Vincent et al. Critical Care 2011, 15:229 Page 2 of 8http://ccforum.com/content/15/4/229Table 1. Examples of available methods to measure cardiac outputMethod System LimitationsThermodilution PAC Invasiveness - training requiredTranspulmonary PiCCO® Decreased accuracy?indicator dilution Need for dedicated arterial catheter LiDCO™ Decreased accuracy? Need for lithium injection Interference by non-depolarizing muscle relaxants; inaccurate in case of hyponatremia COstatus® Decreased accuracy? VolumeView™ Decreased accuracy? Need for dedicated arterial catheterArterial-pressure PiCCO®, LiDCO™, Vigileo™, Decreased accuracy, need for optimal arterial pressure tracingwaveform-derived MostCare™Esophageal Doppler CardioQ™, WAKIe TO Training required, intermittent measurementSuprasternal Doppler USCOM® Difficult in some patientsEchocardiography Vivid™, Sonosite MicroMaxx®, Training required, intermittent measurement Philips CX50™, and so onPartial CO2 rebreathing NiCO® Less reliable in respiratory failureBioimpedance Lifegard®, TEBCO®, Hotman®, Less reliable in critically ill patients, not applicable in cardiothoracic surgery BioZ®, and so onBioreactance NICOM® Validated in only one study in critically ill patientsPAC, pulmonary artery catheter.in any detail, not to provide readers with a shopping list, over the previous 10 minutes. The averaged values havenor to identify one system that would be suitable in all the advantage of eliminating variability in the presence ofpatients; rather, we will brieﬂy review the advantages and arrhythmias, but the disadvantage of not being real-timelimitations of each system, and propose ten key principles values, thus limiting the usefulness of this approach forto guide choice of monitoring system(s) in today’s acutely assessing rapid hemodynamic changes in unstableill patients. patients. The PAC has a key advantage over many other systemsAvailable systems for monitoring cardiac output in that it provides simultaneous measurements of otherExamples of the main systems that are available for hemodynamic parameters in addition to cardiac output,estimating cardiac output are listed in Table 1. including pulmonary artery pressures, right-sided and left-sided ﬁlling pressures, and SvO2.Thermodilution (pulmonary artery catheter)The intermittent thermodilution technique, in which Transpulmonary or ultrasound indicator dilutionboluses of ice-cold ﬂuid are injected into the right atrium The PiCCO® (Pulsion Medical Systems, Munich, Germany),via a PAC and the change in temperature detected in the LiDCO™ (LiDCO Ltd, London, UK), VolumeView™blood of the pulmonary artery used to calculate cardiac (Edwards Life Sciences), and COstatus® (Transonic Systemsoutput, is still widely considered as the standard method Inc., Ithaca, NY, USA) systems allow cardiac output to beof reference. Adaptation of the PAC to incorporate a investigated less invasively, using a central venous (tothermal ﬁlament (Vigilance™, Edwards Life Sciences, allow calibration) and an arterial catheter, rather thanIrvine, CA, USA) or thermal coil (OptiQ™, ICU Medical, needing to introduce a catheter into the pulmonarySan Clemente, CA, USA) that warms blood in the artery. The PiCCO® and recently launched VolumeView™superior vena cava and measures changes in blood systems require a femoral artery catheter. These devicestemperature at the PAC tip using a thermistor, provides a use the same basic principles of dilution to estimate thecontinuous measure of the trend in cardiac output, with cardiac output as with PAC thermodilution. PiCCO® andthe displayed values representing an average of the values VolumeView™ use injections of ice cold intravenous ﬂuid
Vincent et al. Critical Care 2011, 15:229 Page 3 of 8http://ccforum.com/content/15/4/229as the indicator, measuring change in temperature down- Echocardiography and echo-Dopplerstream to calculate cardiac output, whereas LiDCO™ uses Echocardiography allows measurement of cardiac outputminute amounts of lithium chloride as the indicator and using standard two-dimensional imaging or, more com-measures levels using a lithium-selective electrode. monly, Doppler-based methods. The main interest inCOstatus® calculates cardiac output by using ultrasound echocardiography in general is that it can be used nottechnology to measure changes in blood ultrasound only for measurement of cardiac output but also for thevelocity and blood ﬂow following an injection of warm