Increased Oxygen Delivery for High-Risk Surgery
ACP J Club. 1995 Mar-April;122:54. doi:10.7326/ACPJC-1995-122-2-054
To the Editor
The response by Drs. Ventura and Mehra (1) to my recent letter concerns me because it shows a fundamental error in the interpretation of clinical research. The study by Tuchschmidt and colleagues (2) on management of patients with sepsis failed to shown any improvement between "normal therapy" and "optimal therapy" (P = 0.14). Only by a post hoc subset analysis of patients who actually achieved target variables compared with those who did not, did the study reach statistical significance. Thus, the study shows only that the ability to achieve supraphysiologic variables is a marker for improved survival. It should not be interpreted as evidence that this therapy is beneficial.
In the study by Boyd and colleagues (3), supraphysiologic oxygen delivery (as defined by the target delivery of > 600 mL/min) was achieved by only a fraction of patients and the protocol used a novel agent, dopexamine hydrochloride, which is not available to most clinicians. General use of supraphysiologic oxygen delivery should not be advocated, especially when it is achieved by agents other than dopexamine.
John A. Kellum, MD
University of Pittsburgh School of Medicine
1. Ventura H, Mehra M.Increased Oxygen Delivery for High-Risk Surgery. ACP J Club. 1994 Nov-Dec;121:84.
3. Boyd O, Grounds RM, Bennett ED. A randomized clinical trial of the effect of deliverate perioperative increase of oxygen delivery on mortality in high-risk surgical patients. JAMA. 1993;270:2699-707.