1. Neurosurgical Emergency Transfers: an Analysis of Mortality
Ahmed E Hussein MD, Darian R Esfahani MD, Ioana Darie MD, Sepideh Amin-Hanjani MD,
Konstantin V Slavin MD , Xinjian Du MD MPH, Fady T Charbel MD, Ali Alaraj MD
Department of Neurosurgery, University of Illinois at Chicago, Chicago, IL

2. Disclosures : DISCLOSURE OF FUNDING : None
SOURCE OF FINANCIAL SUPPORT/INDUSTRY AFFILIATIONS
Ahmed E. Hussein - None
Darian R. Esfahani - None
Ioana Darie - None
Sepideh Amin-Hanjani - Material Research Support GE Healthcare and VasSol, Inc
Konstantin V. Slavin - Consultant Medtronic, St Jude Medical, Boston Scientific, Nevro,
Nuvectra, Integra, Stimwave, Stockholder Vycor Medical and Stimrelieve
Xinjian Du - None
Fady T. Charbel - Owner and Founder VasSol, Inc; Consultant for Transonic, Inc
Ali Alaraj - Consultant for Cordis-Codman

3. Introduction
Interhospital transfer is a common source of admission for tertiary centers.
Neurosurgical patients are a complex population where transfer is frequent, in part due to limited coverage at many community hospitals.
Patients with severe disease, such as intracerebral or subarachnoid hemorrhage, are often recommended for transfer.
Despite advances in emergency room and ambulance care, mortality for transfer patients remains common, as high as 14-23% in previous studies.
Our objective is to analyze and quantify risk factors predicting neurological deterioration and death in neurosurgery transfers.

4. Methods
A consecutive review of all transfers with cranial pathology to a tertiary academic neurosurgery service was performed over a two year period.
Detailed data was obtained, including demographics, medical comorbidities, use of anticoagulants, and duration between presentation at the outside hospital and arrival at our institution.
Diagnoses included intracerebral hemorrhage (ICH), subarachnoid hemorrhage (SAH), subdural hematoma (SDH), traumatic contusion, intraventricular hemorrhage (IVH), ischemic stroke, tumor, incidental vascular finding, hydrocephalus, seizure, and infection.
Patient GCS at arrival to the outside hospital and arrival at the tertiary center was measured and compared; patients were considered to have “deteriorated” if their GCS decreased during transfer or if new weakness or loss of brainstem reflexes were observed.
Mortality was also defined as cardiovascular or neurologic death on arrival or at any point during admission.

5. Results Over two years, 1429 transfers were reviewed.
154 patients (10.8%) experienced deterioration in their neurological status and 99 mortalities (6.9%) occurred during hospitalization.
Intraparenchymal hemorrhage was the most common transferring diagnosis (23.1%) and was significantly associated with death (P<0.001, odds ratio (OR) 2.66), followed by subarachnoid hemorrhage and then ischemic stroke.

6. Results
Significant predictors of neurologic deterioration included advanced age (P=0.05), hydrocephalus (P=0.02, OR 1.71), and use of clopidogrel (P=0.002, OR 3.75), warfarin (P=0.001, OR 2.79) or other systemic anticoagulants (P<0.001, OR 7.71).
Transfers (n=1429)
Deterioration (n=154, 10.8%)
Stable (n=1275, 89.2%)
Odds Ratio
P value
Mean Age
59.97
57.03
1.01 ( )
.05
Sex; Female (%)
72 (46.8%)
579 (45.4%)
.75
Mortality (%)
25 (16.2%)
74 (5.8%)
3.15 ( )
<.001
Hydrocephalus
28 (18.2%)
147 (11.5%)
1.71 ( )
.02
Anticoagulants
Any
Aspirin
Clopidogrel
Warfarin
Other Systemic
62 (40.3%)
26 (16.99%)
7 (4.55%)
14 (9.09%)
8 (5.19%)
349 (27.4%)
233 (18.27%)
16 (1.25%)
44 (3.45%)
9 (0.71%)
1.81 ( )
3.75 ( )
2.79 ( )
7.71 ( )
.70
.002
.001

7. Results
Patients with any hemorrhage were more likely to deteriorate (P<0.001, OR 2.07), with intraparenchymal hemorrhages most likely to worsen (P<0.001, OR 3.25).
Patients who ultimately deteriorated presented with significantly worse initial GCS scores (P<0.001, Mann-Whitney U). A mean GCS drop of 4.5 points was observed. Transfer time did not predict neurologic deterioration.

8. Results
Significant predictors of mortality included advanced age (P=0.002), neurologic deterioration (P<0.001, OR 3.15), renal failure (P=0.003, OR 2.92) and use of clopidogrel (P<0.001, OR 6.24), and warfarin (P=0.02, OR 3.41)).
Transfers (n=1429)
Death (n=99, 6.9%)
Survival
(n=1330, 93.1%)
Odds Ratio
P value
Mean Age
62.49
56.97
1.02 ( )
.002
Sex; Female (%)
53 (53.5%)
598 (45.0%)
.10
Deterioration
25 (25.3%)
129 (9.7%)
3.15 ( )
<.001
Medical Comorbidity
Any
Hypertension
Diabetes
Hyperlipidemia
Renal Failure
54 (54.5%)
47 (47.5%)
17 (17.2%)
9 (9.1%)
739 (55.6%)
674 (50.7%)
244 (18.3%)
253 (19.0%)
44 (3.3%)
.43 ( )
2.92 ( )
.84
.54
.77
.01
.003
Anticoagulants
Aspirin
Clopidogrel
Warfarin
Other Systemic
32 (32.3%)
10 (10.1%)
7 (7.07%)
11 (11.1%)
0 (0%)
379 (28.5%)
249 (18.7%)
16 (1.2%)
47 (3.5%)
17 (1.3%)
.49 ( )
6.24 ( )
3.41 ( )
.42
<

9. Results
Transfer times were significantly faster for patients with any hemorrhage (p<0.001) , intracerebral hemorrhage (p=0.013), or subarachnoid hemorrhage (p=0.02).
Less than half of transfers (44.4%) were initiated in the evening (6p-6a), and more than half (59.6%) arrived after hours. 3pm was the most frequent time transfers were initiated and 7pm the most common time of arrival. Transfers initiated overnight exhibited a slightly higher likelihood of death (7.2%) versus transfers during the day (6.7%), but this did not achieve significance (P=0.674).

10. Discussion and Summary Points
Interhospital transfers to tertiary care centers are increasing. For the complex neurosurgical patient, risk of mortality is high and expeditious transfer is important to improve survival.
Transfer patients with hemorrhages fare more poorly than average; patients with intraparenchymal hemorrhages have the worst outcomes.
Hydrocephalus and use of warfarin, clopidogrel, or other systemic anticoagulants are predictive of deterioration and mortality. Systemic anticoagulants, like low molecular weight heparin and rivaroxiban were among the highest risk factors in the cohort.
Identification of these harbingers of neurologic deterioration provides an opportunity to improve patient outcomes on transfer acceptance. Recognition of high-risk anticoagulants and use of reversal agents, such as prothrombin complex concentrate (PCC) may prove valuable in preventing deterioration.
Placement of an external ventricular drain by the local neurosurgeon, if available at the transferring facility, also has potential to prevent deterioration, but must be weighed against the delay for the surgeon to arrive.
Education of transferring physicians on the significance of hydrocephalus management and prompt anticoagulation reversal may help make the sickest of transfer patients salvageable.