Puzzler: The blue wheezer

August 1, 2009

A 3-month-old is rushed into hospital after he stopped breathing; he is diagnosed with benign teratoma.

Short of breath, and short on answers

In anticipation of the impending patient, you think through the possible etiologies for such an event, given that the child reportedly now looks well. There's gastroesophageal reflux disease (GERD), seizure, primary arrhythmia, or maybe something idiopathic. You begin to formulate your thoughts as the paramedic walks through the double doors with a car seat in hand.

The mother reports that initially her son's cough seemed to improve with the nebulizer treatments, and now he was receiving treatments only as needed. Over the past weekend, however, she noticed that the cough had worsened somewhat. She had already planned a return visit to the pediatrician's office for the next day.

Upon further questioning, you discover that there had been no episodes of fever, vomiting, rash, or sick contacts. He has been active, playful, and feeding well. The cyanotic episode today did not seem to be related to a preceding feed, and there is no history of substantial regurgitation, so you think GERD-induced laryngospasm may be less likely. The child did not seem to have a post-ictal phase, so you are less inclined towards the diagnosis of a seizure. Although cardiac arrhythmia is still a distinct possibility, you begin to rethink your initial differential diagnosis of an ALTE. Perhaps this patient's preceding respiratory symptoms could be related to his cyanotic event today.

Listening carefully

You proceed to a thorough physical exam of the patient. The vital signs reveal tachypnea with a respiratory rate of 48 bpm, but normal pulse oximetry on room air. Four-extremity blood pressures and pre- and post-ductal saturations do not reveal any evident gradients. The child is alert, in mild respiratory distress with subcostal retractions, but no nasal flaring. You pay particular attention to the upper airway to hear if there is any evidence of stridor. You remember the mother mentioned a history of noisy breathing, and wonder if there might be an underlying tracheo- or laryngomalacia. Patients with these structured anomalies, you know, are prone to collapse their upper airways with the negative pressure of inspiration, and occasionally present with ALTEs. On your exam, however, you hear no evidence of stridor. You do note on lung auscultation, however, that there are decreased breath sounds anteriorly, and an occasional monophonic wheeze on the right posterior field. Perhaps there is a respiratory etiology to this patient's presenting episode after all.