Alvarez F J, Alfonso L F, Gastiasoro E, Lopez-Heredia J, Arnaiz A, Valls-i-Soler A
Department of Pediatrics, Hospital of Cruces, Basque University School of Medicine, Bilbao, Spain.
Acta Anaesthesiol Scand. 1995 Oct;39(7):970-4. doi: 10.1111/j.1399-6576.1995.tb04207.x.
To test the effect on pulmonary gas exchange and mechanics of multiple small doses of exogenous surfactant as an alternative to bolus delivery in experimental respiratory failure induced by lung lavage.
After anesthesia, tracheostomy and constant volume ventilation, respiratory failure was induced by lung lavage in 20 rats. Animals were randomly assigned to an untreated control group or two experimental groups. Equal total doses of modified porcine surfactant (200 mg.kg-1 body weight), were given by tracheal instillation, either as a single bolus or in four (50 mg.kg-1 b.w.) fractional doses at 10-min intervals. Arterial pH and blood gases, and peak inspiratory pressure (PIP) were measured.
After lavage, a rapid decrease in arterial pH and PaO2, and an increase in PaCO2 and PIP were observed in all animals. In both surfactant-treated groups, PaO2 increased after surfactant instillation, and remained significantly higher than controls throughout the experiment. Arterial pH was significantly higher and PaCO2 significantly lower only in the single bolus group. In the multiple dose group, these levels were similar to those of controls.
In surfactant-depleted rats with respiratory failure, instillation of four fractional surfactant doses did not result in the same enhancement on gas exchange and PIP, in the following 60 min, as same total dose given by a single bolus.
在肺灌洗诱导的实验性呼吸衰竭中，测试多次小剂量外源性表面活性剂替代大剂量给药对肺气体交换和力学的影响。
20只大鼠在麻醉、气管切开和定容通气后，通过肺灌洗诱导呼吸衰竭。动物被随机分为未治疗的对照组或两个实验组。通过气管内滴注给予等量总剂量的改良猪表面活性剂（200mg·kg-1体重），要么单次大剂量给药，要么分四次（50mg·kg-1体重）以10分钟的间隔分次给药。测量动脉pH值、血气和吸气峰压（PIP）。
灌洗后，所有动物的动脉pH值和动脉血氧分压（PaO2）迅速下降，动脉血二氧化碳分压（PaCO2）和PIP升高。在两个表面活性剂治疗组中，表面活性剂滴注后PaO2升高，并且在整个实验过程中显著高于对照组。仅单次大剂量给药组的动脉pH值显著更高，PaCO2显著更低。在多次给药组中，这些水平与对照组相似。
在表面活性剂缺乏的呼吸衰竭大鼠中，在接下来的60分钟内，分四次滴注表面活性剂剂量在气体交换和PIP方面的增强效果与单次大剂量给予相同总剂量的效果不同。
