In Reply:--We emphasize that the scope of our study and subsequent conclusions were limited to patients undergoing infrainguinal peripheral vascular surgery (PVS). Trials cited [2,3]by de Leon-Casasola and Lema as evidence that postoperative analgesia impacts cardiac outcome studied other surgical populations, including intraabdominal procedures.
Our data offer little encouragement to those who wish to improve cardiac outcome after PVS by providing postoperative epidural analgesia. Within the epidural group, 40% received 3 mg in 10 ml epidural morphine during surgery. Generally, a second bolus was given immediately before catheter removal at 24 h after surgery. Therefore, epidural analgesia would have been expected to be in the range of 36-48 h. This is well into the period when poor cardiac outcome becomes evident. The myocardial infarction rate for the epidural morphine group was 4.9% versus 3.6% and 3.7%, respectively, for the patients who received general or spinal, both with postoperative parenteral opioids. As we pointed out in our discussion of these results, patients undergoing lower extremity PVS probably do not experience the same intensity of postoperative pain as do patients undergoing other types of surgery, such as intraabdominal procedures. Any beneficial effects of postoperative epidural analgesia may, therefore, be rendered inconsequential.
In this era of severe cost constraints, we reduced costs by making various changes, such as shortening length of stay, but we continue to use arterial and pulmonary artery catheters in most of our PVS patients. Having established morbidity and mortality rates achieved with intensive perioperative monitoring, we believe that the onus is on those who deviate from this practice to show similar or better results.
As de Leon-Casasola and Lema correctly point out, our study design had no protocol to guide participating anesthesiologists and surgeons in the use of vasoactive drugs and fluids. There was no "tune-up" or "hemodynamic optimization" before surgery, as was described by others. More than 100 anesthesiologists (residents and staff) and surgeons were involved directly in the care of our study patients. Each physician used their own judgment in the use of hemodynamic data. It is hard to imagine how such a large group of practitioners could introduce a consistent and significant bias into the methods.
Robert H. Bode, Jr., M.D.; Keith P. Lewis, M.D.; Eric T. Pierce, Ph.D., M.D.; Department of Anaesthesia; Deaconess Hospital; Harvard Medical School; Boston, Massachusetts 02215-9985
(Accepted for publication April 18, 1996.)