additional assessment of cardiac function. Echocardio-saline solution. graphy is particularly useful as a diagnostic tool because Cardiac output values measured using transpulmonary it allows the visualization of cardiac chambers, valves andor ultrasound indicator dilution techniques correlate well pericardium. Small ventricles (‘kissing ventricles’) maywith those measured using PAC thermodilution [3-6] incite ﬂuid administration whereas a poorly contractileand may show less respiratory phase-dependent variation myocardium may suggest that a dobutamine infusion is a. The PiCCO® and the VolumeView™ systems provide better choice. Right ventricular dilatation may orientvariables in addition to cardiac output, such as global towards the diagnosis of massive pulmonary embolism orend-diastolic volume and measurements of extravascular myocardial infarction whereas the presence of pericardiallung water. The COstatus® system also provides some ﬂuid may suggest a diagnosis of pericardial tamponade.derived variables, including total end diastolic volume Severe valvulopathy can also be recognized promptly.index. However, echocardiography instruments and expertise may not be readily available everywhere; in someArterial pressure trace-derived estimation of cardiac institutions, this is still the domain of the cardiologistsoutput and they need to be called to do the procedure.In addition to the intermittent indicator dilution cardiac If an ultrasound beam is directed along the aorta using aoutput measurements discussed above, the PiCCO® and probe, part of the ultrasound signal will be reﬂected backLiDCO™ systems can also estimate cardiac output on a by the moving red blood cells at a diﬀerent frequency. Thecontinuous basis from the arterial pressure waveform resultant Doppler shift in the frequency can be used towith (PiCCO2® and LiDCOplus™) or without (LidCOrapid™) calculate the ﬂow velocity and volume and hence cardiacthe need for recalibration when changes in vascular com- output. Echo-Doppler evaluation can provide reasonablepliance may have occurred. The PiCCO® system uses a estimates of cardiac output, but again is operator-pulse contour analysis and the LiDCO™ system a pulse dependent and continuous measurement of cardiacpower analysis. In addition to these, Vigileo™ (Edwards output using this technique is not possible. Echo-DopplerLife Sciences) and MostCare™ (Vytech, Padova, Italy, evaluation may be applied either transthoracically orusing the Pressure Recording Analytical Method (PRAM)) transesophageally. However, transthoracic techniques dosystems have been developed for arterial waveform not always yield good images and transesophagealanalysis without external calibration. Each of these techniques are more invasive such that some sedation,systems contains a proprietary algorithm for converting a and often endotracheal intubation, is required in order topressure-based signal into a ﬂow measurement. The obtain reliable measurements. Moreover, the esophagealspeciﬁc algorithms have individual characteristics and probe is uncomfortable in non-intubated patients,make diﬀerent assumptions - for example, related to although may be better tolerated if inserted nasally, andarterial compliance (Vigileo™) or pressure (MostCare™) - should be used cautiously in patients with esophagealwhich can make them more or less accurate depending lesions. The signal produces diﬀerent waveforms that canon the clinical circumstances. The level of accuracy and be used to distinguish to some extent changes in preload,precision of each device needs to be understood as the afterload and left ventricular contractility. Doppler ﬂowdata cannot be superimposed from one system to studies focusing on the descending thoracic aorta may notanother. The advantages of these arterial pressure-based provide a reliable measurement of the total cardiac outputcardiac output monitoring systems over PAC-derived (for example, with epidural use), and are invalid in themeasurements is primarily their less invasive nature. presence of intra-aortic balloon pumping. Echo-Doppler The major weakness of all these devices is the drift in cardiac output estimates vary considerably for severalvalues whenever there is a major change in vascular reasons, including diﬃculty in assessment of the velocitycompliance, as, for example, in vascular leak syndrome time integral, calculation error due to the angle ofwith increased vessel wall edema leading to decreased insonation, and problems with correct measurement ofarterial compliance. Aortic valve regurgitation may the cross-sectional area. Some training is required whenfurther decrease the accuracy of these techniques. Over- using these techniques. Esophageal-Doppler techniquesor under-damped arterial pressure waveforms will also have been shown to be useful for optimizing ﬂuiddecrease the precision of these monitors. administration in high risk surgical patients [7,8].
