasive arterial blood pressure monitoring in the cardiac intensive care unit.</article-title> <source>Clin Res Cardiol</source>. <year>2015</year>;<volume>104</volume>:<fpage>518</fpage>&#x2013;<lpage>24</lpage>. <pub-id pub-id-type="doi">10.1007/s00392-015-0816-5</pub-id><pub-id pub-id-type="pmid">25618259</pub-id></mixed-citation></ref>
<ref id="r22"><label>22</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Meidert</surname><given-names>AS</given-names></name><name><surname>Huber</surname><given-names>W</given-names></name><name><surname>M&#x00FC;ller</surname><given-names>JN</given-names></name></person-group>. <article-title>Radial artery applanation tonometry for continuous non-invasive arterial pressure monitoring in intensive care unit patients: comparison with invasively assessed radial arterial pressure.</article-title> <source>Br J Anaesth</source>. <year>2014</year>;<volume>112</volume>:<fpage>521</fpage>&#x2013;<lpage>8</lpage>. <pub-id pub-id-type="doi">10.1093/bja/aet400</pub-id><pub-id pub-id-type="pmid">24355832</pub-id></mixed-citation></ref>
<ref id="r23"><label>23</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Ameloot</surname><given-names>K</given-names></name><name><surname>Palmers</surname><given-names>PJ</given-names></name><name><surname>Malbrain</surname><given-names>ML</given-names></name></person-group>. <article-title>The accuracy of noninvasive cardiac output and pressure measurements with finger cuff: a concise review.</article-title> <source>Curr Opin Crit Care</source>. <year>2015</year>;<volume>21</volume>:<fpage>232</fpage>&#x2013;<lpage>9</lpage>. <pub-id pub-id-type="doi">10.1097/MCC.0000000000000198</pub-id><pub-id pub-id-type="pmid">25922896</pub-id></mixed-citation></ref>
<ref id="r24"><label>24</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Kotake</surname><given-names>Y</given-names></name><name><surname>Yamada</surname><given-names>T</given-names></name></person-group>. <article-title>Nagata H i sur. Improved accuracy of cardiac output estimation by the partial CO2 rebreathing method.</article-title> <source>J Clin Monit Comput</source>. <year>2009</year>;<volume>23</volume>:<fpage>149</fpage>&#x2013;<lpage>55</lpage>. <pub-id pub-id-type="doi">10.1007/s10877-009-9172-1</pub-id><pub-id pub-id-type="pmid">19301132</pub-id></mixed-citation></ref>
<ref id="r25"><label>25</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Biais</surname><given-names>M</given-names></name><name><surname>Berthezene</surname><given-names>R</given-names></name><name><surname>Petit</surname><given-names>L</given-names></name><name><surname>Cottenceau</surname><given-names>V</given-names></name><name><surname>Sztark</surname><given-names>F</given-names></name></person-group>. <article-title>Ability of esCCO to track changes in cardiac output.</article-title> <source>Br J Anaesth</source>. <year>2015</year>;<volume>115</volume>:<fpage>403</fpage>&#x2013;<lpage>10</lpage>. <pub-id pub-id-type="doi">10.1093/bja/aev219</pub-id><pub-id pub-id-type="pmid">26209443</pub-id></mixed-citation></ref>
<ref id="r26"><label>26</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Yamada</surname><given-names>T</given-names></name><name><surname>Tsutsui</surname><given-names>M</given-names></name></person-group>. <article-title>Sugo Y i sur. Multicenter study verifying a method of noninvasive continuous cardiac output measurement using pulse wave transit time: a comparison with intermittent bolus thermodilution cardiac output.</article-title> <source>Anesth Analg</source>. <year>2012</year>;<volume>115</volume>:<fpage>82</fpage>&#x2013;<lpage>7</lpage>. <pub-id pub-id-type="doi">10.1213/ANE.0b013e31824e2b6c</pub-id><pub-id pub-id-type="pmid">22467885</pub-id></mixed-citation></ref>
<ref id="r27"><label>27</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Peyton</surname><given-names>PJ</given-names></name><name><surname>Chong</surname><given-names>SW</given-names></name></person-group>. <article-title>Minimally invasive measurement of cardiac output during surgery and critical care: a meta-analysis of accuracy and precision.</article-title> <source>Anesthesiology</source>. <year>2010</year>;<volume>113</volume>:<fpage>1220</fpage>&#x2013;<lpage>35</lpage>. <pub-id pub-id-type="doi">10.1097/ALN.0b013e3181ee3130</pub-id><pub-id pub-id-type="pmid">20881596</pub-id></mixed-citation></ref>
