Does isolated traumatic subarachnoid hemorrhage merit a lower intensity level of observation than other traumatic brain injury?

Evidence is emerging that isolated traumatic subarachnoid hemorrhage (ITSAH) may be a milder form of traumatic brain injury (TBI). If true, ITSAH may not benefit from intensive care unit (ICU) admission, which would, in turn, decrease resource utilization. We conducted a retrospective review of all TBI admissions to our institution between February 2010 and November 2012 to compare the presentation and clinical course of subjects with ITSAH to all other TBI. We then performed descriptive statistics on the subset of ITSAH subjects presenting with a Glasgow Coma Score (GCS) of 13-15. Of 698 subjects, 102 had ITSAH and 596 had any other intracranial hemorrhage pattern. Compared to all other TBI, ITSAH had significantly lower injury severity scores (p<0.0001), lower head abbreviated injury scores (p<0.0001), higher emergency department GCS (p<0.0001), shorter ICU stays (p=0.007), higher discharge GCS (p=0.005), lower mortality (p=0.003), and significantly fewer head computed tomography scans (p<0.0001). Of those ITSAH subjects presenting with a GCS of 13-15 (n=77), none underwent placement of an intracranial monitor or craniotomy. One subject (1.3%) demonstrated a change in exam (worsened headache and dizziness) concomitant with a progression of his intracranial injury. His symptoms resolved with readmission to the ICU and continued observation. Our results suggest that ITSAH are less-severe brain injuries than other TBI. ITSAH patients with GCS scores of 13-15 demonstrate low rates of clinical progression, and when progression occurs, it resolves without further intervention. This subset of TBI patients does not appear to benefit from ICU admission.