Erector Spinae Block Versus PECS Block Type II for Breast Surgeries: a Randomized Controlled Trial

This prospective, randomized controlled trial will include 30 adult female patients below 65 years of age scheduled for surgery for breast cancer. Inclusion criteria will include also American Society of Anesthesiologists (ASA) physical status I-II and unilateral surgery. Exclusion criteria will include obesity defined as body mass index > 35 kg/m2), known allergy to the study drugs, coagulopathy, skin infection at the site of needle puncture, and recent use of opioid drugs.

Patients will be assessed the day before surgery in a preoperative visit for evaluation of their medical status and laboratory investigations. They will be informed about the technique of the blocks and written informed consents will be obtained. All patients will be informed how to report pain on a numeric rating scale (NRS) ranging from 0 (no pain) to 10 (worst imaginable pain). In the pre-anesthetic room, midazolam 0.02 mg/kg IV will be given to the patients for sedation after fixation of a 20 G cannula as an IV line. Randomization will be done using consecutively numbered opaque sealed envelopes. Patients will be randomized into two groups according to the type of analgesia. The first group will receive single-shot ESP block (ESP group) and the other group will receive PECs II block (PECs group).

ESP technique:

ESP block will be performed in following standardized monitoring, including noninvasive blood pressure, electrocardiogram, and pulse oximetry. It will be done unilaterally with the patient in the prone position about 20 min before induction of general anesthesia. Skin is prepared by 10% povidone iodine. The US probe will be covered with a sterile cover. All blocks will be by the same anesthesiologists who are experienced in US-guided nerve blocks. An ultrasound machine with a large bandwidth, multifrequency convex probe (1-8 MHz) will be used for block performance. A 22G, 50-mm, insulated facet type needle will be used during all blocks. The blocks will be performed at the T4 level of the spine using an in-plane approach. A convex probe will be placed 2-3 cm laterally to the spine using a sagittal approach. Once the erector spinae muscle and the transverse processes is identified, the needle will be inserted deep into the muscle. The needle will be directed from a cranial to a caudal direction. Following confirmation of the correct position of the needle tip with administration of 0.5-1 ml of local anesthetic, 20 ml of 0.25% bupivacaine will be administered for block performance. Distribution of local anesthetic will be observed in both cranial and caudal directions.

PECs II block Technique: