Clinical study on adaptive support ventilation in treatment of severe asthma

Objective To study the effect of adaptive support ventilation (ASV) in treatment of severe asthma.Methods Forty-nine cases of severe asthma were divided into ASV group (25 cases) and control group (24 cases,tradition mechanical ventilation).The arterial blood gas,respiratory dynamics,mechanical ventilation time,hospital stay and thorax barotrauma was compared between two groups.Results The arterial blood gas and respiratory dynamics was improved after mechanical ventilation compared with that before mechanical ventilation in two groups,and there was significant difference (P ＜ 0.05 or ＜ 0.01).The airway peak voltage,lung dynamic compliance and platform pressure after mechanical ventilation of 2,12 and 24 h in ASV group was better than that in control group[2 h:(33 ± 12) cm H2O(1 cm H2O =0.098kPa) vs.(37 ± 11) cm H2O,(16 ± 9) ml/cm H2O vs.(17 ± 10) ml/cm H2O,(27 ± 6) cm H2O vs.(30 ±12) cm H2O; 12 h:(23 ± 12) cm H2O vs.(25 ± 11) cm H2O,(28 ± 6) ml/cm H2O vs.(23 ± 10) ml/cm H2O,(20 ±6) cm H2O vs.(25 ±4) cm H2O; 24 h:(18 ± 12) cm H2O vs.(20 ± 11) cm H2O,(32 ±9)ml/cm H2O vs.(28 ± 10) ml/cm H2O,(12 ±7) cm H2O vs.(16 ±7) cm H2O],and there was significant difference(P＜ 0.05 or ＜ 0.01).The mechanical ventilation time and hospital stay in ASV group was shorter than that in control group [(46 ± 8) h vs.(56 ± 6) h,(7 ± 2) d vs.(10 ± 3) d],and there was significant difference (P＜ 0.01).The thorax barotrauma was not observed in ASV group; 3 cases showed subcutaneous emphysema and 2 cases showed pneumothorax in control group.Conclusions ASV mode could decrease airway peak voltage and platform pressure,improve arterial blood gas and lung dynamic compliance,shorten mechanical ventilation time and hospital stay.It is safe and effective for patients with severe asthma. Key words: Asthma;  Pulmonary ventilation