Sinclair et al developed an equation that can be used to predict the probability of postoperative nausea and vomiting (PONV) for a patient having outpatient surgery. This can help the anesthesiologist identify patients who may need antiemetic therapy. The authors are from the University of Pittsburgh.
Parameters:
(1) age in years
(2) sex
(3) smoking status
(4) history of PONV
(5) duration of surgery
(6) anesthesia type
(7) type of surgery
|
Parameter |
Finding |
Points |
|---|---|---|
|
age |
age in years |
(age) / 10 |
|
sex |
female |
0 |
|
|
male |
1 |
|
smoking status |
nonsmoker |
0 |
|
|
smoker |
1 |
|
history of previous PONV |
no |
0 |
|
|
yes |
1 |
|
duration of surgery |
duration in minutes |
(duration) / 30 |
|
anesthesia type |
other than general |
0 |
|
|
general |
1 |
|
ENT surgery done |
no |
0 |
|
|
yes |
1 |
|
ophthalmologic surgery done |
no |
0 |
|
|
yes |
1 |
|
plastic surgery done |
no |
0 |
|
|
yes |
1 |
|
gynecologic surgery other than D & C done |
no |
0 |
|
|
yes |
1 |
|
orthopedic surgery to knee done |
no |
0 |
|
|
yes |
1 |
|
orthopedic surgery to shoulder done |
no |
0 |
|
|
yes |
1 |
|
orthopedic surgery to site other than knee or shoulder |
no |
0 |
|
|
yes |
1 |
where:
• Sometimes smoking status infers cigarette smoking only.
• The duration of surgery is based on 30 minute increments. I did not round this in the implementation.
• It appears that the system takes into account the possibility of more than 1 procedure being done while a person is under anesthesia. I am not sure if there should be an adjustment if both knees or shoulders were done at the same time.
probability of PONV =
= 1 / (1 + EXP((-1) * X))
X =
= (-5.97) – (0.14 * (points for age)) – (1.03 * (points for sex)) – (0.42 * (points for smoking status)) + (1.14 * (points for PONV history)) + (0.46 * (points for duration of surgery)) + (2.36 * (points for general anesthesia)) + (1.48 * (points for ENT surgery)) + (1.77 * (points for ophthalmologic surgery)) + (1.90 * (points for plastic surgery)) + (1.20 * (points for gynecologic surgery)) + (1.04 * (points for orthopedic surgery to knee)) + (1.78 * (points for orthopedic surgery to shoulder)) + (0.94 * (points for orthopedic surgery other than knee or shoulder))
Purpose: To predict a patient's risk for developing postoperative nausea and vomiting (PONV) after outpatient surgery.
Specialty: Anesthesiology, Gastroenterology, Pharmacology, clinical
Objective: severity, prognosis, stage, complications, response to therapy, adverse effects
ICD-10: R11, Z48,
