The Clinical Application Of Adaptive Support Ventilation

Object: To study the clinical application of adaptive support ventilation. Methods: 24 elderly patients were selected in elderly wards in our hospital from Jan 2004 to Mar 2005 and were divided into two groups: COPD group and non-COPD group. In the COPD group, three modes in which minute volume was consistent were applied: CMVi (tidal volume of 7⁹ml/kg/min, respiratory rate of 16¹8/min), ASV and CMV₂ (the same parameters as ASV). In the non-COPD group, two modes in which minute volume was consistent were applied: ASV and PS-SIMV. The variables of respiratory mechanics were recorded, meanwhile, the variables of hemodynamics and arterial blood analysis were measured after 30min in all modes. Results: In the COPD group, compared with CMV₁, tidal volume increased and respiratory rate decreased in ASV, meanwhile, inspiratory flow, inspiratory time constants and expiratory time constants increased (P>0.05),and expiratory flow decreased (P>0.05), but airway peak pressure, mean airway pressure, inspiratory resistance and expiratory resistance had no change (P<0.05). Compared with CMV₂, the variables of respiratory mechanics, hemodynamics and arterial blood analysis of the patients had no change in ASV (P>0.05). In the non-COPD group, compared with PS-SIMV, the variables of respiratory mechanics, hemodynamics and arterial blood analysis had no change in ASV. In the two groups, the patients applied with ASV felt more comfortable. Conclusions: The patients with COPD can be applied with the strategy of "high tidal volume, low respiratory rate". ASV can be applied with less parameters, easier manipulation, less respiratory effort and better patient-ventilator interaction.