Application of ultrasound guidance for ilioinguinal or iliohypogastric nerve block in pediatric inguinal surgery

Abstract

To evaluate the efficacy of ultrasound guidance for ilioinguinal or iliohypogastric nerve block in pediatric outpatients undergoing inguinal surgery. The present study was approved by the ethics committee of our hospital. One hundred children with ASA status I, aged 4 - 8 years old, scheduled for unilateral inguinal surgery were randomly divided into ultrasound group (Group U) and traditional group (Group T) (n = 50 each). Upon entering operation room, they were monitored by electrocardiography (ECG), heart rate (HR) and oxygen saturation (SpO(2)). After an induction of general anesthesia, intravenous access was established and laryngeal mask inserted with spontaneous breathing. Intraoperative anesthesia was maintained with 2% sevoflurane in 50% nitrous oxide with 50% oxygen. Children in Group U received an ilioinguinal or iliohypogastric block under ultrasonic guidance with a mixture of 0.8% lidocaine and 0.25% levobupivacaine at 0.2 ml/kg while those in Group T performed according to the traditional method of anatomical localization with the same local anesthetic at 0.3 ml/kg. During surgery, the vital signs of HR, respiratory rate (RR), SpO(2), partial pressure of end-tidal carbon dioxide (P(ET)CO(2)) and exhaled sevoflurane concentration were recorded. Additional intraoperative analgesic requirements were recorded. Face legs activity cry consolability (FLACC) score was used to assess the pain score postoperatively at recovery time, 2 and 4 h postoperation respectively. If the pain score was above 3, the child received acetaminophen rectally. The number of postoperative rectal acetaminophen was recorded. The degrees of parental satisfaction were investigated at 2 and 4 h postoperation. Intra-or postoperative adverse events were also recorded. HR at skin incision and sac traction in Group U was significantly lower than those in Group T (P < 0.05). Six children (12%) needed to increase inhaled sevoflurane concentration during operation in Group U versus 17 (34%) in Group T (P < 0.05). The pain score at recovery time, 2 and 4 h postoperation in Group U was significantly lower than those in T group (P < 0.05). Only 4 children (8%) needed postoperative rectal acetaminophen in Group U versus 13 (26%) in Group T (P < 0.05). The degree of parental satisfaction at 2 h postoperation was significantly higher in Group U than that in Group T (P < 0.05). One case in Group T had needle puncturing into blood vessels. No other adverse event was observed in two groups. The method of ultrasonic guidance for ilioinguinal or iliohypogastric nerve block is both feasible and effective. It can not only enhance the effect of nerve block, reduce the occurrences of complications, lower the quantity of local anesthetic and alleviate the medicinal toxicity.