This document discusses definitions of hypotension after traumatic brain injury (TBI) and management strategies. It summarizes several studies that identify optimal systolic blood pressure thresholds for defining hypotension in TBI patients of different ages, and find that aggressive fluid resuscitation is recommended to treat hypotension and improve outcomes for severe TBI patients. Maintaining a systolic blood pressure above 110 mmHg is important to prevent secondary brain injuries and reduced mortality.

1. Dr. Joseph A. Di Como

2.  Severe traumatic brain injury (TBI) is common in
patients with major trauma and typically involves
young adult men.
 Despite current management strategies, patients
with severe TBI have a high mortality rate (31%-
49%) and a large number of survivors have
persistent severe neurological disability.
 There are 80 000 to 90 000 were cases of survivors
with long-term disability after head injury
annually in the United States.
 The mean lifetime cost of each TBI survivor with
severe disability from TBI exceeds US $2 million.

3.  After initial head trauma, secondary brain injury
may occur due to hypoxia, hypotension, or
elevated intracranial pressure (ICP) and is
associated with a worse neurological outcome.
 Patients with hypotension after severe TBI have
twice the mortality rate of normotensive patients.
 Therefore, aggressive resuscitation with
intravenous fluids is recommended in current
guidelines for the management of patients with
severe TBI.
 Treatment of increased ICP in patients with TBI is
also likely to improve outcomes.

4. • Traumatic Brain Injury (TBI)
– Accounts for 51.6% of mortality amongst trauma
patients
Dutton. J Trauma. 2010.
 Systemic hypotension is a well documented
predictor of increased mortality following
traumatic brain injury (TBI).
 Hypotension is traditionally defined as systolic
blood pressure (SBP) < 90 mm Hg.

5. • Repeat head CT scans
– Beneficial in setting of neurological deterioration
Brown. J Trauma. 2007.
Kaups. J Trauma. 2004.
– Debated for patients with normal or stable clinical
exams
Wang. J Trauma. 2006.
Sifri. J Trauma. 2006.

6.  Hyperosmolar Therapy
 Mannitol to maintain ICPs <20mmHg
 Early okay
 Late not much data Shackford, JoT, 1998
 Hypertonic Saline-no current evidence to support
the use/disuse
 Does decrease ICPs
 No change in outcomes
Himmelseher, Cur Op An, 2007

7.  Antiseizure Prophylaxis
 Decrease incidence of EARLY seizures (<7d)
 Dilantin, maybe Valproate
 NO prevention of LATE seizures (PTS)
 Steroids
 No use
 Hyperventilation
 No use

8.  Sedation/Induced Coma - EEG burst
suppression
 Prophylactically not recommended
 Refractory elevated ICP after med mgmt: YES
 Criteria:
 Refractory intracranial hypertension
 Na 145-155 (but < 160), Osm 320-330
 Repeat Head CT without surgically treatable lesion
 Nsgy eval recommends non surgical treatment

9. Surgery
 Indications: elevated ICP refractory to medical
management
 Aims to decrease ICP / increase perfusion, by
opening a closed system, allowing room for swelling
/expansion

10.  Berry C, Ley EJ, Bukur M, et al. Redefining hypotension in
traumatic brain injury. Injury. 2012;43(11):1833-7.
 A retrospective database review of all adults (≥15 years)
with isolated moderate to severe TBI (head abbreviated
injury score (AIS) ≥ 3, all other AIS ≤ 3), admitted from five
Level I and eight Level II trauma centres (Los Angeles
County), between 1998 and 2005. Several fit statistic
analyses were performed for each admission SBP from 60 to
180 mm Hg to identify the model that most accurately
defined hypotension for three age groups: 15–49 years, 50–
69 years, and ≥70 years. The main outcome variable was
mortality, and the optimal definition of hypotension for
each group was determined from the best fit model.
Adjusted odds ratios (AOR) were then calculated to
determine increased odds in mortality for the defined
optimal SBP within each age group

11.  Results- A total of 15,733 patients were analysed. The
optimal threshold of hypotension according to the best
fit model was SBP of 110 mm Hg for patients 15–49
years (AOR 1.98, CI 1.65–2.39, p < 0.0001), 100 mm Hg
for patients 50–69 years (AOR 2.20, CI 1.46–3.31,
p = 0.0002), and 110 mm Hg for patients ≥70 years
(AOR 1.92, CI 1.35–2.74, p = 0.0003).

12.  Fuller G, Hasler RM, Mealing N, et al. The association
between admission systolic blood pressure and mortality in
significant traumatic brain injury: a multi-centre cohort
study. Injury. 2014;45(3):612-7.
 Methods- Conducted a multicentre cohort study using
data from the largest European trauma registry.
Consecutive adult patients with AIS head scores >2
admitted directly to specialist neuroscience centres
between 2005 and July 2012 were studied. Multilevel
logistic regression models were developed to examine
the association between admission SBP and 30 day
inpatient mortality. Models were adjusted for
confounders including age, severity of injury, and to
account for differential quality of hospital care.

