Child obesity and anaesthetic morbidity

A clinical trial evaluating the laryngeal mask airway-Supreme in obese children during general anesthesia

INTRODUCTION

The laryngeal mask airway (LMA)-Supreme is a disposable double-lumen laryngeal mask airway that is widely used in clinical practice. However, its use in obese children has not been evaluated. The aim of this study was to determine whether the LMA-Supreme could perform equally as well as endotracheal intubation in obese children having a minor surgical procedure.

MATERIAL AND METHODS

After ethical board approval, 100 obese male children receiving non-emergent appendectomy for chronic appendicitis or surgery to correct concealed penis were randomly divided into an endotracheal intubation group and an LMA-Supreme group. Endotracheal intubation was performed under direct vision laryngoscopy. In the LMA group, a size-3 LMA-Supreme was placed and a stomach tube inserted via the drainage tube of the mask. Cardiovascular and respiratory parameters, time taken for placement, placement attempts, time to removal of the endotracheal tube/LMA, length of stay in the post-anesthesia care unit (PACU), and complications were recorded.

RESULTS

Insertion time was significantly longer (p < 0.001) in the LMA-Supreme group than in the endotracheal intubation group. Peak airway pressure was significantly higher, and pulmonary compliance and PACU stay time lower in the LMA-Supreme group. No significant differences between endotracheal intubation and the LMA-Supreme were seen in other parameters, except for a higher incidence of coughing in the endotracheal intubation group.

CONCLUSIONS

The LMA-Supreme can be easily inserted and effectively used for airway management in obese children undergoing minor surgery.

Appendicitis in obese children

During the past two decades, the incidence of childhood obesity has increased at alarming rates throughout the world. Obesity is associated with a variety of physiological changes that may impair a patient's response to surgery. With the rising rates of childhood obesity, pediatric surgeons must appreciate differences in the management and outcomes of these patients. Difficult physical examination, elevated inflammatory blood markers, and negative influence of obesity on the detection rate of the appendix on ultrasound have been reported causing diagnostic challenging of appendicitis in obese children. Moreover, obesity is associated with longer hospital stay and higher morbidity and minimal invasive techniques' superior outcomes over open technique in children undergoing appendectomy.

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.

Pharmacokinetics and Drug Dosing in Obese Children

OBJECTIVES

To review pharmacokinetics in obese children and to provide medication dosing recommendations.

METHODS

EMBASE, MEDLINE, and International Pharmaceutical Abstracts databases were searched using the following terms: obesity, morbid obesity, overweight, pharmacokinetics, drug, dose, kidney function test, creatinine, pediatric, and child.

RESULTS

We identified 10 studies in which the authors examined drug dosing or pharmacokinetics for obese children. No information was found for drug absorption or metabolism. Obese children have a higher percent fat mass and a lower percent lean mass compared with normal-weight children. Therefore, in obese children, the volume of distribution of lipophilic drugs is most likely higher, and that of hydrophilic drugs is most likely lower, than in normal-weight children. Serum creatinine concentrations are higher in obese than normal-weight children. Total body weight is an appropriate size descriptor for calculating doses of antineoplastics, cefazolin, and succinylcholine in obese children. Initial tobramycin doses may be determined using an adjusted body weight, although using total body weight in the context of monitoring serum tobramycin concentrations would also be an appropriate strategy. We found no information for any of the opioids; antibiotics such as penicillins, carbapenems, vancomycin, and linezolid; antifungals; cardiac drugs such as digoxin and amiodarone; corticosteroids; benzodiazepines; and anticonvulsants. In particular, we found no information about medications that are widely distributed to adipose tissue or that can accumulate there.

CONCLUSIONS

The available data are limited because of the small numbers of participating children, study design, or both. The number and type of drugs that have been studied limit our understanding of the pharmacokinetics in obese children. In the absence of dosing information for obese children, it is important to consider the nature and severity of a child's illness, comorbidities, organ function, and side effects and physiochemical properties of the drug. Extrapolating from available adult data is possible, as long as practitioners consider the effects of growth and development on the pharmacokinetics relevant to the child's age.