Analgesia for retrobulbar block--comparison of remifentanil, alfentanil and fentanyl

BACKGROUND: The injection of retrobulbar block is associated with significant pain and discomfort. Therefore a short-acting IV analgesic before retrobulbar injection has been advocated. OBJECTIVE: To compare remifentanil, alfentanil and fentanyl in providing analgesia for retrobulbar block injection. METHODS: 69 patients were enrolled randomly into three groups of 23 each to receive either Remifentanil 1 microg/kg, Alfentanil 20 microg/kg or Fentanyl 2 microg/kg as an IV bolus dose prior to retrobulbar injection. Mean arterial pressure (MAP) and heart rate (HR) were recorded and Numerical Pain Score (NPS) were assessed by a blinded observer. RESULTS: Remifentanil prevented increase in MAP and HR while alfentanil and fentanyl were ineffective in this purpose (p < 0.05). NPS was significantly lower in remifentanil group (p < 0.05). CONCLUSION: Remifentanil 1 microg/kg prior to retrobulbar injection provide excellent hemodynamic stability and ensure analgesia.