Abstract

PIP: This case illustrates the effect of abnormal pseudocholinesterase on the metabolism and actions of chloroprocaine in a postpartum patient. The patient apparently could not adequately metabolize chloroprocaine which may have led to excessive somnolence intraoperatively. It also led to a prolonged chloroprocaine block (normally the block would last only 45-60 minutes) of 3 hours as well as to detectable serum chloroprocaine 5 hours after administration. Abnormal pseudocholinesterase was verified by the prolonged apnea following subsequent succinylcholine administration and by the fact that her dibucaine number at 6 weeks postpartum was indicative of a homozygote for the atypical cholinesterase variant or a heterozygote with 1 gene for the atypical variant and one for the silent variant. This case suggests that an abnormal reaction to chloroprocaine can occur in a patient with atypical cholinesterase and that an abnormal reaction to chloroprocaine has clinical implications beyond a prolonged epidural block. An abnormal reaction to chloroprocaine should alert the anesthesiologist to the possibility of a pseudocholinesterase deficiency which should suggest that the subsequent use of succinylcholine may result in a prolonged neuromuscular blockade.