Case 80 - PACU discharge

Question 1

what is the cause of N/V?

Answer 1

• vomiting center located in medulla
• recieves input from chemoreceptor zone and GI tract
• CTZ stimulated by neurotransmiters like serotonin, dopamine, acetylcholine

Question 2

what are RF for PONV?

Answer 2

three categories: patient factors, surgical factors, anesthetic factors

1) Patient
* female, non-smoker, prior history PONV, motion sickness
2) Surgery
* laparoscopy, strabismus, middle ear surgery, surgical duration > 30 min
3) Anes

• periop opioid use
• volataile agents, N2O
• etomidate, ketamine

Question 3

what are strategies to reduce incidence of PONV?

Answer 3

per 2007 SAMBA guidelines of mgmt of PONV

• use regional anesthesia with minimal opioid use
• use propofol with induction and mainteance
• avoid N2O
• avoid volatile
• minimize periop opioids
• hydration
• prophylactic admin of ondansetron
• multimodal pharmacologic therapy for high-risk pts

Question 4

What are drugs that could be used to tx or prevent PONV?

Answer 4

• consider meds that affect CTZ -> serotonin antagonists, dopamine antagonists, anticholinergics
• other meds: steroids, propofol

5HT3 - ondansetron

Da antag - droperidol

• black box - QT pronlongation –> risk for torsade
• admin requires 2-3 hrs of postop EKG monitoring

Steroid - Decadron

• unknown mechanism in PONV
• caution in diabetics

Anticholinergic - Scopolamine

mixed serotoinin and dopamine antag - metoclopramide

• increase GI emptying, increase lower esophageal sphincter

Question 5

does gastric suctioning at end of case help decrease PONV?

Answer 5

theorectially makes sense, but this has not been shown to be efficacious

Question 6

what is the Aldrete scoring system?

Answer 6

• used to assess readiness for discharge from PACU
• Score > 9 = acceptable

Aldrete Scoring system

• 5 categories, 0-2 points each category, max 10 pts
  1) respiration
• able to take deep breath, shallow breathing, apnea
  2) SaO2
• >92% RA, require o2 supplment for >90%, <90% on supplmental oxygen
  3) consciousness
• fully awake, arousable on calling, no response

4)

• BP 20mmHg w/i baseline, 20-50 mmHg w/i baseline, > 50 mm Hg from baseline
  5) Acitiivty
• move all extrem, move two extrem, move no extrem