The Impact of Body Mass Index on Local Anaesthetic Inguinal Hernia Repair

Background: Open mesh repair of inguinal hernia is acceptable and can be performed under local anaesthesia (LA). Individuals with high BMI (Body Mass Index) have often been excluded from LA repairs for varying reasons including safety concerns. Open repair of unilateral inguinal hernia (UIH) amongst individuals with different BMI groups was studied. Its safety profile was investigated using LA volume and length of operation (LO) as endpoints. Operative pain and patient satisfaction were also evaluated. Patients and methods: A total of 438 adult patients were studied having excluded underweight patients, those requiring any additional intra-operative analgesia, multiple procedures, or records with incomplete data. Operative pain, patient satisfaction, LO and LA volume were retrospectively studied from the existing data from clinical and operative notes. Results: It was a predominantly male population (93.2% males) with an age range of 17-94 years peaking in the 60-69 years age group. BMI ranged 19-39 kg/m(2) with BMI above normal at 62.8%. LO was 13-100 minutes (average 37 mins {SD = 12}) utilising an average LA volume of 45 ml (SD = 11) per patient. Across BMI groups, no significant difference in LO (P = 0.168) or patient satisfaction (P = 0.388) was seen. Although LA volume (P = 0.011) and pain score (P<0.001) demonstrated statistically significant differences, these did not appear to be clinically relevant. Over 90% in each BMI group experienced mild or no pain and with severe pain reported in only one patient in the entire population. Overall, LA volume required per patient was low and dosage was safe in all BMI groups with significant proportion (89%) of patients evaluated for satisfaction rating their experience ≥ 90 out of 100. Conclusion: LA repair is safe and well tolerated irrespective of BMI. BMI is not a viable reason for exclusion of obese/overweight individuals from LA repair.