Airway reactivity in infants: a positive response to methacholine and metaproterenol.
Airway reactivity in infants: a positive response to methacholine and metaproterenol.
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婴儿气道反应性：对乙酰甲胆碱和异丙肾上腺素呈阳性反应。
DOI：
10.1152/jappl.1987.62.3.1155
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
Tepper,RS
中科院分区：
文献类型：
--
作者：
Tepper,RS
由于婴儿是否存在支气管平滑肌反应性仍有争议，我们对10名年龄小于15月龄的正常无症状男婴进行气道反应性评估，方法是在甲胆碱支气管激发试验中测量功能剩余容量最大呼气流量（VmaxFRC）的变化。睡眠中的婴儿通过2分钟潮汐呼吸吸入浓度加倍的甲胆碱，开始时浓度为0.075 mg/ml，当VmaxFRC下降至少40%时停止支气管刺激。使VmaxFRC比对照值降低2 SD所需的甲胆碱阈值浓度为0.43 mg/ml（0.11-0.90）。当甲胆碱浓度为1.2 mg/ml时，所有婴儿的VmaxFRC降低至少40%（范围40-75%），而使40%降低所需的平均剂量为0.72 mg/ml。气道反应性与基线流量无关。在甲胆碱刺激期间，没有婴儿出现喘息，但氧饱和度百分比从94%显著下降到92% （P < 0.05）。在给予甲胆碱后，婴儿吸入支气管扩张剂甲丙肾上腺素，10分钟后，VmaxFRC恢复到基线。本研究表明，婴儿表现出气道反应性，如甲胆碱支气管收缩和随后甲丙肾上腺素支气管扩张。
Because the presence of bronchial smooth muscle reactivity in infants remains controversial, airway reactivity was assessed in 10 normal, asymptomatic male infants less than 15 mo of age by measuring the changes that occurred in the maximal expiratory flows at functional residual capacity (VmaxFRC) during a methacholine bronchial challenge test. Sleeping infants inhaled doubling concentrations of methacholine by 2 min of tidal breathing, starting with a concentration of 0.075 mg/ml, and the bronchial challenge was stopped when VmaxFRC decreased by at least 40%. The threshold concentration of methacholine required to produce a decrease in VmaxFRC by 2 SD's of the control value was 0.43 mg/ml (0.11–0.90). By a methacholine concentration of 1.2 mg/ml, all infants decreased VmaxFRC by at least 40% (range 40–75%), and the mean dose required to produce a 40% decrease was 0.72 mg/ml. The airway reactivity was not related to base-line flows. During the methacholine challenge, no infant developed wheezing, but the percent oxygen saturation for the group decreased significantly (P less than 0.05) from 94 to 92%. Following the methacholine, the infants inhaled the bronchodilator metaproterenol, and 10 min later, VmaxFRC returned to base line. This study demonstrates that infants exhibit airway reactivity as evidenced by bronchoconstriction with methacholine and the subsequent bronchodilation with metaproterenol.