The use of combined physiological parameters in the early recognition of the deteriorating acute medical patient

Abstract

BACKGROUND: Early warning scores (EWS) are widely used to allow early recognition of the deteriorating patient. We aimed to test their ability to predict major deterioration in medical patients. METHODS: Two cohorts were prospectively identified who were admitted to an acute medical admissions unit and to the respiratory unit but not admitted to the intensive care unit (ICU): medical-non ICU and respiratory-non ICU groups. Two further cohorts were retrospectively identified that required ICU admission from these units (medical-ICU and respiratory-ICU groups). Discriminant analysis and receiver operating characteristic curves were used to discriminate between groups, and time relationships were analysed. RESULTS: Heart rate (HR) and respiratory rate (RR) were significantly higher--and oxygen saturation (SaO₂) significantly lower--in the medical-ICU group as compared with the medical non-ICU group, and in the respiratory-ICU group as compared with [corrected] the respiratory-non ICU group. Discriminant functions incorporating HR, RR and SaO₂ performed at least as well as existing EWS systems in predicting ICU admission. CONCLUSIONS: Commonly used physiological parameters and existing EWS systems are useful at identifying sick patients. The discriminant functions described here appear to have a role in this setting but require validation in future studies.