Persistent Desaturations in Clinically Improving CAP with Cardiomegaly

Diagnostic Approach

The American Geriatrics Society recommends performing pulse oximetry to document the degree of hypoxemia, as oxygen saturation <90% is associated with higher mortality and indicates need for intervention 1
The American Journal of Respiratory and Critical Care Medicine suggests that repeat chest radiograph should be considered to evaluate for pulmonary edema, pleural effusions, or worsening infiltrates despite clinical improvement 2, 1
The American Journal of Respiratory and Critical Care Medicine recommends arterial blood gas if oxygen saturation remains <90% or if there is concern for CO2 retention, especially given advanced age 2

The American Journal of Respiratory and Critical Care Medicine notes that ventilation-perfusion mismatch from resolving pneumonia can persist even as clinical symptoms improve 3
The American Journal of Respiratory and Critical Care Medicine suggests that increased dead space ventilation may persist in recovering pneumonia 4, 3
The American Journal of Respiratory and Critical Care Medicine recommends considering pulmonary vascular changes, including possible pulmonary hypertension from chronic cardiac disease exacerbated by acute pneumonia 3, 5

The Critical Care Medicine journal recommends that if cardiac complication is identified, acute heart failure should be treated by initiating diuretics, optimizing afterload reduction, and considering non-invasive ventilation if respiratory distress develops 6
The Circulation journal suggests that if no cardiac complication but persistent hypoxia, supplemental oxygen should be continued to maintain saturation ≥90% 7, 1
The Critical Care journal recommends considering extended monitoring period before discharge given advanced age and persistent hypoxia 8

The Critical Care journal notes that the incidence of CAP rises to 48.5 per 1,000 in those aged 90 or older, and mortality doubles from 7.8% in 65-69 year-olds to 15.4% in those aged 90+ 8