Adding pectoral nerve blocks to general anaesthesia reduces immediate postoperative pain in patients undergoing breast cancer surgery, according to a study presented here at the ANESTHESIOLOGY 2015, the Annual Meeting of the American Society of Anesthesiologists (ASA).
Despite the recent shift toward less invasive procedures, breast cancer surgery is still associated with moderate-to-severe acute postoperative pain that can sometimes lead to chronic pain.
Although thoracic epidural and paravertebral blocks have been used to treat acute postoperative pain, both are technically demanding and sometimes contraindicated for anticoagulated patients.
The recently introduced pectoral nerve blocks may be an easy alternative to thoracic epidural and paravertebral blocks. However, their beneficial effects have yet to be verified.
In the current prospective, randomised study, Shinichi Sakura, MD, Shimane University School of Medicine, Izumo City, Japan, and colleagues assessed the benefits of adding pectoral nerve blocks to general anaesthesia during unilateral breast cancer surgery.
The study included 35 patients undergoing unilateral breast cancer surgery, including mastectomy and breast-conservative surgery. Patients were randomised to receive pectoral nerve blocks and general anaesthesia or general anaesthesia alone. All patients were given fentanyl 50 μg and midazolam 1mg intravenously upon arrival to the operating room.
The pectoral blocks were performed under ultrasound guidance by injecting 10 and 20 ml of 0.5% ropivacaine between the pectoralis major and minor muscles and superficial to the anterior serratus muscle, respectively. This was followed by sensory assessment on the dermatome between T2 and T6 for the next 15 minutes in both groups, and general anaesthesia with endotracheal intubation induced with propofol and fentanyl 150 μg. All patients received intravenous patient-controlled analgesia with fentanyl (10 μg on demand bolus/10-minute lockout) for the first 24 postoperative hours.
At 24 hours postop, the Visual Analog Scale (VAS) pain score was significantly lower in the pectoral block group. However, at 48 hours, the VAS pain score was similar between the groups.
Half the patients in the pectoral block group experienced loss of cold sensation on some of the dermatomes tested 15 minutes after block. Fentanyl consumption was similar between the 2 groups, and most of the patients experienced loss of sensation to pinprick regardless of their group. Five patients from each group complained of pain 1 month after surgery.[Presentation title: Effects of Pectoral Nerve Blocks on Acute and Chronic Postoperative Pain From Breast Cancer Surgery: A Prospective, Randomized, Controlled Study. Abstract A3211]