Background: Facial pain and headache of various etiologies can be treated by sphenopalatine ganglion block (SPGB) using local anesthetic; with the aid of endoscopy during functional endoscopic sinus surgery (FESS).
The objective of this study was to compare the efficacy of injection of lidocaine with epinephrine in the sphenopalatine ganglion endoscopically just posterior to middle meatus and transoral greater palatine foramen injection at the start of endoscopic sinus surgery (ESS) for surgical field hemostasis and control of surgical conditions.
Methods: A prospective, double blinded, randomized clinical trial of 30 patients diagnosed to have chronic rhinosinusitis (CRS) undergoing FESS under general anasthesia. All patients received injection of 2 mL 2% lidocaine with epinephrine regardless the technique Group 1 one side injected trans-oral technique while group 2 the other side trans-nasal injection and a piece of gauze soaked with lidocaine and adrenaline was passed along the middle turbinate.
Intraoperative vital signs in the form of heart rate and mean arterial blood pressure were measured over the operative time every 2 minutes. Postoperatively, patients were hospitalized for the first 24 hours. Pain was asked for and documented 6 and 24 hours after surgery and documented using a 10-cm visual analog scale (VAS). 
The need for postoperative rescue analgesia was recorded for all patients.
Results: There were statistically significant differences in blood pressure measurement and heart rate between the 2 groups over the operative time.
None of the patients had severe pain postoperatively. No complications were encountered in either group.
Conclusion: SPGB at the beginning of surgery can be considered as safe, simple, noninvasive, and effective method for controlled surgical conditions as well as short-term pain control for sinus surgery.
Keywords: Endoscopic sinus surgery; pain; analgesia; lidocaine; epinephrine; sphenopalatine ganglion block.