The authors present results of a meta-analysis to investigate the role of sphenopalatine ganglion block (SPGB) in reducing postoperative pain in endoscopic sinus surgery (ESS). An electronic database search (Pubmed, SCOPUS, Google Scholar, Embase, and the Cochrane Register of Controlled Trials) using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines was conducted to identify related studies written in English up to June 2018. Results between the treatment group (receiving SPGB) and the control group (no treatment or saline injection) were compared. Statistical analyses used included standardised mean difference (SMD), odds ratio, Duval and Tweedie’s trim and fill, and I2 test.
Eight studies with 441 participants were reviewed. Intraoperative bleeding (SMD= -0.83; P<0.0001) was lower in the treatment group than in the control group but showed significant interstudy heterogeneity (I2>50%). Nausea and vomiting (log odds ratio= -0.98; P=0.0117); recovery from sedation time (SMD=-0.77; P<0.0001); postoperative pain at one hour (SMD=-0.98; P<0.0001); postoperative pain at six hours (SMD=-0.96; P<0.0001); postoperative pain at 12 hours (SMD=-1.05, P<0.0001), postoperative pain at 24 hours (SMD=-0.96, P<0.0001); and postoperative (0-24 hours) analgesic requirements (SMD=-0.69, P<0.0001) were all statistically lower in the treatment group.
There was no significant interstudy heterogeneity for any of these postoperative morbidities (I2<50%). The analysis did not consider the SPB approach of transoral (four studies) vs. transnasal route. While there were no adverse effects from the transnasal approach, it was associated with a higher rate of dental numbness.