Low-Dose Ketamine for Outpatient Hysteroscopy: A Prospective, Randomised, Double-Blind Study

Outpatient hysteroscopy is often accompanied by pain and discomfort along with frequent occurrence of bradycardia and hypotension. This study aimed to observe if intravenous low-dose ketamine reduces the pain scores along with lowering the incidence of bradycardia and hypotension during hysteroscopy.

This prospective, randomised, double-blind trial was conducted in operating rooms in a tertiary care hospital. In this study, we enrolled 72 patients with American Society of Anesthesiologists status I to II undergoing hysteroscopy. We randomised patients into two groups, and both groups received paracervical block. The control group received intravenous pentazocine and promethazine along with saline infusion. The ketamine group received ketamine infusion (0.75 mg kg^-1 bolus followed by infusion at the rate of 10 mcg kg^-1 min^-1). We analysed visual analogue scale (VAS), rescue analgesic consumption, hemodynamic parameters, lowest recorded heart rate, blood pressure, level of sedation, patient's comfort, surgeon's satisfaction and nursing staff's satisfaction.

Analysis of the data revealed that the pain scores were similar in both the groups (p=0.493, p<0.001). Rescue analgesic was required by 47% patients in control group, compared to only 5.6% patients in ketamine group. Episodes of bradycardia and hypotension were more pronounced in the control group than in the ketamine group [77.4±10.9 vs. 78.4±5.5; 67.6±8 vs. 70.1±6 respectively] (p<0.001). Patient comfort and surgeon's satisfaction were higher in the ketamine group, but nursing satisfaction was higher in the control group. Disorientation was present in 75% patients in the ketamine group as compared to none in the control group.

We concluded that low-dose ketamine in day-care hysteroscopy is an effective and safe agent.