Polysomnography after adenotonsillectomy in mild pediatric obstructive sleep apnea

Upper airway reconstruction using long-range optical coherence tomography: Effects of airway curvature on airflow resistance

OBJECTIVES

Adenotonsillectomy (AT) is commonly used to treat upper airway obstruction in children, but selection of patients who will benefit most from AT is challenging. The need for diagnostic evaluation tools without sedation, radiation, or high costs has motivated the development of long-range optical coherence tomography (LR-OCT), providing real-time cross-sectional airway imaging during endoscopy. Since the endoscope channel location is not tracked in conventional LR-OCT, airway curvature must be estimated and may affect predicted airway resistance. The study objective was to assess effects of three realistic airway curvatures on predicted airway resistance using computational fluid dynamics (CFD) in LR-OCT reconstructions of the upper airways of pediatric patients, before and after AT.

METHODS

Eight subjects (five males, three females, aged 4-9 years) were imaged using LR-OCT before and after AT during sedated endoscopy. Three-dimensional (3D) airway reconstructions included three airway curvatures. Steady-state, inspiratory airflow simulations were conducted under laminar conditions, along with turbulent simulations for one subject using the k-ω turbulence model. Airway resistance (pressure drop/flow) was compared using two-tailed Wilcoxon signed rank tests.

RESULTS

Regardless of the airway curvatures, CFD findings corroborate a surgical end-goal with computed post-operative airway resistance significantly less than pre-operative (P < 0.01). The individual resistances did not vary significantly for different airway curvatures (P > 0.25). Resistances computed using turbulent simulations differed from laminar results by less than ∼5%.

CONCLUSIONS

The results suggest that reconstruction of the upper airways from LR-OCT imaging data may not need to account for airway curvature to be predictive of surgical effects on airway resistance. Lasers Surg. Med. 51:150-160, 2019. © 2018 Wiley Periodicals, Inc.

Sleep and Breathing the First Night After Adenotonsillectomy in Obese Children With Obstructive Sleep Apnea

STUDY OBJECTIVES

There are few studies measuring postoperative respiratory complications in obese children with obstructive sleep apnea (OSA) undergoing adenotonsillectomy (AT). These complications are further compounded by perioperative medications. Our objective was to study obese children with OSA for their respiratory characteristics and sleep architecture on the night of AT.

METHODS

This was a prospective study at a tertiary pediatric hospital between January 2009-February 2012. Twenty obese children between 8-17 years of age with OSA and adenotonsillar hypertrophy were recruited. Patients underwent baseline polysomnography (PSG) and AT with or without additional debulking procedures, followed by a second PSG on the night of surgery. Demographic and clinical variables, surgical details, perioperative anesthetics and analgesics, and PSG respiratory and sleep architecture parameters were recorded. Statistical tests included Pearson correlation coefficient for correlation between continuous variables and chi-square and Wilcoxon rank-sum tests for differences between groups.

RESULTS

Baseline PSG showed OSA with mean obstructive apnea-hypopnea index (oAHI) 27.1 ± 22.9, SpO₂ nadir 80.1 ± 7.9%, and sleep fragmentation-arousal index 25.5 ± 22.0. Postoperatively, 85% of patients had abnormal sleep studies similar to baseline, with postoperative oAHI 27.0 ± 34.3 (P = .204), SpO₂ nadir, 82.0 ± 8.7% (P = .462), and arousal index, 24.3 ± 24.0 (P = .295). Sleep architecture was abnormal after surgery, showing a significant decrease in REM sleep (P = .003), and a corresponding increase in N2 (P = .017).

CONCLUSIONS

Obese children undergoing AT for OSA are at increased risk for residual OSA on the night of surgery. Special considerations should be taken for postoperative monitoring and treatment of these children.

COMMENTARY

A commentary on this article appears in this issue on page 775.

