Avaliação da força muscular respiratória em pacientes submetidos à ventilação mecânica prolongada pré e pós extubação em um hospital de Fortaleza/CE

Abstract

Introduction: The evaluation of the strength of respiratory muscles is the key to weaning from mechanical ventilation. Objective: To assess respiratory muscle strength in patients undergoing prolonged mechanical ventilation pre and post extubation. Methods: Field research, descriptive, observational and longitudinal with a quantitative approach, conducted carried out from August to November 2009, in the Intensive Care Unit Respiratory Messejana Hospital - Fortaleza - CE. The study included patients regardless of sex, aged 18, with conditions to extubation. The variables analyzed were age, sex, personal history, diagnosis, duration of mechanical ventilation, Acute Physiology and Chronic Health Evaluation (APACHE II) score and values of maximal inspiratory and expiratory pressure. The values of maximum inspiratory and expiratory pressures were measured at two time points: before extubation, after the patient had a favorable response to spontaneous breathing test and 24 hours after extubation. Results: The sample consisted of 12 patients on prolonged mechanical ventilation and extubation phase. When analyzing the values of the maximum pressure before extubation, we found an average of - 38.3 ± 3.01 cmH2O for maximal inspiratory pressure and + 47.5 ± 3.36 cmH2O for maximal expiratory pressure. The indexes 24 hours after extubation were - 47 ± 3.36 cmH2O for maximal inspiratory pressure and + 50 ± 6.25 cmH2O for maximal expiratory pressure. All patients had successful extubation. Conclusion: we observed an improvement in respiratory muscle strength after 24 hours of extubation, suggesting that mechanical ventilation for prolonged periods can cause respiratory muscle weakness and atrophy.