The Latest Ways to Tackle PONV

‘The Big Little Problem’ of post-op nausea and vomiting is particularly relevant for patients and providers in ambulatory settings.

Most patients know to expect some pain following surgery, as their own common sense tells them that an operation will hurt. However, they generally do not go into surgery expecting nausea and vomiting to be one of their subsequent experiences. In fact, the unanticipated nature of postoperative nausea and vomiting (PONV) can be a significant drag on how many of them rate their overall patient experience.

Indeed, most patients complain more bitterly about nausea and vomiting than they do about pain, which can negatively impact their perception of their surgical outcome and your business as a surgical facility.

If PONV is a recurring issue at your center, here’s a refresher on how to prevent and treat it.

‘Big deal’ for patients

In his presentation at last year’s the American Society of Anesthesiologists Annual Meeting in Philadelphia, Tong J. Gan, MD, MBA, MHS, FRCA, FASA, reviewed updated PONV management guidelines and discussed how to prevent the complication in the context of enhanced-recovery protocols. The session was titled “The Big Little Problem: Updates in the Management of Postoperative Nausea and Vomiting.”

“Sometimes we don’t think PONV is a big deal, but patients do, especially if they don’t expect it,” says Dr. Gan, the head of anesthesiology, critical care and pain medicine at The University of Texas MD Anderson Cancer Center in Houston. “PONV is the leading reason for patient dissatisfaction. Preventing it also reduces costs, as it means less time for patients in the recovery room.”

Approximately 30% of the general surgical population and about 80% of high-risk surgical patients experience nausea or vomiting post-procedure. PONV doesn’t just make patients unhappy — it can carry clinical implications that negatively impact outcomes, as vomiting is potentially damaging to surgical wounds. PONV also extends the patient’s average length of stay and their dissatisfaction could dominate their review of the experience, even if the outcome was otherwise stellar.

Yet recent studies suggest that only 35% to 50% of surgical professionals adhere to evidence-based preventive measures to combat PONV. The entire surgical and nursing team and staff should share the same understanding of how to combat this problem. “Consistency makes a big difference in positive outcomes,” notes Dr. Gan.

Risk factors

One of the most important things you can do to prevent PONV is to identify those most at risk for it. Evidence supports using the Apfel Simplified Risk Score (SRS) in predicting these at-risk patients. The SRS assessment tool measures risk factors such as gender, smoking status, history of motion sickness and/or prior PONV episodes and whether a patient is using opioids postoperatively.

It’s also important to consider medical history, the type of anesthesia being used for surgery and the kind of surgery being performed, notes Dr. Gan.

Women are three times more likely to experience PONV than men are, while smokers are less likely. Patients with a history of motion sickness and those who use post-op opioids are at greater risk, as are patients undergoing lengthy surgeries. Laparoscopic, middle ear, bariatric and gynecological surgeries can also heighten PONV risk.

Some experts advocate placing an alert in patients’ electronic medical records if they have three or more risk factors in order to let staff know they are at high risk for experiencing PONV.

What to do

There are two basic methods to prevent PONV: prophylaxis prior to surgery, and rescue or treatment after surgery. Antiemetics are among the most important steps to take, including dopamine antagonists and serotonin 5-HT3 receptor antagonists. It is often helpful to use these preventive drugs in combination, which has been shown to help prevent PONV by an additional 25%. Using one medicine reduces the risk by 30% to 40% percent, while adding a second reduces it by 50% to 60%. For higher-risk patients with three or more risk factors, three or four medicines may be needed. It is not recommended to utilize more than four agents preventatively.

Studies recommend starting by administering dexamethasone, a corticosteroid, after induction of anesthesia and ondansetron, a 5-HT3 receptor antagonist, five to 10 minutes before emergence at the end of the case. Patients with three or more risk factors require a more aggressive multimodal approach.

Other ways to reduce the baseline risk for adults, according to the Fourth Consensus Guidelines for the Management of Postoperative Nausea and Vomiting from the International Anesthesia Research Society include IV acetaminophen, perioperative NSAIDs, regional anesthesia and supplemental oxygen. Using less volatile anesthetics and opioids also helps.

