gms | German Medical Science

Objective: To evaluate the fluid content in chronic subdural hematoma (cSDH) patients and analyze their effect on the outcome of patients.

Methods: In the setting of the prospective trial we evaluated the fluid content. Hematoma fluid was withdrawn during initial evacuation and analyzed with respect to protein amount, specific weight, albumin, osmolarity, hemoglobin, erythrocytes and leucocyte amount. Principal component analysis and dimensional reductions as well was Partitioning Around Medoids clustering was used to identify subgroups based on similarities across all patient’s hematoma fluid. Outcome was assessed 6 months after evacuation of cSDH and dichotomized into favorable (mRS 0-3) and unfavorable (mRS 4-6).

Results: 361 patients were included in the trial. Hematoma fluid was available for analysis in 283 patients. Cluster analysis revealed two subgroups of patients based on differences in hemoglobin (cluster 1 2.73 mg/dl vs cluster 2 12.2 mg/dl, p<0.001) and erythrocyte count (cluster 1 0.7 mio/dl vs cluster 2 4.1 mio/dl, p<0.001). The remaining parameters did not show a significant difference between the two groups. Patients of cluster 2 showed a significantly worse outcome with respect to mRS 6 months (mRS 4-6 cluster 1 4.4% cluster 2 13.2% p=0.024) after evacuation of cSDH. In addition, a significantly higher risk of recurrence was observed in cluster 2 (cluster 1 20% vs cluster 2 26.5%).

Conclusion: Cluster analysis yields two distinct groups of cSDH patients. The groups were defined by significant differences in hemoglobin and erythrocytes. Patients with higher amounts of hemoglobin and erythrocytes in their hematoma fluid more often had an unfavorable outcome.