Low-Dose Ketamine as Perioperative Analgesia in Caesarean Sections in Remote Areas with Limited Medical Supplies

Introduction: Cesarean section is the most common surgical procedure performed in the world and its postoperative pain is still a major issue in several countries. In a low-resource setting, this management poses a challenge for anesthesiologists. Ketamine is the most used anesthetic drug in the world due to its easy access and proven benefits. Objective: This research aims to analyze the effectiveness of low-dose ketamine as postoperative analgesia in cesarean sections conducted in areas with limited medical supplies. Methods: A Randomized Controlled Trial (RCT) was done from August 2020 to January 2021 with consenting pregnant patients who had undergone cesarean section. The sampled population was randomized to receive either ketamine intravenously or a placebo before the Subarachnoid Block (SAB). Low dose ketamine was divided into three groups 0.15 mg/kg, 0.25 mg/kg, and 0.5 mg/kg. The outcome was divided into primary outcome (pain score after 1-hour post-operation, 2 hours post-operation, 24 hours post-operation, and 48 hours post-operation) and secondary outcome (Apgar Score in the first minute and 5 minutes, hypotension after SAB, sedative effect during operation, postoperative nausea vomiting, time to receive opioid postoperative as rescue analgesia and total opioid uses). Results: This study screened 105 patients and recruited 90 patients that were randomized into two groups consisting of 45 patients that received either low-dose ketamine or a placebo. The groups administered ketamine showed a lower pain score in 1 hour (p-value = 0.0037) and 2 hours post-operation (p-value = 0.0037). They also showed that it could prolong the administration of fentanyl (p-value = 0.0003) and lower total fentanyl used (p-value = 0.0008). The groups administered ketamine showed that there was a sedation effect (p-value = 0.0001) that depended on the dosage used. Conclusion: Intravenous ketamine with low doses can reduce pain scores at 1 hour to 2 hours post-operation and shows the need to reduce opioid requirements.