The prevalence and significance of abnormal vital signs prior to in-hospital cardiac arrest

Background: Patients suffering in-hospital cardiac arrest often show signs of physiological deterioration before the event. The purpose of this study was to determine the prevalence of abnormal vital signs 1-4. h before cardiac arrest, and to evaluate the association between these vital sign abnormalities and in-hospital mortality. Methods: We included adults from the Get With the Guidelines^® - Resuscitation registry with an in-hospital cardiac arrest. We used two a priori definitions for vital signs: abnormal (heart rate (HR)≤60 or ≥100min^-1, respiratory rate (RR)≤10 or >20min^-1 and systolic blood pressure (SBP)≤90mmHg) and severely abnormal (HR≤50 or ≥130min^-1, RR≤8 or ≥30min^-1 and SBP≤80mmHg). We evaluated the association between the number of abnormal vital signs and in-hospital mortality using a multivariable logistic regression model. Results: 7851 patients were included. Individual vital signs were associated with in-hospital mortality. The majority of patients (59.4%) had at least one abnormal vital sign 1-4. h before the arrest and 13.4% had at least one severely abnormal sign. We found a step-wise increase in mortality with increasing number of abnormal vital signs within the abnormal (odds ratio (OR) 1.53 (CI: 1.42-1.64) and severely abnormal groups (OR 1.62 (CI: 1.38-1.90)). This remained in multivariable analysis (abnormal: OR 1.38 (CI: 1.28-1.48), and severely abnormal: OR 1.40 (CI: 1.18-1.65)). Conclusion: Abnormal vital signs are prevalent 1-4. h before in-hospital cardiac arrest on hospital wards. In-hospital mortality increases with increasing number of pre-arrest abnormal vital signs as well as increased severity of vital sign derangements.