Effects of inspiratory muscle training using a new breathing device (BreatheMAX) for 7 days in patients with mechanical ventilator dependence: a pilot study of randomized controlled trial

Abstract

Inspiratory muscle strength is a crucial factor of spontaneous breathing without mechanical ventilator dependence or success of weaning.  The aim of this study was to preliminarily evaluate the effects of specific inspiratory muscle training, using a new loaded breathing device made in Thailand, on inspiratory muscle strength, weaning capability and acceptability and safety of the training.  Ten patients with mechanical ventilator dependence and had been on weaning trial with medical weaning protocol participated in the study.  Seven (6 females, 1 male) of 10 patients age 58 ± 10.6 years completed the study.  The patients were randomly allocated to an inspiratory muscle training group (IMT: n = 4) and a control group (C: n = 3). The patients in IMT group were trained by loaded breathing exercise at 50 % of peak negative inspiratory pressure (PNIP) 6 breaths/set, 10 sets everyday for 7 days combined with medical weaning protocol (MWP) which included  spontaneous breathing  either with continuous positive airway pressure (CPAP) and/or T-piece. The patients in C group were only trained by MWP.  Cardiopulmonary functions were measured at pre- and immediate post-loaded breathing exercise everyday.  PNIP and duration of spontaneous breathing with MWP were evaluated at pre- training and post-training (first and seventh day).  The results showed that cardiopulmonary functions were not significantly altered at the immediate post– compared to pre- loaded breathing exercise.  The median levels of PNIP of all patients in IMT increased from 20 to 25 cm H₂O (25 % increase, P = 0.045) but not in C group at pre- and post- training.  Duration of spontaneous breathing with CPAP was prolonged in IMT group (median = 5 hours) but decreased in C group (median = 1 hour). The duration of controlled breathing with mechanical ventilator was reduced in IMT but increased in C group.  Nevertheless these changes were not statistically significance.  Two of four patients in IMT could start T-piece trial at end of training program.  In conclusion, the specific inspiratory muscle training with the new device was acceptable and safe to be used and increase inspiratory muscle strength and improve spontaneous breathing capability in weaning trial.