Heart Rate Variabitlity at the Emergency Department: a New Triage Parameter?

Predictive parameters that can predict the outcome are very scarce. Vital parameters such as heart rate, blood pressure, saturation, etc. can be normal for a long time or only slightly changed, even in seriously ill patients. Heart rate variability is a parameter that can be used as a measure of autonomic dysfunction. Lower heart rate variability is associated with increased mortality and morbidity according to recent studies. Heart rate variability could thus be used to identify the need for intervention and treatment more quickly.

In this study, we want to investigate whether there is indeed a relationship between heart rate variability at admission to the emergency department and eventual mortality and morbidity in critically ill patients.

Therefore, heart rate variability will be determined in patients admitted to the emergency department who were triaged in red or orange according to the Manchester Triage System (internationally validated triage system that is also used in the emergency department at UZ Gent). Subanalyses will be made for patients with trauma, sepsis, pneumonia, CVA and acute myocardial infarction. Determination of heart rate variability will be done by EKG monitoring during the first 5 minutes and after 3 hours. There are several parameters that can reflect heart rate variability. Both frequency domain measurements and non-linair measurements will be determined. Use will be made of the Kubios programme, a free programme that can determine these different parameters on the basis of EKG monitoring. Patients who are resuscitated on arrival will be excluded, as well as patients in VKF, as the heart rate variability on arrival cannot be determined for these two groups. Demographic data (age, sex,...), history and home medication, vital parameters (heart rate, blood pressure, saturation, temperature, respiratory rate) and some lab data (lactate, CRP) will also be collected. The primary outcome will be mortality after 30 days. Secondary outcomes that will be studied are the total duration of hospital stay and the duration of stay in the intensive care unit, as well as the need for life-saving interventions (need for surgery, ventilation, inotropics, PCI or thrombolysis).

By collecting these data, we want to find out whether heart rate variability is a good predictor of outcome, and thus the need for ICU admission, faster invasive interventions,... During this study, the patient's management will remain unchanged.