Effects of salbutamol inhalations on transcutaneous blood gases in children during the acute asthmatic attack: from acute deterioration to recovery

Abstract

Nine children, 7-16 years of age, were studied repeatedly during an acute asthmatic attack, from acute deterioration to recovery. The transcutaneous blood gases, forced expiratory volume in 1 s (FEV1) and maximum expiratory flow when 25% of vital capacity remained to be expelled (MEF25) were monitored before and after salbutamol inhalation. The flow-volume variables were markedly impaired in the acute phase but improved gradually by the time of recovery. The transcutaneous PO2 (tcPO2) decreased in the acute and early recovery phase but improved by the late recovery phase. In the acute phase, the salbutamol inhalations increased the FEV1, indicating an improvement in central airway function, but also reduced the MEF25 and tcPO2 in some of the children. The changes in tcPO2 after the inhalations correlated with the changes in MEF25 (p < 0.001), thereby indicating a common denominator, probably the condition of the peripheral airways. In the recovery phase, the FEV1, MEF25 and tcPO2 improved after the inhalations (p < 0.05). In conclusion, transcutaneous PO2 can be used to evaluate the effects of treatment in children with acute asthmatic symptoms and may add information about peripheral airway function which may prove particularly valuable in small children where few methods are available for such measurements.