Frantz I D, Close R H
Pediatr Res. 1985 Feb;19(2):162-6. doi: 10.1203/00006450-198502000-00002.
In order to understand the pressures and volumes delivered during ventilation with the Emerson flow-interrupting high frequency ventilator, we have measured dynamic and mean pressures at the airway opening, trachea, and alveoli as well as delivered volumes in vivo in closed-chest adult rabbits ventilated at rates of 2-37.5 Hz. To measure alveolar pressure we opened the chest, glued an alveolar capsule to the visceral pleural surface, punctured the pleura and lung surface through the capsule, inserted a pressure transducer into the capsule and closed the chest. We measured delivered volume with a pressure plethysmograph. Alveolar pressure swings fell with increasing frequency, as did delivered volume. Alveolar pressure swings were always lower than those at the airway opening or in the trachea. Removal of the rib cage resulted in a decrease in alveolar pressure swings although muscle paralysis had little effect. Mean pressures were equal at the airway opening, trachea, and alveoli at all frequencies. These results suggest that using the high frequency ventilator tested, to minimize alveolar barotrauma one should choose the highest frequency where gas exchange is adequate.
为了解艾默生流量中断高频呼吸机通气期间输送的压力和容积，我们在成年闭胸兔体内以2 - 37.5Hz的频率通气时，测量了气道开口、气管和肺泡处的动态压力和平均压力以及输送的容积。为测量肺泡压力，我们打开胸腔，将肺泡囊粘贴到脏胸膜表面，通过该囊穿刺胸膜和肺表面，将压力传感器插入囊中并关闭胸腔。我们用压力体积描记器测量输送的容积。随着频率增加，肺泡压力波动和输送的容积均下降。肺泡压力波动始终低于气道开口或气管处的波动。去除胸廓导致肺泡压力波动减小，尽管肌肉麻痹影响不大。在所有频率下，气道开口、气管和肺泡处的平均压力相等。这些结果表明，使用所测试的高频呼吸机时，为使肺泡气压伤最小化，应选择气体交换充足的最高频率。
