Incidence and Risk Factors of Diaphragmatic Paralysis After Ultrasound-guided Supraclavicular Block at Kenyatta National Hospital Operating Theatres

Abstract

Background: For upper limb procedures, peripheral nerve blocks can be used instead of, or in addition to, general anesthesia. The supraclavicular block gives a quick onset, dense block that is surgically acceptable, although it has been linked to an increased incidence of hemidiaphragmatic paralysis, particularly in high-risk populations. For some patients, inadvertent hemi-diaphragmatic paralysis has resulted in prolonged hospital stays. The incidence of diaphragmatic paralysis globally varies widely, and we do not have local data. Determining the incidence of hemi-diaphragmatic paralysis and the associated risk factors assists in adequate planning for the perioperative care of patients undergoing supraclavicular nerve block. Broad Objectives: To determine the incidence of diaphragmatic paralysis in patients undergoing ultrasound-guided supraclavicular nerve block in KNH theatres. Methodology: This was a descriptive cross-sectional study. Participants were recruited by consecutive sampling methods from the elective and emergency theatre lists. Ethical approval was granted by KNH-UoN Ethics and Research Committee before recruitment of study subjects and data collection. For the enrolled participants with duly signed informed consent, observations were recorded preoperatively on patient characteristics, intra-operatively on the supraclavicular block technique, respiratory rate, oxygen saturations, supplemental oxygen requirement, diaphragmatic excursion, and velocity before and after the block. Pre-block and post-block data were compared. Data Analysis: Excel and SPSS software were used for data analysis. Descriptive statistics were used to provide information on the variables. Chi-square tests, multivariate analysis, and logistic regression were used for prediction of significant risk factors for hemi-diaphragmatic paralysis. Conclusion: There was a 57.1% incidence of hemi diaphragmatic paralysis following ultrasound guided supraclavicular blocks in patients undergoing upper limb surgeries in KNH operating theatres. Patients require close monitoring after supraclavicular block since oxygen supplementation was required in a subset of patients (18.4%). Most patients will not develop clinically significant respiratory symptoms following hemi diaphragmatic paralysis. There could be an association between female gender and development of hemidiaphragmatic paralysis.