Introduction: Spontaneous intraparenchymal hemorrhage (IPH) is a common neurological emergency with significant morbidity and mortality. Hemorrhage size and expansion have been associated with worse outcome. In this study, we analyze a cohort of IPH transfer patients to identify specific thresholds associated with a high risk of neurologic deterioration and mortality.
Methods: A consecutive review of all nontraumatic IPH transfer patients to a tertiary academic neurosurgery service was performed over two years. Risk factors, including demographics, comorbidities, and anticoagulant use were studied. IPH volume at the outside hospital and upon arrival were calculated for each patient, using the standard A*B*C/2 formula. Outcomes included mortality and neurologic deterioration in transit, defined as a decrease in Glasgow Coma Scale score. A maximum Youden index was calculated to determine the threshold of initial IPH volume and expansion most predictive of deterioration or mortality.
Results: 331 IPH transfer patients were reviewed; 202 met inclusion criteria with sufficient imaging available. Both initial volume at the outside hospital and IPH expansion were found to be significantly correlated with risk of death and neurologic deterioration (P<0.001). The most predictive thresholds for mortality were 32ccs of initial IPH volume (area under the curve (AUC) 0.758, P<0.001, CI 1.012-1.035) and 1cc of IPH expansion. The threshold for neurologic deterioration was 18ccs of initial volume (AUC 0.690, P=0.004, CI 1.004-1.025) and 1cc of expansion.
Conclusions: Our data confirm volume and growth of IPH as predictors of death and neurologic deterioration in patients with IPH, and identify specific high risk thresholds. IPH with >32ccs of initial volume is associated with significantly increased mortality risk. The threshold for neurologic deterioration appears to occur with a smaller IPH volume of >18ccs. Any measurable IPH expansion is predictive of increased risk of mortality and deterioration.
Patient Care: Intraparenchymal hemorrhage (IPH) is, unfortunately, both common and devastating in neurosurgery. Despite its frequency, however, IPH presents differently from patient to patient, and the underlying factors that separate good and poor outcomes are not completely understood. In this study, we identify several IPH volume thresholds that, if exceeded, precipitate a significantly increased risk of mortality or neurologic deterioration.
Identifying certain IPH volumes is clinically useful in the prognosis of the critically ill neurosurgical patient. In transfer patients, this is particularly valuable as patients with hemorrhages above these thresholds warrant a more expedient transfer, as they are significantly more likely to deteriorate and die. Calculation of hemorrhage size, through the standard A*B*C/2 formula, is accessible and easily done by an emergency physician. Although outcomes are dependent on many factors, with a threshold to compare to, both accepting neurosurgeons and transferring physicians alike can identify patients most at risk.
Learning Objectives: By the conclusion of this session, participants should be able to:
1) Quantify the risk of mortality and neurologic deterioration in intraparenchymal hemorrhage (IPH).
2) Predict the likelihood of a poor outcome based on IPH volume and growth.
3) Identify the Youden index as a statistical tool to determine the optimal threshold for a diagnostic test.