09 Apr 10
By S Greenberg, G Murphy and J Vender
Curr Opin Crit Care 2009;15:249–253
Purpose of review
The pulmonary artery catheter is one of the most scrutinized monitors used in intensive care today. Pulmonary artery catheter use is declining due to limited demonstrated beneficial outcomes and the advancement of less invasive monitoring. This study discusses the current use of the pulmonary artery catheter and problems associated with its use including inaccuracy of measurements and data interpretation, inappropriately applied therapeutic interventions, inappropriate delays in applying interventions, and inappropriate patient selection.
This overview presents current controversies surrounding the pulmonary artery catheter. It also discusses commonly used monitors and their lack of demonstrated benefits. In addition, data show that intensivists do not have sufficient knowledge to effectively use the pulmonary artery catheter. When utilized in a timely appropriate manner, pulmonary artery catheter monitoring may benefit a selected patient population.
In summary, the pulmonary artery catheter monitor continues to be used for intensive care patients. To date, no single monitor is associated with an abundance of clear outcome benefits. There are some clinical data showing that the pulmonary artery catheter may still be useful when applied to the right patient population using appropriately timed therapies
11 Oct 09
By C Grissom, A Morris, P Lanken, M Ancukiewicz, J Orme, D Schoenfeld, T Thompson; for the National Institutes of Health/National Heart, Lung and Blood Institute Acute Respiratory Distress Syndrome Network
Crit Care Med 2009; 37:2720 –2726
To correlate physical examination findings, central venous pressure, fluid output, and central venous oxygen saturation with pulmonary artery catheter parameters.
Data from the multicenter Fluid and Catheter Treatment Trial of the National Institutes of Health Acute Respiratory
Distress Syndrome Network.
Five hundred thirteen patients with acute lung injury randomized to treatment with a pulmonary artery catheter.
Correlation of physical examination findings (capillary refill time >2 secs, knee mottling, or cool extremities), central venous pressure, fluid output, and central venous oxygen saturation with parameters from a pulmonary artery catheter.
We determined association of baseline physical examination findings and on-study parameters of central venous pressure and central venous oxygen saturation with cardiac index <2.5 L/min/m2 and mixed venous oxygen saturation <60%. We determined correlation of baseline central venous oxygen saturation and mixed venous oxygen saturation and predictive value of a low central venous oxygen saturation for a low mixed venous oxygen saturation.
Measurements and main results
Prevalence of cardiac index <2.5 and mixed venous oxygen saturation <60% was 8.1% and 15.5%, respectively. Baseline presence of all three physical examination findings had low sensitivity (12% and 8%), high specificity (98% and 99%), low positive predictive value (40% and 56%), but high negative predictive value (93% and 86%) for cardiac index <2.5 and mixed venous oxygen saturation <60%, respectively. Central venous oxygen saturation <70% predicted a mixed venous oxygen saturation <60% with a sensitivity 84%, specificity 70%, positive predictive value 31%, and negative predictive value of 96%. Low cardiac index correlated with cool extremities, high central venous pressure, and low 24-hr fluid output; and low mixed venous oxygen saturation correlated with knee mottling and high central venous pressure, but these correlations were not found to be clinically useful.
In this subset of patients with acute lung injury, there is a high prior probability that cardiac index and mixed venous oxygen saturation are normal and physical examination findings of ineffective circulation are not useful for predicting low cardiac index or mixed venous oxygen saturation. Central venous oxygen saturation <70% does not accurately predict mixed venous oxygen saturation <60%, but a central venous oxygen saturation >70% may be useful to exclude mixed venous oxygen saturation <60%.
12 Dec 08
By GA Ospina-Tascon, RL Cordioli, JL Vincent
Intensive Care Med 2008; 34:800-820
Lack of evidence that some monitoring systems can improve outcomes has raised doubts about their use in the intensive care unit (ICU). The objective of this study was to determine which monitoring techniques have been shown to improve outcomes in ICU patients.
Comprehensive literature review.
We conducted a highly sensitive search, up to June 2006, in the Cochrane Central Register of Controlled Trials (CENTRAL) and MedLine, for prospective, randomized controlled trials (RCTs) conducted in adult patients in the ICU and the operating room (major surgical procedures) and focusing on the impact of monitoring on outcome.
Measurements and results
Of 4,175 potential articles, 67 evaluated the impact of monitoring in acutely ill adult patients. There were 40 studies related to hemodynamic monitoring, 17 to respiratory monitoring, and10 to neurological monitoring. Seven studies were classified in two different categories. Positive non-mortality outcomes were observed in 17 of 40 hemodynamic studies, 11 of 17 respiratory, and in all 10 neurological studies. Mortality was evaluated in 31 hemodynamic studies, but a beneficial impact was demonstrated in only 10. For respiratory monitoring, 7 studies evaluated mortality, but only 3 of them showed an improved outcome. We found no neurological monitoring studies that assessed mortality.
There is no broad evidence that any form of monitoring improves outcomes in the ICU and most commonly used devices have not been evaluated by RCT. This review puts into perspective the recent negative studies on the use of the pulmonary artery catheter in the acutely ill.
24 Nov 08
By GD Rubenfeld, E McNamara-Aslin, L Rubinson
In this issue of JAMA, an investigation using a nationally representative administrative database reported a marked decline in the use of pulmonary artery (PA) catheters from 5.66 per 1000 medical admissions in 1993 to 1.99 per 1000 medical admissions in 2004. These significant declines in PA catheter utilization were most prominent for patients with myocardial infarction (81% decrease), but also were significant for surgical patients (63% decrease) and for patients with septicemia (54% decrease).
These national data are consistent with trends at our institution, an academic public hospital and level 1 trauma center with 75 intensive care unit (ICU) beds with a relatively low volume of patients with acute myocardial infarction. For example, from July 2002 to May 2003, the hospital billed patients for 871 PA catheters. Although the ICU census has increased, the use of PA catheters has declined to 262 catheters from July 2006 to May 2007. Recently, nurses and residents gathered around the bedside of the sole patient in the medical ICU with a PA catheter so they could actually observe one in use. If the demise of the PA catheter is more than a rumor, why has this occurred and what are the implications for clinical care and training?
Forty years have passed since the afternoon in 1967 when Jeremy Swan watched boats from a Santa Monica beach and conceived of a bedside procedure that would use cardiac output to sail a catheter into the pulmonary arteries. PA catheterization was initially used to assess patients with acute myocardial infarction, but use of this procedure spread rapidly to the operating department and from there to a broad range of patients in the ICU. The addition of mixed venous oximetry and cardiac output measurement to central venous and pulmonary arterial pressure monitoring provided clinicians with detailed feedback about physiological response to therapy. This information, coupled with clinical evaluation, allowed clinicians to titrate fluids, inotropes, vasopressors, and vasodilators to optimize oxygen delivery to tissues. Twenty years after its invention (in 1987), more than 2 million PA catheters had been sold worldwide annually. However, enthusiasm was not universal, and in the late 1980s concerns were raised about the unknown benefits of PA catheter–guided therapy in the face of potential risks from an invasive procedure.