The analgesic effect of three different doses of nitroglycerine when added to lidocaine for intravenous regional anesthesia in trauma patients

BACKGROUND: Nitroglycerine (NTG) has analgesic properties. The aim of the present study was to assess the analgesic effect of three different doses of NTG (200 µg, 300 µg and 400 µg) when added to lidocaine in intravenous regional anesthesia (IVRA) in trauma patients. METHODS: One hundred patients undergoing hand surgery were randomly allocated to four groups to receive 3 mg/kg 2% lidocaine diluted with saline to a total dose of 40 mL in the control group (Group LS, n = 25) or 200, 300, 400 µg NTG plus 3 mg/kg 2% lidocaine diluted with saline to a total dose of 40 mL in the NTG group (Groups LN1, LN2, LN3 respectively; n = 25 in each group). Before and after the tourniquet application, hemodynamic variables, tourniquet pain, sedation, and analgesic use were recorded. RESULTS: Sensory and motor block onset times were significantly shorter in the LN3 group compared with Groups LN1, LN2, and LS (p<0.05). Sensory and motor block recovery times were statistically prolonged in the LN3 group when compared with Groups LN1 and LS (p<0.05). Postoperative visual analogue scale (VAS) scores were significantly lower at 2, 4, 8, 12, and 24 hours after tourniquet release in Group LN3 compared with Group LS (p<0.05). CONCLUSION: The addition of 400 µg NTG to lidocaine in IVRA shortens the onset of sensory and motor block in trauma patients and improves the quality of anesthesia and perioperative analgesia better than the addition of 200 µg or 300 µg NTG, without causing side effects.