Pre-treatment with intravenous granisetron to alleviate pain on propofol injection: A double-blind, randomized, controlled trial

BACKGROUND: Propofol is one of the widely used intravenous (i.v.) anaesthetics, although pain on injection still remains a considerable concern for the anaesthesiologists. A number of techniques has been tried to minimize propofol-induced pain with variable results. Recently, a 5-HT(3) antagonist, ondansetron pre-treatment, has been shown to reduce propofol-induced pain. The aim of our randomized, placebo-controlled, double-blinded study was to determine whether pre-treatment with intravenous granisetron, which is routinely used in our practice for prophylaxis of post-operative nausea and vomiting, would reduce propofol-induced pain. METHODS: Eighty-two women, aged 18-50 years, American society of Anaesthesiologist grading (ASA) I-II, scheduled for various surgeries under general anaesthesia were randomly assigned to one of the two groups. One group received 2 mL 0.9% sodium chloride while the other group received 2 mL granisetron (1 mg/mL), and were accompanied by manual venous occlusion for 1 min. Then, 2 mL propofol was injected through the same cannula. Patients were asked by a blinded investigator to score the pain on injection of propofol with a four-point scale: 0=no pain, 1=mild pain, 2=moderate pain, 3=severe pain. RESULTS: Twenty-four patients (60%) complained of pain in the group pre-treated with normal saline as compared with six (15%) in the group pre-treated with granisetron. Pain was reduced significantly in the granisetron group (P<0.05). Severity of pain was also lesser in the granisetron group compared with the placebo group (2.5% vs. 37.5%). CONCLUSION: We conclude that pre-treatment with granisetron along with venous occlusion for 1 min for prevention of propofol-induced pain was highly successful.