Postoperative Clinical Outcomes and Inflammatory Markers After Inguinal Hernia Repair With Local or Spinal or General Anesthesia: A Randomized Trial

After approval by Siriraj Institutional Review Board, a prospective randomized study in patients scheduled to undergo elective unilateral inguinal hernia repair at Siriraj Hospital will be undertaken. Patients, ASA I-III, greater than 18 years old will be approached in the outpatient surgical department and recruited in this study. Informed written consent will be obtained from each of them. Exclusion criteria are allergy to any medication used this study, femoral hernia, recurrent hernia, bilateral hernia, bleeding abnormalities, severe hepatic, renal or cardiovascular disease, chronic use of opioid, history of using steroidal or nonsteroidal anti-inflammatory drugs in the past 6 months, inability to communicate in Thai or to understand the purpose of the study.

Anesthesia and surgical procedure

All patients will be admitted one day before operation as routine and receive no premedication. Patients will be randomly allocated in the morning of the operation to receive one of the three anesthetic techniques: local anesthesia (LA), spinal anesthesia (SA) or general anesthesia (GA) for their inguinal hernia repair. The randomization process will be done by the use of a computer-generated number sealed in a brown envelope. All the patients will undergo standardized inguinal hernia repairs by three surgeons, A Trakarnsanga; V Chinsawangtanakul; T Akaraviputh, who agree to follow a precise protocol using Lichtenstein technique as described by Amid.

In the LA group, patients will receive local anesthesia similar to that described by Amid et al. except that 1% lidocaine with adrenaline (1:200,000) will be used instead of a mixture of lidocaine and bupivacaine. Surgeons will be taught to do the local anesthetic technique in a standardized manner.

In the SA group, patients will be positioned in the lateral position and a Whitacre 25 G needle will be inserted at L3-4 intervertebral space and then heavy bupivacaine 0.5% 15 mg will be injected. Sensory block (T4 and below dermatomes) to cold and pinprick will be tested before starting operation. An incremental dose containing 1 mg of midazolam and 25 mcg of fentanyl will be intravenously given if patients in the LA and SA group require.