Clinical efficiency of adaptive support ventilation on withdrawing from ventilatory support during weaning in elderly COPD patients with respiratory failure

Objective To investigate the clinical efficiency of adaptive support ventilation on withdrawing from ventilatory support during weaning in elderly COPD patients with respiratory failure. Methods 60 cases with acute exacerbation of chronic obstructive pumonary disease (AECOPD) complicating respiratory failure who needed ASV were randomized into two groups (n=30, each). The treatment group was assigned to adaptive support ventilation (ASV), while the control group were assigned to synchronized intermittent mandatory ventilation plus pressure support ventilation (SIMV+ PSV). The respiratory mechanics indices, meanwhile oxygen dynamic parameters, weaning time, ventilator alarms, and manual ventilator settings manipulations were recorded and compared between the two groups. Results The respiratory rate (RR), intrinsic positive end-expiratory pressure (PEEPi) and inspiratory resistance (RI) were decreased in treatment group as compared with the control group (t=4.200, 4.731, 3.562, P=0.032, 0.000 and 0.015, respectively). The airway occlusion pressure at 0.1 s (P0.1) and static compliance (Cstat) were increased in treatment group as compared with control group (t=4.064 and 4.051, P=0.000 and 0.022). The imposed work of breathing (WOBimp) and inspiratory pressure-time product (PTP) were lower in treatment group than in control group (t=3.181 and 4.836, P=0.046 and 0.021). The weaning time (WT), duration of ICU stay (DI), ventilator alarm (VA), apnea ventilation time (AT) were lower in treatment group than in control group 〔(93.1±9.28) h vs. (117.6±10.05) h, (11.9±1.15) d vs. (18.2±1.66) d, (4.3±0.5) times vs. (8.2±0.7) times, (3.2±0.2) times vs. (5.3±0.4) times, t=3.878, 3.776, 3.195, 3.743, respectively, P=0.022, 0.046, 0.000, 0.018〕. Conclusions Adaptive support ventilation could reduce the respiratory rate, PEEPi and inspiratory resistance, which could decrease the respiratory muscle work and shorten the duration of mechanical ventilation in elderly COPD patients with respiratory failure. Key words: Pulmonary disease, chronic obstructive; Respiratory insufficiency; Ventilator weaning