摘要
OBJECTIVE: To investigate the impact of proportional assist ventilation (PAV) on tolerance and breathlessness in ventilated chronic obstructive pulmonary disease (COPD), and to describe the patient-ventilator interaction, hemodynamic state, breathing pattern and work of breath during PAV and pressure support ventilation (PSV). METHODS: Ten intubated COPD patients on weaning from mechanical ventilation were studied. Elastance and resistance were measured by both the inspiratory-hold technique during a brief period of volume control ventilation and runaway technique during PAV. Each assistance level of PAV (80%, 60% and 40%) and PSV was selected randomly. Patients' response, hemodynamics, blood gas and lung mechanics were monitored. RESULTS: Tidal volume and respiratory rate didn't change in a consistent manner as the level of assist was decreased (P > 0.05). With the level of assist increasing, peak inspiratory pressure was increasing significantly (P
目的 建立比例辅助通气 (PAV)临床应用的方法 ,评价治疗慢性阻塞性肺疾病 (COPD)急性发作期患者的疗效 ,并与压力辅助通气 (PSV)比较。方法 选取 10例COPD机械通气患者 ,分别采用吸气阻断法和脱逸法设定参数。每例随机先后采用PAV或PSV ,PAV辅助水平分别设为 80 %、6 0 %和 4 0 %。同时监测主观感受、血流动力学、氧动力学和呼吸力学指标。结果 吸气阻断法与脱逸法设定的参数有很好的相关性r=0 92 8(P <0 0 1)。PAV不同的辅助水平只影响吸气峰压、呼吸机及患者做功 ,对通气指标无显著影响 (P >0 0 5 )。对循环功能稳定者 ,两组的血流动力学指标无显著差异 (P >0 0 5 ) ,氧合均保持在满意水平。在患者做功相同时 ,PAV组比PSV组潮气量有减小趋势 (P >0 0 5 ) ,动脉血PaCO2 显著增高 (P <0 0 5 ) ,吸气峰压显著减低 (P <0 0 1)。结论 采用脱逸法设定参数简单可靠。PAV是安全有效的通气模式 ,人机协调性好。在做功相同时 ,PAV比PSV吸气峰压降低 ,根据患者的需要保持相应的通气量。
