Comparison of sub-Tenon's block with i.v. fentanyl for paediatric vitreoretinal surgery.

ABSTRACT

BACKGROUND: Vitreoretinal (VR) surgery is associated with moderate to severe pain and significant postoperative nausea and vomiting (PONV). The study aimed to assess the effectiveness of sub-Tenon's block for providing perioperative analgesia in children undergoing VR surgery. METHODS: In a randomized, observer-blinded trial, after obtaining institutional ethical committee approval and parental consent, 200 ASA grade I-II children aged 5-16 yr were allocated to receive either a sub-Tenon's block (Group SB) or 2 microg kg(-1) i.v. fentanyl (Group F) after induction of anaesthesia and topical anaesthesia of the conjunctiva with proparacaine 0.5% drops. Patients in Group F received fentanyl 0.5 microg kg(-1) and those in Group SB were given a corresponding volume of normal saline i.v. every hour from preloaded syringes. Increases in heart rate or mean arterial pressure by more than 20% of baseline were treated with additional 0.5 microg kg(-1) i.v. fentanyl boluses in both groups. The incidence of oculocardiac reflex (OCR), need for additional analgesics, postoperative pain, and PONV were recorded for the first 24 h after surgery. RESULTS: More patients in Group F (47.96%) had moderate to severe pain in the first 24 h when compared with Group SB (31.36%) (P=0.023). The need for postoperative ibuprofen was higher in Group F (66.3%) compared with Group SB (47.95%) (P=0.012). The incidence of OCR was significantly higher in Group F (31.6%) compared with Group SB (5.1%) (P<0.001). The incidence of PONV was similar in both groups. CONCLUSIONS: Sub-Tenon's block provides more effective analgesia than i.v. fentanyl for paediatric VR surgery.