Wolfsdorf J, Swift D L
Pediatr Res. 1978 Nov;12(11):1062-5. doi: 10.1203/00006450-197811000-00007.
Twelve heartworm-free mongrel dogs (10 males, 2 females) mean weight 22.2 kg (range 17.7--28.2 kg) were sedated and placed in a supine position with the neck extended. A double tracheotomy was performed under sterile conditions. The first tracheotomy tube was inserted 2 cm above the sternum in the direction of the carina using a shortened Silastic American tracheotomy tube (id 10 mm); the second was inserted two cartilage rings proximal to the first and approximately 5 cm distal to the larynx. All animals were kept deeply anesthesized by repeated iv injections of 3--6 mg/kg pentobarbitone sodium so that all reflexes (in particular laryngeal and palatal) were abolished. After control translaryngeal pressure measurements were obtained, the vocal cords were visualized, and steam was introduced onto the through the cords for a mean of 10 sec from above. For 2 hr after this, repeat pressure measurements, as described above, were made. After an overnight stabilizing period, two to three of five randomly chosen air environments were passed over the larynx at 10 liters/min via the proximal tracheotomy, and four half-hourly pressure measurements taken with control periods of at least 2 hr, as described above, separating each experiment. Environments utilized were as follows: i) "cold dry" air, i.e., air at a mean temperature of 9 degrees, obtained by passing compressed air through a coil placed in a solution of alcohol/Dry Ice; ii) "cold moist" air, i.e., air as above, subsequently passed over cold water at a mean temperature of 11 degrees; iii) "warm dry" air, i.e., air at a mean temperature of 36.5 degrees, obtained by passing compressed air through a copper coil, immersed in hot water; iv) "warm moist" air at a mean temperature of 36 degrees, obtained by passing compressed air through a heated Puritan humidifier; v) "ultrasonically produced mist" at room temperature (24 degrees), produced by a De Vilbiss ultrasonic nebulizer 900, set at maximum output. Six 2-hr experimental periods were utilized for each regimen of treatment (i--v). The mean of the combined experimental resistance calculations for each environment were compared statistically with those of its similarly acquired control data, expressed as a positive or negative percentage change, and displayed as a histogram. In addition, the data from each experimental environment were compared with the others, and mean percentage changes from control against time were calculated. Results indicate no statistically significant change in resistance from control for ultrasonic mist or warm moist treatment regimens. Warm dry, cold dry, and cold moist treatments, however, all produced significant reductions in translaryngeal resistance (74%, 60%, and 54%, respectively), there being no difference between cold dry and cold moist and warm dry and cold dry. Significant differences between warm dry and cold moist treatments were obtained, the former decreasing translaryngeal resistance the greatest amount...
12只未感染心丝虫的杂种犬（10只雄性，2只雌性），平均体重22.2千克（范围17.7 - 28.2千克），经镇静后置于仰卧位，颈部伸展。在无菌条件下进行双气管切开术。使用缩短的硅橡胶美式气管切开管（内径10毫米），在胸骨上方2厘米处朝着隆突方向插入第一根气管切开管；第二根在第一根近端两个软骨环处、距喉部约5厘米处插入。通过反复静脉注射3 - 6毫克/千克戊巴比妥钠使所有动物保持深度麻醉，以便消除所有反射（特别是喉部和腭部反射）。在获得经喉压力对照测量值后，观察声带，并从上方将蒸汽通过声带平均持续10秒。在此之后2小时内，按上述方法进行重复压力测量。经过一夜的稳定期后，并以10升/分钟的速度通过近端气管切开术使五种随机选择的空气环境中的两到三种在喉部通过，按照上述方法，在每个实验之间至少有2小时的对照期，每半小时进行四次压力测量。所使用的环境如下：i）“冷干”空气，即平均温度为9度的空气，通过将压缩空气通过置于酒精/干冰溶液中的盘管获得；ii）“冷湿”空气，即上述空气，随后通过平均温度为11度的冷水；iii）“暖干”空气，即平均温度为36.5度的空气，通过将压缩空气通过浸入热水中的铜盘管获得；iv）平均温度为36度的“暖湿”空气，通过将压缩空气通过加热的普里坦加湿器获得；v）室温（24度）下由德维比斯900型超声雾化器以最大输出量产生的“超声产生的雾”。每种治疗方案（i - v）使用六个2小时的实验期。将每个环境下合并的实验阻力计算平均值与其同样获取的对照数据进行统计学比较，以正或负百分比变化表示，并绘制成直方图。此外，将每个实验环境的数据与其他环境的数据进行比较，并计算相对于时间的对照平均百分比变化。结果表明，超声雾化或暖湿治疗方案的阻力与对照相比无统计学显著变化。然而，暖干、冷干和冷湿治疗均使经喉阻力显著降低（分别为74%、60%和54%），冷干与冷湿以及暖干与冷干之间无差异。暖干与冷湿治疗之间存在显著差异，前者使经喉阻力降低的幅度最大……
