Correspondence
Pulmonary-Artery Catheters in High-Risk Surgical Patients
N Engl J Med 2003; 348:2035-2037May 15, 2003
- Article
To the Editor:
The study by Sandham et al. (Jan. 2 issue)1 showed no improvement in outcome resulting from goal-directed therapy guided by pulmonary-artery catheter in high-risk surgical patients. The main targets (an oxygen-delivery index of 550 to 600 ml per minute per square meter of body-surface area and a cardiac index of 3.5 to 4.5 liters per minute per square meter) were reached by only about 20 percent of the patients preoperatively and by less than 80 percent during the postoperative period. However, trials that showed a benefit with this strategy have suggested that hemodynamic optimization has to be achieved before surgery.2-4
It is unclear whether all the goals had to be met, or whether the main targets could be achieved at the expense of those considered secondary (mean arterial pressure and heart rate). Indeed, the proposed therapeutic interventions can have conflicting effects on different hemodynamic end points. For example, beta-agonist agents used to increase cardiac output may have decreased the mean arterial pressure or induced tachycardia, changes that in turn may have compromised tissue perfusion pressure, myocardial oxygen balance, or both, despite increased oxygen delivery. The high incidence of congestive heart failure during the postoperative period in the group that received catheter-guided therapy (12.6 percent), despite frequent use of inotropic support (48.9 percent), raises the question of the potential role of a high pulmonary-capillary wedge pressure (18 mm Hg) among the goals.
The effect of the pulmonary-artery catheter on the outcome cannot be separated from the use that is made of it. The results of this study should not prevent us from continuing to search for end points that are meaningful and harmless in the effort to improve tissue perfusion and, possibly, the outcome.
4 ReferencesBernard P. Cholley, M.D., Ph.D.
Didier Payen, M.D., Ph.D.
Hôpital Lariboisière, 75 010 Paris, France
bernard.cholley@lrb. ap-hop-paris. fr 1
Sandham JD ,Hull RD ,Brant RF , et al. A randomized, controlled trial of the use of pulmonary-artery catheters in high-risk surgical patients. N Engl J Med 2003;348:5-14
Full Text | Web of Science | Medline2
Shoemaker WC ,Appel PL ,Kram HB ,Waxman K ,Lee TS . Prospective trial of supranormal values of survivors as therapeutic goals in high-risk surgical patients. Chest 1988;94:1176-1186
CrossRef | Web of Science | Medline3
Boyd O ,Grounds RM ,Bennett ED . A randomized clinical trial of the effect of deliberate perioperative increase of oxygen delivery on mortality in high-risk surgical patients. JAMA 1993;270:2699-2707
CrossRef | Web of Science | Medline4
Wilson J ,Woods I ,Fawcett J , et al. Reducing the risk of major elective surgery: randomised controlled trial of preoperative optimisation of oxygen delivery. BMJ 1999;318:1099-1103
CrossRef | Web of Science | Medline
To the Editor:
Before the finding reported by Sandham and colleagues — that pulmonary-artery catheters are of no benefit and may be harmful — leads to new calls for a moratorium on the use of pulmonary-artery catheters (if it has not already done so), three factors must be considered.
First, pulmonary-artery catheters will probably benefit only high-risk patients, yet 87 percent of the patients in this study were in American Society of Anesthesiologists risk class III and hence at moderate risk (and thus, in practice, were unlikely to require pulmonary-artery catheters). Second, the physiological goals in the study group may have affected mortality rates in favor of the control group. Specifically, patients in the catheter group received substantially more colloid and red cells; such excess transfusion may be harmful.1-3 Third, the increased incidence of pulmonary embolism in the catheter group may have been due to detection bias,4 since the study was not blinded and since not all the patients were screened for deep-vein thrombosis or pulmonary embolism. The results of the study may therefore not be an accurate representation of the risks and benefits of pulmonary-artery catheters.
4 ReferencesKeyvan Karkouti, M.D.
Duminda N. Wijeysundera, M.D.
Scott W. Beattie, M.D., Ph.D.
University of Toronto, Toronto, ON M5G 2C4, Canada
keyvan.karkouti@uhn. on. ca 1
Hebert PC ,Wells G ,Blajchman MA , et al. A multicenter, randomized, controlled clinical trial of transfusion requirements in critical care. N Engl J Med 1999;340:409-417[Erratum, N Engl J Med 1999;340:1056.]
