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PRU assays, 7% of patients taking any aspirin, and 27% of patients
taking clopidogrel were not therapeutic, respectively. After plate-
let transfusion, 47% of patients on any aspirin and 49% of pa-
tients on any clopidogrel failed to be reversed. The ARU increased
by 71
–
76 per unit of platelets, and the PRU increased by 48
–
46 per
unit of platelets. This study provides a means for detecting pa-
tients reported to be on antiplatelet agents whom have function-
ing platelets and receive unnecessary transfusions following a TBI.
In addition, a single platelet transfusion may not be sufficient to
reverse platelet inhibition in patients who are therapeutic on their
antiplatelet therapy. The aspirin and P2Y12 response unit assays
have utility in the TBI population and require prospective evalua-
tion as tools for determining whether to transfuse platelets in TBI
patients.
Keywords: platelet, aspirin, platelet reactivity, platelet transfusion,
clopidogrel
C3-06
TRANSFUSION REVERSAL OF PRE-MORBID ORAL AS-
PIRIN USE IS NOT PROTECTIVE AGAINST RADIO-
GRAPHIC PROGRESSION OF INTRACRANIAL
PATHOLOGY
Joshua Bauer
1
, Phillip Choi
1
, Benjamin Zusman
1
, David
Panczykowski
2
, Phillip Parry
2
, Ava Puccio
1
, David Okonkwo
1,2
1
University of Pittsburgh School of Medicine, Neurosurgery, Pitts-
burgh, USA
2
UPMC, Neurosurgery, Pittsburgh, USA
There remains controversy for reversal of antiplatelet agents in
traumatic brain injury (TBI) patients. The purpose of this study is to
longitudinally evaluate the effect transfusion reversal of antiplatelet
agents has on radiographic progression of intracranial pathology. A
prospective comparative analysis of TBI patients (
>
65 years) with
evidence of intracranial pathology on computed tomography (CT)
scan was conducted at our institution from June 2013-Janurary 2015.
We assessed baseline demographics, coagulation parameters, plate-
let dysfunction using a platelet function assay for aspirin (Ver-
ifyNow), transfusion management, and clinical course. The primary
endpoint was radiographic progression of intracranial injury defined
as expansion of admission pathology using the components ABC/2
method for measuring intracranial lesion. Descriptive data were
stratified by having a therapeutic platelet function assay for aspirin
on admission, and analyzed via Chi-square test. A total of 96 patients
suffering TBI with radiographic intracranial injury and aspirin use
were assessed; 86% (83) therapeutic vs 14% (13) sub-therapeutic on
aspirin. A logistic regression analysis was performed to compare
groups and identify predictors of radiographic progression. Covari-
ates included: age, admission Glasgow coma score (GCS), and
baseline Rotterdam scores for CT scan severity. Subgroup multi-
variate analysis of only those with a therapeutic aspirin response did
not demonstrate a significantly different rate of progression in either
those being transfused, or those achieving non-therapeutic status
post-transfusion (OR
=
4.19 (1.37–12.8), p
=
0.01). Transfusion re-
versal of aspirin use was not protective against radiographic pro-
gression of intracranial hemorrhage. This data refutes the reflexive
transfusion of patients on antiplatelet therapy as a means for thera-
peutic intervention of aspirin use. Given the latter, the evidence fully
supports the need for a randomized clinical trial aimed at identifying
an algorithm for platelet transfusion in a subgroup of patients within
the TBI population.
Keywords: AntiPlatelets, Transfusions, Hemorrhage Progression
C3-07
INSIGHTS FROM HIGH FREQUENCY INTRACRANIAL
PRESSURE DATA: A TREATMENT THRESHOLD BELOW
20MMHG MAY BE MORE APPROPRIATE
Gregory Hawryluk
1,2
, Lara Zimmerman
3
, Rajiv Saigal
2
, Adam
Ferguson
2
, Ding Quan
4
, Geoffrey Manley
2
1
University of Utah, Neurosurgery, Salt Lake City, USA
2
University of California, San Francisco, Neurosurgery, San Fran-
cisco, USA
3
University of California, Los Angeles, Neurosurgery, Los Angeles,
USA
4
University of California, San Francisco, Physiological Nursing, San
Francisco, USA
Introduction:
Intracranial pressure (ICP) elevation is a compartment
syndrome which impairs the flow of blood to the brain. The precise
intracranial threshold at which brain injury begins to occur remains
uncertain.
Methods:
A computer system automatically collected and stored q1
minute physiological data from ICU patients over a 6 y period. Data
for 516 patients who underwent ICP monitoring was collected, 372 of
whom had a traumatic brain injury; outcome data (GOS) was avail-
able for all but 19. Mean ICP was calculated for epochs up to 30d
from the start of intensive care. The proportion of ICP values above
thresholds from 1 mmHg to 80 mmHg in were calculated in 1 mmHg
increments for these same epochs. The relationship between these
measures and outcome was explored. A complementary principal
component analysis (PCA) was used to explore physiologic changes at
various ICP thresholds.
Results:
A total of 4,090,964 q1 minute ICP measurements were
recorded for the included patients (7.78 patient years of recordings).
8.9% and 3.7% were above 20 and 25 mmHg respectively. Mean ICP
values correlated with outcome for 14d after admission. ICP values
below 20 mmHg were associated with outcome and time spent above
ICPs from 17 to 19 seemed most strongly associated with outcome.
The PCA suggested physiologic changes above intracranial pressures
of 19 mmHg and 24 mmHg.
Conclusions:
This study provides strong evidence supporting a cor-
relation between ICP values and outcome but does not provide evidence
of a causal relationship. It suggests that ICP values below 20mmHg may
be harmful and that ICP might best be kept lower than 19mmHg.
Keywords: treatment threshold, high frequency, physiology, neu-
romonitoring
C3-08
PATIENTS WITH SPINAL CORD INJURIES FAVOR AD-
MINISTRATION OF METHYLPREDNISOLONE BUT HAVE
LITTLE INPUT INTO ITS ADMINISTRATION
Christian Bowers
1
, Jeffrey Rosenbluth
2
,
Gregory Hawryluk
1
1
University of Utah, Neurosurgery, Salt Lake City, USA
2
University of Utah, Physical Medicine and Rehabilitation, Salt Lake
City, USA
Object:
The use of methylprednisolone sodium succinate (MPSS) for
acute spinal cord injury (SCI) is associated with small functional
benefits and elevated risk of adverse events. We sought to learn the
opinions and preferences of SCI patients regarding MPSS as well as
their involvement in the decision to administer MPSS.
Methods:
27 SCI experts adjudicated a document summarizing
the literature regarding MPSS use in acute SCI. They rated it neutral,
A-82