Send letter to journal:
Re: Should permissive oliguria and anuria be added to permissive hypotension?

These findings have a rational metabolic amplified in a succession of earlier rapid responses to this and other BMJ publications. Permissive hypotension was the norm in adalts following, for example, abdominal aortic surgery until the advent of "haemodynamic management", that is optimizing filling pressures and maintaining a blood pressure high enough to ensure glomerular filtration and a good urine output.

With the former practice of permissive hypotension in adults peripheral circulation and urine output seemed to return as the postoperative temperature returned to normality despite the practice at that time of "keeping patients dry" by restricting fluid input in the first 24 hours after surgery in accordance with Frannie Moore's metabolic teachings at Harvard. Permissive hypotension is considered suboptimal in adults today because of the reduced incidence of renal failure, seen in combat casualties during the Korean war, following the introduction of aggressive resuscitation with crystaloids pioneered by Zuidema and Shires. This change in practice, which has since become an entrenched surgical meme, was accompanied by the appearance of pulmonary problems, Da Nang lung as it was dubbed in the Vietnam war. It has, however, never been clearly established whether the one complication is better than the other.

The success of renal transplantation has established that oliguria and even anuria are compatible with the return of normal renal function. In the absence of any good evidence-base to support the practice of keeping the blood pressure high enough to ensure glomerular filtration might the addition of permissive oliguria and even anuria to permissive hypotension be accompanied by an even greater improvement in outcome? Should "renal failure" then develop it could be managed expectantly just as it is after renal transplanatation today. Management of renal failure has improved greatly since the Korean war between 1950 and 1953. Even peritoneal dialysis was unavailable at that time (1). It was not much more advanced in the Vietnam war, 1961-1975.