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Overview :
The Hypothermia
Outcome Score (HOS) can be used to estimate the risk of death for hypothermic
patients within 24 hours of presentation to the Emergency Department. A
logistic regression equation based on the same parameters can give a more
precise probability of death.
Patient Database:
• hypothermic
patients presenting at 13 facilities
• core body
temperatures <= 35°C (15.6 to 35°C)
• 95% of
patients were > 20 years of age
• 296 men and
132 women
Parameters:
(1) BUN in mg/dL
on admission
(2) systolic
blood pressure in mm Hg
(3) history of
prehospital CPR
(4) need for
tracheal intubation
(5) need for
nasogastric tube placement
No separate
measure for neurologic dysfunction is used. Patients with severe neurologic
dysfunction would most likely be identified by the need for intubation and/or
nasogastric tube placement.
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Variable
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Finding
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Points
for HOS
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Logistic
Equation
|
|
BUN on
admission
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<= 100
mg/dL
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0
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BUN value
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|
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> 100 mg/dL
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12
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BUN value
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systolic blood
pressure (SBP)
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> 70 mm Hg
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0
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SBP value
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|
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measurable and
<= 70 mm Hg
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2
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SBP value
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|
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absent
(unmeasurable)
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11
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0
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prehospital
CPR?
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yes
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11
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1
|
|
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no
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0
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0
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tracheal
intubation?
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yes
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3
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1
|
|
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no
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0
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0
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nasogastric
tube placement?
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yes
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3
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1
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no
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0
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0
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Prediction from Hypothermia Outcome Score
hypothermia
outcome score =
= SUM(points for
5 variables)
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Hypothermia
Outcome Score
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Probability
of Death within 24 hours
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> 18
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71%
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> 12 to 18
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60%
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> 6 to 12
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42%
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> 3 to 6
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33%
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> 0 to 3
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20%
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0
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3%
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(from Table 5,
page 230)
Prediction from Logistic Regression
Equation
Y variable =
= (-2.604) -
(0.007 * (systolic blood pressure in mm Hg) + (1.759 * (prehospital CPR)) +
(1.235 * (tracheal intubation)) + (0.502 * (nasogastric tube)) + (0.0235 * (BUN
in mg/dL))
probability of
death within first 24 hours of presentation to hospital =
= 1 / (1 +
EXP(-Y))
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