Patient selection: surgical patient undergoing general anesthesia, age >= 18 years of age
Hypothermia was defined as a core body temperature < 36.0°C
Parameters:
(1) magnitude of the surgery
(2) volume of intravenous fluid in mL
(3) duration of surgery in hours
(4) mode of patient warming
(5) body mass index (BMI)
(6) ambient temperature in operating room in °C
(7) baseline core temperature in °C
|
Parameter
|
Finding
|
Beta-Ceofficient
|
|
magnitude of surgery
|
minor or intermediate
|
0
|
|
|
major or major plus
|
0.201
|
|
volume of IV fluids
|
<= 1,000 mL
|
-0.1847
|
|
|
> 1,000 mL
|
0
|
|
duration of surgery
|
<= 2 hours
|
0
|
|
|
> 2 hours
|
0.5299
|
|
patient warming
|
passive
|
0
|
|
|
active
|
-0.2269
|
|
body mass index
|
< 25 kg per sq m
|
0
|
|
|
>= 25 kg per sq m
|
-0.306
|
|
ambient temperature
|
|
-0.1912 * (OR temp)
|
|
baseline core temperature
|
|
-3.1057 * (core temp)
|
value of X =
= SUM(points for the parameters) + 119
probability of intraoperative hypothermia =
= 1 / (1 + EXP((-1) * X))
Comments on Figure 2:
(1) The value of X to achieve a predictor score of 67% is 0.708.
(2) The value 0.491 is EXP((-1) * 0.708).
Performance:
• The area under the ROC curve is 0.76.
