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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.
|
Variable |
Finding |
Points for
HOS |
Logistic
Equation |
|
BUN on
admission |
<= 100
mg/dL |
0 |
BUN
value |
|
|
> 100
mg/dL |
12 |
BUN
value |
|
systolic
blood pressure (SBP) |
> 70 mm
Hg |
0 |
SBP
value |
|
|
measurable
and <= 70 mm Hg |
2 |
SBP
value |
|
|
absent
(unmeasurable) |
11 |
0 |
|
prehospital
CPR? |
yes |
11 |
1 |
|
|
no |
0 |
0 |
|
tracheal
intubation? |
yes |
3 |
1 |
|
|
no |
0 |
0 |
|
nasogastric tube
placement? |
yes |
3 |
1 |
|
|
no |
0 |
0 |
Prediction from Hypothermia Outcome
Score
hypothermia
outcome score =
= SUM(points for
5 variables)
|
Hypothermia Outcome
Score |
Probability of Death within 24
hours |
|
> 18 |
71% |
|
> 12 to
18 |
60% |
|
> 6 to
12 |
42% |
|
> 3 to
6 |
33% |
|
> 0 to
3 |
20% |
|
0 |
3% |
(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))
| References: | |
Danzl DF, Hedges JR, et al. Hypothermia
outcome score: Development and implications. Crit Care Med. 1989; 17:
227-231.
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