Indications for tonsillectomy stratified by the level of evidence

Background: One of the most significant clinical trials, demonstrating the efficacy of tonsillectomy (TE) for recurrent throat infection in severely affected children, was published in 1984. This systematic review was undertaken to compile various indications for TE as suggested in the literature after 1984 and to stratify the papers according to the current concept of evidence-based medicine. Material and methods: A systematic Medline research was performed using the key word of "tonsillectomy" in combination with different filters such as "systematic reviews", "meta-analysis", "English", "German", and "from 1984/01/01 to 2015/05/31". Further research was performed in the Cochrane Database of Systematic Reviews, National Guideline Clearinghouse, Guidelines International Network and BMJ Clinical Evidence using the same key word. Finally, data from the "Trip Database" were researched for "tonsillectomy" and "indication" and "from: 1984 to: 2015" in combination with either "systematic review" or "meta-analysis" or "metaanalysis". Results: A total of 237 papers were retrieved but only 57 matched our inclusion criteria covering the following topics: peritonsillar abscess (3), guidelines (5), otitis media with effusion (5), psoriasis (3), PFAPA syndrome (6), evidence-based indications (5), renal diseases (7), sleep-related breathing disorders (11), and tonsillitis/pharyngitis (12), respectively. Conclusions: 1) The literature suggests, that TE is not indicated to treat otitis media with effusion. 2) It has been shown, that the PFAPA syndrome is self-limiting and responds well to steroid administration, at least in a considerable amount of children. The indication for TE therefore appears to be imbalanced but further research is required to clarify the value of surgery. 3) Abscesstonsillectomy as a routine is not justified and indicated only for cases not responding to other measures of treatment, evident complications, or with a significant history of tonsillitis. In particular, interval-tonsillectomy is not justified as a routine. 4) TE, with or without adenoidectomy, is efficacious to resolve sleep-related breathing disorders resulting from (adeno)tonsillar hypertrophy in children. However, the benefit is reduced by co-morbidities, such as obesity, and further research is required to identify prognostic factors for this subgroup of patients. Further research is indicated to clarify selection criteria not only for this subpopulation that may benefit from less invasive procedures such as tonsillotomy in the long-term. 5) Further trials are also indicated to evaluate the efficacy of TE on the clinical course in children with psoriasis guttata as well as on psoriasis vulgaris in adults, not responding to first-line therapy. 6) Conflicting results were reported concerning the role of TE in the concert to treat Ig-A nephropathy, mandating further clinical research. 7) Most importantly, randomized-controlled clinical trials with an adequate long-term follow-up are desirable to clarify the benefit of TE in patients with recurrent episodes of tonsillitis, with or without pharyngitis. Factors like age, spontaneous healing rate and postoperative quality of life have to be included when comparing TE with antibiotic therapy.

Respiratory polygraphy for follow-up of obstructive sleep apnea in children

OBJECTIVES

(1) To evaluate the effectiveness of adenotonsillectomy for the treatment of Obstructive Sleep Apnea Hypopnea Syndrome (OSAHS) in children. (2) To evaluate the usefulness of respiratory polygraphy (RP) for controlling post-adenotonsillectomy effects.

METHODS

The children studied were referred to the Burgos Sleep Unit (SU) with clinical suspicion of OSAHS before undergoing adenotonsillectomy. For all patients, a clinical history was taken and a general physical examination, as well as a specific ear, nose, and throat examination was done. RP before adenotonsillectomy, and seven months afterwards, was also done. OSAHS was diagnosed if the Apnea Hypopnea Index (AHI) was ≥ 4.6.

RESULTS

Of the 100 children studied, 68 were male and 32 female, with an age of 4.17 ± 2.05 years. Using RP, 86 of them were diagnosed with OSAHS before undergoing adenotonsillectomy. There was a significant improvement in all clinical and polygraphic variables after adenotonsillectomy. The pre and post surgery AHI index was 11.9 ± 11.0 and 2.6 ± 1.5, respectively, with a significant mean difference (9.4 ± 10.9, p<0.01). The residual OSAHS was 11.6% (CI 95%: 4.3-19%).

CONCLUSIONS

Respiratory polygraphy is a useful tool for monitoring the effectiveness of surgical treatment and the detection of residual OSAHS in children with adenotonsillar hypertrophy.

Outcome, risk, and error and the child with obstructive sleep apnea

Adenotonsillectomy is the mainstay of treatment for pediatric obstructive sleep apnea syndrome (OSAS). However, there is evidence that the child with severe OSAS is at increased risk of respiratory compromise. The most difficult risk factor to assess is the severity of OSAS, and these difficulties are reviewed.

Executive summary of respiratory indications for polysomnography in children: an evidence-based review

OBJECTIVE

This comprehensive, evidence-based review provides a systematic analysis of the literature regarding the validity, reliability, and clinical utility of polysomnography for characterizing breathing during sleep in children. Findings serve as the foundation of practice parameters regarding respiratory indications for polysomnography in children.

METHODS

A task force of content experts performed a systematic review of the relevant literature and graded the evidence using a standardized grading system. Two hundred forty-three evidentiary papers were reviewed, summarized, and graded. The analysis addressed the operating characteristics of polysomnography as a diagnostic procedure in children and identified strengths and limitations of polysomnography for evaluation of respiratory function during sleep.

