The Effect of Rhomboid Intercostal Block and Serratus Anterior Plane Block on Postoperative Respiratory Functions (RIBSAB)

The Effect of Rhomboid Intercostal Block and Serratus Anterior Plane Block on Postoperative Respiratory Functions

The Effect of Ultrasound-guided Rhomboid Intercostal Block and Serratus Anterior Plane Block on Postoperative Respiratory Functions and Analgesia After Breast Surgery

Rhomboid intercostal block is used to block lateral cutaneous branches of intercostal nerves between T3 and T9 dermatomes. Serratus anterior plane block is used to block lateral cutaneous branches of intercostal nerves between T2 and T6, in addition, it is also known to block thoracodorsal nerve and long thoracic nerve. Both of the blocks are usually performed for postoperative analgesia following breast surgery. The primary hypothesis of the study is that FEV1 value of the patients who will receive modified radical mastectomy (MRM) and rhomboid intercostal plane (RIP) block combined with serratus anterior plane (SAP) will be higher than FEV1 value of the patients in the no-block group. The secondary hypothesis is that RIP+SAP blocks will provide reduction in the pain scores and opioid consumption in the postoperative first 24 hours.

The patients who are scheduled for MRM under general anesthesia, aged between 18-65 years and ASA scores I-II will be included in the study. Respiratory functions (FEV₁, FVC, FEV₁/FVC, PEF, FEF25-75) of the patients will be measured by a hand-held spirometry device prior to the operation in the surgical ward. The induction of anesthesia will be provided similarly in all patients, then patients will be intubated and randomly divided into two groups. One group will receive RIP+SAP block using 40 milliliters of %0.25 bupivacaine and patients in the control group will receive no block procedures. The standard analgesia will be provided by intraoperative intravenous (iv) infusion of dexketoprofen 50 mg and iv tramadol 1 mg/kg which will be administered in 15 minutes before end of the surgery. Respiratory functions of the patients will be measured at the postoperative 2nd, 4th and 24th hours. Pain intensity of the patients will be evaluated by Numerical Rating Scale (NRS) which is a scale ranges between 0 (no pain) and 10 (the worst pain that a person can stand). NRS scores will be evaluated at the postoperative 15th, 30th minutes and 1st, 2nd, 6th, 12th and 24th hours, and opioid consumption will be recorded at the postoperative 24th hour.

Analgesia, postoperative pain, rhomboid intercostal block, serratus anterior plane block, respiratory function

The patients will be under general anesthesia and will not know if they received a block procedure or not. The investigator, the data collector and the outcome assessor will be completely blind to the study groups. Only the care provider who will perform the block procedures will know the study groups.

After endotracheal intubation, patients will be positioned in lateral decubitus position. A linear ultrasound probe will be placed at the edge of scapula at the level of T5-T6. Under sterile conditions, the landmark points (rhomboid major muscle, 5th and 6th ribs, and intercostal muscles) will be observed and a block needle will be directed to the interfacial plane between rhomboid major muscle and intercostal muscle. RIB will be performed by injecting 20 ml of bupivacaine 0.25%. In the same position, the probe will be placed at the midaxillary line at the level of T3, and the landmark points (latissimus dorsi muscle and serratus muscle and intercostal muscles) will be observed. Under sterile conditions, a SAP block will be performed by injecting 20 ml of Bupivacaine 0.25% into the plane between serratus muscle and intercostal muscle.

RIB block will be performed after endotracheal intubation, then a SAP block will be performed. No other intervention will be performed to the patients.

FEV1 of the patients in the block group will be higher at the postoperative second hour than the patients in the control group

The pain scores of the patients in the block group will be lower than the patients in the control group at the postoperative second hour.

The opioid consumption of the patients in the block group will be lower than the patients in the control group at the postoperative 24th hour.

FVC value of the patients in the block group will be higher at the postoperative second hour than the patients in the control group

FEV1/FVC value of the patients in the block group will be higher at the postoperative second hour than the patients in the control group

FEF25-75 values of the patients in the block group will be higher at the postoperative second hour than the patients in the control group

PEF values of the patients in the block group will be higher at the postoperative second hour than the patients in the control group

Inclusion Criteria: ASA I-II patients Female Ages between 18-65 Patients who will receive breast cancer surgery under general anesthesia Exclusion Criteria: Known respiratory diseases Rhinitis and atopic dermatitis story New York Heart Association Class equal to higher than class 2 Respiratory diseases story in the last two weeks Alchol or substance or chronic opioid consumption story Any pain killers intake in the last 24 hours prior to surgery Active smokers or ex-smokers Body mass index over 35 kg/m2 İnfection at the injection sites Known allergy to local anesthetics Known psychiatric diseases Operations longer than 3 hours