<ref id="r28"><label>28</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Raue</surname><given-names>W</given-names></name><name><surname>Swierzy</surname><given-names>M</given-names></name><name><surname>Koplin</surname><given-names>G</given-names></name><name><surname>Schwenk</surname><given-names>W</given-names></name></person-group>. <article-title>Comparison of electrical velocimetry and transthoracic thermodilution technique for cardiac output assessment in critically ill patients.</article-title> <source>Eur J Anaesthesiol</source>. <year>2009</year>;<volume>26</volume>:<fpage>1067</fpage>&#x2013;<lpage>71</lpage>. <pub-id pub-id-type="doi">10.1097/EJA.0b013e32832bfd94</pub-id><pub-id pub-id-type="pmid">19412107</pub-id></mixed-citation></ref>
<ref id="r29"><label>29</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Squara</surname><given-names>P</given-names></name><name><surname>Denjean</surname><given-names>D</given-names></name><name><surname>Estagnasie</surname><given-names>P</given-names></name><name><surname>Brusset</surname><given-names>A</given-names></name><name><surname>Dib</surname><given-names>JC</given-names></name><name><surname>Dubois</surname><given-names>C</given-names></name></person-group>. <article-title>Noninvasive cardiac output monitoring (NICOM): a clinical validation.</article-title> <source>Intensive Care Med</source>. <year>2007</year>;<volume>33</volume>:<fpage>1191</fpage>&#x2013;<lpage>4</lpage>. <pub-id pub-id-type="doi">10.1007/s00134-007-0640-0</pub-id><pub-id pub-id-type="pmid">17458538</pub-id></mixed-citation></ref>
<ref id="r30"><label>30</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Waldron</surname><given-names>NH</given-names></name><name><surname>Miller</surname><given-names>TE</given-names></name></person-group>. <article-title>Thacker JK i sur. A prospective comparison of a noninvasive cardiac output monitor versus esophageal Doppler monitor for goal-directed fluid therapy in colorectal surgery patients.</article-title> <source>Anesth Analg</source>. <year>2014</year>;<volume>118</volume>:<fpage>966</fpage>&#x2013;<lpage>75</lpage>. <pub-id pub-id-type="doi">10.1213/ANE.0000000000000182</pub-id><pub-id pub-id-type="pmid">24681660</pub-id></mixed-citation></ref>
<ref id="r31"><label>31</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Latham</surname><given-names>HE</given-names></name><name><surname>Bengtson</surname><given-names>CD</given-names></name></person-group>. <article-title>Satterwhite L i sur. Stroke volume guided resuscitation in severe sepsis and septic shock improves outcomes.</article-title> <source>J Crit Care</source>. <year>2017</year>;<volume>42</volume>:<fpage>42</fpage>&#x2013;<lpage>6</lpage>. <pub-id pub-id-type="doi">10.1016/j.jcrc.2017.06.028</pub-id><pub-id pub-id-type="pmid">28672146</pub-id></mixed-citation></ref>
<ref id="r32"><label>32</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Kumar</surname><given-names>A</given-names></name><name><surname>Anel</surname><given-names>R</given-names></name></person-group>. <article-title>Bunnell E i sur. Pulmonary artery occlusion pressure and central venous pressure fail to predict ventricular filling volume, cardiac performance, or the response to volume infusion in normal subjects.</article-title> <source>Crit Care Med</source>. <year>2004</year>;<volume>32</volume>:<fpage>691</fpage>&#x2013;<lpage>9</lpage>. <pub-id pub-id-type="doi">10.1097/01.CCM.0000114996.68110.C9</pub-id><pub-id pub-id-type="pmid">15090949</pub-id></mixed-citation></ref>
<ref id="r33"><label>33</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Cannesson</surname><given-names>M</given-names></name><name><surname>Musard</surname><given-names>H</given-names></name></person-group>. <article-title>Desebbe O i sur. The ability of stroke volume variations obtained with Vigileo/FloTrac system to monitor fluid responsiveness in mechanically ventilated patients.</article-title> <source>Anesth Analg</source>. <year>2009</year>;<volume>108</volume>:<fpage>513</fpage>&#x2013;<lpage>7</lpage>. <pub-id pub-id-type="doi">10.1213/ane.0b013e318192a36b</pub-id><pub-id pub-id-type="pmid">19151280</pub-id></mixed-citation></ref>