Vincent et al. Critical Care 2011, 15:229 Page 4 of 8http://ccforum.com/content/15/4/229 Simpliﬁed transesophageal Doppler techniques can be monitoring device must be suﬃciently accurate to be ableconvenient as the probe is smaller than for standard to inﬂuence therapeutic decision making; the dataesophageal echocardiography techniques. Simpliﬁed trans- obtained from the monitoring system must be relevant tothoracic Doppler systems allow estimation of aortic blood the patient being monitored; and changes in managementﬂow and may be even less invasive; however, although these made as a result of the data obtained need to be able totechniques can be simple to perform in healthy volun- improve outcomes. If the data are interpreted or appliedteers, access to good images may be more diﬃcult in incorrectly, or the therapies themselves are ineﬀective orcritically ill patients. Moreover, there is a fairly prolonged harmful, the resultant change in management will notlearning curve for correct use of this system . These improve patient status and may be deleterious.methods need further validation in critically ill patients. If these three conditions are not met, monitoring is unlikely to be associated with improved outcomes, andCO2 rebreathing this may account for the lack of evidence of improvedCO2 rebreathing systems, based on the Fick principle, use outcomes in acutely ill patients with use of anya CO2 sensor, a disposable airﬂow sensor and a disposable monitoring device, not only the PAC .rebreathing loop. CO2 production is calculated fromminute ventilation and its CO2 content, and the arterial Principle 2: monitoring requirements may vary over timeCO2 content is estimated from end-tidal CO2. Partial re- and can depend on local equipment availability andbreathing reduces CO2 elimination and increases the trainingend-tidal CO2. By combining measurements taken during The optimal monitoring system will depend on theand without rebreathing, venous CO2 content can be individual patient, the problem already present oreliminated from the Fick equation. However, intra- potentially arising for which the monitoring is required,pulmonary shunting of blood and rapid hemodynamic and the devices and expertise available at the institutionchanges aﬀect the accuracy of the measurement, so that in question.this technique is not considered to be reliable in acutely For initial evaluation of the critically ill patient, anill patients. invasive approach is still often needed, which includes insertion of an arterial catheter and a central venousBioimpedance and bioreactance catheter; this is because of the need for secureBioimpedance is based on the fact that the conductivity intravenous and arterial access in such patients and theof a high-frequency, low-magnitude alternating current presumed increased accuracy of measurements based onpassed across the thorax changes as blood ﬂow varies direct pressure monitoring. The data provided canwith each cardiac cycle. These changes can be measured already guide initial treatment. Analysis of the arterialusing electrodes placed on a patient’s chest and used to pressure trace can identify ﬂuid responsiveness ingenerate a waveform from which cardiac output can be mechanically ventilated patients, although there are somecalculated. Bioreactance has developed out of bio- limitations to this technique, including adaptation to theimpedance and measures changes in the frequency of the respirator (often with high doses of sedative agents andelectrical currents traversing the chest, rather than even paralysis), need for absence of arrhythmias, and usechanges in impedance, potentially making it less sensitive of relatively large tidal volumes. Response to passive legto noise. These techniques are non-invasive and can be raising can be used if beat-by-beat measurements ofapplied quickly. They have been used for physiological stroke volume are monitored. Once stabilized, lessstudies in healthy