POSTOPERATIVE PAIN MANAGEMENT IN EMERGENCY ABDOMINAL SURGERY: BIMODAL VERSUS UNIMODAL ANALGESIA

Abstract

Introduction Emergency abdominal surgery may be the right intervention for patients who have traumatic abdominal injuries or surgically correctible abdominal disease processes. The pain after surgery can be distressful to patients if not optimally managed. Postoperative pain management in developing countries like Ghana is considered to be suboptimal. In Ghana, there is a paucity of data comparing the efficacy of parenteral opioids as unimodal analgesia with a combination of paracetamol and opioids in postoperative pain management. Aim This study compared the efficacy of intramuscular (i.m.) morphine as unimodal analgesic with bimodal administration of i.v paracetamol and i.m. morphine in managing postoperative pain in emergency abdominal surgery.

Methods/Design This study was conducted at the Surgery Directorate of Komfo Anokye Teaching Hospital, Kumasi, Ghana. It was a single-blinded randomised controlled trial (RCT). Participants were randomised into two arms: those receiving i.m. morphine only and those receiving a combination of i.v. paracetamol and i.m. morphine. Inclusion criteria were patients between 18 and 80 years undergoing emergency abdominal surgery. Elective surgery, contraindications to morphine or paracetamol were exclusion criteria. Pain intensity was measured at intervals of one, three, six, twelve and twenty-four hours after a patient received the first dose of analgesia at the recovery ward, using the Numeric Rating Scale for pain. Data were collected with a structured questionnaire, using an electronic data capturing system and extracted onto STATA 13 for analysis. Chi-Square test and multivariate logistic regression analysis were carried out, putting into consideration odd ratios where statistical significance was derived with p<0.05.

Results A total of 110 participants were recruited and data from 108 were analysed of which 75% were males and 25% were females. Mean pain scores were lower at six hours, twelve hours and twenty-four hours after the administration of the first dose of analgesia with statistical significance (P-value 0.02, 0.002 and 0.001 respectively) for those who received only Morphine as opposed to morphine with paracetamol. There was no statistically significant difference between the length of stay and whether a participant received morphine or morphine with paracetamol (P-value 0.33). Those who received only morphine had their first bowel movement earlier than those who received a combination of morphine and paracetamol (P-value 0.03). Nausea and/or vomiting was likely to occur if a participant received only morphine as opposed to receiving morphine with paracetamol ( P-value 0.02). Conclusion Receiving morphine alone or morphine with paracetamol provided adequate pain relief after emergency abdominal surgery even though those who received morphine alone had a lower mean pain score. Whether a patient received morphine alone or morphine with paracetamol did not have any statistical difference in the length of stay. Nausea and vomiting were common in those who received morphine only.