<ref id="r34"><label>34</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Jacob</surname><given-names>R</given-names></name><name><surname>Dierberger</surname><given-names>B</given-names></name><name><surname>Kissling</surname><given-names>G</given-names></name></person-group>. <article-title>Functional significance of the Frank-Starling mechanism under physiological and pathophysiological conditions.</article-title> <source>Eur Heart J</source>. <year>1992</year>;<volume>13</volume> <supplement>Suppl E</supplement>:<fpage>7</fpage>&#x2013;<lpage>14</lpage>. <pub-id pub-id-type="doi">10.1093/eurheartj/13.suppl_E.7</pub-id><pub-id pub-id-type="pmid">1478214</pub-id></mixed-citation></ref>
<ref id="r35"><label>35</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Michard</surname><given-names>F</given-names></name><name><surname>Teboul</surname><given-names>JL</given-names></name></person-group>. <article-title>Predicting fluid responsiveness in ICU patients: a critical analysis of the evidence.</article-title> <source>Chest</source>. <year>2002</year>;<volume>121</volume>:<fpage>2000</fpage>&#x2013;<lpage>8</lpage>. <pub-id pub-id-type="doi">10.1378/chest.121.6.2000</pub-id><pub-id pub-id-type="pmid">12065368</pub-id></mixed-citation></ref>
<ref id="r36"><label>36</label><mixed-citation publication-type="web">Cecconi M, Parsons AK, Rhodes A. What is a fluid challenge? Curr Opin Crit Care <ext-link ext-link-type="uri" xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.ncbi.nlm.nih.gov/pubmed/215088382011;17:290%E2%80%935">https://www.ncbi.nlm.nih.gov/pubmed/215088382011;17:290&#x2013;5</ext-link>.</mixed-citation></ref>
<ref id="r37"><label>37</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Rivers</surname><given-names>E</given-names></name><name><surname>Nguyen</surname><given-names>B</given-names></name></person-group>. <article-title>Havstad S i sur. Early goal-directed therapy in the treatment of severe sepsis and septic shock.</article-title> <source>N Engl J Med</source>. <year>2001</year>;<volume>345</volume>:<fpage>1368</fpage>&#x2013;<lpage>77</lpage>. <pub-id pub-id-type="doi">10.1056/NEJMoa010307</pub-id><pub-id pub-id-type="pmid">11794169</pub-id></mixed-citation></ref>
<ref id="r38"><label>38</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Payen</surname><given-names>D</given-names></name><name><surname>de Pont</surname><given-names>AC</given-names></name></person-group>. <article-title>Sakr Y i sur. A positive fluid balance is associated with a worse outcome in patients with acute renal failure.</article-title> <source>Crit Care</source>. <year>2008</year>;<volume>12</volume>:<fpage>R74</fpage>. <pub-id pub-id-type="doi">10.1186/cc6916</pub-id><pub-id pub-id-type="pmid">18533029</pub-id></mixed-citation></ref>
<ref id="r39"><label>39</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Benes</surname><given-names>J</given-names></name><name><surname>Kirov</surname><given-names>M</given-names></name></person-group>. <article-title>Kuzkov V i sur. Fluid therapy: double-edged sword during critical care?</article-title> <source>BioMed Res Int</source>. <year>2015</year>;<volume>2015</volume>:<elocation-id>729075</elocation-id>. <pub-id pub-id-type="doi">10.1155/2015/729075</pub-id><pub-id pub-id-type="pmid">26798642</pub-id></mixed-citation></ref>
<ref id="r40"><label>40</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Vignon</surname><given-names>P</given-names></name><name><surname>Repesse</surname><given-names>X</given-names></name></person-group>. <article-title>Begot E i sur. Comparison of echocardiographic indices used to predict fluid responsiveness in ventilated patients.</article-title> <source>Am J Respir Crit Care Med</source>. <year>2017</year>;<volume>195</volume>:<fpage>1022</fpage>&#x2013;<lpage>32</lpage>. <pub-id pub-id-type="doi">10.1164/rccm.201604-0844OC</pub-id><pub-id pub-id-type="pmid">27653798</pub-id></mixed-citation></ref>
