Jefferies A L, Kawano T, Mori S, Burger R
Department of Pediatrics, Mount Sinai Hospital, Toronto, Ontario, Canada.
J Appl Physiol (1985). 1988 Feb;64(2):562-8. doi: 10.1152/jappl.1988.64.2.562.
Experiments were performed to determine the effects of conventional mechanical ventilation (CMV) and high-frequency oscillation (HFO) on the clearance of technetium-99m-labeled diethylenetriamine pentaacetate (99mTc-DTPA) from lungs with altered surface tension properties. A submicronic aerosol of 99mTc-DTPA was insufflated into the lungs of anesthetized, tracheotomized rabbits before and 1 h after the administration of the aerosolized detergent dioctyl sodium sulfosuccinate (OT). Rabbits were ventilated by one of four methods: 1) spontaneous breathing; 2) CMV at 12 cmH2O mean airway pressure (MAP); 3) HFO at 12 cmH2O MAP; 4) HFO at 16 cmH2O MAP. Administration of OT resulted in decreased arterial PO2 (PaO2), increased lung wet-to-dry weight ratios, and abnormal lung pressure-volume relationships, compatible with increased surface tension. 99mTc-DTPA clearance was accelerated after OT in all groups. The post-OT rate of clearance (k) was significantly faster (P less than 0.05) in the CMV at 12 cmH2O MAP [k = 7.57 +/- 0.71%/min (SE)] and HFO at 16 cmH2O MAP (k = 6.92 +/- 0.61%/min) groups than in the spontaneously breathing (k = 4.32 +/- 0.55%/min) and HFO at 12 cmH2O MAP (4.68 +/- 0.63%/min) groups. The clearance curves were biexponential in the former two groups. We conclude that pulmonary clearance of 99mTc-DTPA is accelerated in high surface tension pulmonary edema, and this effect is enhanced by both conventional ventilation and HFO at high mean airway pressure.
进行实验以确定传统机械通气（CMV）和高频振荡（HFO）对表面张力特性改变的肺中锝-99m标记的二乙三胺五乙酸（99mTc-DTPA）清除的影响。在雾化的去污剂二辛基磺基琥珀酸钠（OT）给药前和给药后1小时，将99mTc-DTPA的亚微米气溶胶吹入麻醉、气管切开的兔肺中。兔通过以下四种方法之一进行通气：1）自主呼吸；2）平均气道压（MAP）为12 cmH2O的CMV；3）MAP为12 cmH2O的HFO；4）MAP为16 cmH2O的HFO。OT给药导致动脉血氧分压（PaO2）降低、肺湿重与干重比值增加以及肺压力-容积关系异常，这与表面张力增加相符。所有组在OT给药后99mTc-DTPA清除均加快。在MAP为12 cmH2O的CMV组[k = 7.57 +/- 0.71%/分钟（标准误）]和MAP为16 cmH2O的HFO组（k = 6.92 +/- 0.61%/分钟）中，OT给药后的清除率（k）显著快于自主呼吸组（k = 4.32 +/- 0.55%/分钟）和MAP为12 cmH2O的HFO组（4.68 +/- 0.63%/分钟）（P < 0.05）。前两组的清除曲线为双指数曲线。我们得出结论，在高表面张力肺水肿中99mTc-DTPA的肺清除加快，并且这种效应在高平均气道压下通过传统通气和HFO均得到增强。
