KANSAS CITY, MO. – Seventeen percent of American children and adolescents are obese, and an increasing number of them are landing in operating rooms for related issues. They bring to the table particular perioperative concerns.
Dr. Moises Auron of the Cleveland Clinic offered an example during a talk on pediatric perioperative management at the meeting: A 15-year-old African American with a body mass index of 60 kg/m
For this high-risk patient, he said, cardiovascular concerns top the list, because obese children and adolescents are predisposed to hypertension at roughly a threefold higher risk than nonobese children. As a result, they can develop left ventricular hypertrophy that can produce a hypertrophic cardiomyopathy–like scenario, as well as diastolic dysfunction that also can predispose them to develop heart failure.
Childhood obesity is typically defined as a BMI at or above the 95th percentile for age and sex, while morbid obesity, as in the above patient, is a BMI that exceeds the 99th percentile.
Three times as many U.S. youth are obese now as were just one generation ago, the most recent data from the Centers for Disease Control and Prevention suggest.
In addition, one in seven low-income, preschool-aged children is obese.
“Unfortunately, we are seeing more and more and more of these cases,” said Dr. Auron, a pediatric hospitalist with the Center for Pediatric Hospital Medicine at the Cleveland Clinic.
Obese patients may require surgery not only for a variety of common ailments such as tonsillitis, but also for obesity-related conditions such as slipped capital femoral epiphysis, Blount's disease, cholelithiasis, and polycystic ovary syndrome.
In addition, they present with comorbid conditions such as insulin resistance, hypertension, and idiopathic intracranial hypertension.
In the examination of these patients, Dr. Auron suggests that the history include any symptoms of sleep apnea or hypoventilation, such as falling asleep while watching television or when talking with friends, and poor tolerance to exercise, including breathlessness and asthma, because these may in fact represent symptoms of left ventricular dysfunction.
Documentation of recent weight loss or gain, as well as a careful history of current medications – especially herbs or special mixtures taken to lose weight – is paramount. Weight loss may be associated with malnutrition, while the use of common herbs can interfere with anesthesia or hemostasis and even be associated with tachycardia, hypertension, or dysrhythmias.
“Garlic and ginger are very good antiplatelet agents,” Dr. Auron said. “It's like taking baby aspirin, but it's not good if you're having surgery. You can bleed to death.
“Medications that contain ephedra can trigger a severe sympathetic response, including hypertensive crises and tachyarrhythmias.”
Other perioperative considerations to be wary of in the morbidly obese pediatric patient are diabetes/insulin resistance; gastroesophageal reflux; and nonalcoholic fatty liver disease (NAFLD), including its progressive form, nonalcoholic steatohepatitis (NASH).
“When they develop NASH, it can evolve to cirrhosis, horribly,” Dr. Auron said at the meeting sponsored by the Society of Hospital Medicine, the American Academy of Pediatrics, and the Academic Pediatric Association. “It's even worse than alcoholic cirrhosis or viral hepatitis cirrhosis. I'm not sure why this is, but it causes substantial morbidity in the obese population who develops it,” he noted.
The prevalence of NAFLD and NASH varies by setting. Among 41 morbidly obese adolescents aged 13-19 years undergoing gastric bypass surgery, 83% had NAFLD and 20% had NASH. Mean fasting glucose level was significantly higher in those with NASH, although the prevalence of the metabolic syndrome was not (Gastroenterol. Hepatol. 2006;4:226-32).
A second study, however, recently reported that fatty liver disease, independent of visceral fat and intramyocellular lipid content, plays a central role in the pathogenesis of insulin resistance in obese adolescents (Diabetes Care 2010; 33:1817-22).
Dr. Auron said he recommends echocardiography for hypertensive patients, although he noted that there is not a lot of evidence, even in the adult literature, to support an echocardiogram for every patient. The one exception is patients with cardiomegaly on x-ray; echocardiography is recommended for this patient group (Circulation 2009;120:86-95).
Preoperative fasting should follow the same rules as for nonobese patients, albeit perhaps a bit more fasting would not lead obese patients astray, he said, tongue in cheek.
Dr. Auron reported no relevant financial relationships.
A careful history of current meds – especially herbs or special mixtures taken to lose weight – is paramount.
Source DR. AURON