The Efficacy of Serratus Anterior Plane Block (ESAPB) for Thoracotomy: a Prospective Study

Thoracotomy is considered the most painful surgical procedure. Ultrasound-guided serratus anterior plane block (SAPB) is a relatively new truncal block method treating thoracotomy pain. In this study, investigators aim to ascertain the efficacy of SAPB in thoracotomy.

Thoracotomy is considered the most painful surgical procedure, even with thoracic epidural analgesia (TEA) as a golden standard for acute post-thoracotomy pain. Ultrasound-guided serratus anterior plane block (SAPB) is a relatively new truncal block method treating thoracotomy pain, yet more evidence is needed to ascertain its efficacy. This is a prospective study carried out in a tertiary hospital. Patients scheduled for thoracotomy are randomized into two groups: Group M (intravenous patient-controlled-analgesia morphine) and Group S (intravenous patient-controlled analgesia morphine and SAPB). Morphine consumption, VAS pain score and Prince-Henry pain score are recorded for 72 hours respectively at PACU, 2hr, 6hr, 12hr, 24hr, 48hr and 72hr, with heart rate, systolic pressure, diastolic pressure, mean arterial pressure and SpO2. Moreover, the profile of opioids-related side effects and length of hospital stay are documented. The primary objective of the study is to evaluate the efficacy of SAPB. The secondary objective is to compare the opioids-related side effects (including nausea, vomiting and pruritus), hemodynamic parameters and the length of hospital stay.

In this group, serratus anterior plane block (SAPB) was performed before extubation with injection of 30 ml of 0.25% bupivacaine hydrochloride followed by 0.1ml/kg/hr of 0.12% bupivacaine hydrochloride. In addition to SAPB, intravenous patient-controlled-analgesia morphine was used. Morphine solution was prepared at a concentration of 0.5 mg/mL with the device programmed to 2 mg of bolus dose and 10 min of locking time.

In this group, intravenous patient-controlled-analgesia morphine was used. Morphine solution was prepared at a concentration of 0.5 mg/mL with the device programmed to 2 mg of bolus dose and 10 min of locking time.

Serratus anterior plane block was applied in Group S. It was performed at the end of the operation following the skin closure, while the patient lay on his side with his arm above the head. After proper site cleaning, the first and second ribs were identified with a linear probe in the midclavicular line. The USG probe was advanced caudally in the sagittal plane, and the fourth and fifth ribs were visualized. The USG probe was then directed posteriorly and the serratus, latissimus dorsi and intercostal muscles were visualized. Bupivacaine 0.25% 30 mL was administered to the lower plane of the serratus muscle through an inserted catheter under the guidance of USG through the in-line technique. Afterwards, 0.12% bupivacaine hydrochloride was maintained at the rate of 0.1ml/kg/hr.

Morphine solution was prepared at a concentration of 0.5 mg/mL with the device programmed to 2 mg of bolus dose and 10 min of locking time.

Inclusion Criteria: ASA I-II BMI 18-28kg/m2 Wedge incision and lobectomy Exclusion Criteria: Uncontrolled hypertension or chronic conditions History of opioid dependence Allergy to bupivacaine hydrochloride Severe bleeding during operation or post operation Inability to communicate with investigators.