How should I approach the initial assessment and management of a patient presenting with acute hypoxaemic respiratory failure?

Initial assessment of a patient presenting with acute hypoxaemic respiratory failure should include a thorough clinical evaluation focusing on the severity of breathlessness, level of consciousness, presence of cyanosis, and general condition to determine the need for hospital treatment versus home management ¹.

Use pulse oximetry to assess oxygen saturation, being aware that some pulse oximeters may overestimate or underestimate saturation, especially in people with dark skin ¹.

In hospital settings, perform arterial blood gas analysis to measure oxygen and carbon dioxide levels and assess acid-base status, as well as record the inspired oxygen concentration ¹.

Additional investigations should include chest X-ray to identify underlying causes, ECG to exclude cardiac comorbidities, full blood count, urea and electrolytes, and sputum culture if purulent sputum is present ¹.

Management involves providing appropriate oxygen therapy to correct hypoxaemia while avoiding hyperoxia, considering non-invasive ventilation (NIV) if there is hypercapnia or acidosis, and invasive ventilation if NIV is insufficient or contraindicated ¹.

Monitor recovery with regular clinical assessments, pulse oximetry for non-hypercapnic patients, and intermittent arterial blood gases for those with hypercapnia or acidosis until stable ¹.

Before discharge, ensure the patient is stable with satisfactory oxygenation or arterial blood gas results, re-establish optimal maintenance therapy, and provide education on medication and oxygen use ¹.