Skelton R, Jeffery H
Department of Perinatal and Fetal Medicine, King George V. Hospital for Mothers and Babies, Camperdown NSW, Australia.
Pediatr Pulmonol. 1994 Jun;17(6):383-9. doi: 10.1002/ppul.1950170608.
Appropriate and early treatment with exogenous surfactant has clinical and economic benefits for neonates with pulmonary surfactant deficiency. In order to rapidly and reliably identify such neonates, we have evaluated the shake and click tests, biophysical tests of surfactant function, using 0.2 mL samples of tracheal (TA) and gastric aspirates (GA). Samples from 181 neonates with a gestational age range of 24-40 weeks were shaken with 95% ethanol. If bubbles formed (positive shake test) they were examined in air-free water under a microscope. In a positive shake or click test, the bubbles rhythmically increase and then decrease in size, denoting the presence of active surfactant. The probability of the tests to predict clinical surfactant deficiency was analyzed. The latter was defined as respiratory distress syndrome or transient tachypnea of the newborn diagnosed by chest radiography and clinical criteria. The click test on TA from preterm infants was most accurate, with a 100% positive predictive value and specificity, and a 93% and 94% negative predictive value and sensitivity respectively. These values for GA were 73%, 84%, 97%, and 95%, respectively. The test is quick, simple, inexpensive, reproducible, and unaffected by contamination with blood. The accuracy of this test on TA in diagnosing surfactant deficiency in neonates would permit early and optimal treatment with exogenous surfactant. When performed on GA, the test could aid decisions regarding transfer of neonates to tertiary level care.
对于患有肺表面活性物质缺乏症的新生儿，早期给予适当的外源性表面活性物质治疗具有临床和经济效益。为了快速、可靠地识别这类新生儿，我们使用0.2 mL气管抽吸物（TA）和胃吸出物（GA）样本，对表面活性物质功能的摇振试验和咔嗒试验这两种生物物理试验进行了评估。对181名胎龄在24至40周的新生儿的样本与95%乙醇进行摇振。如果形成气泡（摇振试验阳性），则在无空气的水中用显微镜检查。在摇振试验或咔嗒试验阳性时，气泡大小有节奏地先增大后减小，表明存在活性表面活性物质。分析了这些试验预测临床表面活性物质缺乏症的概率。后者定义为通过胸部X线摄影和临床标准诊断的呼吸窘迫综合征或新生儿短暂性呼吸急促。早产儿TA的咔嗒试验最准确，阳性预测值和特异性均为100%，阴性预测值和敏感性分别为93%和94%。GA的这些值分别为73%、84%、97%和95%。该试验快速、简单、廉价、可重复，且不受血液污染的影响。该试验对TA诊断新生儿表面活性物质缺乏症的准确性将允许早期和最佳地使用外源性表面活性物质进行治疗。对GA进行该试验时，可辅助做出将新生儿转诊至三级医疗机构的决策。
