Patient's data
serratus anterior block, pain
HEART
At the operative theater, all patients were sedated by IV midazolam 2 mg, and standard monitoring was applied. General anesthesia was induced by IV propofol, atracurium, and fentanyl with doses of 2.5 mg/kg, 0.5 mg/kg, and 1 μg/kg, respectively. A single-lumen endotracheal tube was used. All patients were kept on pressure-controlled volume mode, with a 1:2 I/E ratio and 4 ml/kg tidal volume. The respiratory rate was adjusted to keep ETCO2 around 35 mmHg. Maintenance of anesthesia was done via a mixture of isoflurane and 50% air in oxygen, and atracurium (0.1 mg/kg) increments were administered when needed. The block procedures were performed before skin incision under aseptic conditions under ultrasound guidance. We used Philips Clear Vue 350, WA, USA) with a high-frequency linear transducer (6 – 12 MHz).In Group R, RIB was done in the lateral position, with the operating side directed superiorly with the abduction of the ipsilateral arm. The linear ultrasound probe was positioned in the oblique sagittal plane medial to the medial scapular border, and the following structures were identified; rhomboid muscle, trapezius muscle, intercostal muscles, pleura, and lungs. Then, a 21-gauge sono-visible needle was inserted at the level of T 5–6 till reaching the plane between the rhomboid and intercostal muscles, where 20 ml of bupivacaine 0.25% was injected. The spread of the local anesthetic was noted by ultrasound, and the procedure was repeated for the opposite side after adjusting the patient's position (Fig. The rhomboid block technique: In Group S, SABP was performed in the lateral position. The probe was positioned in the sagittal plane over the thoracic region in the midaxillary line, where the seventh rib was identified along with the following muscles; serratus anterior, latissimus dorsi, and teres major. The sonovisible 18-gauge needle was advanced till reaching the plane superficial to the serratus muscle, where 20 ml of bupivacaine 0.25% was injected. The procedure was repeated for the opposite side (Fig. The serratus anterior block technique: No block procedure was done in Group C, as patients in this group received conventional IV analgesia. Heart rate (HR) and mean arterial pressure (MAP) were recorded basally, with skin incision, and then every 15 min till the procedure ended. At the end of the procedure all patients received acetaminophen with doses of 1 mg/kg.Patients were transferred to the recovery room where VAS score was recorded immediately, 1, 3, 6, 12, and 24 h after the operation. Postoperative analgesia was achieved by IV ketorolac (30 mg/12 h) and IV acetaminophen (1 gm/8 h). IV fentanyl (1 μg/kg) was also commenced for breakthrough pain, and it was repeated after 4 h till the patient had a VAS of 3 or less. Time to the first rescue analgesia and total postoperative opioid consumption was also recorded. Patient satisfaction was graded by the same person(trained nurse) according to a five-point Likert scale; weak, medium, good, very good, and excellent [