individuals and may be useful in invasive monitoring techniques should be employed.perioperative applications , but are less reliable in Importantly, monitoring systems are not necessarilycritically ill patients . Electrical interference may also mutually exclusive and can sometimes be used tooccur in the ICU environment. complement each other. For example, echocardiography can provide additional information in the early assess-Key principles of hemodynamic monitoring ment of critically ill patients (Figure 1).Having brieﬂy discussed some of the advantages and There is still a place for the PAC (Swan-Ganz), whichlimitations of the available systems, we now consider has the advantage of allowing measurement of cardiacsome key principles than can help when considering ﬁlling pressures and pulmonary artery pressures, cardiacwhich hemodynamic monitoring system to use. output and SvO2 (and now also extravascular lung water). However, although in the past a PAC was inserted earlyPrinciple 1: no hemodynamic monitoring technique can in all critically ill patients, today its insertion is no longerimprove outcome by itself necessary during initial resuscitation, but should ratherHemodynamic monitoring can only improve outcomes if be reserved for complex cases, for example, patients withthree conditions are met: the data obtained from the right ventricular dysfunction, diﬃcult assessment of
Vincent et al. Critical Care 2011, 15:229 Page 5 of 8http://ccforum.com/content/15/4/229 PAP Hemodynamic instability RAP PAOP EKG arterial catheter End-diastolic central venous catheter volumes Heart rate Arterial pressure Fluid responsiveness ? CO Microcirculation (low CVP ?) (OPS, NIRS, …) Urine output Mental status PgCO2 Cutaneous perfusion present absent Sublingual capnometry Lactate echocardiography CO2 gap SvO2 hypovolemia likely small chambers tamponade Figure 2. Factors influencing the interpretation of cardiac output large ventricles RV dilation (CO). EKG, electrocardiogram; NIRS, near-infrared spectral imaging; poor contractile state (obstructive) OPS, orthogonal polarization spectral imaging; PAOP, pulmonary fluid challenge valvulopathy artery occlusion pressure; PAP, pulmonary artery pressure; PgCO2, (cardiogenic) gastric intramucosal carbon dioxide partial pressure; RAP, right atrial Figure 1. Diagnostic algorithm based on use of pressure; SvO2, mixed venous oxygen saturation. echocardiography. CVP, central venous pressure; RV, right ventricular. and blood lactate levels (Figure 2). Alarms should thus beoptimal ﬂuid management, or speciﬁc cases of cardiac individualized for each patient and reevaluated regularly.failure. Principle 4: we need to combine and integrate variablesPrinciple 3: there are no optimal hemodynamic values that Any variable on its own provides relatively little informa-are applicable to all patients tion - it is just one piece of a large puzzle. We need ratherAlthough it may be appealing to have some simple to integrate all the available data from multiple sources.targets, such as keeping the mean arterial pressure above For example, a hypotensive patient with a low cardiac65 mmHg, the central venous pressure (CVP) above output will present diﬀerent diagnoses (hypovolemia,8 mmHg, or DO2 above 600 mL/minute/M², such targets decreased contractility or obstruction) and hence requireare overly simplistic and may even be potentially diﬀerent treatments to a hypotensive patient with a highdangerous. For example, the acceptable minimal arterial cardiac output (decreased vascular tone). Likewise, aspressure may be very diﬀerent in a young individual discussed earlier, correct interpretation of a low cardiacwithout co-morbidity compared to an elderly athero- output involves consideration of many factors (Figure 2),sclerotic, previously hypertensive patient. Likewise, the including some assessment of cardiac ﬁlling (pressures orCVP may remain low in adequately resuscitated patients dimensions) to assess ventricular preload.or may be high at baseline in patients with pulmonaryhypertension due to underlying chronic lung disease. Principle 5: measurements of SvO2 can be helpfulSimilarly, it is diﬃcult to deﬁne an optimal level of SvO2 reﬂects the balance between oxygen consumptioncardiac output as cardiac output is an adaptative para- (VO2) and DO2 and thus provides an indication of themeter for which there is no single ‘normal’ value, but only adequacy of tissue oxygenation. If