Full Text | Web of Science | Medline2
Lowell JA ,Schifferdecker C ,Driscoll DF ,Benotti PN ,Bistrian BR . Postoperative fluid overload: not a benign problem. Crit Care Med 1990;18:728-733
CrossRef | Web of Science | Medline3
Slinger PD . Perioperative fluid management for thoracic surgery: the puzzle of postpneumonectomy pulmonary edema. J Cardiothorac Vasc Anesth 1995;9:442-451
CrossRef | Web of Science | Medline4
Feinstein AR . An additional basic science for clinical medicine. III. The challenges of comparison and measurement. Ann Intern Med 1983;99:705-712
Web of Science | Medline
To the Editor:
The majority of pulmonary-artery catheters are used in patients undergoing cardiac surgery. For these patients (and, we argue, for all patients), the catheter is used primarily for the prevention, early detection, and treatment of ventricular dysfunction, as well as the control of increased pulmonary intravascular pressure (minimization of pulmonary transudation). However, this practice was not evaluated, and the usefulness (or lack thereof) of pulmonary-artery catheters for patients undergoing cardiac surgery should not be inferred.
Nanette M. Schwann, M.D.
Dennis T. Mangano, Ph.D., M.D.
Multicenter Study of Perioperative Ischemia, San Francisco, CA 94134for the Multicenter Study of Perioperative Ischemia Research Group
Author/Editor Response
In response to Drs. Cholley and Payen: our physiological goals were prioritized, and so was the order in which therapies were offered. Our highest-priority goal was a specific oxygen-delivery index, and the first therapy offered was fluid, which would be administered until the target oxygen-delivery index was reached or until the goal of a pulmonary-artery wedge pressure of 18 mm Hg was achieved. If the goal for the oxygen-delivery index was not reached in association with a wedge pressure of 18 mm Hg, we recommended the addition of inotropes or vasodilator therapy, depending on the mean arterial pressure and cardiac index. Physiological status was not compromised by catheter-directed therapy, as evidenced by median values for the mean arterial pressure of 97, 85, and 86 mm Hg in the preoperative, intraoperative, and postoperative periods, respectively; median wedge pressures were 11, 13, and 13 mm Hg, and median heart rates were 73, 73, and 85 beats per minute, respectively. There was a history of congestive heart failure preoperatively in 16.2 percent of the standard-care group and 16.1 percent of the catheter group, but there was clinical evidence of congestive heart failure in only 11.2 percent and 12.6 percent, respectively, during the study. Thus, there was no evidence that our therapeutic goals created congestive heart failure.
In response to Dr. Karkouti and colleagues: we agree that there is no need to call for a moratorium on the use of pulmonary-artery catheters, but we do conclude that there is no evidence to support their routine use in the group of patients we studied. We differ with their statements about our population of patients, for whom routine preoperative pulmonary-artery catheterization has been recommended and variably used.1-4 Our comments in response to Drs. Cholley and Payen about our physiological goals are also applicable to the concerns expressed by Dr. Karkouti and colleagues. Although it is reasonable to be concerned about a detection bias in our observation of pulmonary emboli, investigation for pulmonary emboli was based on clinical suspicion by the attending physician, and the numbers of patients evaluated were similar in the two groups, as were the numbers and types of diagnostic tests, making detection bias unlikely. In view of these facts, we consider our study an accurate representation of the risks and benefits of using pulmonary catheters in the population of patients we studied.
In response to Drs. Schwann and Mangano: we did not evaluate the role of routine perioperative use of pulmonary-artery catheters in patients undergoing cardiac surgery, and we agree that the results of our study cannot be generalized to such patients.
4 ReferencesJ. Dean Sandham, M.D.
Russell D. Hull, M.B., B.S.
Rollin F. Brant, Ph.D.
University of Calgary, Calgary, AB T2N 2T9, Canada
sandham@ucalgary.ca 1
Savino JA ,Del Guercio LR . Preoperative assessment of high-risk surgical patients. Surg Clin North Am 1985;65:763-791
Web of Science | Medline2
Shoemaker WC ,Appel PL ,Kram HB ,Waxman K ,Lee TS . Prospective trial of supranormal values of survivors as therapeutic goals in high-risk surgical patients. Chest 1988;94:1176-1186
CrossRef | Web of Science | Medline3
Boyd O ,Grounds RM ,Bennett ED . A randomized clinical trial of the effect of deliberate perioperative increase of oxygen delivery on mortality in high-risk surgical patients. JAMA 1993;270:2699-2707
CrossRef | Web of Science | Medline4
Wilson J ,Woods I ,Fawcett J , et al. Reducing the risk of major elective surgery: randomised controlled trial of preoperative optimisation of oxygen delivery. BMJ 1999;318:1099-1103
CrossRef | Web of Science | Medline
- Citing Articles (3)
Citing Articles
1
(2006) Catheters and the Treatment of Acute Lung Injury. New England Journal of Medicine 355:9, 956-958
Full Text2
Damon C Scales, William J Sibbald. (2004) Medical technology in the intensive care unit. Current Opinion in Critical Care 10:4, 238-245
CrossRef3
D.A. Groneberg. (2003) Severe acute respiratory syndrome: global initiatives for disease diagnosis. QJM 96:11, 845-852
CrossRef
