Comparison of Erector spinae block and transverse abdominis plane block as post op analgesia in patients undergoing inguinal hernia repair under spinal anesthesia, a randomized, single blinded study

INTRODUCTION:

Spinal anaesthesia is the most well-known technique usedin Inguinal Hernia operations. However, spinal anaesthesia does not provide adequate postoperative pain relief. Various techniques are used for postoperative pain relief after Inguinal hernia surgery under spinal anaesthesia,including intrathecal and/or systemic opioids, abdominal nerve blocks, and truncal blocks such as the transversus abdominis plane (TAP) block with parenteral analgesics and erector spinae plane (ESP) block.

AIM:

PRIMARY OBJECTVE:

•To compare the duration of analgesic effect of transversus abdominus block and erector spinae block as post operative analgesia in patients undergoing inguinal hernia repair under spinal anaesthesia.

SECONDARY OBJECTIVE:

•To determine the total requirement of opioids as rescue analgesia in the first 24 hours

•To compare the hemodynamic stability of transverse abdominus block and erector spinae block

•To assess the post operative pain severity using visual analog score at rest and after cough.

METHODS:

STUDY POPULATION:

Study population consisted of ASA 1,2 and 3 patients scheduled to undergo elective and emergency surgery under spinal anaesthesia.

STUDY DESIGN:

Randomized, single blind study.

INCLUSION CRITERIA:

Patient coming for Inguinal hernia repair under spinal anesthesia, ASA grade1, grade 2, grade 3

EXCLUSION CRITERIA:

•Patient refusal

•If the duration of surgery is more than 3 hours

•Contraindications to regional anaesthesia

•Known allergy to local anaesthetics

•Bleeding diathesis/Use of anti-coagulants

•Severe kidney or liver disease

•Patient with psychiatric disorders.

SAMPLE SIZE

n = 25 samples per group

• the total sample size will be 50 (25 participants in TAP group and 25 participants in ESPB group)

METHODOLOGY:

All patients will be premedicated with alprazolam 0.5 mg orally 4 hours prior to surgery. Spinal anaesthesia will be administered in all patients using 26G Quincke needle with 3.5 ml of 0.5% hyperbaric bupivacaine with 0.5 ml of Fentanyl in the L3–L4 subarachnoid space. The surgery will be started after checking the level of the blockade.

•ESP BLOCK

•Patient allocated to the ESP group will undergo ESP block. The patient will be turned into the lateral position to receive the block. After sterilization of the skin at the level of the ninth thoracic transverse process, a curvi-linear ultrasound probe will be placed vertically 3 cm lateral to the spinous process to visualize erector spinae muscles.

•An 18-G needle will be inserted in the cranial-caudal direction using the in-plane method until it makes contact with the transverse process. The needle tip will be confirmed to be correctly positioned by injection of 1 mL of saline and visualization of linear fluid spreading between the erector spinae muscle and the transverse process. After aspiration to exclude vascular puncture, 20 mL of 0.75% ropivacaine with clonidine 50mcg will be injected.

•TAP BLOCK

•Patients in the TAP group will undergo a TAP block in the supine position. According to the routine technique used in our institute, a linear probe will be placed transversely on the anterolateral abdominal wall in the midaxillary line between the costal margin and iliac crest to identify the three layers of

muscles, i.e., external oblique, internal oblique, and transversus abdominis.

•An 18-G needle will be introduced using the in-plane technique to reach the TAP between the internal oblique and transversus abdominis muscles. After

aspiration to exclude vascular puncture, 20 mL of 0.75% ropivacaine with clonidine 50mcg will be injected.

•The spinal level will be assessed and recorded before either type of block was administered. At the end of surgery, patient will be transferred to the

postoperative anaesthesia care unit.

•All patients will be given Inj. Paracetamol 900mg in 100ml NS IV as soon as the patient is received in the recovery room and continued as TDS dosage.

•Postoperative pain will be assessed by the visual analog scale (VAS) pain score (range, 0–10; 0-no pain; 10-worst pain) at rest and after cough.

•Basic vitals will be measured on arrival in the postoperative anaesthesia care unit hourly for 24 hours.

•The primary study outcome will be the duration of analgesia achieved by each type of block. The secondary outcomes will be the postoperative pain severity assessed by the VAS pain score at rest and after cough at 0,1,2,3,4,8,12 and 24 hours, total tramadol consumption.

•Patients will be given intravenous tramadol 1 mg/kg with emeset 4mg if VAS >3 or patient complain of pain. At any time, if pain relief was inadequate (VAS >6), Diclofenac will be given in a dose of 1.5 mg/kg intravenously. Total analgesic consumption in the 24-hour postoperative period will be recorded. Any complications related to interventions will be noted as well.

END POINTS

This study will be used to compare the post operative analgesia effect of erector spinae and transverse abdominus plane block of Ropivacaine (0.75%) with clonidine 50 mcg in patients undergoing inguinal hernia repair using subarachnoid block. Additional analgesic requirement if any in the 1st 24 hours will be noted. VAS score compared postoperatively between 2 groups.

ETHICAL CONSIDERATION:

After obtaining approval by the Institutional Human Ethics Committee and CTRI registration, and written informed patient consent, 50 patients under ASA physical status I, II, III patients scheduled for inguinal hernia repair will be included in a randomized single-blinded study at Chettinad Hospital and

Research Institute, Kelambakkam, Chennai.

REFERENCES:

1.McDonnell JG, Curley G, Carney J, et al. The analgesic efficacy of transversus abdominis plane block after caesarean delivery: a randomized controlled trial. Anesth Analg. 2008; 106:186–191.

2.Salman AE, YetiÅŸir F, Yurekli B, Aksoy M, Yildirim M, Kilic M. The efficacy of the semi-blind approach of transversus abdominis plane block on postoperative analgesia in patients undergoing inguinal hernia repair: a prospective randomized double-blind study. Local Reg Anesth. 2013;

3.McDonnell JG, O’Donnell B, Curley G, Heffernan A, Power C, Laffey JG. The analgesic efficacy of transversus abdominis plane block after abdominal surgery: a prospective randomized controlled trial. Anesth Analg. 2007; 104:193–197

4.Petersen PL, Stjernholm P, Kristiansen VB, et al. The beneficial effect of transversus abdominis plane block after laparoscopic cholecystectomy in day-case surgery: a randomized clinical trial. Anesth Analg. 2012; 115:527–533