there is no PAC in situ,normal ranges. Since the purpose of the cardiovascular the oxygen saturation in the superior vena cava (ScvO2)system is to match blood ﬂow to metabolic demand, and can be measured using a central venous catheter and hasthis demand may vary widely even over short time been proposed as a surrogate for SvO2. Importantly,intervals, targeting a speciﬁc cardiac output or even ScvO2 represents just an approximation of the SvO2 sustaining a threshold value may be inappropriate. For and the absolute values of ScvO2 and SvO2 are notexample, keeping a cardiac output above 5 or 6 liters per interchangeable. The diﬀerence between these two para-minute in an adult would be like driving constantly at meters is inﬂuenced by the sampling site of central80 km/h, whether in a small town or on the freeway. In venous blood, the presence of left-to-right shunts, in-the critically ill, cardiac output increases in sepsis, as in complete mixing of venous blood, oxygen extraction inanemia, but may be reduced with sedation or anesthesia. the renal and the splanchnic beds, redistribution of bloodMultiple factors therefore need to be considered when ﬂow through the upper and lower body, level of con-determining whether cardiac output is optimal for a sciousness (anesthesia) and myocardial VO2. The relia-particular patient, including the degree of tissue bility of ScvO2 is also dependent on the position of the tipperfusion as estimated from a careful clinical examination of the catheter, with right atrial measurements closely
Vincent et al. Critical Care 2011, 15:229 Page 6 of 8http://ccforum.com/content/15/4/229 oxygen extraction, rather than adequate perfusion, such CARDIAC OUTPUT that patients may still deteriorate even with a high SvO2. In sepsis, a high cardiac output, like a high SvO2, can be HIGH LOW associated with worse outcomes. SvO2 SvO2 Principle 7: cardiac output is estimated, not measured No bedside method is available to directly assess cardiac HIGH LOW HIGH LOW output, so all values obtained are estimates. As such, INFLAMMATION (incl. SEPSIS) ANEMIA LOW VO2 LOW OUTPUT comparison of measurements obtained with diﬀerent HYPOXEMIA (anesthesia, SYNDROME EXCESSIVE HIGH VO2 hypothermia,...) (hypovolemia, techniques results in relatively poor agreement and signi- BLOOD FLOW (hypervolemia, heart failure, ﬁcant bias. The intermittent thermodilution technique is pulm. embolism...) excessive vasoactive therapy) generally considered as the ‘reference’ standard, but has Figure 3. Diagnostic algorithm based on mixed venous oxygen its own limitations. A measurement obtained by a less saturation (SvO2) and cardiac output. VO2, oxygen consumption. invasive technique may be preferable if it can be obtained more rapidly and easily, even if it is slightly less accurate. Importantly, the accuracy of absolute values may be lessapproximating SvO2 and high vena cava measurements important if one is following trends, for example, to trackoften deviating substantially from SvO2. In general, SvO2 the short-term eﬀects of therapies, such as ﬂuid loading.is more useful when the value is below normal (seebelow), even though in these conditions it may not reﬂect Principle 8: monitoring hemodynamic changes over shorta hemodynamic problem. Simultaneous measurements periods of time is importantof blood lactate levels can be helpful. A diagnostic Monitoring of acute changes in cardiac output can bealgorithm based on SvO2 and cardiac output is shown in important, for example, in patients at risk of acuteFigure 3. bleeding or in assessing the response to ﬂuid adminis- tration to separate ﬂuid responders from non-responders.Principle 6: a high cardiac output and a high SvO2 are not Evaluating the response to a dobutamine or to a nitratealways best infusion is another example of this functional monitoringAlthough ICU physicians may like to increase cardiac that may also have sound clinical applications. Thisoutput and SvO2 by giving more ﬂuid and inotropic assessment of hemodynamic variations observed duringagents, is this always good? Excessive ﬂuid administration the challenge of the cardiovascular system has beento increase cardiac output may result in ﬂuid overload termed ‘functional hemodynamic monitoring’ . Thewith massive edema formation and this may be associated study of slow changes in cardiac output over several dayswith worse outcomes ; some systems measure may be less relevant in most