Apfel et al developed a risk score ("Score 2") for predicting the risk postoperative vomiting in an adult based on the type of surgery. This can help identify a patient who may benefit from more aggressive management to prevent vomiting. The authors are from the University of Wuerzburg in Germany.
Parameters:
(1) gender
(2) age (in decades)
(3) history of motion sickness or postoperative nausea and vomiting (PONV)
(4) surgery type
|
Parameter |
Finding |
Beta Coefficient |
|
gender |
male |
0 |
|
|
female |
0.547 |
|
age |
age in decades (see below) |
(-0.124) * (age in decades) |
|
history of MS or PONV |
no |
0 |
|
|
yes |
1.464 |
|
type of surgery |
bone surgery |
-0.086 |
|
|
breast surgery |
0.807 |
|
|
cataract surgery |
-0.366 |
|
|
laparoscopy |
-1.015 |
|
|
laparotomy |
-0.114 |
|
|
strabismus surgery |
-0.243 |
|
|
thyroid surgery |
0.997 |
|
|
vascular surgery |
0.485 |
|
|
other |
0 |
where:
• A positive beta coefficient reflects increased risk for PONV, while a negative coefficient indicates a reduced risk.
• There are two ways that age might be handled: (1) (age)/10; (2) INT(age/10).
• I assume that only 1 kind of surgery can be done at a time.
• The beta coefficient for an operation not listed is unclear. I will use a 0 but there probably are other options.
X =
= SUM(beta coefficients for all 4 parameters) - 1.023
probability of postoperative vomiting =
= 1 / (1 + EXP((-1) * X))
Performance:
• As indicated on page 508, this risk score did not predict postoperative vomiting better than the simple model described 31.11.01 (which was published immediately prior in the same journal).
Specialty: Anesthesiology, Gastroenterology, Pharmacology, clinical
ICD-10: ,
