| 1. ObjectivesThe purpose of the study is to reveal the differences between two modes [proportional assist ventilation(PAV) vs pressure support ventilation(PSV)] in the respects of ventilatory response and hemodynamics in patients with acute left heart failure .To appraise the accommodation and safety of PAV mode and PSV mode in patients with acute left heart failure.2. MethodsThe clinical datum during 2008. 5～2009. 4 were retrospectively reviewed. 32 cases were definitely diagnosed as having acute left heart failure(cardiac function:Ⅲ～Ⅳ) . After conventional treatments (cardiotonic, diuretic, extended tube, oxygen) were ineffective for half an hour , 32 cases were randomly divided into three groups : control group(12 cases continued conventional treatment) ; PSV group(12 cases were treated with PSV mode of noninvasive mechanical ventilation and continued conventional treatment); PAV group(8 cases were treated with PAV mode of noninvasive mechanical ventilation and continued conventional treatment.).All the datum(blood gas analysis, blood pressure, heart rate, respiratory rate, oxygenation index, rales, dyspnoea score, ventilation index: peak airway pressure and degree of comfort) were recorded.3. Results3.1 The baseline haemodynamics index (MAP, HR) were not different among three groups before treatment. While MAP, HR significantly decreased among three groups after treatment (P<0.05) .However, MAP and HR were not different among three groups after treatment.3.2 The baseline PaO2, RR and oxygen index were not different among three groups before treatment. PaO2, RR and oxygen index were singnificantly improved among three groups after treatment (P <0.05). While PaO2 and oxygen index in noninvasive ventilation groups were higher than those in control group (P <0.01). However, PaO2 and oxygen index were not different between of two noninvasive ventilation groups after treatment.3.3 The time of alleviating breathing difficulty in noninvasive ventilation groups was shorter than that in control group. However, The time of alleviating breathing difficulty was not different between of two noninvasive ventilation groups after treatment.3.4 The peak airway pressure in PAV group was lower than that in PSV group. (P <0.05).3.5 The index of degree of comfort (VAS score, auxiliary respiratory muscles score ) in PAV group was better than those in PSV group.(P <0.05).3.6 Two groups of noninvasive ventilation in patients with adverse reactions had abdominal distension, dry mouth and nasopharyn, mask complaint. However, the incidence of the adverse reactions was not different between two groups after treatment.4. Conclusions4.1 Two different modes(PSV and PAV) of noninvasive mechanical ventilation can improve the oxygenation and relief dyspnoea in patients with acute left heart failure.4.2 PAV and PSV had the similar effect in patients with acute left heart failure.4.3 The synchronization and comfort in PAV mode were better than those in PSV mode. |
