The Effects of Manual Lung Hyperinflation on Pulmonary Function after Weaning from Mechanical Ventilation among Patients with Abdominal Surgeries: Randomized Clinical Trial

Introduction: After abdominal surgery, the patients who are separated from mechanical ventilation and provided with oxygen therapy via a T-piece are at risk for respiratory complications. Therefore, they need additional respiratory support. This study aimed to evaluate the effects of manual hyperinflation (MHI) on pulmonary function after weaning. Methods: This randomized clinical trial included 40 patients who had undergone abdominal surgery and were receiving oxygen via a T-piece. Patients were selected from the intensive care units (ICU) of two hospitals in Mashhad, Iran. The subjects were randomly allocated to intervention (MHI) and control groups. Patients in the MHI group were provided with three 20-minute MHI rounds using the Mapleson C, while the control group received routine cares. Tidal volume (Vt), Rapid Shallow Breathing Index (RSBI), and the ratio of arterial oxygen partial pressure to fractional inspired oxygen (P/F ratio) were measured before the intervention, as well as 5 and 20 minutes after the intervention. Atelectasis prevalence was assessed before and 24 hours after the intervention. Data were analysed by SPSS software version 13. Results: At baseline, there were no significant differences between the groups regarding Vt, RSBI, P/F ratio, and atelectasis rate. No significant difference was also found between the groups regarding atelectasis rate 24 hours after the intervention. However, at both posttests, Vt, RSBI, and P/F ratio in the MHI group were significantly better than the control group. Conclusion: In patients with artificial airway and spontaneous breathing, MHI improves pulmonary function.