Subcutaneous wound infiltration of ketamine is superior to bupivacaine in terms of pain perception and opioid consumption after cesarean section: a double-blinded randomized placebo-controlled clinical trial.

ABSTRACT

OBJECTIVE: The aim of the present study was to evaluate the analgesic efficiency of SC ketamine, either alone or in combination with bupivacaine, following CS by means of postoperative pain and opioid need. PATIENTS AND METHODS: One hundred and twenty women were allocated into 4 groups in this prospective, double-blind, placebo-controlled, randomized trial. Group K (Ketamine, n=30) received SC 1 mg/kg ketamine. Group B (Bupivacaine, n=30) received SC 20 mL bupivacaine 0.5%. Group KB (Ketamine+Bupivacaine, n=30) received SC ketamine 1 mg/kg plus SC 20 mL bupivacaine 0.5%. Group P (Placebo, n=30) received SC 30 mL 0.9% saline (placebo). RESULTS: VAS scores at resting and on coughing and analgesic consumptions were compared. Visual analogue scale (VAS) pain scores at rest and coughing, at 15 and 60 minutes, and 2, 6 and 12 hours, and total opioid necessity were measured. VAS scores at rest in Group P were higher than in Group KB at the 6th hour, while lower in Group K and Group KB than in Groups B or P at the 12th hour. Patients receiving placebo had higher coughing VAS scores than those receiving ketamine or ketamine+bupivacaine at 2nd, 6th and 12th hours. Patients in Groups P and B required higher doses of morphine than those in groups K or KB. CONCLUSIONS: Subcutaneous ketamine, either alone or in combination with bupivacaine, provides a better postoperative pain relief and reduces postoperative opioid consumption when compared to use of bupivacaine alone.