Rouby J J, Simonneau G, Benhamou D, Sartene R, Sardnal F, Deriaz H, Duroux P, Viars P
Anesthesiology. 1985 Nov;63(5):473-82. doi: 10.1097/00000542-198511000-00002.
An external spirometric method using a differential linear transformer was used to measure tidal volume (VT) and to determine factors influencing CO2 elimination and HFJV-induced "PEEP effect" in 15 critically ill patients under HFJV. VT increased with increasing driving pressure (DP) and decreasing frequency (f) and was influenced little by changes in I/E ratio. CO2 elimination, as reflected by the measurement of PaCO2, was mainly influenced by the absolute level of VT rather than by the product VT X frequency (PaCO2 = 5715/VT, r = 0.75, P less than 0.05). The primary phenomenon explaining HFJV-induced "PEEP effect" was intrapulmonary gas trapping due to incomplete exhalation of the first VT administered: the spontaneous relaxation times of these first VT were longer than expiratory time allotted to the ventilatory settings. HFJV-induced "PEEP effect" increased with I/E ratio, DP, and f and was markedly influenced by the mechanical properties of the total respiratory system. At given ventilatory settings, HFJV-induced "PEEP effect" was greater in patients with a normal or elevated time constant of the total respiratory system (tau RS) than in patients with a low tau RS. These results suggest that HFJV should not be used in patients with chronic obstructive pulmonary disease and asthma, and should be preferentially administered to patients having stiff lungs or decreased chest wall compliance.
采用一种使用差动线性变压器的体外肺量测定法，对15例接受高频喷射通气（HFJV）的重症患者测量潮气量（VT），并确定影响二氧化碳清除及HFJV诱导的“呼气末正压效应”的因素。VT随驱动压力（DP）增加和频率（f）降低而增加，且受吸呼比（I/E）变化的影响较小。通过测量动脉血二氧化碳分压（PaCO2）反映的二氧化碳清除，主要受VT的绝对水平影响，而非VT与频率的乘积（PaCO2 = 5715/VT，r = 0.75，P < 0.05）。解释HFJV诱导的“呼气末正压效应”的主要现象是由于首次给予的VT呼气不完全导致肺内气体潴留：这些首次VT的自主松弛时间长于通气设置所分配的呼气时间。HFJV诱导的“呼气末正压效应”随I/E比、DP和f增加，且明显受整个呼吸系统机械特性的影响。在给定的通气设置下，整个呼吸系统时间常数（tau RS）正常或升高的患者中，HFJV诱导的“呼气末正压效应”大于tau RS较低的患者。这些结果表明，HFJV不适用于慢性阻塞性肺疾病和哮喘患者，应优先用于肺顺应性降低或胸壁顺应性下降的患者。
