Subcutaneous Wound Infiltration of Ketamine or Bupivacaine Pain Perception After Cesarean Section

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.

Aim: To assess the analgesic efficacy of subcutaneous infiltration of ketamine, either alone or as an adjuvant to bupivacaine, following CS and to compare their effects on postoperative pain scores and opioid consumption.

Methods: Included patients were allocated to four treatment groups using computer-generated randomization number chart as follows; Group 1 (Ketamine, n=30) received subcutaneous infiltration of ketamine, Group 2 (Bupivacaine, n=30) received subcutaneous infiltration of bupivacaine 0.5%, Group 3 (Ketamine+Bupivacaine, n=30) received subcutaneous infiltration of ketamine+bupivacaine 0.5% and Group 4 (Placebo, n=30) received subcutaneous infiltration of placebo (0.9% saline solution). Patients, anesthetist, surgeon, and other medical and nursing staff were blinded to the contents of the medications. VAS scores at resting and on coughing and analgesic consumptions were compared.

the Group 1 (Ketamine, n=30) received subcutaneous infiltration of ketamine 1 mg/kg (Ketalar®, 10 mL inj., 50 mg ketamine hydrochloride/ml, Pfizer Drug Company, USA). The Group 2 (Bupivacaine, n=30) received subcutaneous infiltration of 20 mL (100 mg) of bupivacaine 0.5% (Marcaine®, 20 mL inj. 5 mg bupivacaine hydrochloride/ml, AstraZeneca Drug Company, Turkey). The Group 3 (Ketamine+Bupivacaine, n=30) received subcutaneous infiltration of ketamine 1 mg/kg (Ketalar®) plus subcutaneous infiltration of 20 mL (100 mg) of bupivacaine 0.5% (Marcaine®). The Group 4 (Placebo, n=30) received subcutaneous infiltration of 30 mL placebo (0.9% saline solution). All medications were diluted with sterile 0.9% saline solution to 30 ml solutions in the similar volume and shape syringes and were infiltrated subcutaneously along the skin wound edges and close to the fascia prior to skin closure. There were four separate syringes which were prepared by an anesthesiology technician for four different treatment groups labeled G1, G2, G3 and G4 containing the ketamine, bupivacaine, ketamine plus bupivacaine and normal saline solution. Patients, anesthetist, surgeon, and other medical and nursing staff were blinded to the contents of the medications.

Inclusion Criteria:

• singleton term pregnancy,
• between 38-41th weeks of gestation,
• absence of any medical or obstetrical problems.

Exclusion Criteria:

• multiple pregnancies,
• intrauterine fetal deaths,
• active stage of labor,
• obstetric emergencies such as antepartum hemorrhage, eclampsia and acute fetal distress,
• special request for general anesthesia,
• history of allergic reaction or sensitivity to any of the drugs used in the study,
• reflected anxiety and depression during the cesarean operation,
• any systemic diseases (chronic hypertension, thyroid diseases, renal or hepatic insufficiency, psychiatric disorders,
• chronic pain syndrome, epilepsy or intracranial hypertension)
• medications that would affect the perception of pain,
• current or past history of narcotic use or a history of narcotic abuse,
• inability to understand how to score a 10-cm visual analogue scale (VAS) for pain.