Wattwil L M, Sjöstrand U H, Borg U R, Eriksson I A
Crit Care Med. 1983 Jan;11(1):38-43. doi: 10.1097/00003246-198301000-00010.
The ventilatory patterns of a conventional ventilator for volume-controlled ventilation (SV-900) and a low-compression ventilator utilizing the pneumatic valve principle for pressure/flow-generated, volume-controlled ventilation (system H) were studied in a lung model and in 10 patients with respiratory failure. System H was used at frequencies of 20 (H-20) and 60 (H-60 = high-frequency positive-pressure ventilation [HFPPV]) breath/min, and SV-900 at a frequency of 20 (SV-20) breath/min. With system H, inspiration constituted 22% (no inspiratory pause) and with SV-900, 25% (with 10% inspiratory pause). System H delivers an instantaneous accelerating flow which rapidly decelerates during the second part of the inspiratory phase. Maximal flow rates studied were 1.3 (H-60), 0.9 (H-20), and 0.7 (SV-20) L/sec. Thus, HFPPV delivers an effective tidal volume with highest linear velocity. This increased velocity increases gas mixing by increasing turbulence in conducting airways. In the 10 patients with respiratory failure, intrapulmonary gas distribution (measured as the nitrogen washout delay) was improved from 106% during SV-20 to 74% with H-60 (p less than 0.05). H-60 also increased carbon dioxide elimination in the 2 patients with the most severe pulmonary dysfunction.
在肺模型和10例呼吸衰竭患者中，研究了用于容量控制通气的传统呼吸机（SV - 900）和利用气动阀原理进行压力/流量产生的容量控制通气的低压缩呼吸机（系统H）的通气模式。系统H以20次/分钟（H - 20）和60次/分钟（H - 60 = 高频正压通气[HFPPV]）的频率使用，SV - 900以20次/分钟（SV - 20）的频率使用。使用系统H时，吸气占22%（无吸气暂停），使用SV - 900时，吸气占25%（有10%的吸气暂停）。系统H提供瞬时加速气流，在吸气阶段的后半部分迅速减速。研究的最大流速分别为1.3（H - 60）、0.9（H - 20）和0.7（SV - 20）升/秒。因此，高频正压通气以最高的线性速度输送有效的潮气量。这种增加的速度通过增加传导气道中的湍流来增加气体混合。在10例呼吸衰竭患者中，肺内气体分布（以氮洗脱延迟衡量）从SV - 20时的106%改善到H - 60时的74%（p小于0.05）。H - 60还增加了2例肺功能最严重的患者的二氧化碳清除。
