Evaluation of the ordering of serum theophylline concentrations

The ordering of serum theophylline concentrations in a 900-bed university hospital was evaluated. Data were collected during the first week of three consecutive months from the records of adult inpatients who had serum theophylline assays performed. The appropriateness of ordering the serum theophylline determinations was evaluated on the basis of criteria including sampling at steady-state concentrations and sampling in proper relationship to the dosage schedule to represent a peak or trough concentration. A total of 113 determinations in 79 patients were reviewed. Pulmonary service patients accounted for 54 (48%) of the determinations. For the 56 concentrations ordered for patients receiving aminophylline continuous infusions, 25 (45%) of the determinations did not meet the criteria for appropriateness. For the 57 other determinations (oral theophylline products and intermittent bolus injections of aminophylline), 42 (74%) were not ordered according to the established criteria. Overall, 67 (59%) of 113 serum theophylline determinations were found to be ordered inappropriately. Corrective educational programs based on standard guidelines for ordering serum theophylline concentrations were established.