Provocation test for children with bronchial asthma monitored by 81mKr ventilation and perfusion lung scans

A provocation test of bronchial asthma was performed on two children. The test involved the continuous inhalation of krypton-81m gas and intermittent intravenous injections of krypton-81m glucose solution. The patient's response was carefully monitored in order to clarify the relationship between the time of the appearance and the intensity of ventilation and perfusion defects. The bronchial sensitivity of each patient was determined according to the dose of allergen or bronchoconstrictor delivered before the first ventilation defects were observable. The test was sensitive enough for the children not to develop asthmatic symptoms during and after the test. The results showed that perfusion defects appeared after ventilation defects and were less intense. The perfusion defects disappeared rapidly and before the ventilation defects had become undetectable.