Predictive Ability of the Classification of Ground Level Falls As Syncopal Versus Mechanical in a Mixed Intensive Care Unit Population: A Retrospective Cohort Study.

Introduction Ground-level falls are a common mechanism of trauma, especially in the elderly. They are typically classified by etiology as syncopal or mechanical, based on a report of syncope (loss of consciousness due to transient reduction of cerebral blood flow). Syncopal falls generally prompt an evaluation of the cause of syncope, but the utility of this investigation and hence this classification system remains uncertain. Methods This retrospective registry review compares outcomes for patients with falls classified as syncopal versus mechanical. The data source is the Medical Information Mart for Intensive Care (MIMIC) III database. Patients experiencing a fall documented in the history of present illness (HPI) or during the admission were included. Syncopal versus mechanical etiology was analyzed as a predictive factor for length of stay, mortality, and cardiovascular and neurologic outcomes. Significance for categorical variables was tested with a chi-square and continuous variables with a T-test. Multivariate analysis was performed with logistic regression for binary outcomes and linear regression for continuous outcomes. Results Overall mortality for mechanical falls was 384 (54.2%) versus 480 (45.2%) for syncopal (p<0.001). Conditions more common among the syncopal group include cardiac valve disorder - 151 (14.2%) versus 76 (10.7%) (p=0.038), arrhythmia - 540 (50.8%) versus 322 (45.5%) (p=0.03), orthostatic hypotension - 38 (3.6%) versus 8 (1.1%) (p=0.003), and need for pacemaker implant or revision - 87 (8.2%) versus 13 (1.8%) (p<0.001). The difference in myocardial infarction was not significant. Syncopal etiology was an independent predictor of outcomes including overall mortality - adjusted odds ratio (OR) 0.75 (p=0.005), gastrointestinal bleed- (OR) 1.74 (p=<0.001), orthostatic hypotension - OR 3.34 (p=0.002), and need for pacemaker placement or revision - OR 4.0 (p<0.001). Conclusion Mortality was lower for patients with syncopal falls. Cardiovascular conditions were significantly more common among syncopal fall patients, but the incidence, especially for arrhythmia, was high and nearly equal in the mechanical group. We believe that a standard workup for orthostasis and arrhythmia should be performed for both groups, regardless of syncopal versus mechanical etiology.