Comparison of analgesic efficacy of ultrasound-guided lateral erector spinae plane block versus erector spinae plane block in patient undergoing Modified Radical Mastectomy: A randomised control trial

For a long time, various regional anesthesia techniques including thoracic paravertebral block, Erector spinae plane block, Pecs block etc. has been used for perioperative analgesia in breast cancer surgery to decrease opioid consumption and its side effect.The Erector spinae plane block (ESPB) is an interfascial regional anaesthesia technique where local anaesthetic is infiltrated into an interfacial space between erector spinae muscles and transverse process on the posterior chest wall at the level T5. Lateral ESPB is a novel approach for ESPB where local anaesthetic is infiltrated into an interfacial space slight laterally on the rib. Just two case series have been done which has shown that this approach is efficacious in providing analgesia. In lateral ESP block, local anaesthetic is infiltrated into an interfacial space between erector spinae and intercostal muscle on posterior chest wall at the level T5. It has been also found to provide good analgesia. There is no RCT comparing these two blocks.

Novelty– This study is one of its kind where USG guided lateral ESP blocks will be performed in MRM and will be compared to the group where conventional ESP block will be performed in terms of analgesic efficacy

Aim (One sentence) – To compare the analgesic efficacy of lateral erector spinae plane block with conventional erector spinae plane block in patient undergoing MRM/abdominal surgery.

Primary Objective- To compare postoperative opioid consumption.

Secondary Objective (Optional)

1. Time to first rescue analgesia
2. Total intraoperative opioid consumption
3. Numerical rating score of pain in first 24 hours post operatively : at 1st, 2nd,

6th, 12th, 24th hour 4. PONV Methodology:

A. Study design: A randomized controlled and double-blind study

B. Study participants– Female with breast cancer undergoing Unilateral MRM with or without axillary dissection under GA at AIIMS Patna

i. Inclusion criteria -

ASA I and II Patients between the ages of 18-70 years

BMI <= 35 kg/m2

b. Sample size calculation: Alpha: 5% Confidence interval (2 – sided): 95% Beta :20%, Ratio of sample size (Group LESPB/Group EPSB): 1:1, Total 88 (44 in each group)

ii. Exclusion criteria –

1. History of severe liver, renal or cardiovascular disease or chronic pain disease
2. Pre-existing neurological or psychiatric illness
3. Any bleeding abnormality
4. Diagnosis of allergy to the study drug
5. History of alcohol or drug abuse
6. History of chronic use of analgesics, sedatives, opioids, or steroids
7. Procedure site infection8. History of previous mastectomy 9. Severe spine/chest wall deformity

Group Lateral Erector Spinae 20 ml of 0.25% bupivacaine deposited between erector spinae and 5th rib just lateral to the transverse process of the side to be operated

Group Erector Spinae 20 ml of 0.25% bupivacaine deposited between erector spinae and 5th transverse process of the side to be operated

Appropriate statistical analysis will be done

Expected outcome: Administration of lateral ESP is expected to provide same analgesic efficacy as conventional ESP in the early perioperative period.