Intra-operative low-dose ketamine does not reduce the cost of post-operative pain management after surgery: a randomized controlled trial in a low-income country

Background: In developing countries, post-operative pain remains underestimated and undertreated due to economic constraints, lack of awareness and limited resources. In contrast, ketamine is an effective, readily available, easy to use and inexpensive drug frequently used in poor settings. Objectives: The aim of this study was to explore the overall reduction in the medication treatment cost of acute post-operative pain by adding intra-operative low-dose ketamine to traditional intravenous morphine for surgery in a low-income country. Methods: A double blind randomized controlled trial with placebo-controlled parallel group was performed in Mulago National Hospital (Uganda). Consenting adults scheduled for elective surgery were randomized into two study arms: Group K received ketamine 0.15 mg/kg bolus at induction and a continuous infusion of 0.12 mg/kg/hour till start of skin closure; Group C (control) received normal saline. Both groups received Morphine 0.1 mg/kg IV at debulking. The total medication cost was registered. NRS pain scores and other measurements such vital signs and incidence of major and minor side effects were also recorded. Results: A total of 46 patients were included. Patients' baseline characteristics were comparable in both groups. No statistically significant difference was found between the groups concerning the overall medication cost of post-operative pain management. Pain scores, patients' satisfaction in the first 24 hours after surgery and hospital length of stay were similar in both groups. Conclusion: Our results do not support the utilization of intra-operative low dose ketamine as a cost-saving post-operative pain treatment strategy for all types of surgery in low-resource settings.