Cause of metabolic acidosis in prolonged surgery

Abstract

In this patient population, a common source of increasing base deficit is related to chloride administration. The largest source of chloride is usually normal saline. Classically, dilutional acidosis would explain the predominance of this acidotic change; however, no increase in plasma volume occurred. The absence of plasma volume change would suggest that the mechanism postulated to result in dilutional acidosis is incomplete. The common treatment of administering more fluid for intraoperative acidosis may be inappropriate, may have caused the acidosis, and may further exacerbate the acidosis. Chloride levels should be assessed whenever a metabolic acidosis is seen perioperatively.