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 NICE NG115.
Use pulse oximetry to assess oxygen saturation, being aware that some pulse oximeters may overestimate or underestimate saturation, especially in people with dark skin NICE NG115.
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 NICE NG115.
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 NICE NG115.
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 NICE NG115.
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 NICE NG115.
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 NICE NG115.