A re-evaluation of the ventilator score as an indicator of prognosis in the adult respiratory distress syndrome.

ABSTRACT

OBJECTIVE: To determine whether the ventilator score of Smith and Gordon (1986) can accurately predict outcome in patients with severe Adult Respiratory Distress Syndrome (ARDS). DESIGN: Retrospective study of data from case records and flow sheets. SETTING: University Hospital Intensive Care Unit. SUBJECTS: Fifty-five patients with severe Adult Respiratory Distress Syndrome. MEASUREMENTS AND MAIN RESULTS: The ventilator score of Smith and Gordon (1986), based on a compound score of the patient's age, alveolar to arterial oxygen tension difference and mean peak airway pressure, was calculated daily for for each patient. In contrast to the original report, a high ventilator score ( greater than 80) had a predictive value for death of only 59%, and a specificity of only 29%. The use of a higher ventilator score ( greater than 100) resulted in a predictive value of only 70% with a specificity of 75%. The use of inverse ratio ventilation was associated with a significant improvement in survival in those patients with ventilator scores greater than 100. This finding has not been reported previously. CONCLUSIONS: The ventilator score does not provide a satisfactory predictor of outcome in ARDS and cannot be used as a prognostic tool. It may have some use as an indicator of the severity of respiratory failure. A ventilator score greater than 100 may be an indication for the institution of inverse ratio ventilation.