Quantification of the source, amount and duration of aspiration in the lungs of infants using gamma scintigraphy

Background: Aspiration can cause acute symptoms and chronic lung disease in the developing lung. However, the source of aspiration in infants is often unclear, making the choice of intervention difficult. Objective: To quantify the source, amount and duration of lung aspiration in infants using gamma scintigraphy. Methods: Two infants with clinical evidence of gastroesophageal reflux and oropharyngeal dysphagia swallowed formula radiolabeled with ^99mtechnetium on Visit 1. Radiolabeled-formula was instilled by nasogastric tube on Visit 2. Lung aspiration was quantified over four hours and expressed as percent of total radioactivity administered. Results: Aspiration was greatest with swallowing, compared to instillation, peaking between 2.0% and 2.4% within 30 min and between 0.40% and 0.65% within 20 min, respectively. Radioactivity remained above zero four hours after either administration. Conclusions: Quantification of the source, amount and duration of lung aspiration in infants is feasible using gamma scintigraphy. The impact of aspiration accrual on clinical care deserves further investigation.