BANISH THE BASIN Pre- and intraoperative actions can reduce the incidence and severity of post-operative nausea and vomiting.

Few things slow a patient's progress toward discharge quite like post-operative nausea and vomiting. Wouldn't it be great if you could avoid treating all female non-smokers who require intraoperative narcotics and have a history of PONV — statistically speaking, the patients most likely to suffer it? That's not a great way to run a surgical facility, however. So instead focus on proven ways to reduce incidence of PONV from the moment patients enter your facility to when they're heading home after surgery.

KNOW AND GO Pre-op assessments often provide clues to patients' susceptibility to PONV.

Pre-op precautions
It's reasonable to assume that, for patients, the only thing worse than suffering PONV is not expecting it as a possible outcome. In the interest of keeping patients informed and prepared, candidly discuss the potential problem during pre-op assessment interviews. Mention that it's the most common significant side effect of anesthesia (about 30% of surgical patients reportedly suffer PONV). Then ask patients to help you identify their level of potential risk.

In addition to young, female, non-smoking, narcotized patients, individuals with a history of motion sickness are also frequently at risk. Using my aptly named "Sinha's Indirect test of Motion Sickness" (a.k.a. "SIMS"), I'll ask patients if they enjoy theme-park rides. The population cleanly divides into those who love them ("SIMS negative") and those who hate them ("SIMS positive"), with very little middle ground. I've found that "SIMS positive" patients are probably at a higher risk of PONV. Granted, this is entirely anecdotal and based on personal observation. But it's a fairly accurate test that lets you be more proactive with a potentially high-risk group.

Consider giving at-risk patients a scopolamine patch or aprepitant (Emend) tablets pre-operatively. Either of them is an effective adjunct to the 5HT3 antagonist ondansetron (Zofran). Keep in mind that while scopolamine lasts for 24 hours, it takes 4 hours to start working.

Don't underestimate the power of the mind. When my patients are drifting off to anesthetic sleep, I tell them, "You will wake up warm, comfortable and hungry." I've not subjected this practice to a randomized, prospective, placebo-controlled clinical trial, but anecdotally it seems to work. New OR personnel sometimes ask me, "Why did you say 'hungry?'" It's simple: In most cases, when you're hungry, you're not going to be nauseous.

Intraoperative insights
Pay close attention to the details of fluid administration, pain control and oxygenation. For those deemed high risk, a multimodal prophylaxis is advisable and often helpful.

A multimodal approach to PONV prophylaxis uses drugs from different classes to help block different receptor subtypes in the chemoreceptor trigger zone, which is what stimulates the emetic center. Giving multiple drugs that affect the same receptor group does nothing in terms of additional protection. But a combination that includes a 5HT3 antagonist, a steroid (almost always safe) and a scopolamine patch (if there's no contraindication) is my favorite triple-cocktail for patients most at risk. Additional drugs that may be effective include droperidol and metoclopramide.

Avoid nitrous oxide. For nearly a decade we've known that nitrous oxide (as opposed to air) causes 12% more PONV. Think about that: If you're using nitrous, every eighth patient who wouldn't have hurled if you were giving them air, will with nitrous oxide. Perhaps total intravenous anesthesia (TIVA) is the answer. Propofol has antiemetic properties, which is a large part of the reason it's so popular for use as an ambulatory anesthetic.

Use the least amount of opioids possible. Non-narcotic anesthesia techniques are showing promise in many patient classes. Initially driven by the need to avoid respiratory depression and its potentially deadly consequences among patients with sleep apnea, the move away from narcotic sedation can also remove a large trigger for nausea. Combining intraoperative dexmetedomidine, ketamine, clonidine or remifentanil with NSAIDs (such as IV ibuprofen and IV acetaminophen) or local anesthetics to assist in post-op pain management can prove effective.

PACU pearls
When you think about what patients go through at the end of surgery, as they're emerging from anesthesia, it's a wonder that only about a third of them wake up nauseous.

