Outcome after acute respiratory failure is more dependent on dysfunction in other vital organs than on the severity of the respiratory failure

INTRODUCTION: The incidence and outcome of acute respiratory failure (ARF) depend on dysfunction in other organs. As a result, reported mortality in patients with ARF is derived from a mixed group of patients with different degrees of multiorgan failure. The main goal of the present study was to investigate patient outcome in single organ ARF. PATIENTS AND METHOD: From 1 January 2000 to 1 July 2002, all adult patients (>16 years) in the intensive care unit (ICU) at Haukeland University Hospital were scored daily using the Sequential Organ Failure Assessment (SOFA) score for organ failure. ARF was defined by the SOFA criteria: ratio of arterial oxygen tension to fractional inspired oxygen, with a value < 26.6 kPa (200 mmHg) in more than one recording during the ICU stay (SOFA score 3 or 4). Patients with ARF alone and in combination with other severe organ failure (SOFA score 3 or 4) were included. Survival was recorded on discharge from the ICU, at hospital discharge and at 90 days after ICU discharge. RESULTS: During the period of study, 832 adult patients were treated and 529 (63.0%) had ARF. The ICU, hospital and 3-month mortality rates were lowest in single organ ARF (3.2, 14.7 and 21.8%, respectively), with increasing mortality with each additional organ failure. When ARF occurred with four or five additional organ failures, the 3-month mortality rate was 75%. No significant differences in mortality were found between early and late ARF. CONCLUSION: The prognosis for ICU patients with single organ ARF is good, both in the short and long terms. The high overall mortality rate observed is caused by dysfunction in other organs.