The comparative assessment of the effects of two methods of pressure support adjustment on respiratory distress in patients under mechanical ventilation admitted to intensive care units

Abstract

Background: Incorrect adjustment of the respiratory parameters of the mechanical ventilator increases respiratory distress and work of breathing (WOB) in mechanically ventilated patients. The accurate adjustment of pressure support increases the patient’s comfort and decreases respiratory distress and WOB, etc.; thus, the present study was conducted to compare the effects of two pressure support adjustment methods on respiratory distress in patients under mechanical ventilation to investigate whether the rapid shallow breathing index (RSBI) method can reduce patients’ respiratory distress more and faster than the tidal volume (VT) and respiratory rate (RR) methods. Patients and methods: The study was conducted in 2020 on 56 mechanically ventilated patients with respiratory distress. The patients’ respiratory distress was first measured using RSBI and the respiratory distress observation scale (RDOS). The pressure support was then adjusted in the patients according to the RSBI (in the trial group, n = 33) and VT and RR (in the control group, n = 23). The patients’ respiratory distress was measured again in both groups 15 and 30 minutes after the pressure support adjustment. Results: The results showed no significant differences between the two groups in the mean RSBI and RDOS before (p = 0.374, p = 0.657 respectively) and 30 (p = 0.103, p = 0.218 respectively) minutes after the adjustment of the pressure support, but these mean values differed significantly (p = 0.025 for RSBI and p = 0.044 for RDOS) between the groups 15 minutes after the adjustment. Moreover, the interaction effect of the group * time for RDOS has become significant nonlinearly (p = 0.037), but none of the interaction effects of the group * time were significant for RSBI (linear: p = 0.531; nonlinear: p = 0.272). Conclusion: These two methods finally reduced the patients’ respiratory distress almost equally, but RSBI method can relieve the patients’ respiratory distress faster than the VT and RR methods.