Nicol M E, Dritsopoulou A, Wang C, Holdcroft A, Chakrabarti M K, Whitwam J G
Department of Anaesthesia, Royal Postgraduate Medical School, Hammersmith Hospital, London, UK.
Pediatr Pulmonol. 1994 Nov;18(5):317-22. doi: 10.1002/ppul.1950180509.
Changes in aortic blood flow were measured in rabbits with both normal and surfactant depleted lungs in order to elucidate the effect of different modes of ventilation on the circulation while optimizing arterial oxygenation (PaO2). Conventional mechanical ventilation (CMV), reversed inspiratory to expiratory ratio of CMV (IRV), high frequency positive pressure ventilation (HFV), and high frequency oscillation (HFO) were used. Normocapnia was maintained throughout during different modes of ventilation. In normal lungs the aortic blood flow during IRV was significantly lower with similar levels of PaCO2 compared with CMV, HFV, and HFO. In lavaged lungs, without positive end-expiratory pressure (PEEP), the aortic blood flow during CMV was significantly higher than with other modes of ventilation. When 10 cm H2O of PEEP was applied, the PaO2 increased maximally to normal values at all modes of ventilation, but the aortic blood flow was significantly reduced (P < 0.05) during CMV and IRV compared to HFV and HFO. The aortic blood flows at 5 cm H2O of PEEP were very similar during CMV, HFV, and HFO but significantly reduced during IRV. This study showed that at an optimal arterial oxygenation with higher PEEP levels, maintenance of aortic blood flow was maximal during HFV and HFO.
为了阐明不同通气模式对循环系统的影响，同时优化动脉血氧分压（PaO2），对正常肺和表面活性剂缺乏肺的兔子进行了主动脉血流变化的测量。采用了传统机械通气（CMV）、CMV的反向吸呼比（IRV）、高频正压通气（HFV）和高频振荡（HFO）。在不同通气模式下全程维持正常碳酸血症。在正常肺中，与CMV、HFV和HFO相比，IRV期间的主动脉血流在PaCO2水平相似时显著降低。在灌洗肺中，在没有呼气末正压（PEEP）的情况下，CMV期间的主动脉血流显著高于其他通气模式。当施加10 cm H2O的PEEP时，在所有通气模式下PaO2最大程度地升高至正常值，但与HFV和HFO相比，CMV和IRV期间的主动脉血流显著降低（P < 0.05）。在5 cm H2O的PEEP下，CMV、HFV和HFO期间的主动脉血流非常相似，但IRV期间显著降低。这项研究表明，在较高PEEP水平实现最佳动脉氧合时HFV和HFO期间主动脉血流的维持最大。
