Introduction

Acute respiratory failure is a common reason for admission to critical care. This chapter focuses on acute respiratory failure as a consequence of primary lung or chest wall disease, examining the assessment and specific medical management of these conditions. Acute conditions, such as asthma and community-acquired pneumonia, have clear criteria for referral to critical care; however, admission of patients limited by chronic respiratory disease may not be straightforward.

Primary respiratory conditions in those with previously normal lungs

Clinical assessment of community acquired pneumonia involves recognizing treatable coexisting complications and comorbidities, including parapneumonic effusion or empyema, which should be drained. Detailed microbiological investigations should be performed, including blood and sputum/tracheal aspirate for culture and sensitivities (preferably before starting antibiotic treatment) and urine for both pneumococcal and legionella antigen. In addition, sputum should be examined by Gram stain and direct immunofluorescence for viral pathogens. Additional investigations for severe community acquired pneumonia include paired viral and atypical serology. The incidence of Staphylococcus aureus and Legionella pneumophila is increased in severe pneumonia, and a history of influenza symptoms and foreign travel should be sought.