If positive expiratory pressure is less than what percent with persistent severe symptoms, the patient requires oxygen and admission?

• A. <20%
• B. <30%
• C. <40%
• D. <50%

Answer: (C)

Positivity in expiratory pressure reflects how well a patient can keep airways open during exhalation and clear secretions. When persistent severe symptoms are present, a markedly reduced ability to generate expiratory pressure means the patient isn’t ventilating effectively and is at risk for ongoing hypoxemia. If the PEP is below 40% of the expected level, supplemental oxygen is typically needed and admission for closer monitoring and treatment is warranted. Values above this threshold suggest better expiratory mechanics and may not require immediate admission. The lower cutoffs (<20% or <30%) imply even more severe dysfunction, while higher values (around 50%) indicate milder impairment, so the 40% threshold best fits the decision to provide oxygen and admit.