Abstract

We examined the effect of patient-controlled intravenous analgesia (PCIA) using metoclopramide hydrochloride and morphine hydrochloride in 30 patients (15 males, 15 females) who underwent spine fusion surgery under general anesthesia. The intravenous administration of 2 mg morphine hydrochloride was done prior to the completion of surgery. Subsequently, morphine hydrochloride was administed via venous injection at a dose of 1 ml/hr. Additionally, a 1 ml bolus dosage was administered at a 60-minute lockout interval employing a pump which contained 36 mg of morphine hydrochloride, 30 mg of metoclopramide hydrochloride in 62 ml of physiologic saline. At approximately 72 hours, we observed the resting VAS (visual analog scale) and the side effects of morphine hydrochloride and thereafter the button pressing frequency (1 button have 0.5 mg morphine hydrochloride) was investigated. The resting VAS was stable through 72 hours in 13 males and 15 females of the 30 cases exhibiting from 2 to 3. The frequency of button pressing was investigated regarding time and gender. One male and two female patients exhibited metastatic tumors of the spine but demonstrated no button manipulation. For the remaining 27 subjects the button pressing frequency increased in most instances furthermore, from 24-48 hours after surgery, the frequency for male patients clearly increased. From 48 hours after surgery, no gender differences were evident regarding the button frequency. However, differences were observed regarding the disease, gender and postoperative time course of analgesia. As a result, no alteration in the background dose appeared to provide the best result, as did a short duration lockout interval.