Red flags for bariatric surgery complications
Pulmonary embolisms, leaks, strictures can occur
By Charlotte Huff
While the risk of serious complications from bariatric surgery is relatively low, alert hospitalists can help quickly identify various issues that might arise postoperatively.
Complications can range from those immediately urgent in nature, such as a gastric leak at the surgical site, to longer-term digestion and related nutritional challenges, according to doctors who treat bariatric surgery patients.
Image from Thinkstock.
About 150,000 U.S. adults annually undergo bariatric surgery procedures, the bulk of which are now performed with laparoscopic techniques, according to the American Society for Metabolic and Bariatric Surgery.
Approximately 7% of bariatric patients experienced at least 1 postsurgical issue, according to an analysis involving 15,275 Michigan surgeries published in the July 28, 2010, Journal of the American Medical Association (JAMA). Most were wound problems or other relatively minor complications. The risk of a potentially life-threatening or fatal complication was 2.6%.
The rate of serious complications can vary depending on the surgical approach used, from a low of 0.86% for the gastric band to 2.2% for the sleeve gastrectomy and 3.6% for the gastric bypass, according to the JAMA analysis. Gastric band patients did better if they had a significantly lower body mass index and fewer other existing medical conditions before surgery.
During the first few weeks after surgery, pulmonary embolism and a gastric leak from the anastomosis lead the list of life-threatening complications, according to James A. Madura II, MD, director of the bariatric surgery program at the Mayo Clinic in Scottsdale, Ariz.
Sometimes the symptoms can be subtle, he said. “Oftentimes the patients will not manifest the physiologic signs and symptoms that a nonobese patient would,” said Dr. Madura, who is also senior author of a review article on postbariatric surgery care published in the February 2012 Journal of Hospital Medicine. “They don't appear sick. Sometimes they will just have an isolated tachycardia.”
Any sustained heart rate reaching 120 beats per minute should be a red flag to check for a potential leak, Dr. Madura said. Christopher Still, DO, FACP, director of Geisinger's Obesity Institute in Danville, Pa., strongly agreed. “Tachycardia greater than 120 with or without left-side shoulder pain should be a leak until proven otherwise,” he said.
Other symptoms include shortness of breath, fever and abdominal pain, Dr. Still said. To rule out a leak, he recommended a complete blood count, chest X-ray and abdominal CT scan. If a leak is identified, the patient should ideally be referred to the bariatric surgeon who performed the procedure, Dr. Still said.
Unfortunately, even a CT scan and upper gastrointestinal series will not catch all anastomotic leaks, Dr. Madura said. “There are areas that can leak that may not be adequately visualized by the studies,” he said. One study, published in the January 2007 Journal of the American College of Surgeons, found that those diagnostic tools together still missed 30% of leaks. If a patient continues to be acutely ill, taking them back to surgery should be considered, Dr. Madura said.
Shortness of breath and tachycardia, according to both surgeons, also can be 2 potential red flags for another rare but life-threatening complication—pulmonary embolism.
“Obese patients, number 1, are at risk for pulmonary embolism just by being obese,” said Dr. Madura. “Number 2, they have a tendency to become dehydrated. Number 3, there is a prothrombotic state that is accompanying surgical intervention, whether it's bariatric surgery or any other surgery.”
The patient with an anastomotic leak is more likely to also have developed a fever and a high white blood cell count than the pulmonary embolism patient, Dr. Still said.
To help prevent a pulmonary embolism, it's vital to get postsurgery patients moving as quickly as possible and prescribe a clot-preventing drug like heparin, Dr. Still said. Patients with limited mobility prior to surgery are particularly at risk. To check for an embolism in patients who present with suspicious symptoms, Dr. Still typically orders a spiral CT scan.
Obese patients also may have respiratory or sleep apnea difficulties that can make their postsurgical care more challenging, said Donna Mercado, MD, FACP, medical director of the Comprehensive Adult Weight Management Program at Baystate Medical Center in Springfield, Mass.
Since general anesthesia reduces lung volume in the initial days after surgery, this can be a concern for patients with existing breathing issues, said Dr. Mercado, who has cared for bariatric surgery patients both in the hospital and in the clinic setting. Plus, sleep apnea episodes can become more frequent. “Anesthesia changes sleep architecture, making episodes more frequent and potentially longer,” she said.
In situations in which the patient is quite obese, Dr. Mercado often will order pulmonary function tests to get a pre-surgery sense of the patient's lung volume. After surgery, the lung function of bariatric patients should be monitored closely and they should be encouraged to get moving as quickly as possible and to use an incentive spirometer frequently, she said.
Once the initial postsurgical period of a month or so has passed, patients may still have significant digestion and eating difficulties, some of which might be urgent in nature, Dr. Mercado said. A bariatric surgeon should be consulted immediately if a patient returns to the hospital with gastrointestinal symptoms of nausea or vomiting, she stressed.
The cause could simply be patients' inability to follow their postsurgery diets, Dr. Mercado said, but if a patient has been vomiting over a period of days, there could be a stricture at the surgical site. A stricture or some other type of obstruction develops in 1.5% of bariatric surgeries, according to the Michigan surgical data.
Prolonged vomiting and poor nutrition can lead to dehydration and related deficiencies in key vitamins, such as thiamine, niacin or B12, Dr. Mercado said. The patient might exhibit neurological symptoms consistent with a neuropathy, or even symptoms of Wernicke's encephalopathy, such as mental confusion, dizziness or ataxia, she said.
The connection to bariatric surgery may not be obvious if a patient visits an emergency department with a mix of gastrointestinal and neurological symptoms weeks to months after surgery, Dr. Mercado said. “Sometimes ER clinicians don't get a good surgical history,” she said. “It might not be apparent that they had weight loss surgery weeks or months before.”
To prevent later readmissions, hospitalists can play a vital role while the patient is still on the unit, Dr. Still said. Postsurgical patients should be asked to consume a considerable amount of fluids, 40 to 60 ounces, to guard against dehydration.
Getting patients moving as quickly as possible, along with prescribing compression stockings and clot-prevention drugs, helps reduce the risk of pulmonary embolism, Dr. Still said.
Dr. Madura noted that before surgery was even scheduled, patients should have been screened and educated regarding the diet and lifestyle changes required “We find in many situations that the abdominal discomfort is related to dietary indiscretion,” Dr. Madura said.
Charlotte Huff is a freelance writer in Fort Worth, Texas.
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