The efficacy of a simple standard multimodal analgesic protocol on acute post-operative pain after major abdominal surgery at Kenyatta National Hospital.

Abstract

Background: Management of post-operative pain is regarded as routine in surgical practice. Many studies have however shown that its management is often poor. Opioid analgesics are most commonly used in treatment of moderate to severe pain after major abdominal surgery. Intramuscular pethidine given in varying dosages has been shown to be the most common analgesic used in Kenyatta National Hospital (KNH). This method has received numerous criticisms from various authors. Multimodal analgesia is a strategy of combining different classes of analgesics by various routes of administration to reduce side effects of opioids and increase analgesic effect. Objectives: To assess the effect of a standardized multimodal analgesic post-operative pain management protocol in patients recovering from major abdominal surgery at KNH Methodology: This was an age matched case control study of patients undergoing major abdominal surgery in the General Surgical Wards at KNH. The cases were patients who post-operatively received the study analgesic protocol of pethidine combined with diclofenac. The control group consisted of patients whose post-operative treatment was a single analgesic agent either an opioid or Non-Steroidal Anti-Inflammatory Drug (NSAID). The study period was 3 months during which convenient (non-random) sampling was utilized to enrol study participants meeting the enrolment criteria until the desired sample size of 50 in each arm was attained. The main Outcome variables were pain scores measured at rest in the first 72 hours using the Visual Analogue Scale and the incidence of common opioid side effects i.e. nausea; vomiting and sedation. These were compared in the two study arms. Data collected was entered and verified in Microsoft Excel and data analysis performed using SPSS version 17. Results: patients who received the study’s multimodal analgesic protocol had significantly lower pain scores. Mean VAS score at 12 hours was 5.125 and 1.062 at 72 hours compared with 6.175 at 12 hours and 1.66 at 72 hours. P value was <0.05. There was no significant difference in the occurrence of sedation, nausea or vomiting between the two groups.