The Annals of Thoracic Surgery, Vol 22, 41-43, Copyright © 1976 by The Society of Thoracic Surgeons
Free-water clearance and the early recognition of acute renal insufficiency after cardiopulmonary bypass
RG Landes, RC Lillehei, WG Lindsay and DM Nicoloff
The predictive value of free-water clearance measurements for the early
recognition of acute renal insufficiency was evaluated in 59 patients
immediately following cardiopulmonary bypass. Blood urea nitrogen and serum
creatinine measurements were taken before and after operation.
Intraoperatively, immediately after completion of bypass, urine and serum
samples were obtained for osmolality. Duration of bypass, urine output,
degree of hemolysis, and quality of perfusion were recorded. Fifty-four
patients developed no signs of renal insufficiency following bypass, and
all had free-water clearance values equal to or less than - 20 ml per hour.
Five patients who had free-water clearance values equal to greater than -8
ml per hour developed manifestations of an acute renal insufficiency state.
There were no false-negative or false- positive determinations.
Consequently, free-water clearance measurements appear to be a reliable
indicator of those patients who will develop renal insufficiency following
cardiopulmonary bypass. Early recognition provides an opportunity
immediately after operation for initiating treatment consisting of
administration of diuretics, potassium restriction, and oliguric fluid
regimens.
