Introduction: Hematoma enlargement (HE) in intracerebral hemorrhage (ICH) possibly occurs soon after onset but is not captured due to delays in imaging. The Mobile Stroke Unit (MSU) can identify ICH patients in the prehospital setting and can increase our understanding of ICH patients in the first hour of onset.
Methods: This was a prospective, observational study to examine patients within 4 hours of symptom onset and early HE in ICH due to hypertension and/or coagulopathies. A baseline head CT (HCT) was performed on the MSU, followed by a 1-hour HCT at the destination hospital. Patients during MSU control weeks were included but not required to have a 1-hour HCT. Blood pressure was treated to a systolic goal of <150mmHg. Hematoma volume (HV) was measured by the ABC/2 method. HE was defined as an increase in HV by >6cc or >30% between scans. Patients were categorized by time to first HCT (≤61min, 62-120min, and 120-270min). Overall HE for each group was calculated using the scan nearest to 24 hours. HE on the 1-hour HCT was calculated for the ≤61min group and for the all patients collectively. The additional HE between the 1-hour HCT and scan nearest to 24 hours was also captured.
Results: Twenty-three patients (19 MSU) were included. Four of 8 (50%) patients in the ≤61min group, 3/7 (42.9%) in the 62-120min group, and 3/8 (37.5%) in the 120-270min group had HE in the first 24hrs, p=1.0 (Figure 1). Among the patients who had a 1-hour HCT, the incidence of HE over the first hour in the ≤61min group was 0.4 (2/5) and 0.36 (4/11) for all 3 groups. Additional HE beyond the 1-hour HCT occurred in only 1/9 patients (no follow up scan in 2 patients).
Conclusion: There was a high incidence of HE 1 to 2 hours after onset in ICH patients. This period may be an optimal window for treatment. Limitations include a small sample size and confounding due to early intervention in the MSU group. A larger study is currently ongoing.