patients, although can beextravascular lung water, which can help document this. useful to follow the clinical course of the cardiac patient.Similarly, excessive doses of dobutamine can be detri- Combining measures of multiple variables and theirmental, compromising myocardial function, especially in dynamic interactions in response to time and speciﬁcpatients with coronary artery disease; giving inotropic treatments often increases the sensitivity and speciﬁcity ofagents in the presence of coronary artery disease is like these monitoring modalities to identify speciﬁc diseasetrying to stimulate a tired horse. Using vasoactive agents processes and quantify whether therapy is eﬀective or not.and ﬂuids to increase DO2 to supranormal levels in allpatients may result in excessive mortality rates and this Principle 9: continuous measurement of all hemodynamicstrategy has been abandoned . A high ScvO2 has been variables is preferablesuggested as a target for some high risk patients or in Although there are no data to demonstrate theshock resuscitation, with Rivers and colleagues  superiority of continuous cardiac output measurementsreporting that septic patients assigned to an early goal- over intermittent monitoring, there has been a globaldirected therapy algorithm had higher ScvO2 values and evolution towards more continuous measurement ofreduced mortality rates. However, this was a strategy for variables. We can now routinely measure various hemo-early resuscitation of patients with severe sepsis in a dynamic variables continuously, including heart rate,single institution, and needs further validation in multi- arterial pressure and CVP. Using the thermodilutioncenter studies, several of which are currently ongoing. technique, one may not wish to go back to intermittentImportantly, applying the same strategy in general ICU measurements of cardiac output by repeated injections ofpatients may not improve outcomes . Indeed, in cold water boluses. It may even be preferable to have real-patients with sepsis, a high SvO2 may be the result of time (beat-by-beat) continuous cardiac output measure-maldistribution of peripheral blood ﬂow and altered ment rather than a built-in delay like the semi-continuous
Vincent et al. Critical Care 2011, 15:229 Page 7 of 8http://ccforum.com/content/15/4/229Table 2. The key properties of an ‘ideal’ hemodynamic choose devices that have a maximum of these attributes,monitoring system bearing in mind that there is no ‘one size ﬁts all’ type ofProvides measurement of relevant variables system and one should, therefore, select the system mostProvides accurate and reproducible measurements appropriate for each patient and, perhaps even more importantly, for each type of problem. It is important toProvides interpretable data be familiar with the technology being used, proﬁtingIs easy to use from its advantages but recognizing its limitations. MostIs readily available systems now oﬀer (almost) continuous measurements,Is operator-independent with the possible exception of echocardiography tech-Has a rapid response-time niques because it is diﬃcult to leave the probe in placeCauses no harm for prolonged periods. Hemodynamic monitoring can be particularly helpful in the early stages of resuscitation,Is cost-effective but is less useful when organ failure is established. MostShould provide information that is able to guide therapy importantly, one must never forget that it is not the monitoring itself that can improve outcomes but thecardiac output provided with the Vigilance™ system. changes in therapy guided by the data obtained.Systems that are not continuous (for example, echo-cardiography) or that require calibration (for example, Abbreviations CVP, central venous pressure; DO2, oxygen delivery; PAC, pulmonary arterytranspulmonary indicator dilution) may not provide the catheter; ScvO2, central venous oxygen saturation; SvO2, mixed venous oxygenreal-time data needed for optimal acute management of saturation; VO2, oxygen consumption.unstable critically ill patients, whereas systems thatprovide continuous non-calibrated cardiac output measure- Competing interests J-LV has received grants from Edwards Lifesciences and Pulsion Medicalments suﬀer from reduced accuracy. Systems. AR has received lecture fees from LiDCO and advisory board fees from Cheetah and Edwards. AP is a member of the medical advisory boardPrinciple 10: non-invasiveness is not the only issue of