What laboratory tests should be considered in the assessment of lower airway obstruction?

The assessment of lower airway obstruction focuses on understanding the underlying causes and effects on respiratory function. Viral studies and arterial blood gas (ABG) analysis are particularly relevant in this context.

Viral studies can help identify respiratory infections caused by viruses, which are common contributors to lower airway obstruction, especially in pediatric populations or during certain seasonal outbreaks. Conditions like asthma exacerbations or bronchiolitis can be triggered by viral infections, leading to compromised airway patency.

Arterial blood gas analysis is a critical test when evaluating a patient with suspected lower airway obstruction. It provides valuable information about the patient's oxygenation status, carbon dioxide retention, and acid-base balance. In cases of significant obstruction, patients may exhibit hypoxemia (low oxygen levels) and hypercapnia (elevated carbon dioxide levels), both of which can guide treatment decisions and interventions.

In contrast, other options like complete blood count, urinalysis, and bacterial cultures have less direct relevance to the acute assessment of lower airway obstruction. While a complete blood count can provide insights into potential infections, it does not specifically address the condition of the airways. Urinalysis is not useful in this context, as it evaluates renal function and hydration status rather than respiratory function. Bacterial