Noninvasive cardiac output and blood pressure monitoring cannot replace an invasive monitoring system in critically ill patients

Reto Stocker,Renato Lenherr,Thomas A Neff,Bernhard Zoller,Markus Béchir,John F Stover,Silvia R Cottini

doi:10.1186/1471-2253-9-6

Reto Stocker, Renato Lenherr + Show 5 more

Open Access

https://doi.org/10.1186/1471-2253-9-6

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Journal: BMC Anesthesiology	Publication Date: Oct 12, 2009
Citations: 117	License type: cc-by

Affiliation: University Hospital of Zurich

Abstract

BackgroundMonitoring of cardiac output and blood pressure are standard procedures in critical care medicine. Traditionally, invasive techniques like pulmonary artery catheter (PAC) and arterial catheters are widely used. Invasiveness bears many risks of deleterious complications. Therefore, a noninvasive reliable cardiac output (CO) and blood pressure monitoring system could improve the safety of cardiac monitoring. The aim of the present study was to compare a noninvasive versus a standard invasive cardiovascular monitoring system.MethodsNexfin HD is a continuous noninvasive blood pressure and cardiac output monitor system and is based on the development of the pulsatile unloading of the finger arterial walls using an inflatable finger cuff. During continuous BP measurement CO is calculated. We included 10 patients with standard invasive cardiac monitoring system (pulmonary artery catheter and arterial catheter) comparing invasively obtained data to the data collected noninvasively using the Nexfin HD.ResultsCorrelation between mean arterial pressure measured with the standard arterial monitoring system and the Nexfin HD was r2 = 0.67 with a bias of -2 mmHg and two standard deviations of ± 16 mmHg. Correlation between CO derived from PAC and the Nexfin HD was r2 = 0.83 with a bias of 0.23 l/min and two standard deviations of ± 2.1 l/min; the percentage error was 29%.ConclusionAlthough the noninvasive CO measurement appears promising, the noninvasive blood pressure assessment is clearly less reliable than the invasively measured blood pressure. Therefore, according to the present data application of the Nexfin HD monitoring system in the ICU cannot be recommended generally. Whether such a tool might be reliable in certain critically ill patients remains to be determined.

Highlights

Monitoring of cardiac output and blood pressure are standard procedures in critical care medicine
Besides the advantages of these invasive techniques for clinical decision-making, these methods both bear the risks of deleterious complications as e.g., bleeding, pneumothorax and infection; pulmonary artery catheter (PAC) is associated with the risk of inducing pulmonary artery rupture [8,9]
Baseline characteristics and clinical data A total of ten critically ill patients monitored with PAC, standard invasive arterial blood pressure monitoring and Nexfin HD were included in this study

Summary

Introduction

Monitoring of cardiac output and blood pressure are standard procedures in critical care medicine. Besides the advantages of these invasive techniques for clinical decision-making, these methods both bear the risks of deleterious complications as e.g., bleeding, pneumothorax and infection; PAC is associated with the risk of inducing pulmonary artery rupture [8,9]. Our hypothesis was that the Nexfin device produces results comparable to a standard invasive blood pressure monitoring system, i.e., PAC and arterial line. The limits of agreement between the new and the reference technique of ± 30% is considered acceptable [14]

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