readings In otherwise healthy children with no feeding difficulty or respiratory distress, recent American Academy of Pediatrics recommendations suggest that a pulse oximeter reading of 90% or greater is acceptable for patients with bronchiolitis Patients suspected of having reversible bronchospasm should be given an inhaled bronchodilator, such as albuterol, while proceeding with further evaluation and management Expeditious management is essential in patients with poor baseline pulmonary function because they can develop respiratory failure quickly Such patients include children with significant CLD and advanced cases of progressive chronic lung disorders such as CF Moreover, in patients with chronic respiratory insufficiency, careful titration of inspired oxygen concentration is important to avoid respiratory drive suppression CHILDREN YOUNGER THAN YEAR OLD An algorithm for elucidating the cause of wheezing in the child younger than year old is presented in Figure 84.1 It is important to note that age cutoffs are not absolute The abrupt onset of wheezing, often immediately preceded by an episode of choking, gagging, or vomiting, is highly suggestive of pulmonary aspiration of a foreign body If wheezing is subacute in presentation and accompanied or preceded by fever or respiratory symptoms, bronchiolitis or asthma should be considered Most infants who present with a first episode of wheezing have bronchiolitis A similar complex of physical findings in an older infant with a history of bronchiolitis or wheezing and clear improvement after bronchodilator administration is characteristic of asthma The remaining disorders are often found in infants who have overt evidence of chronic or severe underlying illness and who typically present with recurrent or persistent episodes of wheezing and respiratory distress Pulmonary aspiration of gastric contents may occur in infants and children with neurologic disability, as well as the occasional otherwise healthy child or adolescent A report of mechanical ventilation at birth and/or a prolonged neonatal intensive care unit admission may be a clue to CLD Recurrent pneumonia, failure to thrive, and steatorrhea are characteristic of infants with CF, whereas pneumonia in association with repeated extrapulmonary infection is suggestive of an immune deficiency A heart murmur and other clinical findings consistent with congestive heart failure are indicative of congenital heart disease and pulmonary edema Wheezing accompanied by stridor commonly indicates the coexistence of viral croup but may reflect intrinsic congenital airway narrowing, such as tracheobronchomalacia or extrinsic compression by a mediastinal mass In the