Chronic aspiration in children: evaluation of the lipid-laden macrophage index

Abstract

Chronic pulmonary aspiration (CPA) causes significant morbidity, but is underdiagnosed because of difficulties in establishing a diagnosis. The lipid-laden macrophage index (LLMI) is said to differentiate between those with and without CPA. Records of 113 patients were reviewed to determine specificity and sensitivity of the LLMI for CPA. Diagnostic accuracy was inferred from treatment outcome. Mean LLMI for aspirators was 104 +/- 62 (range, 20-233), and for nonaspirators, 44 +/- 39 (range, 0-170) (P < 0.05). Sensitivity and specificity were 0.69 and 0.79, respectively. While the LLMI provides clinically helpful information, it does not stand alone as the gold standard for the diagnosis of CPA. Failure to thrive and neurological impairment correlated with CPA, using Fisher's exact test. CPA was not diagnosed in any patient with normal growth, normal neurological development, and an LLMI <86. No other clinical observation (cough, wheeze, vomiting, difficulty feeding, choking with feeding, recurrent pneumonia, bronchopulmonary dysplasia, chronic chest X-ray changes, endotracheal tube, tracheostomy tube, nasogastric feeding tube, or transpyloric feeding tube) or diagnostic study (upper gastrointestinal series, gastroesophageal scintigraphy, modified barium swallow, or pH probe) correlated with the diagnosis of CPA.