摘要
从上午10点开始,连续3天观察姿势对13例哮喘患者通气功能的影响。在患者仰卧4小时前后分别以坐位测量肺功能。仰卧位每0.5 h测定呼气峰流量(PEF)。取仰卧前、仰卧中、仰卧后的血样,测定血浆儿茶酚胺含量。初始肺功能测试后,吸入安慰剂或溴化异丙托品(0.125 mg)。第三天,整个试验都是坐着进行的,不含任何药物,作为对照实验。在服用安慰剂的那一天,仰卧使PEF开始迅速下降,随后在4小时内逐渐下降。PEF的渐进性下降明显是由支气管收缩引起的。异丙托溴铵预防了这种体位诱发的支气管收缩。在坐着的那一天,PEF也有下降的趋势,尽管不如安慰剂日的仰卧位明显。 No significant alterations in plasma levels of catecholamines were observed. We conclude that the supine posture is a stimulus to bronchoconstriction in asthma, likely to be involved in nocturnal wheezing. Postural bronchoconstriction is not explained by lowered plasma levels of adrenaline, as has been suggested for nocturnal asthma. The results raise the question of whether cholinergic mechanisms are involved.