Pulsion Medical Systems and consultant to BMEYE. GSM is a member of the medical advisory board of Pulsion Medical Systems. GDR has no conflictsNon-invasiveness is not the only goal. Although it is related to this manuscript. BV is an advisor to, and has received lecture feesalways preferable to be less invasive, being non-invasive from, Edwards. MRP is a paid advisor to LiDCO Ltd, Edwards LifeSciencesis not always possible and may even be counter eﬀective. Inc., and Applied Physiology; he has stock options with LiDCO and Cheetah Medical and has received honoraria from Cheetah Medical. CKH has receivedFor example, continuous monitoring of arterial pressure lecture fees and research grants from Pulsion Medical Systems and Edwardsis more invasive than intermittent monitoring but is Lifesciences. J-LT is a member of the medical advisory board of Pulsionhelpful in hypotensive (or severe hypertensive) states. Medical Systems. W-PdeB has received research grants from Transonic Systems Inc. and Pulsion Medical Systems. SS has received research grants from VygonLikewise, a central venous catheter can be helpful to and Vythec. AV-B has received research grants from General Electric andmonitor the CVP and the ScvO2 (and also facilitates the Maquet. DDeB has received grants and material for studies from Edwardsrapid administration of ﬂuids). Whenever possible, we Lifesciences, Pulsion Medical Systems, LiDCO and Vytech and honoraria for lectures from Edwards Lifesciences and Pulsion Medical Systems. KRW has noshould of course try to be as non-invasive as possible, but conflicts related to this manuscript. MM is a member of the medical advisoryarterial pressure monitoring and CVP monitoring are board of Pulsion Medical Systems. MS is on the Advisory Board for Deltexstill invasive. Echocardiography must be promoted more Medical and Covidien; Deltex Medical provide unrestricted research grants.for its ability to oﬀer a direct evaluation of cardiac Author detailsfunction than for its non-invasiveness. Even though it is 1 Department of Intensive Care, Erasme Hospital, Université Libre dethe most invasive method, the PAC is still of value in very Bruxelles, 808 route de Lennik, 1070-Brussels, Belgium. 2Department of Intensive Care Medicine, St George’s Healthcare NHS Trust, Blackshaw Road,sick patients with complex problems, for example, London, SW17 0QT, UK. 3Department of Anesthesiology and Intensive Care,respiratory failure with shock and oliguria. At the other Sheba Medical Center, Tel Aviv University, Tel Aviv, 52621 Israel. 4Division ofextreme, completely non-invasive bioimpedance has a Pulmonary, Allergy and Critical Care, Emory University School of Medicine, Grady Memorial Hospital, 615 Michael Street, Suite 205, Atlanta, GA 30322,place in healthy individuals, but little place in critically ill USA. 5Department of Anesthesia and Intensive Care Medicine, Universitypatients. Other monitoring systems are of use in patients Hospital, Medical School, University of Udine, P.le S. Maria della Misericordia,with conditions somewhere between these two extremes. 1533100 Udine, Italy. 6Department of Anesthesiology and Critical Care Medicine, Pôle d’Anesthesie Reanimation, Hôpital Claude Huriez, rue MichelThe optimal device depends on the type of patient, the Polonoski, CHU Univ Nord de France, 59000 Lille, France. 7Departmentquestion being asked, and the condition being managed of Critical Care Medicine, 606 Scaife Hall, 3550 Terrace Street, Pittsburgh,or anticipated. PA 15261, USA. 8Institute of Anaesthesiology and Intensive Care Medicine, Triemli City Hospital Zurich, Birmensdorferstr. 497, 8063 Zurich, Switzerland. 9 Service de réanimation médicale, Centre Hospitalo-Universitaire de Bicêtre,Conclusion Assistance Publique-Hôpitaux de Paris, EA 4046, Université Paris Sud, 78The ideal hemodynamic monitoring system should rue du Général Leclerc, 94 270 Le Kremlin-Bicêtre, France. 10Department of Neonatology, Radboud University Nijmegen Medical center, PO Box 9101,comprise all the key factors listed in Table 2; however, 6500 Nijmegen, The Netherlands. 11Department of Anaesthesia and Intensivesuch a system does not currently exist so we must try and Care, University of Siena, Viale Bracci, 1, 53100 Siena, Italy. 12Réanimation
