RESUMO
BACKGROUND: Inadequate acute postoperative pain control after modified radical mastectomy (MRM) can compromise pulmonary function. This work aimed to assess the postoperative pulmonary effects of a single-shot thoracic paravertebral block (TPVB) and erector spinae plane block (ESPB) in female patients undergoing MRM. METHODS: This prospective, randomized comparative trial was conducted on 40 female American Society of Anesthesiologists (ASA) II-III, aged 18 to 50 years undergoing MRM under general anesthesia (GA). Patients were divided into two equal groups (20 in each group): Group I received ESPB and Group II received TPVB. Each group received a single shot with 20 ml volume of 0.5% bupivacaine. RESULTS: Respiratory function tests showed a comparable decrease in forced vital capacity (FVC) and forced expiratory volume (FEV1) from the baseline in the two groups. Group I had a lower FEV1/FVC ratio than Group II after 6 h. Both groups were comparable regarding duration for the first postoperative analgesic request (P value = 0.088), comparable postoperative analgesic consumption (P value = 0.855), and stable hemodynamics with no reported side effects. CONCLUSION: Both ultrasound guided ESPB and TPVB appeared to be effective in preserving pulmonary function during the first 24 h after MRM. This is thought to be due to their pain-relieving effects, as evidenced by decreased postoperative analgesic consumption and prolonged time to postoperative analgesic request in both groups. GOV ID: NCT03614091 registration date on 13/7/2018.