Treatment outcomes of adaptation support ventilation vs synchronized intermittent mandatory ventilation for patients with respiratory failure in ICU

Objective To evaluate the clinical value of adaptive support ventilation (ASV) in patients with respiratory failure in ICU. Methods Between January 2014 and January 2016, a total of 257 patients with respiratory failure due to various causes, registered to ICU, Yueyang Second People’s Hospital of Hunan Province and requiring mechanical ventilation, were randomized to the receive ASV (the ASV group) or synchronized intermittent mandatory ventilation (SIMV) plus pressure support ventilation (the SIMV group) , respectively. At 30 min and 4 h of mechanical ventilation, the two groups were compared for respiratory mechanics. At 4 h of mechanical ventilation, the two groups were compared for blood gas and hemodynamics. The duration of mechanical ventilation, length of ICU stay, the rate of difficult weaning, the number of ventilator alarms, the need for ventilator parameter adjustment and incidence of ventilator-related complications were recorded for the two groups. Results A total of 223 patients completed the study, including 112 in the ASV group and 111 in the SIMV group. Respiratory mechanics showed that, compared with SIMV group at 30 min of mechanical ventilation, the ASV group showed a decrease of respiratory rate and an increase of tidal volume [ (18.96±4.28) times/min vs (23.71±4.14) times/min, (386.12±79.63) ml vs (356.37±85.37) ml, both P 0.05) . There were no significant differences in blood gas analysis and hemodynamics between the two groups at 4 h of mechanical ventilation (all P>0.05) . The ASV also showed shorter duration of mechanical ventilation [ (87.2±58.2) h vs (100.5±54.9) h] and length of ICU stay [ (6.02±2.03) d vs (8.83±2.69) d], fewer number of ventilator alarms [ (7.0±2.8) times vs (18.0±6.3) times], less need for ventilator parameter adjustment [ (3.2±2.1) times vs (8.6±6.7) times], and lower rate of difficult weaning [11.6% (13/112) vs 24.3% (27/111) ], respectively (all P 0.05) . The incidence of ventilator-associated pneumonia in the ASV group was significantly lower than that in the SIMV group [3.57% (4/112) vs 9.01% (10/111) , P<0.05]. Conclusion In patients with respiratory failure in ICU, ASV mode may shorten the duration of mechanical ventilation and length of ICU stay, improve respiratory mechanics and reduce the incidence of ventilator-associated pneumonia, compared with the SIMV+PSV mode. Key words: Mechanical ventilation; Adaptive support ventilation; Synchronized intermittent mandatory ventilation; Press support ventilation