Hedlin G, Freyschuss U, Hedenstierna G
Clin Physiol. 1985 Feb;5(1):19-34. doi: 10.1111/j.1475-097x.1985.tb00743.x.
Asthma was provoked by histamine inhalation in five children in order to study the hypoxaemia that might ensue and the underlying ventilation-perfusion (VA/Q) mismatching. The distribution of the VA/Q ratios was measured by a multiple inert gas technique before the provocation, during the asthmatic attack and after salbutamol inhalation. All children displayed a unimodal distribution of ventilation and perfusion under baseline conditions. During asthma they all developed a bimodal distribution, one mode lying within normal VA/Q regions but with increased perfusion to regions with VA/Q ratios of 0.1-1, which correlated with the observed hypoxaemia; the other mode was centered on a VA/Q ratio of approximately 10 and the magnitude of this mode correlated with FEV1 in percent of the predicted value. Salbutamol improved the VA/Q distribution and restored the blood gases to normal. We hypothesize that histamine-induced asthma causes a state of hyperinflation which compromises regional ventilation and blood flow, resulting in a VA/Q mismatching with one normal and one high VA/Q mode, and hypoxaemia.
为了研究可能随之发生的低氧血症以及潜在的通气-灌注（VA/Q）不匹配情况，对5名儿童通过吸入组胺诱发哮喘。在诱发前、哮喘发作期间以及吸入沙丁胺醇后，采用多惰性气体技术测量VA/Q比值的分布。所有儿童在基线条件下均表现出通气和灌注的单峰分布。在哮喘发作期间，他们均出现双峰分布，一个峰位于正常VA/Q区域内，但VA/Q比值为0.1 - 1的区域灌注增加，这与观察到的低氧血症相关；另一个峰以VA/Q比值约为10为中心，该峰的大小与预测值百分比的FEV1相关。沙丁胺醇改善了VA/Q分布并使血气恢复正常。我们推测，组胺诱发的哮喘会导致肺过度充气状态，这会损害局部通气和血流，导致VA/Q不匹配，出现一个正常和一个高VA/Q模式，并导致低氧血症。
