Original contributionTranspulmonary thermodilution cardiac output measurement using the axillary artery in critically ill patients
Introduction
In many patients with hemodynamic instability or critical illness, it is important to measure cardiac output (CO) to assess perfusion to the various organs and tissues. The value of CO is also important in determining responsiveness to volume loading and to various hemodynamic maneuvers. The ideal “gold standard” method for the measurement of CO is still to be determined. Various methods of measuring CO include use of the Fick equation, pulmonary artery (PA) thermodilution, acetylene gas rebreathing, and Doppler probes introduced into the esophagus, to name a few. The most common method of measuring CO involves the use of the pulmonary artery catheter (PAC), utilizing the thermodilution technique. However, in recent years, the use of PACs has become controversial.1
A relatively new technique of CO measurement is that of transpulmonary indicator dilution (TPID), or arterial thermodilution. In this method, a cold indicator solution is injected into a central vein and the temperature change is measured by a thermistor-tipped arterial catheter inserted into a large artery.2 This technique can provide CO measurements without the need for a PAC, and is thus beneficial in many patients in whom the insertion of a PAC may be problematic or risky. A major advantage of this method is that because many patients in the ICU and the operating room require the use of central venous cannulation and an arterial catheter anyway, obtaining CO measurements in these patients may be achieved without additional invasive monitoring. Recently, the validity of this technique has been demonstrated in patients undergoing cardiac surgery,3, 4 and critically ill patients.5
The technique of transpulmonary CO measurement requires the insertion of a thermistor-tipped catheter into a large artery, most commonly the femoral artery. In many patients who require invasive monitoring, the use of the femoral artery for cannulation is impractical; for example, in patients undergoing vascular surgery such as aortofemoral bypass, patients with severe atherosclerosis, or patients who undergo coronary artery bypass graft (CABG) but are expected to benefit from intraaortic balloon assist after surgery. We therefore examined the feasibility and accuracy of arterial thermodilution with axillary artery cannulation. We compared the CO measurements obtained with a new transpulmonary thermodilution system (PiCCO, Pulsion Medical Systems, Munich, Germany) through the axillary artery to conventional measurements using a PAC.
Section snippets
Materials and methods
After approval of the Sheba Medical Center ethics committee and obtaining of informed consent, 22 ICU patients (ages 27 to 79 years) who required invasive monitoring with a PAC were entered into the study.
After insertion of the PAC (Swan-Ganz VIP, Baxter Health Care Corporation, Edwards Critical Care Division, CA) via the right jugular vein using a 8.5 Fr introducer (Arrow International, Reading, PA), the axillary artery was cannulated using a sterile technique with a 4F thermistor- tipped
Results
A total of 190 measurements were performed in 20 patients (4 to 16 measurements per patient, mean 9.5). Two patients were excluded from the study due to failure of axillary artery cannulation. In one patient, the study was stopped after four measurements due to axillary catheter failure. The mean COax was 6.56 ± 1.57 L/min and the mean COpa was 6.29 ± 1.56 L/min. The correlation coefficient between the two measurements was 0.82 (R2) (Figure 1), the precision (bias, mean difference) between
Discussion
The position that the PAC has traditionally held in the armamentarium of the ICU clinician as the major monitoring tool for hemodynamic management is changing significantly.8 It has been shown that many clinicians who are using the PAC are not familiar with it.9 Connors et al. 1showed that mortality is increased in patients who are monitored with this tool.
A relatively new technique for CO monitoring is arterial thermodilution. This technique is used for bolus measurements of CO, and it uses a
References (10)
- et al.
Comparison of cardiac output assessed by pulse-contour analysis and thermodilution in patients undergoing minimally invasive direct coronary artery bypass grafting
J Cardiothorac Vasc Anesth
(1999) - et al.
The effectiveness of right heart catheterization in the initial care of critically ill patients. SUPPORT Investigators
JAMA
(1996) - et al.
Cardiac output determination with transpulmonary thermodilution. An alternative to pulmonary artery catheterization?
Anaesthesist
(1996) - et al.
