A Double-blind Evaluation of Intrathecal Bupivacaine Without Glucose and a Standard Solution of Hyperbaric Tetracaine

Abstract

The effect of a 0.75% glucose-free solution of bupivacaine and a standard solution of 0.5% tetracaine in 5% dextrose with 0.2 mg of epinephrine were compared following subarachnoid administration in 60 healthy orthopedic surgical patients. Each anesthetic solution was randomly injected into 30 patients and the anesthetic profile of the two solutions were evaluated in a double-blind fashion. Frequency of adequate anesthesia, onset and regression of anesthesia, and onset, intensity, and duration of motor block were assessed. Heart rate and blood pressure were monitored prior to and throughout the duration of anesthesia. Tetracaine produced a significantly shorter latency, higher maximal level of anesthesia, and longer duration of sensory anesthesia. Duration of complete motor blockade was also significantly longer in the tetracaine treated group. On the other hand, the frequency of tourniquet pain was lower and the degree of hypotension was less in the patients in whom bupivacaine was administered intrathecally. The results of this double-blind study suggest that glucose-free bupivacaine may be a useful spinal anesthetic agent for orthopedic surgical procedures of 2 to 4 hours duration.