Effect of Intravenous Ketamine Infusion on Hemodynamics of Patients Undergoing Cesarean Delivery after Spinal Anaesthesia: A Randomized, Double-Blind, Controlled Trial.

Objective: Hypotension is the most frequent side effect of intrathecal anaesthesia, with an incidence of more than 80%. Following neuraxial anaesthesia, perioperative shivering is a serious complication affecting 40-60% of patients undergoing surgery. This study aimed to determine the effectiveness of low-dose ketamine on blood pressure in patients undergoing cesarean delivery after spinal anaesthesia.

Methods: We included 126 female patients undergoing cesarean deliveries, American Society of Anesthesiologists (ASA)-(II and III), and aged 21-40 selected from the outpatient clinics of the anaesthesia department. Patients were randomized to two groups; Group K (63 patients), who received 0.3 mg kg^-1 of ketamine IV diluted to 10 mL, followed by an infusion of 0.1 mg kg^-1 h^-1. Group C (Controlled) (63 patients) received 10 mL of normal saline, followed by an infusion of 0.1 mL kg^-1 h^-1, which started before spinal anaesthesia.

Results: Compared with the saline group, the average heart rate, blood pressure, and level of sedation were significantly higher in the ketamine group (P < 0.05). The ketamine group reported a significantly lower incidence of shivering (P < 0.01). The ketamine groups exhibited significantly less mild or severe hypotension (P < 0.05). There was no significant difference between the two groups in terms of nystagmus, diplopia, hallucinations, or neonatal outcomes (P > 0.05).

Conclusion: Ketamine decreases the incidence of hypotension and shivering in patients undergoing spinal anaesthesia during cesarean delivery. In addition, it resulted in improved sedation for the mother and prolonged postoperative analgesia without neonatal illness.