<ref id="r41"><label>41</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Monnet</surname><given-names>X</given-names></name><name><surname>Osman</surname><given-names>D</given-names></name><name><surname>Ridel</surname><given-names>C</given-names></name><name><surname>Lamia</surname><given-names>B</given-names></name><name><surname>Richard</surname><given-names>C</given-names></name><name><surname>Teboul</surname><given-names>JL</given-names></name></person-group>. <article-title>Predicting volume responsiveness by using the end-expiratory occlusion in mechanically ventilated intensive care unit patients.</article-title> <source>Crit Care Med</source>. <year>2009</year>;<volume>37</volume>:<fpage>951</fpage>&#x2013;<lpage>6</lpage>. <pub-id pub-id-type="doi">10.1097/CCM.0b013e3181968fe1</pub-id><pub-id pub-id-type="pmid">19237902</pub-id></mixed-citation></ref>
<ref id="r42"><label>42</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Preisman</surname><given-names>S</given-names></name><name><surname>Kogan</surname><given-names>S</given-names></name><name><surname>Berkenstadt</surname><given-names>H</given-names></name><name><surname>Perel</surname><given-names>A</given-names></name></person-group>. <article-title>Predicting fluid responsiveness in patients undergoing cardiac surgery: functional haemodynamic parameters including the respiratory systolic variation test and static preload indicators.</article-title> <source>Br J Anaesth</source>. <year>2005</year>;<volume>95</volume>:<fpage>746</fpage>&#x2013;<lpage>55</lpage>. <pub-id pub-id-type="doi">10.1093/bja/aei262</pub-id><pub-id pub-id-type="pmid">16286349</pub-id></mixed-citation></ref>
<ref id="r43"><label>43</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Bentzer</surname><given-names>P</given-names></name><name><surname>Griesdale</surname><given-names>DE</given-names></name><name><surname>Boyd</surname><given-names>J</given-names></name><name><surname>MacLean</surname><given-names>K</given-names></name><name><surname>Sirounis</surname><given-names>D</given-names></name><name><surname>Ayas</surname><given-names>NT</given-names></name></person-group>. <article-title>Will this hemodynamically unstable patient respond to a bolus of intravenous fluids?</article-title> <source>JAMA</source>. <year>2016</year>;<volume>316</volume>:<fpage>1298</fpage>&#x2013;<lpage>309</lpage>. <pub-id pub-id-type="doi">10.1001/jama.2016.12310</pub-id><pub-id pub-id-type="pmid">27673307</pub-id></mixed-citation></ref>
<ref id="r44"><label>44</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Monnet</surname><given-names>X</given-names></name><name><surname>Rienzo</surname><given-names>M</given-names></name></person-group>. <article-title>Osman D i sur. Passive leg raising predicts fluid responsiveness in the critically ill.</article-title> <source>Crit Care Med</source>. <year>2006</year>;<volume>34</volume>:<fpage>1402</fpage>&#x2013;<lpage>7</lpage>. <pub-id pub-id-type="doi">10.1097/01.CCM.0000215453.11735.06</pub-id><pub-id pub-id-type="pmid">16540963</pub-id></mixed-citation></ref>
<ref id="r45"><label>45</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Benomar</surname><given-names>B</given-names></name><name><surname>Ouattara</surname><given-names>A</given-names></name><name><surname>Estagnasie</surname><given-names>P</given-names></name><name><surname>Brusset</surname><given-names>A</given-names></name><name><surname>Squara</surname><given-names>P</given-names></name></person-group>. <article-title>Fluid responsiveness predicted by noninvasive bioreactance-based passive leg raise test.</article-title> <source>Intensive Care Med</source>. <year>2010</year>;<volume>36</volume>:<fpage>1875</fpage>&#x2013;<lpage>81</lpage>. <pub-id pub-id-type="doi">10.1007/s00134-010-1990-6</pub-id><pub-id pub-id-type="pmid">20665001</pub-id></mixed-citation></ref>
<ref id="r46"><label>46</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Saugel</surname><given-names>B</given-names></name><name><surname>Cecconi</surname><given-names>M</given-names></name><name><surname>Wagner</surname><given-names>JY</given-names></name><name><surname>Reuter</surname><given-names>DA</given-names></name></person-group>. <article-title>Noninvasive continuous cardiac output monitoring in perioperative and intensive care medicine.</article-title> <source>Br J Anaesth</source>. <year>2015</year>;<volume>114</volume>:<fpage>562</fpage>&#x2013;<lpage>75</lpage>. <pub-id pub-id-type="doi">10.1093/bja/aeu447</pub-id><pub-id pub-id-type="pmid">25596280</pub-id></mixed-citation></ref>
