Anesthesia for Pediatric Obesity

Confronting the challenges of effective pain management in children following tonsillectomy

Tonsillectomy is an extremely common surgical procedure associated with significant morbidity and mortality. The post-operative challenges include: respiratory complications, post-tonsillectomy hemorrhage, nausea, vomiting and significant pain. The present model of care demands that most of these children are managed in an ambulatory setting. The recent Federal Drug Agency (FDA) warning contraindicating the use of codeine after tonsillectomy in children represents a significant change of practice for many pediatric otolaryngological surgeons. This introduces a number of other safety concerns when deciding on a safe alternative to codeine, especially since most tonsillectomy patients are managed by lay primary caregiver's at home. This review outlines the safety issues and proposes, based on currently available evidence, a preventative multi-modal strategy to manage pain, nausea and vomiting without increasing the risk of post-tonsillectomy bleeding.

Anesthetizing the obese child

The prevalence of childhood obesity is increasing. The focus of this review is the special anesthetic considerations regarding the perioperative management of obese children. With obesity the risk of comorbidity such as asthma, obstructive sleep apnea, hypertension, and diabetes increases. The obese child has an increased risk of perioperative complications especially related to airway management and ventilation. There is a significantly increased risk of difficult mask ventilation and perioperative desaturation. Furthermore, obesity has an impact on the pharmacokinetics of most anesthetic drugs. This has important implications on how to estimate the optimal drug dose. This article offers a review of the literature on definition, prevalence and the pathophysiology of childhood obesity and provides suggestions on preanesthetic evaluation, airway management and dosage of the anesthetic drugs in these patients. The authors highlight the need of supplemental studies on various areas of the subject.

Incidence of perioperative adverse events in obese children undergoing elective general surgery

BACKGROUND

A worldwide increase in the prevalence of obesity has been observed in both developed and developing countries. Few studies have addressed the anaesthetic or perioperative implications of childhood obesity.

METHODS

Children aged 2-16 yr undergoing general surgery were classified using age- and sex-adjusted BMI. Patient characteristic, co-morbidity, and perioperative data were collected to ascertain the risks associated with overweight and obese children.

RESULTS

We enrolled 1465 subjects in our study, of which 154 (10.5%) were classified as obese and a further 223 (15.2%) as overweight. After adjusting for age, we identified increased rates of arterial haemoglobin desaturation, difficult mask ventilation, airway obstruction, and bronchospasm in obese children. The relative risk (RR) of adverse respiratory events was higher among obese subjects than non-obese subjects and higher in younger age groups. Controlling for age, adjusted-RR (confidence interval) was 1.49 (1.2-1.86). There was a significant association between obesity and asthma with a higher odds ratio (OR) in younger age groups controlling for age: adjusted-OR=1.8 (1.15-2.82). A significant association was detected between obesity and sleep apnoea controlling for age: adjusted-OR=4.03 (2.37-6.8).

CONCLUSIONS

These results suggest an increased incidence of perioperative adverse respiratory events in obese children, especially at younger ages.

Special considerations in the critically ill morbidly obese child

Obesity has been recognized as an increasing problem not only in North America but globally. With a significant rise in the prevalence of obesity amongst children and adolescents over the past 20 years, the comorbidities associated with obesity are also now emerging at an earlier age. These comorbidities cause specific concern and require special consideration when the morbidly obese child becomes critically ill.

Complications with flexible nailing of femur fractures more than double with child obesity and weight >50 kg

BACKGROUND

Previous studies report that children above the 95th percentile in weight for their age had an increased risk for complications following titanium elastic nailing for femur fractures. The purpose of this study is to examine whether obesity, defined as body mass index (BMI) > 95th percentile, and/or simple weight correlates with an increased rate of complications.

METHODS

The incidence of complications was compared between obese and non-obese patients and also between patients who weighed >/=50 kg and those <50 kg.

RESULTS

The overall complication rate was 23% (16/71). The complication rate was 17% (10/58) for "non-obese" patients and 46% (6/13) for "obese" patients. This difference was statistically significant (P = 0.03). The complication rate was 46% (6/13) in children who weighed >/=50 kg and 17% (10/58) in children who weighed <50 kg. This difference was also statistically significant (P = 0.03).

CONCLUSIONS

This study demonstrates that obesity (BMI > 95th percentile) and weight over 50 kg predispose patients to increased risk of surgical complications when undergoing flexible elastic nailing for femur fractures. Both obese children and children weighing >/=50 kg were two times more likely to have a complication when undergoing this procedure.

Childhood body mass index and perioperative complications

BACKGROUND

Our aim was to describe the incidence of quality assurance events between overweight/obese and normal weight children.

METHODS

This is a retrospective review of the quality assurance database of the Mott Children's Hospital, University of Michigan for the period January 2000 to December 2004. Using directly measured height and weight, we computed the body mass index (BMI) in 6094 children. Overweight and obesity were defined using age and gender-specific cut off according to the National Center for Health Statistics (NCHS)/Centers for Disease Control and Prevention (CDC) (2000) growth charts. Frequency of quality assurance events were compared between normal weight, overweight, and obese children.

RESULTS

There were 3359 males (55.1%) and 2735 females (44.9%). The mean age for the entire population was 11.9 +/- 5.2 while the mean BMI was 21.6 +/- 6.7 kg x m(-2). The overall prevalence of overweight and obesity was 31.6%. Obesity was more prevalent in boys than girls (P = 0.016). Preoperative diagnoses of hypertension, type II diabetes, and bronchial asthma were more common in overweight and obese than normal weight children (P = 0.0001 for hypertension, P = 0.001 for diabetes and P = 0.014 for bronchial asthma). Difficult airway, upper airway obstruction in the postanesthesia care unit (PACU) and PACU stay longer than 3 h and need for two or more antiemetics were more common in overweight and obese than normal weight children (P = 0.001). There was no significant difference in the incidence of unplanned hospital admission following an outpatient surgical procedure between normal weight and overweight/obese children.

DISCUSSION

Studies on perioperative aspects of childhood overweight and obesity are rare. Our report shows a high prevalence of overweight and obesity in this cohort of pediatric surgical patients. Certain perioperative morbidities are more common in overweight and obese than in normal weight children. There is a need for prospective studies of the impact of childhood overweight and obesity on anesthesia and surgical outcome.

Childhood obesity and anesthetic morbidity

BACKGROUND

Obesity is present in a significant proportion of children presenting for anesthesia. Although it is perceived that obese adults have more frequent complications, the incidence of complications in obese children is unknown. Because of anticipated difficulties with mask ventilation, anesthesia is most frequently induced intravenously in obese adults, whereas inhalation induction is usually preferred in uncooperative children with few visible veins. The purpose of this study was to examine and compare anesthetic related complications in obese children undergoing dental surgery with a similar group of nonobese individuals.

METHODS

The charts of 1133 American Society of Anesthesiology (ASA) physical status I and II children less than 12 years old who underwent general anesthesia for dental outpatient procedures in 2003 were retrospectively examined for patient height, weight, preoperative evaluation, anesthetic course and postoperative course. Body mass index was calculated and compared with international normative data to identify those children who were obese. Method of induction and perioperative complications were noted.

RESULTS

A total of 100 obese and 1033 nonobese children were identified. Demographically the two groups were comparable. Inhalation induction was used in the vast majority of obese (99%) and nonobese (99.7%) patients. Overall complication rate was low. Minor respiratory complications were more frequently noted in the obese group. These consisted primarily of a higher incidence of intraoperative oxygen desaturation (2% vs 0.19%) and higher requirements for unexpected overnight hospitalization (2% vs 0.19%). The only complication related directly to inhalation induction was noted in a nonobese child who vomited and aspirated on induction.

CONCLUSIONS

Our study demonstrated a small increase in minor respiratory complications in obese children who underwent anesthesia. Inhalation induction was not associated with an increase in adverse events in this population.