Sequential dosing salivagrams to increase sensitivity for detection of pulmonary aspiration in children

Objectives Salivagrams have high specificity for detecting aspiration of oral secretions in pediatric patients at risk of aspiration pneumonia. Typical standard protocols require only one oral dose administration. Prevalence of false negative studies is reportedly as high as 60%. We examined 14 patients using sequential dosing administration (SDA) to determine if this method would increase sensitivity of detecting pulmonary aspiration and reduce false negative reporting at our institution.

Methods Separate oral doses of 0.2mci Tc99m Sulfur Colloid were given, up to a maximum total of 3 doses (0.6mCi). Following administration of the 1st dose, serial 1-minute images were obtained for 60 minutes. If there was no evidence of aspiration during the first 15 minutes, a 2nd dose was given with no interruption of the acquisition; a 3rd dose was given at 30 minutes if the study remained negative. Sequential doses were withheld at the first sign of pulmonary aspiration. Anterior/Posterior and Right/Left planar images were obtained after the 60 minute flow. Results were tabulated according to the first appearance of radiotracer in the airways.

Results The SDA method was obtained in 14/14 patients. Seven patients showed no pulmonary aspiration following 3 separate doses. One patient showed evidence of aspiration after the 1st dose was administered. One patient had aspirated after the 2nd dose. Five patients had evidence of aspiration after the 3rd dose.

Conclusions Utilization of the Sequential Dosing Administration (SDA) method can increase sensitivity for detection of pulmonary aspiration and reduce false negative reporting, thereby improving patient care in pediatric patients with suspected pulmonary aspiration.