The effects of glossopharyngeal nerve block on postoperative pain relief after tonsillectomy: the importance of the extent of obtunded gag reflex as a clinical indicator.

Abstract

We evaluated the efficacy of glossopharyngeal nerve block (GNB) for the control of post-tonsillectomy pain in adult patients, and correlated the extent of obtunded gag reflex as a clinical indicator of GNB with the extent of pain relief. Seventy-five patients undergoing tonsillectomy received bilateral GNB with 0.75% ropivacaine with epinephrine (Group R), 0.5% bupivacaine with epinephrine (Group B) at the end of the operation, or no intervention (Group C). To evaluate the effects of GNB, we assessed throat pain (100 mm visual analog scale) and severity of gag reflex response 0.5, 8, and 24 h after surgery. In the immediate postoperative period, pain scores at rest and when swallowing in Groups R and B were significantly lower than those in Group C (21 +/- 17 and 23 +/- 13 vs 42 +/- 16, 28 +/- 22 and 32 +/- 19 vs 62 +/- 14, P < 0.001). The analgesic effect of GNB was strongly correlated with the extent of obtunded gag reflex (P < 0.01). GNB is a useful method for the palliation of post-tonsillectomy pain. An obtunded gag reflex response may be a clinical indicator for analgesia from GNB.