Rhomboid Intercostal Plane Block on Chronic Pain Incidence and Acute Pain Scores After Mastectomy

The Effect of Single Shot Rhomboid Intercostal Plane Block on Chronic Pain Incidence and Acute Pain Scores After Mastectomy Surgery

Rhomboid intercostal block is used to block lateral cutaneous branches of intercostal nerves between T3 and T9 dermatomes. RIB has been reported to be successful in attenuating acute pain following breast surgeries. However, it's effect on chronic pain has not been evaluated yet. The primary hypothesis of the study is that the incidence of chronic pain of the patients who will receive Rhomboid intercostal block (RIB) following breast cancer surgery will be lower than the patients who will receive no block intervention at the postoperative 3rd month. The secondary hypothesis is that the incidence ofchronic pain of the patients who will receive Rhomboid intercostal block (RIB) following breast cancer surgery will be lower than the patients who will receive no block intervention at the postoperative 6th month. An other secondary hypothesis is that the total BPI-SF scores will be lower in the RIB group than control group at the postoperative 3rd and the 6th months.

The study is designed as a prospective, double-blinded, randomize controlled study. The patients who will undergo mastectomy surgery with or without axillary dissection will be included in the study. Anesthesia will be inducted with intravenous (iv) thiopental 5 mg/kg, fentanyl 2 mcg/kg and rocuronium bromide 0.6 mg/kg. Following intubation, patients will be allocated into two groups according to a randomization table created by a professional statistician. In the study group, patients will receive a single shot Rhomboid Intercostal Block (RIB) with 30 milliliters of %0.25 bupivacaine and in the control group no block procedure will be performed. All patients will receive a standard analgesia protocol which will include an intraoperative intravenous (iv) infusion of dexketoprofen 50 mg and iv tramadol 1 mg/kg 15 minutes prior to the end of the surgery. Postoperative 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). Pain scores of the patients will be recorded at the postoperative 15. and 30. min in the recovery room and if the NRS score is 4 or more, iv fentanyl 1 mcg/kg will be applied. At the surgical ward, pain scores will be evaluated at the postoperative 1st, 2nd, 6th, 12th and 24th hours and if the NRS score is 4 or more, iv tramadol 50 mg will be applied as rescue analgesia. Opioid consumptions of the patients will be recorded at the postoperative 24th hour. At the postoperative 3. and 6. months, a pain doctor will evaluate all patients by using Brief Pain Inventory Short Form (BPI-SF) and Douleur Neuropathique 4 (DN4) questionnaire.

The patients will be under general anesthesia and will not be aware if they receive 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, but she will not involve in data collection.

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 30 ml of bupivacaine 0.25%.

After endotracheal intubation, patients will be positioned in lateral decubitus position. A RIB will be performed at the level of T5-T6 by ultrasound guidance. A single shot block will be performed by injecting 30 ml of 0.25% bupivacaine to the interfacial plane between rhomboid major muscle and intercostal muscle.

The presence of chronic pain will be evaluated by using the 5. question of Brief Pain Inventory Short Form at the postoperative 3rd month. The question ranges from 0 (which means no pain) to 10 points (which means worst pain). The score equal to or over 4 points indicates the presence of chronic pain. Primary outcome of the study is the difference in the incidence of chronic pain between study and control groups at the postoperative 3rd month.

The presence of chronic pain will be evaluated by using the 5. question of Brief Pain Inventory Short Form at the postoperative 6th month. The question ranges from 0 (which means no pain) to 10 points (which means worst pain). The score equal to or over 4 points indicates the presence of chronic pain. Secondary outcome of the study is the difference in the incidence of chronic pain between study and control groups at the postoperative 6th month.

Total score of Brief Pain Inventory Short Form of all patients will be recorded at the postoperative 3rd month. The form ranges from 0 point (best score) to 120 (worst score) points. The 3rd outcome of the study is the difference in total Brief Pain Inventory Short Form scores of patients in the study and control groups at the postoperative 3rd month.

Total score of Brief Pain Inventory Short Form of all patients will be recorded at the postoperative 6th month. The form ranges from 0 point (best score) to 120 (worst score) points. The 3rd outcome of the study is the difference in total Brief Pain Inventory Short Form scores of patients in the study and control groups at the postoperative 6th month.

The presence of neuropathic pain which will be evaluated by using Douleur Neuropathique 4 (DN4) which ranges from 0 point (no pain) to 10 points (worst pain). Score equal to or over 4 points indicates the presence of neuropathic pain. The 5th outcome of the study is the difference in the incidence of neuropathic pain between the study and control groups.

The presence of neuropathic pain which will be evaluated by using Douleur Neuropathique 4 (DN4) which ranges from 0 point (no pain) to 10 points (worst pain). Score equal to or over 4 points indicates the presence of neuropathic pain. The 6th outcome of the study is the difference in the incidence of neuropathic pain between the study and control groups at the postoperative 6th month.

Postoperative acute pain of the patients will be evaluated by using Numerical Rating Scale which ranges between 0 point (no pain) and 10 points (worst pain). The 7th outcome of the study is the difference in numerical rating scale scores between study and control groups.

Inclusion Criteria: ASA I-II patients Female Ages between 18-65 Patients who will receive breast cancer surgery under general anesthesia Exclusion Criteria: Alcohol or substance or chronic opioid consumption story Any pain killers intake in the last 24 hours prior to surgery Body mass index over 35 kg/m2 Infection at the injection sites Known allergy to local anesthetics Known psychiatric diseases which prevents communication Operations longer than 3 hours