Effectiveness of Regional Blocks for Postoperative Pain Control and Recovery in Breast Cancer Surgery in a Resource-Limited Setting: A Prospective Observational Study

Background and aims Effective postoperative pain management after breast cancer surgery is essential to enhance recovery, minimise opioid use, and prevent chronic post-surgical pain. In low- and middle-income countries (LMICs) like Sri Lanka, limited access to ultrasound and trained personnel often restricts the use of regional anaesthesia (RA). Although regional anaesthesia (RA) is well-established for breast cancer surgery, evidence from low- and middle-income countries remains limited. This study evaluated the effectiveness and feasibility of ultrasound-guided regional nerve blocks in improving postoperative outcomes in a resource-limited healthcare setting. Material and methods A prospective observational study was conducted at the Surgical Oncology Unit, Teaching Hospital Anuradhapura, from October 2023 to February 2024. Fifty-six female patients undergoing major breast cancer surgery under general anaesthesia were allocated to receive either regional anaesthesia (paravertebral, erector spinae, or pectoral nerve block) or local wound infiltration. Forty-one (73.2%) received ultrasound-guided regional blocks (paravertebral (n = 16), erector spinae plane (ESP) (n = 13), or pectoral nerve (PECS I/II) blocks (n = 12)) and fifteen (26.8%) received local anaesthetic infiltration. Pain scores were assessed using the visual analogue scale (VAS) at defined postoperative intervals. Morphine consumption, postoperative nausea and vomiting (PONV), mobilisation time, and three-month chronic pain were compared using independent-samples t-tests and chi-square/Fisher's exact tests, with p < 0.05 considered significant. Results Patients receiving regional anaesthesia (RA) reported significantly lower postoperative pain scores at 4 hours (2.5 ± 1.9 versus 4.7 ± 1.9; p = 0.001), 6 hours (1.9 ± 1.3 versus 3.2 ± 1.5; p = 0.003), and 12 hours (1.4 ± 0.8 versus 2.6 ± 1.5; p = 0.009) compared with the local infiltration group. By 24 hours, pain scores were low and comparable between groups. Mean morphine consumption was significantly lower in the RA group (2.6 ± 5.8 mg versus 7.5 ± 3.6 mg; p = 0.004), and 71% of RA patients required no opioids postoperatively. The incidence of postoperative nausea and vomiting (PONV) was also reduced (mean score: 1.2 ± 0.4 versus 1.7 ± 0.5; p < 0.001). Patients who received RA achieved earlier mobilisation (6.0 ± 1.5 hours versus 7.0 ± 1.4 hours; p = 0.032), and none developed chronic pain at three months, compared with 40% in the infiltration group (p = 0.009). No block-related complications were observed. Conclusions Regional anaesthesia techniques provided superior postoperative analgesia, markedly reduced opioid and antiemetic requirements, and facilitated earlier mobilisation following breast cancer surgery in a resource-limited setting. These blocks were feasible, safe, and highly effective despite infrastructural constraints. Incorporating regional anaesthesia into multimodal analgesia protocols in low- and middle-income countries may substantially improve recovery, enhance patient satisfaction, and reduce the burden of chronic post-mastectomy pain.