Not all aspirations are retrograde
Contributed by: Drs. Vijay Harish, Jay Kumar Rai, Shamily George
Dept of Nuclear Medicine, AIMS, Kochi.

Case History - 7 month old male child born of a non consanguineous marriage, FTND with a birth weight of 2.5kg. Presented in paediatrics with a h/o cough and breathing difficulty since the age of 5 months. Symptoms exaggerated since 2 weeks with noisy breathing. No h/o fever/ regurgitation/ aspiration. No h/o contact with TB. No other constitutional symptoms. Past h/o of similar complaints for which was treated with antibiotics at a local hospital. Development normal for age, immunised for age.

O/E : conscious, active and afebrile. Pulmonary auscultation b/l ronchi and crepts present.

Chest X-ray - was s/o Bronchopneumonia.

Fig 1: Chest X-ray – AP view



Gastro-oesophageal Reflux Scintigraphy - showed no evidence of reflux of gastric contents into the oesophagus.

Fig 2: Gastro-oesophageal Reflux Scintigraphy (Milk scan)


 

Salivagram – evident of significant aspiration into b/l lung fields.

Fig 3: Salivagram


 

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Salivagram Procedure - 99mTc sulphur colloid in a dose of 0.5mCi (18.5MBq) added to 10ml of normal saline. This is instilled into the mouth over a period of 30 minutes with a size 6 French plastic feeding tube. The tube is taped to the child’s face with the distal end of the tube close to the parotid salivary ampulla. If during the study, it is expelled, it will be placed back in position ensuring no contamination of the face or clothes. A constant infusion rate of 20ml/hr is achieved using an infusion pump. If the children fall asleep during the study, they will not be deliberately woken.
Images of the thorax acquired in posterior projection (so as to allow easy access to the face for the infusion and immediate access to the airways in the event of an episode of apnoea). Dynamic images acquired in 128x128 matrix size using a low energy high resolution collimator with a frame rate of 5 seconds per frame. This is followed by 10 minute static acquisitions in anterior-posterior and lateral views. A further 10 minutes static projections in anterior-posterior and lateral planes will be acquired after 2 hours and 4hours.
Aspiration will be reported to be present when radiopharmaceutical activity is detected within the lung fields.

Review of literature:
· Oropharyngeal incoordination is reportedly the most common problem associated with recurrent pneumonias of hospitalized children. -Nelson Textbook of Paediatrics, 18th Ed.

· Medline search – no series on scintigraphic evaluation of antegrade aspiration in otherwise normal children.

· The salivagram was most frequently positive (56%), next was barium videofluroscopy (39%). -Agreement of aspiration tests using barium videofluroscopy, salivagram, and milk scan in children with cerebral palsy – Baikie et al;Development Medicine & Child Neurology 2005,47: 86-93.

Conclusion - Need for high degree of clinical suspicion of ongoing antegrade aspiration in a child with an acute respiratory illness who is being fed enterally and who deteriorates unexpectedly.