Intermittent Subcutaneous Morphine for Postoperative Analgesia Following Coronary Artery Bypass Grafting

Abstract

Introduction: An effective postoperative pain management is of utmost importance following cardiac surgery. Various agents, routes and modes are available for the treatment of postoperative pain. Subcutaneous route of administration is an easy and effective method of postoperative analgesia with improved patient satisfaction and lesser side effects compared to intravenous route. Aim: To evaluate the efficacy of Subcutaneous Morphine (SCM) as postoperative analgesia following Coronary Artery Bypass Grafting (CABG). Materials and Methods: This study was designed as a retrospective analytical survey from June 2015 to June 2017. Medical records of all patients over 18 years of age who underwent coronary artery bypass grafting were reviewed. Patients belonging to ASA PS I, II and III, patients above 18 years of age and those posted for coronary artery bypass grafting were included in the study. Patients were divided into two groups: SCM group and Paracetamol (PCT) group, depending on the primary analgesia they received. The two groups were compared using Student’s t-test for normally distributed continuous data or non-parametric tests if the data were not normally distributed. Categorical data were compared by Fisher’s-exact test. The p-values <0.05 were considered statistically significant. Results: A total of 102 records were reviewed, out of which 49 patients received SCM and 53 patients had received PCT as their primary postoperative analgesia. It was observed that PCT group required more additional analgesia (intravenous fentanyl/ tramadol) than SCM group which was statistically significant with p-value of <0.001 and the duration of Cardiac Intensive Care Unit (CICU) stay was more in PCT group with p-value of 0.001. Postoperative side effects were significantly more in PCT group. Conclusion: SCM can be effectively administered intermittently for postoperative analgesia following CABG with similar haemodynamic stability and minimal side effects as compared to intermittent intravenous PCT.