Lecture 8 Postoperative Nausea and Vomiting

Question 1

Why does PONV matter?

Answer 1

• Patients suffer
• It can delay discharge or cause an unplanned admission
• It causes postoperative dehydration
• Risk for aspiration
• Can cause esophageal tears or compromise the surgery’s results (rare)

Question 2

How common is PONV?

Answer 2

Occurs in 1/3 to 1/2 of all surgical patients without preventative treatment

Question 3

What are the risk factors for PONV?

Answer 3

These factors are additive:

• People who get car sick
• Prev h/o PONV
• Obesity
• NO2 use (Avoid nitrous if PONV is a documented problem)
• Opioid analgesic use
• Use of Acetylcholinesterase Inhibitor (Neostigmine, Edrophonium)
• Post-operative pain
• Females
• Non-smokers
• Gastric distention
• Opthalmic, ear, or laparoscopic surgery

Question 4

Who is less likely to suffer from PONV?

Answer 4

• Regional anesthesia patients (w/o GA)
• General anesthesia (GA) patients who don’t get inhalational agents
• Patients given propofol (slightly decreased risk)

Question 5

How do you prevent PONV?

Answer 5

• Identify those at risk
• Pharmacologic intervention
• Use local/regional anesthesia when able
• Consider avoiding NO2 if pt is high risk
• Consider using propofol (NOT IN SHOCK PTS)
• If possible to avoid muscle relaxant, a reversal agent is avoided (pt’s safety comes first though!)

Question 6

What do we call drugs that prevent PONV?

Answer 6

Anti-emetics

Question 7

What type of anti-emetics are used?

Answer 7

• Serotonin (5HT3) receptor agonists
• Steroids
• Gastroprokinetics
• Buterophenone central dopamine blockers
• Antihistamines
• Anticholinergics
• Vasopressors
• Phenothiazines

Question 8

What Serotonin (5HT3) receptor agonists are used to prevent PONV?

Answer 8

ondansetron, granisatron

Question 9

What steroids are used to prevent PONV?

Answer 9

dexamethasone

Question 10

What gastroprokinetics are used to prevent PONV?

Answer 10

metoclopramide

Question 11

What buterophenone central dopamine blockers are used to prevent PONV?

Answer 11

droperidol (not a first line treatment)

Question 12

What anticholinergics are used to prevent PONV?

Answer 12

scopolamine (not a first line agent)

Question 13

What antihistamine is used to prevent PONV?

Answer 13

diphenylhydramine (not a first line agent)

Question 14

What vasopressor is used to prevent PONV?

Answer 14

ephedrine (not a first line agent)

Question 15

What phenothiazine is used to prevent PONV?promethazine (not a first line agent)

Answer 15

promethazine (not a first line agent)