Challenges of pediatric obesity in perioperative care

The obesity epidemic in the United States has impacted both adult and pediatric populations. The Centers for Disease Control (CDC) states that theprevalenceof obesity in youth in2015-2016was18.5%versus 39.8% in adults. The prevalence of obesity was similar between boys and girls and between different age groups. There has been an increase in obesity from 1999 to 2016 among both adults and children. Obesity, in addition to having multi-system effects, is a major risk factor for morbidity and mortality after major surgery. According to a study released by the World Health Organization (WHO) in 2014, the rate of childhood obesity has doubled since the 1980s, with 39% and 13% of children falling under overweight and obese categories, respectively. Worldwide, 90% of childhood obesity can be attributed to increased calorie consumption and decreased energy expenditure. The increasing prevalence of childhood obesity has particular significance in the hospital setting, with an increasing number of obese patients presenting for surgery. Contrary to popular belief, perioperative complications exist in obese children. Obesity has also created a staggering worldwide 80 to 90 billion dollars in health care costs. It is unclear, however, whether these increases in hospital expenditures are due to greater recognition of the condition, a change in coding behavior, or more than a causal relationship with obesity. Although some have statistical significance, most studies evaluating hospital expenditures have limited applicability to the general pediatric population. Much of the anesthetic knowledge regarding pediatric obesity has been extrapolated from studies carried out in adults. There are conflicting definitions and under-recognition of obesity in children. Body mass index (BMI), calculated as weight in kilograms divided by height in meters squared, is the most commonly usedmetric to define obesity. Although BMI correlates with fat burden in adults, there is a more curvilinear distribution in pediatric patients. In addition, BMI needs to be age matched and calculated as a percentage for age. In 2000, Cole and colleagues developed agespecific and sex-specific charts correlating towhere the BMI crossed 25 and 30 at age 18. Percentiles similar to those found in standard growth charts were also generated. Online calculators are available now to calculate BMIpercentiles for age and sex, such as through theNational Institutes of Health website. These calculators give the BMI number and an age-specific and sex-specific percentile from age 2 years and above. BMI isnot available for childrenyounger than2yearsold.Neck circumference is another tool currently used to screen for obesity in children. Neck circumference has also been used to screen for obstructive sleep apnea, but found to be of limited value. Obesity in pediatric patients presenting for surgery creates many challenges for both the anesthesiologist and the surgical team. Nafiu et al found a nonlinear relationship between BMI and American Society of Anesthesiologists (ASA) physical status, a measure of a patient’s relative anesthetic risk. In a pilot study, Walia et al found a statistically significant number of patients who were >95th percentile for BMI, but considered ASA 1. The etiology of pediatric obesity can be divided into the 3 broad categories of genetics, behavioral factors, and environmental factors; <10% of cases of childhood obesity were found to be due to hormonal and genetic factors and, therefore, will not be discussed in detail here. Table 1 lists the causes of hormonal, genetic, and syndromic disorders associated with obesity. The more common comorbidities associated with exogenous obesity are type 2 diabetes, fatty liver disease, and dyslipidemia.