<ref id="r47"><label>47</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Clowes</surname><given-names>GH</given-names><suffix>Jr</suffix></name><name><surname>Vucinic</surname><given-names>M</given-names></name><name><surname>Weidner</surname><given-names>MG</given-names></name></person-group>. <article-title>Circulatory and metabolic alterations associated with survival or death in peritonitis: clinical analysis of 25 cases.</article-title> <source>Ann Surg</source>. <year>1966</year>;<volume>163</volume>:<fpage>866</fpage>&#x2013;<lpage>85</lpage>. <pub-id pub-id-type="doi">10.1097/00000658-196606000-00008</pub-id><pub-id pub-id-type="pmid">5933801</pub-id></mixed-citation></ref>
<ref id="r48"><label>48</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Shoemaker</surname><given-names>WC</given-names></name><name><surname>Montgomery</surname><given-names>ES</given-names></name><name><surname>Kaplan</surname><given-names>E</given-names></name><name><surname>Elwyn</surname><given-names>DH</given-names></name></person-group>. <article-title>Physiologic patterns in surviving and nonsurviving shock patients. Use of sequential cardiorespiratory variables in defining criteria for therapeutic goals and early warning of death.</article-title> <source>Arch Surg</source>. <year>1973</year>;<volume>106</volume>:<fpage>630</fpage>&#x2013;<lpage>6</lpage>. <pub-id pub-id-type="doi">10.1001/archsurg.1973.01350170004003</pub-id><pub-id pub-id-type="pmid">4701410</pub-id></mixed-citation></ref>
<ref id="r49"><label>49</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Donati</surname><given-names>A</given-names></name><name><surname>Loggi</surname><given-names>S</given-names></name></person-group>. <article-title>Preiser JC i sur. Goal-directed intraoperative therapy reduces morbidity and length of hospital stay in high-risk surgical patients.</article-title> <source>Crit Care Med</source>. <year>2000</year>;<volume>28</volume>:<fpage>3396</fpage>&#x2013;<lpage>404</lpage>.</mixed-citation></ref>
<ref id="r50"><label>50</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Shoemaker</surname><given-names>WC</given-names></name><name><surname>Appel</surname><given-names>PL</given-names></name><name><surname>Kram</surname><given-names>HB</given-names></name></person-group>. <article-title>Role of oxygen debt in the development of organ failure sepsis, and death in high-risk surgical patients.</article-title> <source>Chest</source>. <year>1992</year>;<volume>102</volume>:<fpage>208</fpage>&#x2013;<lpage>15</lpage>. <pub-id pub-id-type="doi">10.1378/chest.102.1.208</pub-id><pub-id pub-id-type="pmid">1623755</pub-id></mixed-citation></ref>
<ref id="r51"><label>51</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Bellamy</surname><given-names>MC</given-names></name></person-group>. <article-title>Wet, dry or something else?</article-title> <source>Br J Anaesth</source>. <year>2006</year>;<volume>97</volume>:<fpage>755</fpage>&#x2013;<lpage>7</lpage>. <pub-id pub-id-type="doi">10.1093/bja/ael290</pub-id><pub-id pub-id-type="pmid">17098724</pub-id></mixed-citation></ref>
<ref id="r52"><label>52</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Jacob</surname><given-names>M</given-names></name><name><surname>Chappell</surname><given-names>D</given-names></name></person-group>. <article-title>Reappraising Starling: the physiology of the microcirculation.</article-title> <source>Curr Opin Crit Care</source>. <year>2013</year>;<volume>19</volume>:<fpage>282</fpage>&#x2013;<lpage>9</lpage>. <pub-id pub-id-type="doi">10.1097/MCC.0b013e3283632d5e</pub-id><pub-id pub-id-type="pmid">23743590</pub-id></mixed-citation></ref>
<ref id="r53"><label>53</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Myles</surname><given-names>PS</given-names></name><name><surname>Bellomo</surname><given-names>R</given-names></name></person-group>. <article-title>Corcoran T i sur. Restrictive versus liberal fluid therapy for major abdominal surgery.</article-title> <source>N Engl J Med</source>. <year>2018</year>;<volume>378</volume>:<fpage>2263</fpage>&#x2013;<lpage>74</lpage>. <pub-id pub-id-type="doi">10.1056/NEJMoa1801601</pub-id><pub-id pub-id-type="pmid">29742967</pub-id></mixed-citation></ref>
