PLASMA ASPIRIN ESTERASE-ACTIVITY IN ELDERLY PATIENTS UNDERGOING ELECTIVE HIP-REPLACEMENT AND WITH FRACTURED NECK OF FEMUR

Plasma aspirin esterase activity was measured in eight elderly patient s undergoing elective hip replacement, and in 11 presenting with femor al-neck fracture. Elective hip surgery was associated with a marked an d significant decline in esterase, from 330 +/- 35.9 (SE) (nmol salicy late/ml plasma/min) pre-operatively to 236 +/- 35.6 on the third post- operative day, and returning to normal (359 +/- 24.3) at recovery phas e. Patients with fractured neck of femur showed a depressed esterase a ctivity on admission (221 +/- 12.7), rising towards normal (290 +/- 15 .4) on recovery. All of these changes were accompanied by a marked acu te-phase response, both to injury and surgery. The data suggest that e lderly patients experiencing injury or undergoing surgery may have sig nificantly impaired drug metabolism, at least as far as this enzyme is concerned.