of human substance neurokinin 1 (NK1) receptors; metoclopramide,
which has antagonist activity at D2 receptors in the chemoreceptor
trigger zone in the central nervous system; ondansetron, which is an
antagonist to serotonin receptors of the 5-HT3 type; and dexametha-
sone, which is believed to work in the chemoreceptor trigger zone of
the brain stem.
There are a couple of important points worth noting that might affect
your decisions regarding whether or not to use a multi-receptor
approach: Metoclopramide is contraindicated in Parkinson's disease, as
it may worsen a patient's symptoms. In addition, metoclopramide may
cause extrapyramidal side effects that can make patients feel anxious,
especially if those patients are already prone to anxiety.
• Don't forget the non-opioid analgesics — NSAIDs, such as ketoro-
lac, and acetaminophen, which is now available in IV form. Used indi-
vidually or combined, they are great for further reducing pain, while
avoiding nausea-provoking opioids.
5
Follow up. PONV prevention doesn't stop when the patient is
discharged. I'll monitor patients for 24 hours after surgery to see
how they're faring. Although most cases of PONV last 1 to 2 days,
lingering cases of 5 days — even longer — are not unheard of.
Extended cases of PONV can lead to other problems, like dehydration,
pulmonary aspiration and electrolyte imbalance, so I give all of my
patients my cell phone number.
OSM
4 6 • O U T PA T I E N T S U R G E R Y M A G A Z I N E • A P R I L 2 0 1 7
Dr. Ma (edna@drednabrands.com) is an anesthesiologist with 90210 Surgery
Medical Center in Beverly Hills, Calif.
