Effect of Ropivacaine in Combined Costoclavicular Brachial Plexus- Cervical Plexus Blocks on Hemidiaphragmatic Paralysis for Humeral Fracture Surgery: A Prospective Single- Centre Cohort Study

Background: The brachial plexus block is conducive to providing postoperative analgesia for patients with humeral fractures. The commonly used brachial plexus block techniques have a high incidence rate of hemidiaphragmatic paralysis (HDP), which may lead to respiratory problems. The combined costoclavicular brachial plexus - cervical plexus blocks (CCB-CPBs) had demonstrated favorable analgesic effects and had reduced the incidence of HDP in shoulder surgeries. However, the clinical experience regarding CCB-CPBs is rather limited. Consequently, our study aims to evaluate its various effects, such as the diaphragmatic and pulmonary functions, as well as the analgesia for humeral fracture surgeries. Patients and Methods: We enrolled 30 patients who were slated to undergo surgery for humeral fractures under the combined use of nerve block and general anesthesia. All the patients underwent CCB-CPBs under the guidance of an ultrasound and a nerve simulator. The anesthetic dosage consisted of 20 ml and 10 ml of 0.5% ropivacaine respectively. Following the operation, all the patients were transferred to the Post-Anesthesia Care Unit (PACU). The diaphragmatic excursion, spirometry outcomes, pain score, along with the sensory and motor block, were evaluated. Results: The diaphragmatic excursion was significantly reduced during the post-block period in contrast to the pre-block period. The mean change in diaphragmatic excursion (with the mean value [SD]) was -25.3 [48.6] %, accompanied by a P-value of 0.001. The forced vital capacity (FVC) during the post-block period was approximately 7% lower compared to that during the pre-block period, with a P-value of 0.032. The numerical rating scale (NRS) scores of the patients in the PACU were 0 (0-0). Conclusion: CCB-CPBs can result in a reduction in hemidiaphragm excursion and may slightly affect lung function to some extent. Nevertheless, they can provide a favorable analgesic effect for humeral fracture surgery. Therefore, patients with poor respiratory reserve should exercise caution when using it.