A disquisition on sleep-disordered breathing in children

Obstructive sleep apnoea and polymorphisms: implications for anaesthesia care

With a worldwide obesity pandemic, the incidence of obstructive sleep apnoea (OSA) is increasing; obesity is the most significant risk factor in children. Increasing evidence suggests that OSA is in part mediated through markers of inflammation. Systemic and pulmonary hypertension, right ventricular hypertrophy, prediabetes, and other conditions are common. Adenotonsillectomy improves only ~70% of children; 30% require other interventions, e.g. weight loss programs. The gold standard for diagnosis is a sleep-polysomnogram which are expensive and not readily available. The McGill oximetry score (saw-tooth desaturations during obstruction and arousal) is more cost-effective. Repeated episodes of desaturation alter the opioid receptors such that analgesia is achieved at much lower levels of opioid than in patients undergoing the same procedure but without OSA. This response is of great concern because a standard dose of opioids may be a relative overdose. Polymorphism variations in cytochrome CYP2D6 have major effects upon drug efficacy and side effects. Codeine, hydrocodone, oxycodone, and tramadol are all prodrugs that require CYP2D6 for conversion to the active compound. CYP2D6 is quite variable and patients can be divided into 4 classes: For codeine for example, poor metaboliser (PM) have virtually no conversion to morphine, intermediate metabolisers (IM) have some conversion to morphine, extensive metabolisers (EM) have a normal rate of conversion to morphine, and ultra-rapid metabolisers (RM) convert excessive amounts of codeine to morphine. Such variations result in some patients achieving no analgesia because there is reduced conversion to the active moiety whereas others convert an excessive amount of drug to the active compound thus resulting in relative or actual overdose despite appropriate dosing. Thus, OSA patients may have both opioid sensitivity due to recurrent desaturations and altered drug metabolism resulting in higher than intended blood levels of opioid. OSA patients should only receive one-third to half the usual dose of opioid. In those under the age of six, an effort should be made to avoid opioids altogether and use opioid sparing techniques such as alternating acetaminophen and ibuprofen.

Pediatric ambulatory anesthesia: an update

PURPOSE OF REVIEW

Ambulatory surgery is the standard for the majority of pediatric surgery in 2019 and adenotonsillectomy is the second most common ambulatory surgery in children so it is an apt paradigm. Preparing and managing these children as ambulatory patients requires a thorough understanding of the current literature.

RECENT FINDINGS

The criteria for undertaking pediatric adenotonsillectomy on an ambulatory basis, fasting after clear fluids, postoperative nausea and vomiting (PONV), perioperative pain management and discharge criteria comprise the themes addressed in this review.

SUMMARY

Three criteria determine suitability of adenotonsillectomy surgery on an ambulatory basis: the child's age, comorbidities and the severity of the obstructive sleep apnea syndrome (OSAS). Diagnosing OSAS in children has proven to be a challenge resulting in alternate, noninvasive techniques, which show promise. Abbreviating the 2 h clear fluid fasting guideline has garnered attention, although the primary issue is that parents do not follow the current clear fluid fasting regimen and until that is resolved, consistent fasting after clear fluids will remain elusive. PONV requires aggressive prophylactic measures that fail in too many children. The importance of unrecognized genetic polymorphisms in PONV despite prophylactic treatment is understated as are the future roles of palonosetron and Neurokinin-1 receptor antagonists that may completely eradicate PONV when combined with dexamethasone. Pain management requires test doses of opioids intraoperatively in children with OSAS and nocturnal desaturation to identify those with reduced opioid dosing thresholds, an uncommon practice as yet. Furthermore, postdischarge nonsteroidal anti-inflammatory agents as well as other pain management strategies should replace oral opioids to prevent respiratory arrests in those who are ultra-rapid CYP2D6 metabolizers. Finally, discharge criteria are evolving and physiological-based criteria should replace time-based, reducing the risk of readmission.

Peri-operative management of overweight and obese children and adolescents

Obesity has become endemic, even in children. Systemic complications associated with obesity include metabolic syndrome, cardiovascular disease, and respiratory compromise. These comorbidities require adequate investigation, targeted optimisation, and, if surgery is required, specific management during the peri-operative period. Specific peri-operative strategies should be used for paediatric patients who are overweight or obese to prevent postoperative complications, and optimising the respiratory function during surgery is particularly crucial. This Review aims to provide up-to-date information on peri-operative management for physicians who are caring for children and adolescents (usually younger than 18 years) who are overweight or obese undergoing surgery, including bariatric surgery. We have particularly focussed on the physiological consequences of obesity-namely, obstructive sleep apnoea, respiratory compromise, and pharmacological considerations.

Perioperative management of the paediatric patient with coexisting neuromuscular disease

Children with neuromuscular diseases present a wide range of clinical manifestations and clinical implications for the anaesthesiologist. Neuromuscular diseases in children affect muscle strength by either directly weakening the muscle fibrils or indirectly by a degenerative nerve supply and weak neuromuscular junction. Of the more than 200 neuromuscular disorders known, the vast majority are genetic in origin. This review focuses on four of the more common neuromuscular disorders with emphasis on their pathophysiology and clinical implications for anaesthesiologists: malignant hyperthermia, the muscular dystrophies (Duchenne's, Becker's, and Emery-Dreifuss), mitochondrial disorders, and cerebral palsy.

[Polysomnography and other sleep studies]

Additional tests are needed for an accurate diagnosis of most sleep disorders in children. Of these additional tests, especially when study of sleep breathing disorders in children is required, complete overnight polysomnography is currently considered the gold standard for the diagnosis of sleep disorders. There are, however, other simplified tests, although less informative and reliable, which may be acceptable diagnostic alternatives, such as respiratory polygraphy and pulse oximetry recording. This article will explain the main indications, methodology and advantages and disadvantages of the various sleep tests.

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.

Anesthesia for pediatric airway surgery: recommendations and review from a pediatric referral center

Pediatric airway surgery presents many significant challenges to the anesthesia provider. The clinical experience of the Massachusetts Eye and Ear Infirmary serves as a guide in this review to describe the clinical reasoning and perioperative management of the pediatric patient needing airway surgery, with specific emphasis on diagnostic procedures, trauma, laryngotracheal reconstruction, juvenile recurrent respiratory papillomatosis, and adenotonsillectomy.

Challenges in pediatric ambulatory anesthesia: kids are different

The care of the child having ambulatory surgery presents a specific set of challenges to the anesthesia provider. This review focuses on areas of clinical distinction that support the additional attention children often require, and on clinical controversies that require providers to have up-to-date information to guide practice and address parental concerns. These include perioperative risk; obstructive sleep apnea; obesity; postoperative nausea and vomiting; neurocognitive outcomes; and specific concerns regarding common ear, nose, and throat procedures.