Abstract
Lung injury by smoke inhalation alone or in combination with large cutaneous burn is thought to be the leading cause of death in fire victims. In this study, lung ventilation and perfusion scintigraphies were performed in six patients with hypoxemia (<70mmHg) following smoke inhalation.
Lung ventilation scintigrams using 133Xenon demonstrated retention of Xenon on washout image showing air trapped in all lung fields. Lung perfusion scintigrams using 99mTc-MAA (microaggregated human serum albumin) demonstrated non-segmental and multiple hypoperfusion areas. The hypoperfusion areas were suspected to show hypoxic pulmonary vasoconstriction secondary to decreased intraalveolar oxygen pressure. These data indicate an increase in mismatched ventilation and perfusion. Hypoxemia persisted for about one week after the injury, and the hypoperfusion areas disappeared one to three weeks after the injury.
We concluded from these data that hypoxemia caused by smoke inhalation was due to an increase in mismatched ventilation and perfusion. Attention should therefore be paid to hypoxia not followed by clinical signs and symptoms for a few hours after the smoke inhalation injury.