Alternative treatments

There are also effective non-drug strategies to prevent PONV. Acupuncture’s efficacy, especially when it is performed between two tendons in the patient’s wrist, is well documented. Reiki, where practitioners place their hands on or near the patient’s body, can make patients feel more relaxed and peaceful.

Aromatherapy is another inexpensive and easy-to-use strategy to ease nausea. Peppermint and lavender are the most effective scents. In some cases, an aromatherapy adhesive patch can be placed on the upper part of the patient’s gown as soon as they enter the PACU.

This intervention produces no side effects, and patients really appreciate this alternative. When surveyed, most say they would like to use it again.

Hypnosis can also be effective. One study shows it can be especially helpful for pediatric patients.

When preventive efforts don’t work, move to another class of drug or wait at least four hours before trying the same drug a second time. Relying on a single antiemetic to prevent PONV is successful about 30% of the time, while a multimodal approach targeting multiple receptors boosts the success rate closer to 90%.

Having patients hydrate preoperatively with clear carbohydrate-rich drinks and administering supplemental intravenous fluids during surgery is helpful. A simple stick of chewing gum can help post-op, as can ginger or music therapy.

No patient wants to suffer from PONV, and there’s a good chance that if they do, your satisfaction ratings will suffer along with them. Putting prevention and rescue strategies into place will go a long way toward preventing this unpleasant side effect. OSM

TECHNOLOGY

Can AI Help Identify Risk Factors for PONV?

ARTIFICIAL PERSPECTIVE An AI-generated image based on the following prompt: “A computer physician looks over a patient in a bed, thinking. The style is artistic and abstract, appropriate for an image in a magazine about learning to use LLMs in healthcare.”

Customer service is important to anyone providing a service, and physicians and surgery centers are no exception. While surgery is a much more complex offering than, say, a cup of coffee, the patient (customer) experience is also that much more complex and important. The hope is that they will have an excellent outcome in terms of their prognosis and their overall experience.

Postoperative nausea and vomiting (PONV) is a common post-surgery complication that can lead to undesirable outcomes, including increased stays in the PACU, the need for additional medications, difficult wound management, increased costs and patient dissatisfaction.

Not surprisingly, the unpleasant experience of PONV is a frequent complaint in unhappy patient reviews — in fact, it ranks above pain.

While every patient is different, there are common risk factors that increase the chance that an individual patient will experience PONV.

There are many solutions for this condition, from the common use of ondansetron to aromatherapy. Fairly extensive guidelines have been released along with ample research on medications, but often the solution comes down to what a physician thinks is best.

Much hinges on proactive and preventive efforts, particularly understanding which patients are most likely to be struck with PONV.

Nathan Hurley, MD, a resident at the University of Wisconsin School of Medicine and Public Health in Madison, was part of a team that investigated artificial intelligence (AI) as a potential support in identifying PONV risk factors, in the hopes that ChatGPT could become a useful tool in this area. The research led to a presentation titled “Large Language Model Identification and Assessment of Post Operative Nausea and Vomiting Risk Factors.”

The goal was to assess AI’s capability to identify post-op risk factors and potentially provide consistent data more quickly than individual surgeons and physicians could.

First, researchers used a well-respected meta-analysis that identified risk factors. Then they created hypothetical patient vignettes. These included five or six sentences about each fictional patient, including medical history, procedure type, planned medications, general versus volatile anesthetics, and opioid usage.

The researchers created 29 such patient profiles and applied the prompt to ChatGPT. The initial results were promising. ChatGPT 3.5 successfully identified the fictional patient’s risk factors 77% of the time, with ChatGPT 4 being correct 86.6% of the time.

“A lot comes down to what this can do in the time that you have to do it,” says Dr. Hurley. “If a physician is reviewing someone’s chart and has a long time to study it, they will be more thorough, but this is impressive when this can be run instantaneously and does a good job. There is a lot of potential here.”

One potential complication is the status of AI as a whole. As Dr. Hurley explains, the best technology comes back to an algorithm that was published in 2018 from a transformer model, and it remains quite new.

“All big tech companies have some flavor of this, but they’re in an arms race — all companies have their own systems,” notes Dr. Hurley. “Lots of places are trying to fiddle with this and apply these models, including startups. Everything is so new and going so quickly it’s hard to keep up with what’s out there.”

— Susan Ethridge