Continuous cardiac output by femoral arterial thermodilution calibrated pulse contour analysiscomparison with pulmonary arterial thermodilution
Crit Care Med
(1999) - et al.
Comparison of PA and arterial thermodilution cardiac output in critically ill patients
Intensive Care Med
(1999)
Cited by (29)
Transcardiopulmonary Thermodilution-Calibrated Arterial Waveform Analysis: A Primer for Anesthesiologists and Intensivists
2015, Journal of Cardiothoracic and Vascular AnesthesiaCitation Excerpt :Some devices can use a transformed peripheral waveform, but the algorithm used to transform a peripheral into an aortic pressure waveform has not been made public.183 Mostly, physicians use 4F or 5F, 15- to 20-cm-long femoral catheters to access the aorta.11,185 For nonfemoral (radial, brachial, or axillary) aortic access, PULSION currently offers catheters equipped with thermistors of various (8-50 cm) lengths.186,187
Arterial waveform analysis
2014, Best Practice and Research: Clinical AnaesthesiologyCitation Excerpt :Indicator dilution can also be transpulmonary using two invasive devices, a central venous catheter, where the indicator is injected, and an arterial indicator sensor [39–41]. Different arterial sites can be used for indicator sampling, including the radial, brachial, axillary, and femoral arteries [42]. Studies have further verified transpulmonary thermodilution reliability [43] and precision [44] against the pulmonary artery thermodilution technique.
Monitoring cardiac function: Echocardiography, pulse contour analysis and beyond
2013, Best Practice and Research: Clinical AnaesthesiologyCitation Excerpt :In general, TPTD is considered to be less invasive compared to PATD as right-heart catheterisation is not necessary. However, the TPTD technique requires both a central venous line and a specialised thermistor-tipped arterial catheter set, which is available for femoral cannulation (4F, 16 cm; 5F, 20 cm), alternatively for axillary (4F, 8 cm) and brachial cannulation (4F, 22 cm), as well as radial artery cannulation (4F, 50 cm) in adults [17]. Furthermore, an arterial cannulation set for infants and neonates is available (3F, 7 cm), but only few studies are available that have reported on TPTD in infants and neonates [18–20].
Hemodynamic Monitoring in the Critical Care Environment
2013, Advances in Chronic Kidney DiseaseCitation Excerpt :Segal likewise found good correlation between TPTD (using an axillary artery as a distal thermistor site) and TD in 22 critically ill patients. ( R2 = 0.82).27 A study by Goepfert found that a goal-directed therapy approach using TPTD in 40 cardiac bypass patients led to reduced pressor use, increased colloid administration, fewer days of mechanical ventilation, and a shorter time to achieve the status “fit for ICU discharge.”28
Effects of extravascular lung water on the measurement of transpulmonary thermodilution cardiac output in acute respiratory distress syndrome patients
2011, Journal of Cardiothoracic and Vascular AnesthesiaCitation Excerpt :Hosie et al15 reported a significant loss of thermal indicator during the transpulmonary passage in patients with ARDS and increased interstitial fluid content. The overestimation of BCItp over CCIpa in the data here (bias = 0.51 L/min/m2) on ARDS patients is higher than in most of the previous studies comparing the 2 techniques.2–6,8–10,12–14,17,29–31 Most of them have been performed on cardiac surgery patients.
Measurement of cardiac output: A comparison between transpulmonary thermodilution and uncalibrated pulse contour analysis
2007, British Journal of AnaesthesiaCitation Excerpt :In this study, we used the transpulmonary thermodilution technique as the reference technique, which has been extensively compared with the clinical ‘gold standard’, i.e. pulmonary artery thermodilution. Previous experimental5–7 and clinical studies4 8 reported a good correlation between pulmonary artery and transpulmonary thermodilution for the measurement of CO. However, transpulmonary thermodilution CO is most often found to be higher than the corresponding pulmonary artery CO, and this is considered to be caused by the cold-induced reduction in the heart rate17 and the loss of indicator.18
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Director, General ICU
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Senior Anesthesiologist
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Director, Neuroanesthesia
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Professor and Chairman, Department of Anesthesiology and Intensive Care