Parameters:
(1) age
(2) gender
(3) ASA physical status score
(4) comorbid medical conditions (preoperative medical conditions)
(5) smoking habit
(6) timeliness of operation
(7) duration of anesthesia
(8) use of opioids
(9) type of surgery
|
Parameter
|
Finding
|
Points
|
|
age of the patient in years
|
< 50 years of age
|
1
|
|
|
>= 50
|
0
|
|
gender
|
male
|
0
|
|
|
female
|
1
|
|
ASA physical status
|
1 or 2
|
1
|
|
|
3 or 4
|
0
|
|
comorbid medical conditions
|
none
|
1
|
|
|
1 or more
|
0
|
|
smoking habit
|
nonsmoker
|
1
|
|
|
smoker
|
0
|
|
timeliness
|
elective
|
1
|
|
|
nonelective (urgent, emergency)
|
0
|
|
duration of surgery
|
< 60 minutes
|
0
|
|
|
>= 60 minutes
|
1
|
|
use of opioids
|
intraoperative (and postoperative)
|
1
|
|
|
none
|
0
|
|
type of surgery
|
ophthalmologic or otologic
|
1
|
|
|
other (except gynecologic in female)
|
0
|
where:
• Protective factors are number of comorbid conditions. This includes being emaciated.
• ASA classes 3 and 4 deal with more urgent surgeries, so this may overlap with timeliness of the procedure.
• The authors list intraoperative opioids as a risk factor. Other studies emphasize postoperative opioid use.
Additional risk factors if female:
(1) gynecologic surgery
(2) menstruating (referenced but not listed in analysis; this is a known risk factor for motion sickness)
total number of risk factors =
= SUM(number of risk factors present)
Interpretation:
• minimum number of risk factors: 0
• maximum number of risk factors for male: 8
• maximum number of risk factors for female: 10 (or possibly 11)
