Intravenous Patient-Controlled Morphine and Intrathecal Morphine Analgesia After Tibial Fracture Surgery Under Spinal Anesthesia

Background: Physiological responses to pain and trauma have negative and dangerous effects on all organs. Objectives: This study aimed to compare intravenous patient-controlled analgesia (PCA) and intrathecal morphine in patients undergoing tibial fracture surgery under spinal anesthesia. Patients and Methods: This double-blind clinical trial was conducted on 80 patients undergoing tibial fracture surgery, aged 20 - 50 years and under class I and II of American Society of Anesthesiologists (ASA). They were randomly divided into two equal groups. Patients in the first group received spinal anesthesia with 3 mL marcaine 0.5% and 2 μg/kg (1 mL) morphine. Patients in the second group received the same, but instead of morphine we used 1 mL of distilled water. In the second group, immediately after the spinal anesthesia, 1 mg/hour morphine PCA pump was connected to the patients. In both groups, the following variables were assessed every hour for 12 hours by a third party (a trained anesthesiologist assistant): pain through visual analog scale, nausea, vomiting, pruritus, respiratory complications, mean arterial pressure, and heart rate. Data were collected using a questionnaire and then analyzed by Student’s t-test, repeated measures analysis of variance (ANOVA) and chi-squared tests in SPSS software. Results: The ANOVA test showed that there was no meaningful difference in pain between the two groups within the 12 hours after the surgery, based on visual analogue scale (VAS) (despite a slightly higher VAS in group one) (P = 0.17). There was no meaningful difference between the patients in pruritus, nausea, vomiting and respiratory complications in the two groups. Conclusions: Given the similar level of pain, complications, and the hemodynamic signs postoperatively in both groups, we concluded that it is better to use a single dose of intrathecal morphine instead of morphine PCA pump.