What is Postoperative Nausea?
Feeling sick or throwing up after surgery, also known as postoperative nausea and vomiting (PONV), often happens after a person has been under anesthesia. This can lead to discomfort and unhappiness in patients. PONV can be harmful, especially in situations where a high heart rate, blood pressure or pressure within the chest or veins is dangerous for the patient. Reports show that in people who are at a higher risk, up to 80% may suffer from PONV, while in the general population, the rate can be around 30%. PONV can lead to higher medical expenses, extended hospital stays, and the need for re-admission to the hospital. Some patients are even willing to pay more, and endure pain, if it means they can avoid PONV. As more surgeries are being conducted without requiring an overnight stay in the hospital, finding ways to prevent PONV is becoming even more important for anesthesiologists to enhance patient care and comfort.
What Causes Postoperative Nausea?
The people at the greatest risk of experiencing postoperative nausea and vomiting (PONV) seem to be young to middle-aged, non-smoking women who have previously suffered from PONV or motion sickness. These are all individual risk factors. Also, the use of certain types of anesthetics that are inhaled, having a long surgery, using nitrous oxide, and a post-surgery need for painkillers can all increase the chances of PONV.
PONV has many causes and it’s thought to come from an area in the brainstem that responds to chemical messages, direct effects on the digestive tract from painkillers, anesthetics, and motion, and from a heightened response from the balance and movement system in the body due to substances regularly used in anesthesiology. The type and location of surgery also matter. Eye and ear surgeries, brain surgeries, abdominal surgeries, and gynecological surgeries tend to carry a higher risk of PONV.
Other factors can make PONV worse such as dehydration, inhaling foreign material into the lungs, changes in body salts, and other complications or health problems present during the surgery. This can lead to a reoccurring cycle where vomiting worsens the health problem that might be causing the PONV in the first place.
Risk Factors and Frequency for Postoperative Nausea
Postoperative nausea and vomiting (PONV) is less likely to occur in people of very young or very old age. However, it’s been noted that women and patients undergoing specific types of surgeries could be at a higher risk. Interestingly, it seems that one of the few advantages of using tobacco, especially smoking, could be a reduced risk of developing PONV.
Signs and Symptoms of Postoperative Nausea
When experiencing nausea, patients may look pale and sweaty. Anxiety can cause them to breathe quickly and their heart to beat faster. Actual vomiting can cause a body response that leads to high blood pressure and a rapid heart rate. The heavy strain caused by vomiting can slow the heart rate and increase pressure in the chest and brain, which can harm patients recovering from specific procedures or with certain illnesses. It is essential to rule out other causes of nausea and vomiting when diagnosing, which may include poor blood flow and potential bowel issues.
Testing for Postoperative Nausea
Doctors need to consider various other factors that can cause nausea, such as heart-related issues, slow digestion, low blood pressure, low levels of oxygen, metabolic irregularities, and other complications from surgery. Patients are carefully observed after surgery, which makes it easier for healthcare providers to spot and deal with more serious causes of nausea.
Excessive vomiting can lead to imbalances in electrolytes (essential minerals in your body) and interfere with the body’s acid-base balance. In such cases, laboratory tests may be necessary. As with any issue that arises after surgery, doctors should conduct a thorough review of the patient’s medical history and a physical exam, especially if postoperative nausea and vomiting (PONV) is unexpected or severe.
Treatment Options for Postoperative Nausea
Postoperative nausea and vomiting (PONV), or feeling sick and being sick after a surgery, is best dealt with using several different medications and it is generally easier to prevent these symptoms rather than treat them after they’ve started. In medical settings, standardized plans are typically developed to estimate the risk of PONV based on various factors. For example, four risk factors may equate to a roughly 80% chance of PONV, and in such cases, the plan may suggest using four preventive medications.
Several different types of medications can be used to help prevent PONV. These include 5-HT3 antagonists like ondansetron, antidopaminergic agents like droperidol, antihistamines like dimenhydrinate, anticholinergic medications such as scopolamine, and steroids like dexamethasone. These medications work differently to either stop nausea and vomiting from happening, or to make them less severe. A newer medication, aprepitant, has shown promise in preventing PONV when given before surgery.
Metoclopramide – a medication that increases the tone of the lower esophagus and enhances stomach emptying – also has anti-vomiting effects. Additionally, propofol, which is given directly into the bloodstream to induce anesthesia, has short-term anti-vomiting properties and can be useful in high-risk patients. However, all opioids used around the time of the surgery have been linked to PONV, so limiting exposure to these drugs can decrease nausea and vomiting after surgery.
Newer sedative drugs like dexmedetomidine and alternative pain medications (such as non-steroidal anti-inflammatory drugs, or NSAIDs, and acetaminophen), can also be used to reduce the exposure to traditional pain medications and decrease the risk of PONV. However, it’s important to be aware that these treatments can have additional side effects. For example, NSAIDs can cause upset stomach, which may exacerbate PONV symptoms. Promethazine, another drug used to combat PONV, can sedate patients and prolong recovery times.
Alternative non-traditional methods to prevent PONV have been tested and show promise. Some have used the smell of isopropyl alcohol swabs, while others have looked at stimulating a point on the wrist called the P6 acupoint using acupuncture, electric stimulation, lasers or pressure. These methods have shown to successfully control PONV. Other measures, like giving supplemental oxygen and rehydrating patients, can also reduce the severity or incidence of PONV.
Dealing with PONV is a critical part of the post-surgery period. It has many causes, known risk factors and is easier to prevent than treat. It also has a significant impact on patient satisfaction, healthcare costs, and length of hospital stay. Therefore, healthcare providers need to pay close attention to prevent PONV, rule out more serious causes, and work within their systems to decrease its prevalence.
What else can Postoperative Nausea be?
The following is a list of conditions, syndromes, or effects from certain medications that could cause similar symptoms or could be related factors:
- Antiarrhythmics (A type of medication)
- Anticonvulsants (Another type of medication)
- Chronic intestinal pseudo-obstruction (A condition that mimics a bowel obstruction)
- Digoxin (A heart medication)
- Gastroparesis (A condition where stomach emptying is delayed)
- Hormonal preparations (Certain types of medical therapies)
- Hydrocephalus (A condition involving build-up of fluid in the brain)
- Irritable bowel syndrome (A common disorder affecting the large intestine)
- Labyrinthitis (An inner ear problem)
- Mass lesion (An abnormal tissue mass)
- Motion sickness (A disturbance of the inner ear)
- Non-ulcer dyspepsia (Indigestion without a clear reason)
- Opiates (A type of narcotic drug)
- Spontaneous bacterial peritonitis (A type of peritoneal infection)
- Urinary tract infection/pyelonephritis (Infections of the urinary system)
What to expect with Postoperative Nausea
Nausea and vomiting after surgery, also known as postoperative nausea and vomiting (PONV), is usually temporary and easier to prevent than to cure. As the effects of inhaling anesthesia during surgery lessen and the use of opioid medications (used for pain relief) decreases, PONV generally fades away.
It’s important to note that PONV can extend the time a patient spends in the hospital, and may increase the length of stays for day surgery procedures. However, if PONV does not lessen over time after surgery, it may indicate an issue other than the normal post-surgical effects. In such cases, it’s essential to check for other potential causes of the symptoms.
