Gastroparesis, or delayed gastric emptying, greatly increases the risk of vomiting and pulmonary aspiration during anesthesia. Two recent near misses reminded me to be alert to gastroparesis.
A 25 y.o. insulin dependent diabetic woman with an insulin pump and BMI of 30, was scheduled for carpal tunnel release under conscious sedation. She had been NPO 13 hrs for food and 8 hours for clear liquids. Glucose 145, HgbA1C 6. As I finished my preop evaluation, she suddenly vomited about 500 ml of partially digested food the consistency of oatmeal. The patient’s pulse was 50 at this point (down from 70) but her blood pressure was 140/80 and she denied dizziness.
Profoundly apologetic, the patient stated that when she became nervous, she sometimes got nauseated and threw up. She reiterated that she had not eaten any food since 1800 the night before. On closer inquiry, she said that when she did vomit, that the emesis usually contained partially digested food.
I decided to proceed because the patient was no longer nauseated and now had a much emptier stomach. As a consequence of the emesis the surgeon, and the patient, agreed to using very light sedation with the local. I pretreated with Ondansetron, Metoclopramide, and Glycopyrrolate (in case this had been a vasovagal reaction).
The patient tolerated the uneventful procedure well. I wrote a note for the patient’s endocrinologist suggesting that they check for gastroparesis. I also told her to alert any future anesthesiologist of the incident.
My patient was a 40 y.o. non-insulin dependent diabetic woman, BMI 25, undergoing repair of a rotator cuff tear. We planned general anesthesia with a preop interscalene nerve block. Her preop glucose was 185 and no HgbA1C available. NPO 8 hrs. I intubated her because of her history of significant heartburn/reflux and because the surgeon was using the beach chair position. I gave 4 mg ondansetron and 4 mg dexamethasone I.V. for nausea prophylaxis. After an uneventful procedure, I extubated the patient after return of gag reflex. Immediately following extubation the patient vomited copious amounts of partially digested food. I called for help. With assistance, we turned her onto her side as best we could in the beach-chair. I suctioned her oropharynx well. fortunately, she was awake enough to guard her own airway.
Once awake enough for interview, she again denied having eaten within 8 hours. She did add, with questioning, that she often felt bloated after a meal and had early satiety. Fortunately, the patient did not aspirate and was discharged after 3 hours of observation with normal SPO2, clear lung sounds, and without problem. She received instruction on what signs/symptoms to look for to seek further treatment. I gave her a note describing gastroparesis and told her to let her primary care physician know what had happened.
What Is Gastroparesis
Gastroparesis is also called delayed gastric emptying. Weak stomach peristalsis (muscular contraction) causes food and liquid to remain in the stomach for an abnormally prolonged period of time. This delay in stomach emptying into the intestinal tract decreases absorption of nutrients. It can lead to poor nutrition as well as poor glycemic control. As a result, there is a potentially large volume of partially digested food sitting in the stomach at any time. Even fasting for 8 hours cannot guarantee an empty stomach.
Gastroparesis can be chronic, or acute and transient.
About 50% of cases are idiopathic. The most common cause of chronic gastroparesis is autonomic neuropathy effecting the vagus nerve. Chronic hyperglycemia can damage the vagus nerve. Gastroparesis has been reported in an many as 30-50% of Type I and II diabetics. Other causes of chronic gastroparesis include thyroid and adrenal gland dysfunction, scleroderma, Ehler’s-Danlos syndrome, and conditions causing neurologic dysfunction, such as Parkinson’s Disease. Chemotherapy can also cause neuropathy of the vagus nerve.
Transient gastroparesis can occur from any acute illness, as well as from pain, trauma and stress.
Symptoms may not alert you. As a resident, I once had a young, healthy, male patient, with recent onset appendicitis who had been NPO for 10 hours. He had minimal pain and had not had any nausea or vomiting. My anesthesia team actually debated the need for a full rapid sequence induction, but we did one anyway. Immediately following intubation, I inserted a nasogastric tube and suctioned out over a liter of bilious fluid. That unnerving incident made me aware that any sick patient can potentially have a very full stomach. Post-operative ileus is a form of gastroparesis caused partly by residual anesthesia and opioid use.
Certain medications, such as opioids, can cause gastroparesis. Ironically cannabinoids, often useful as anti-emetics, can also cause cannabinoid hyperemesis syndrome, with gastroparesis in frequent, heavy users. In this instance the cannabinoids delay gastric emptying by impaired peristalsis.
Suspect Gastroparesis If Your Patient Has:
- Chronic nausea
- Vomiting (especially of undigested food)
- Abdominal pain
- A feeling of fullness after eating just a few bites
Other symptoms can include:
- Abdominal bloating
- Body aches (myalgia)
- Erratic blood glucose levels
- Acid reflux (GERD)
- Lack of appetite
- Morning nausea
- Muscle weakness
- Night sweats
- Spasms of the stomach wall
- Constipation or infrequent bowel movements
- Weight loss, malnutrition
- Difficulty swallowing
Some of these symptoms are rather non-specific. Therefore, have a high index of suspicion.
Diagnosis of Gastroparesis
Gastroparesis is diagnosed by performing:
- barium swallow
- gastric emptying scans
However, the degree of gastroparesis displayed by the test may not match the symptoms. Some patients can have significant gastroparesis by testing, yet not have any symptoms at all.
Decrease The Risk of Pulmonary Aspiration
Aspiration can be a devastating complication. While aspiration can be minor, it can potentially cause chemical pneumonitis and acute respiratory distress syndrome (ARDS). Almost half of all patients who aspirate during surgery develop lung related injury. Aspiration can also be fatal, with a 10-30% 30-day mortality rate in certain studies.
Techniques to decrease the risk of pulmonary aspiration include, among other things:
- good preoperative risk assessment,
- preparation of equipment, especially suction,
- possible premedication prophylaxis,
- careful judgment regarding choice of anesthesia technique,
- teamwork, good communication, and rapid response when vomiting occurs
- always being prepared for potential vomiting
By being vigilant, using good judgment, and preparing for the worst, we can minimize the risk to our patients. For a discussion of preventing and managing pulmonary aspiration during anesthesia see:
Be vigilant. Pulmonary aspiration is a potentially life-threatening complication. Patients with diabetes, serious illness, infection, pain/stress, chemotherapy, and taking medications that interfere with gastric function may suffer from acute or chronic gastroparesis. Considered them higher risk for complications.
Today, more and more general anesthetics are performed using supraglottic airways. Minimze risk by screening patients to the best of our abilities. Use good judgement. And, if vomiting or passive regurgitation occurs despite our best efforts, be ready to act.
Preparing for emergencies requires the ability to visualize those emergencies, as well as the possible responses to them before they happen. My previous review articles discuss many of these emergencies/complications and how to avoid them. Check out:
May the Force Be With You
Christine E Whitten MD, author
Anyone Can Intubate: A Step-By-Step Guide
Pediatric Airway Management: a Step-By-Step Guide