RESULTS

The analysis documents strong face validity and content validity, moderately strong convergent validity when comparing respiratory findings with a variety of relevant independent measures, moderate-to-strong test-retest validity, and limited data supporting discriminant validity for characterizing breathing during sleep in children. The analysis documents moderate-to-strong test-retest reliability and interscorer reliability based on limited data. The data indicate particularly strong clinical utility in children with suspected sleep related breathing disorders and obesity, evolving metabolic syndrome, neurological, neurodevelopmental, or genetic disorders, and children with craniofacial syndromes. Specific consideration was given to clinical utility of polysomnography prior to adenotonsillectomy (AT) for confirmation of obstructive sleep apnea syndrome. The most relevant findings include: (1) recognition that clinical history and examination are often poor predictors of respiratory polygraphic findings, (2) preoperative polysomnography is helpful in predicting risk for perioperative complications, and (3) preoperative polysomnography is often helpful in predicting persistence of obstructive sleep apnea syndrome in patients after AT. No prospective studies were identified that address whether clinical outcome following AT for treatment of obstructive sleep apnea is improved in association with routine performance of polysomnography before surgery in otherwise healthy children. A small group of papers confirm the clinical utility of polysomnography for initiation and titration of positive airway pressure support.

CONCLUSIONS

Pediatric polysomnography shows validity, reliability, and clinical utility that is commensurate with most other routinely employed diagnostic clinical tools or procedures. Findings indicate that the "gold standard" for diagnosis of sleep related breathing disorders in children is not polysomnography alone, but rather the skillful integration of clinical and polygraphic findings by a knowledgeable sleep specialist. Future developments will provide more sophisticated methods for data collection and analysis, but integration of polysomnographic findings with the clinical evaluation will represent the fundamental diagnostic challenge for the sleep specialist.

Practice parameters for the respiratory indications for polysomnography in children

BACKGROUND

There has been marked expansion in the literature and practice of pediatric sleep medicine; however, no recent evidence-based practice parameters have been reported. These practice parameters are the first of 2 papers that assess indications for polysomnography in children. This paper addresses indications for polysomnography in children with suspected sleep related breathing disorders. These recommendations were reviewed and approved by the Board of Directors of the American Academy of Sleep Medicine.

METHODS

A systematic review of the literature was performed, and the American Academy of Neurology grading system was used to assess the quality of evidence. RECOMMENDATIONS FOR PSG USE: 1. Polysomnography in children should be performed and interpreted in accordance with the recommendations of the AASM Manual for the Scoring of Sleep and Associated Events. (Standard) 2. Polysomnography is indicated when the clinical assessment suggests the diagnosis of obstructive sleep apnea syndrome (OSAS) in children. (Standard) 3. Children with mild OSAS preoperatively should have clinical evaluation following adenotonsillectomy to assess for residual symptoms. If there are residual symptoms of OSAS, polysomnography should be performed. (Standard) 4. Polysomnography is indicated following adenotonsillectomy to assess for residual OSAS in children with preoperative evidence for moderate to severe OSAS, obesity, craniofacial anomalies that obstruct the upper airway, and neurologic disorders (e.g., Down syndrome, Prader-Willi syndrome, and myelomeningocele). (Standard) 5. Polysomnography is indicated for positive airway pressure (PAP) titration in children with obstructive sleep apnea syndrome. (Standard) 6. Polysomnography is indicated when the clinical assessment suggests the diagnosis of congenital central alveolar hypoventilation syndrome or sleep related hypoventilation due to neuromuscular disorders or chest wall deformities. It is indicated in selected cases of primary sleep apnea of infancy. (Guideline) 7. Polysomnography is indicated when there is clinical evidence of a sleep related breathing disorder in infants who have experienced an apparent life-threatening event (ALTE). (Guideline) 8. Polysomnography is indicated in children being considered for adenotonsillectomy to treat obstructive sleep apnea syndrome. (Guideline) 9. Follow-up PSG in children on chronic PAP support is indicated to determine whether pressure requirements have changed as a result of the child's growth and development, if symptoms recur while on PAP, or if additional or alternate treatment is instituted. (Guideline) 10. Polysomnography is indicated after treatment of children for OSAS with rapid maxillary expansion to assess for the level of residual disease and to determine whether additional treatment is necessary. (Option) 11. Children with OSAS treated with an oral appliance should have clinical follow-up and polysomnography to assess response to treatment. (Option) 12. Polysomnography is indicated for noninvasive positive pressure ventilation (NIPPV) titration in children with other sleep related breathing disorders. (Option) 13. Children treated with mechanical ventilation may benefit from periodic evaluation with polysomnography to adjust ventilator settings. (Option) 14. