Obesity among children and adolescents has dramatically increased in the Unites States over the past three decades and represents a major public health concern. The National Center for Health Statistics (NCHS) and Center for Disease Control (CDC) have established age and gender specific cutoffs to define obesity. Accordingly, ‘overweight’ is defined by a body mass index between the 85^th and 95^th percentiles, while ‘obese’ is defined with a body mass index above the 95^th percentile, with respect to children of the same age and sex. This child obesity crisis has wide-ranging impacts on health and on anesthesia care.

Over the past 30 years, childhood obesity rates have surged, driven by several factors. These include reduced access to healthy food due to urban sprawl and the rising cost of nutritious food compared to cheaper, processed alternatives. Additionally, children today are less active, with diminished physical education in schools and increased engagement in sedentary activities at home, such as playing computer games and watching TV. In 2008, approximately 20% of children and teenagers aged 6-19 were classified as having obesity. Worldwide, the number of infants and children with obesity increased to 42 million in 2013 and is projected to reach 70 million by 2025. A literature review from 1993 found that a significant portion of preschool and school-age children with obesity continued to have obesity into adulthood, with these children having at least twice the risk as children without obesity. This risk was even higher for children with higher levels of obesity and those who had obesity at older ages.

The child obesity crisis has several important implications that must be carefully considered by the anesthesia team. In terms of lung function, the expiratory reserve volume is significantly decreased with obesity. Furthermore, closing volume, which is the lung volume at which small airways collapse, is increased in patients with obesity. Consequently, alveoli closure may occur even at normal tidal volumes, leading to atelectasis, ventilation-perfusion mismatch, and potentially hypoxemia. If chronic, this process may lead to an inability to normalize the partial pressure of carbon dioxide, leading to hypersomnolence and pulmonary hypertension. Additionally, obese patients may be more difficult to ventilate due to the increased work of breathing from low chest wall compliance secondary to adipose tissue over the thorax. Finally, childhood obesity is associated with increased rates of asthma, which may further complicate anesthesia due to the risk of bronchospasm.

The child obesity crisis also impairs the function of other organ systems, with implications for anesthesia care. Increased cardiac output occurs due to the need to perfuse adipose tissue, resulting in increased heart strain and potential structural changes such as left ventricular hypertrophy. Similarly, persistent hypoxemia associated with obesity may lead to pulmonary vasoconstriction and ultimately right heart strain. Therefore, the impact of anesthesia and surgery on the cardiovascular system is important to consider in young patients with obesity. Another co-morbidity of childhood obesity that should be highlighted is obstructive sleep apnea, which is often underdiagnosed and presents challenges to the anesthesia team because patients may have difficult airways. 

Several studies highlight nausea and vomiting as a post-operative concern that is more likely in pediatric patients with obesity. According to Nafiu et al., retrospective data of nearly 6,000 pediatric patients showed that children who are overweight or have obesity are more likely to have prolonged stays (i.e. more than 3 hours) in the post-anesthesia care unit—presumed to be a reflection of the increased incidence of upper airway obstruction and nausea and vomiting in this population. For this reason, these patients often require more than two anti-emetic agents to manage their symptoms post-operatively.

Overall, the child obesity crisis remains a critical health concern and has important implications for physiology, anesthesia care, and post-operative management.

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