We turn off the gas or IV anesthetic, exposing them to the pain of surgery. We slide a Yankauer into their oropharynx to suction out secretions and pull the pinky-thick endotracheal tube out of the back of their throat. We roll them from the table onto a stretcher and push them to the recovery room on their backs, making a few twists and turns and bumping up against a few doors and walls along the way. As the disoriented patients arrive in PACU, nurses roll them to examine, transfer and position them in the post-op bed. That's an obstacle course of vomit-inducing stimuli.

The nausea they may be suffering immediately after the OR can be treated with a small dose of propofol. Here's how. If you add 2cc or 3cc of lidocaine to your propofol, it'll keep you from drawing the entire vial of sedative into a 20cc syringe. The last 2cc or 3cc of propofol usually gets tossed. But if you draw up the remainder in a sterile manner, and the case lasts less than 3 hours, you can give patients the leftover propofol once they've arrived in PACU to attenuate the vomiting reflex. While the patient takes a short nap, give your report to the PACU nurse. Five minutes later, by the time you're ready to return to the OR, the patient will be responsive, awake and comfortable. As an added bonus, the nursing crew will have a patient who is less likely to suffer PONV.

READ AND REACT
When Patients Feel Nauseous

Most anesthesia providers will claim track records of PONV incidence rates lower than the commonly quoted 30% of patients. Realistically, though, after patients leave their immediate care, very few issues come to their attention, unless it's an extremely serious situation. Sore throats and even PONV are often chalked up to the well-known and acceptable risks of anesthesia. Not hearing about yesterday's or last week's cases implies that you did a good job, and that the surgeon and patient were satisfied with the outcome.

If none of these 3 factors prove concerning on examination, however, prescribe an antiemetic from a class you haven't yet administered: droperidol, for instance, or even Benadryl. Alternatively, less conventional but sometimes effective remedies include acupressure, electro-acupressure, aromatherapy or ginger.

But what if your providers are summoned back to PACU for patient complaints of nausea and the urge to vomit? First and foremost, they should hold off on administering drugs right away. The right way for providers to deal with the situation is to evaluate the patient, considering the following potential issues.

UNEASY FEELING Event the best PONV prevention practices can't ensure patients won't feel sick.

• Dehydration causes nausea and can be easily rectified with appropriate hydration. Providers should be able to calculate a patient's fluid balance, their need (deficit) versus what's been administered. Adequate hydration can also be assessed by urine color and quantity. Other clues may be garnered from the pulse oximeter's waveform or, if available, the arterial line trace showing respiratory variation. If the patient is dehydrated, administer a fluid bolus through the in situ IV and they should start to feel better.
• Ask patients to rate their post-op pain on a numerical scale and evaluate their blood pressure, heart rate and respiration (which, when increased, suggest incomplete pain management) to help you appropriately treat what's ailing them.
• Oxygenation is the easiest to assess. A pulse oximeter number in the high 90s is very reassuring (100 is the maximum). Dipping into the low 90s or high 80s should raise immediate concern.

— Ashish C. Sinha, MD, PhD

Discharge directives
Standard discharge orders generally include requirements to "ambulate before discharge" and "tolerate p.o." But forcing patients to tolerate a clear soft drink and crackers on an empty stomach so soon after anesthesia can be cruel and unusual punishment, especially if they're at high risk for PONV. People don't forget how to eat, just because they've been anesthetized. Why not see if they'll tolerate a few ice chips, then discharge them with the recommendation that they sip a small to moderate amount of clear broth, slowly, when they feel hungry at home? They can follow this with slowly easing into their normal diet.

Lastly, ambulation in a patient who hasn't fully recovered from anesthesia can set off the nausea-and-vomiting cycle, so any walking should be done very slowly and carefully. Make sure the patient's escort knows not to drive like an Andretti on the way home, lest they trigger post-discharge nausea and vomiting (PDNV), which by some accounts is even more common than PONV. We anesthesia providers have little control over this complication in a patient's acute recovery, but should be aware of its possibility, especially if readmission occurs.