A prospective cohort study of thoracic ultrasound in acute respiratory failure: the C3PO protocol

OBJECTIVES This study was performed to assess the clinical utility of a standardised thoracic ultrasound examination when added to standard care in patients with acute respiratory failure admitted to an intermediate care unit. This study aimed to assess the impact on clinical diagnosis, clinician confidence and management. Ultrasound has been shown to have utility in patients admitted to intensive care and emergency; however, utility in a ward setting is unknown. DESIGN Prospective cohort study. SETTING Tertiary hospital in Melbourne, Australia. PARTICIPANTS 50 patients with acute respiratory failure requiring admission to an intermediate care unit. MAIN OUTCOME MEASURES (1) Change in clinical diagnosis or additional clinical diagnosis following thoracic ultrasound. (2) Change in diagnostic confidence following thoracic ultrasound. (3) Change to management following thoracic ultrasound. RESULTS In 34% of patients, ultrasound detected unexpected findings that changed or added to the clinical diagnosis. Diagnostic confidence was increased in 44%, and the treating clinician altered the management plan in 30% as a result of the ultrasound. Ultrasound was particularly useful in clarifying the diagnosis in patients with multiple initial diagnoses, reducing to a single diagnosis in 69%. CONCLUSIONS Thoracic ultrasound has clinical utility in non-intubated adults with acute respiratory failure managed outside intensive care settings. It changed aetiological diagnosis, increases diagnostic confidence and altered clinical management in one out of three patients scanned. Our results suggest extended utility of thoracic ultrasound in acute respiratory failure to a broader context outside the intensive care unit population.