The shock index — the ratio of heart rate to systolic blood pressure — is a new measure that may predict a poor outcome. Most of the studies using the shock index have been in trauma patients and those with sepsis.
This retrospective study of 58,336 adult general emergency department visits at one urban academic center reviewed the shock index measured at initial ED presentation and determined the optimal cutoff for predicting hospitalization and mortality.
A shock index of >1.2 was associated with an increased likelihood of hospital admission (positive likelihood ratio = 12) and increased inpatient mortality (positive likelihood ratio = 6). This cutoff for a general population of adult ED patients is higher than the threshold of >0.9 described in adult trauma patients.
These data suggest that emergency departments should calculate the shock index for all adults presenting to the ED to identify those patients who should be considered for early triage.