Vincent et al. Critical Care 2011, 15:229 Page 8 of 8http://ccforum.com/content/15/4/229médicale, CHU Ambroise Paré, 9 avenue Charles-de-Gaulle, 92104 Boulogne, 9. Lelyveld-Haas LE, van Zanten AR, Borm GF, Tjan DH: Clinical validation of theFrance. 13Critical Care Research Laboratories, Heart and Lung Institute, non-invasive cardiac output monitor USCOM-1A in critically ill patients.University of British Columbia, 166-1081 Burrard Street, Vancouver, British Eur J Anaesthesiol 2008, 25:917-924.Columbia, V6Z 1Y6, Canada. 14Intensive Care Unit, Department of Internal 10. Marque S, Cariou A, Chiche JD, Squara P: Comparison between Flotrac-Medicine, University Hospital Zurich, Raemistrasse 100, CH-8091 Zurich, Vigileo and Bioreactance, a totally noninvasive method for cardiac outputSwitzerland. 15Department of Intensive Care, University College London, monitoring. Crit Care 2009, 13:R73.Cruciform Building, Gower Street, London, WC1E 6BT, UK. 11. Squara P, Denjean D, Estagnasie P, Brusset A, Dib JC, Dubois C: Noninvasive cardiac output monitoring (NICOM): a clinical validation. Intensive Care MedPublished: 18 August 2011 2007, 33:1191-1194. 12. Ospina-Tascon GA, Cordioli RL, Vincent JL: What type of monitoring hasReferences been shown to improve outcomes in acutely ill patients? Intensive Care1. Shah MR, Hasselblad V, Stevenson LW, Binanay C, O’Connor CM, Sopko G, Med 2008, 34:800-820. Califf RM: Impact of the pulmonary artery catheter in critically ill patients: 13. Reinhart K, Kuhn HJ, Hartog C, Bredle DL: Continuous central venous and meta-analysis of randomized clinical trials. JAMA 2005, 294:1664-1670. pulmonary artery oxygen saturation monitoring in the critically ill.2. Squara P, Cecconi M, Rhodes A, Singer M, Chiche JD: Tracking changes in Intensive Care Med 2004, 30:1572-1578. cardiac output: methodological considerations for the validation of 14. Sakr Y, Vincent JL, Reinhart K, Groeneveld J, Michalopoulos A, Sprung CL, monitoring devices. Intensive Care Med 2009, 35:1801-1808. Artigas A, Ranieri VM: High tidal volume and positive fluid balance are3. Goedje O, Hoeke K, Lichtwarck-Aschoff M, Faltchauser A, Lamm P, Reichart B: associated with worse outcome in acute lung injury. Chest 2005, Continuous cardiac output by femoral arterial thermodilution calibrated 128:3098-3108. pulse contour analysis: comparison with pulmonary arterial 15. Dellinger RP, Levy MM, Carlet JM, Bion J, Parker MM, Jaeschke R, Reinhart K, thermodilution. Crit Care Med 1999, 27:2407-2412. Angus DC, Brun-Buisson C, Beale R, Calandra T, Dhainaut JF, Gerlach H, Harvey4. Sakka SG, Reinhart K, Meier-Hellmann A: Comparison of pulmonary artery M, Marini JJ, Marshall J, Ranieri M, Ramsay G, Sevransky J, Thompson BT, and arterial thermodilution cardiac output in critically ill patients. Intensive Townsend S, Vender JS, Zimmerman JL, Vincent JL: Surviving Sepsis Care Med 1999, 25:843-846. Campaign: international guidelines for management of severe sepsis and5. Costa MG, Della Rocca G, Chiarandini P, Mattelig S, Pompei L, Barriga MS, septic shock: 2008. Crit Care Med 2008, 36:296-327. Reynolds T, Cecconi M, Pietropaoli P: Continuous and intermittent cardiac 16. Rivers E, Nguyen B, Havstad S, Ressler J, Muzzin A, Knoblich B, Peterson E, output measurement in hyperdynamic conditions: pulmonary artery Tomlanovich M: Early goal-directed therapy in the treatment of severe catheter vs. lithium dilution technique. Intensive Care Med 2008, 34:257-263. sepsis and septic shock. N Engl J Med 2001, 345:1368-1377.6. Tsutsui M, Matsuoka N, Ikeda T, Sanjo Y, Kazama T: Comparison of a new 17. Gattinoni L, Brazzi L, Pelosi P, Latini R, Tognoni G, Pesenti A, Fumagalli R: A trial cardiac output ultrasound dilution method with thermodilution of goal-oriented hemodynamic therapy in critically ill patients. SvO2 technique in adult patients under general anesthesia. J Cardiothorac Vasc Collaborative Group. N Engl J Med 1995, 333:1025-1032. Anesth 2009, 23:835-840. 18. Pinsky MR, Payen D: Functional hemodynamic monitoring. Crit Care 2005,7. Wakeling HG, McFall MR, Jenkins CS, Woods WG, Miles WF, Barclay GR, 9:566-572. Fleming SC: Intraoperative oesophageal Doppler guided fluid management shortens postoperative hospital stay after major bowel surgery. Br J Anaesth 2005, 95:634-642. doi:10.1186/cc102918. Abbas SM, Hill AG: Systematic review of the literature for the use of Cite this article as: Vincent JL, et al.: Clinical review: Update on oesophageal Doppler monitor for fluid replacement in major abdominal hemodynamic monitoring - a consensus of 16. Critical Care 2011, 15:229. surgery. Anaesthesia 2008, 63:44-51.