<ref id="r54"><label>54</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Cecconi</surname><given-names>M</given-names></name><name><surname>Corredor</surname><given-names>C</given-names></name></person-group>. <article-title>Arulkumaran N i sur. Clinical review: Goal-directed therapy what is the evidence in surgical patients? The effect on different risk groups.</article-title> <source>Crit Care</source>. <year>2013</year>;<volume>17</volume>(<issue>2</issue>):<fpage>209</fpage>. <pub-id pub-id-type="doi">10.1186/cc11823</pub-id><pub-id pub-id-type="pmid">23672779</pub-id></mixed-citation></ref>
<ref id="r55"><label>55</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Pearse</surname><given-names>RM</given-names></name><name><surname>Harrison</surname><given-names>DA</given-names></name></person-group>. <article-title>MacDonald N i sur. Effect of a perioperative, cardiac output-guided hemodynamic therapy algorithm on outcomes following major gastrointestinal surgery: a randomized clinical trial and systematic review.</article-title> <source>JAMA</source>. <year>2014</year>;<volume>311</volume>:<fpage>2181</fpage>&#x2013;<lpage>90</lpage>. <pub-id pub-id-type="doi">10.1001/jama.2014.5305</pub-id><pub-id pub-id-type="pmid">24842135</pub-id></mixed-citation></ref>
<ref id="r56"><label>56</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Pesta&#x00F1;a</surname><given-names>D</given-names></name><name><surname>Espinoza</surname><given-names>E</given-names></name></person-group>. <article-title>Eden A i sur. Perioperative goal-directed hemodynamic optimization using noninvasive cardiac output monitoring in major abdominal surgery: a prospective, randomized, multicenter, pragmatic trial: POEMAS Study (PeriOperative goal-directed thErapy in Major Abdominal Surgery).</article-title> <source>Anesth Analg</source>. <year>2014</year>;<volume>119</volume>:<fpage>579</fpage>&#x2013;<lpage>87</lpage>. <pub-id pub-id-type="doi">10.1213/ANE.0000000000000295</pub-id><pub-id pub-id-type="pmid">25010820</pub-id></mixed-citation></ref>
<ref id="r57"><label>57</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Cecconi</surname><given-names>M</given-names></name><name><surname>Hofer</surname><given-names>C</given-names></name></person-group>. <article-title>Teboul JL i sur. Fluid challenges in intensive care: the FENICE study: a global inception cohort study.</article-title> <source>Intensive Care Med</source>. <year>2015</year>;<volume>41</volume>:<fpage>1529</fpage>&#x2013;<lpage>37</lpage>. <pub-id pub-id-type="doi">10.1007/s00134-015-3850-x</pub-id><pub-id pub-id-type="pmid">26162676</pub-id></mixed-citation></ref>
<ref id="r58"><label>58</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Aya</surname><given-names>HD</given-names></name><name><surname>Rhodes</surname><given-names>A</given-names></name><name><surname>Chis Ster</surname><given-names>I</given-names></name><name><surname>Fletcher</surname><given-names>N</given-names></name><name><surname>Grounds</surname><given-names>RM</given-names></name><name><surname>Cecconi</surname><given-names>M</given-names></name></person-group>. <article-title>Hemodynamic effect of different doses of fluids for a challenge: a quasi-randomized controlled study.</article-title> <source>Crit Care Med</source>. <year>2017</year>;<volume>45</volume>:<fpage>e161</fpage>&#x2013;<lpage>8</lpage>. <pub-id pub-id-type="doi">10.1097/CCM.0000000000002067</pub-id><pub-id pub-id-type="pmid">27655325</pub-id></mixed-citation></ref>
<ref id="r59"><label>59</label><mixed-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Saugel</surname><given-names>B</given-names></name><name><surname>Vincent</surname><given-names>JL</given-names></name><name><surname>Wagner</surname><given-names>JY</given-names></name></person-group>. <article-title>Personalized hemodynamic management.</article-title> <source>Curr Opin Crit Care</source>. <year>2017</year>;<volume>23</volume>:<fpage>334</fpage>&#x2013;<lpage>41</lpage>. <pub-id pub-id-type="doi">10.1097/MCC.0000000000000422</pub-id><pub-id pub-id-type="pmid">28562384</pub-id></mixed-citation></ref>
</ref-list>
</back>
</article>