13.  Results - 5057 patients were included in complete
case analyses. Admission SBP demonstrated a
smooth u-shaped association with outcome in a
bivariate analysis, with increasing mortality at
both lower and higher values, and no evidence of
any threshold effect. Adjusting for confounding
slightly attenuated the association between
mortality and SBP at levels <120 mmHg, and
abolished the relationship for higher SBP values.
Case-mix adjusted odds of death were 1.5 times
greater at <120 mmHg, doubled at <100 mmHg,
tripled at <90 mmHg, and six times greater at
SBP < 70 mmHg, p < 0.01.

14.  Krishnamoorthy V, Vavilala MS, Mills B, Rowhani-rahbar
A. Demographic and clinical risk factors associated with
hospital mortality after isolated severe traumatic brain
injury: a cohort study. J Intensive Care. 2015;3:46.
 Retrospective cohort study using data from the
National Trauma Databank from 2008-2012 to
study all patients admitted with a diagnosis of
severe TBI, excluding children, patients with non-
isolated TBI, transfers, and hospitalization <48 h.
Used multivariable Poisson regression to analyze
the association between demographic, clinical, and
facility-level characteristics and in-hospital
mortality.

15.  Results - A total of 41,590 patients were
included in our analysis. The cumulative
incidence of in-hospital mortality was 10.2 %.
In multivariable analysis, older age (RR 3.92,
95 % CI 3.54-4.34), male gender (RR 1.17, 95 %
CI 1.09-1.25), admission hypotension (RR 1.83,
95 % CI 1.61-2.09), the need for mechanical
ventilation (RR 4.18, 95 % CI 3.64-4.80),
higher injury severity score (RR 1.86, 95 % CI
1.41-2.45), and poor initial neurologic grade
(RR 3.06, 95 % CI 2.74-3.43) were associated
with a higher risk for mortality.

16.  Brenner M, Stein DM, Hu PF, Aarabi B, Sheth K, Scalea TM.
Traditional systolic blood pressure targets underestimate
hypotension-induced secondary brain injury. J Trauma Acute
Care Surg. 2012;72(5):1135-9.

17.  Sixty patients with head Abbreviated Injury Scale score ≥ 3, age >14 years,
"isolated" TBI, and need for intracranial pressure monitoring were
prospectively enrolled at a single, large urban tertiary care facility.
 Outcome was measured by mortality and extended Glasgow Outcome
Scale (GOSE) at 12 months. Continuous, automated, digital data were
collected every 6 seconds for 72 hours after admission, and 5-minute
means of systolic blood pressure (SBP) were recorded. We calculated SBP
as pressure × time dose (PTD) to describe the cumulative amplitude and
duration of episodes above and below clinical thresholds.
 The extent and duration of the insults were calculated as percent time
(%time), PTD, and PTD per day (PTD/D) of defined thresholds (SBP: <90
mm Hg, <100 mm Hg, <110 mm Hg, and <120 mm Hg; mean arterial
pressure: <60 mm Hg and <70 mm Hg; heart rate: >100 bpm and >120
bpm; and SpO(2): <88% and <92%) for the first 12 hours, 24 hours, and 48
hours of intensive care unit admission.
 Analyzed their ability to predict mortality and GOSE by receiver operator
characteristics.

18.  Mean age was 33.9 (range, 16-83) years, mean admission Glasgow
Coma Scale score 6.4 ± 3, and mean head Abbreviated Injury Scale
score 4.2 ± 0.72. The 30-day mortality rate was 13.3%.
 Of the 45 patients in whom GOSE at 12 months was available, 28
(62%) had good neurologic outcomes (GOSE score >4). Traditional
markers of poor outcome (admission SBP, admission Glasgow
Coma Scale, and Marshall score) were not different between
groups with good or poor outcome.
 PTD, PTD/D, and %time SBP <110 mm Hg and SBP <120 mm
Hg predicted mortality at 12 hours, 24 hours, and 48 hours (p <
0.04).
 Percent time SBP <110 mm Hg in the first 24 hours was
predictive of 12-month GOSE (p = 0.02).
 PTD/D SBP <120 mm Hg in the first 24 hours and PTD and
PTD/D in the first 48 hours were also predictive of 12-month
GOSE (p < 0.05).

20.  Patients with isolated moderate to severe TBI
should be considered hypotensive for
SBP < 110 mm Hg.
 Aggressive resuscitation with intravenous
fluids is recommended in current guidelines
for the management of patients with severe TBI
and likely to improve outcomes.