Friday 7th October, 2005
A meta-analysis indicates that use of a pulmonary artery catheter in critically ill patients does not any add benefit.
Hospitalized patients with severe congestive heart failure did not experience a benefit from use of pulmonary artery catheterization, but had more adverse events, according to a study in the October 5 issue of JAMA.
Advances in medical therapy have improved outcomes for many ambulatory patients with heart failure and low ejection fraction (EF; a measure of how much blood the left ventricle of the heart pumps out with each contraction), according to background information in the article. However, each year an estimated 250,000 to 300,000 patients are hospitalized for heart failure with low EF, and the 1-year survival rate after hospitalization may be as low as 50 percent, even with recommended medical therapies. Recent studies have indicated that pulmonary artery catheters (PAC), a device used to monitor hemodynamic status and guide therapy, may increase the risk of death for hospitalized patients.
Lynne W. Stevenson, M.D., of Brigham and Women's Hospital, Boston, and colleagues with the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness (ESCAPE) trial, tested the hypothesis that for patients with severe heart failure, therapy guided by PAC monitoring and clinical assessment would lead to more days alive and fewer days hospitalized during 6 months compared with therapy guided by clinical assessment alone. The randomized controlled trial included 433 patients at 26 sites and was conducted from January 18, 2000, to November 17, 2003. Patients were assigned to receive clinical assessment and a PAC or clinical assessment alone. The primary goal in both groups was resolution of clinical congestion, with other targets based on levels of pulmonary artery and right atrial pressures.
The researchers found that therapy in both groups led to substantial reduction in symptoms, jugular venous pressure, and edema (swelling from fluid buildup). Use of the PAC did not significantly affect the primary end point of days alive and out of the hospital during the first 6 months (133 days vs. 135 days), death (43 patients [10 percent] vs. 38 patients [9 percent]), or the number of days hospitalized (8.7 vs. 8.3). In-hospital adverse events were more common among patients in the PAC group (47 [21.9 percent] vs. 25 [11.5 percent]). There were no deaths related to PAC use, and no difference for in-hospital plus 30-day mortality (10 [4.7 percent] vs. 11 [5.0 percent]). Exercise and quality of life end points improved in both groups with a trend toward greater improvement with the PAC, which reached significance for the time trade-off at all time points after randomization.
"Based on ESCAPE, there is no indication for routine use of PACs to adjust therapy during hospitalization for decompensation of long-term heart failure. It seems probable that there are some patients and some therapies that yield improved outcome with PAC monitoring and others with counterbalancing deleterious effects," the authors write. "For patients in whom signs and symptoms of congestion do not resolve with initial therapy, consideration of PAC monitoring at experienced sites appears reasonable if the information may guide further choices of therapy.
"The ESCAPE trial defined the most compromised patient population to be studied in an National Heart Lung Blood Institute heart failure trial with medical therapy, with 19 percent (83 patients) mortality at 6 months. No diagnostic test by itself will improve outcomes. New strategies should be developed to test both the interventions and the targets to which they should be tailored. Although most trials in a high-event population have focused on reducing mortality, patients with advanced heart failure express willingness to trade survival time for better health during the time remaining. How patients value their daily lives should help guide both the design and evaluation of new therapies," the authors conclude.
Editor's Note: This research was supported by a contract from the National Heart, Lung, and Blood Institute to Duke University Medical Center.
Use of Pulmonary Artery Catheter in Critically Ill Patients Has Neutral Effect
A meta-analysis of previous studies indicates that use of a pulmonary artery catheter in critically ill patients neither increases risk of death or hospital stay or adds benefit, according to another article in this issue of JAMA.
The PAC is used to diagnose various diseases and physiological states, monitor the progress of critically ill patients, and guide the selection and adjustment of medical therapy, according to background information in the article. The PAC is often considered a cornerstone of critical care and a hallmark of the intensive care unit (ICU). Approximately 1 million PACs are used annually in the United States. However, despite widespread use of these devices, there is conflicting data about their effectiveness, and whether they increase risk of illness and death. Since the mid-1980s, randomized clinical trials (RCTs) have been conducted to evaluate the efficacy of the PAC. However, none of these trials have been persuasive individually, because they are limited by small sample sizes in heterogeneous populations. Despite the overwhelmingly negative outcomes of the literature, clinicians continue to use the PAC in ICUs based on personal experience and the belief that careful monitoring will improve decision making and clinical outcomes.
Monica R. Shah, M.D., M.H.S., of Columbia University Medical Center, New York, and colleagues performed a meta-analysis of recently published clinical trials testing the safety and efficacy of the PAC. The researchers located the RCTs, in which patients were randomly assigned to PAC or no PAC, from several databases. Eligible studies included patients who were undergoing surgery, in the ICU, admitted with advanced heart failure, or diagnosed with acute respiratory distress syndrome and/or sepsis; and studies that reported death and the number of days hospitalized or the number of days in the ICU as outcome measures. The researchers found 13 RCTs that included 5,051 patients.
"Our meta-analysis of 13 RCTs evaluating the safety and efficacy of the PAC demonstrates that use of the catheter neither improves outcomes in critically ill patients nor increases mortality or days in hospital. This provides a broader confirmation of the recent results of the ESCAPE trial, which showed that the routine use of the PAC in patients with advanced heart failure did not reduce or increase death or days in hospital," the authors write.
"During the past 60 years, the PAC has evolved from a simple diagnostic tool to a device that is used for monitoring and determining goal-directed therapy. Our meta-analysis shows that despite the widespread acceptance of the PAC, use of this device across a variety of clinical circumstances in critically ill patients does not improve survival or decrease the number of days hospitalized. ? These results suggest that the PAC should not be used for the routine treatment of patients in the ICU, patients with decompensated heart failure, or patients undergoing surgery until or unless effective therapies can be found that improve outcomes when coupled with this diagnostic tool," the authors conclude.
Editor's Note: This meta-analysis was funded by the Duke Clinical Research Institute.
Editorial: Searching for Evidence to Support Pulmonary Artery Catheter Use in Critically Ill Patients
In an accompanying editorial, Jesse B. Hall, M.D., of the University of Chicago, comments on the articles in this week's JAMA on PAC.
"What is the evidence for the broader issue of PAC use in the ICU and perioperative setting? The data collected to date certainly do not support routine use of the catheter in any patient group, and the currently available information could be viewed as justifying 'pulling the pulmonary artery catheter' from routine use, a suggestion made almost 10 years ago. One important additional trial is nearing completion and evaluates the use of PAC in patients with adult respiratory distress syndrome."
"Should there be a positive result attributable to PAC in this trial, a specific niche for this technology may remain in critical care. If the results of this soon-to-be-completed trial show no benefit of PAC monitoring, it is likely that the available data will indicate that it is time to remove the catheter from widespread use, or at the very least relegate this former common monitoring tool to salvage therapy of an extremely small and select number of patients. The need to question the routine use of this monitoring modality was quite real and the results of the last 5 years of study most valuable. Once again the community of critical care physicians has been edified by the approach of 'Don't just do something, stand there! And then think about it. ?'" Dr. Hall concludes.
|Article reviewed by:||
Dr. Tamer Fouad, M.D.
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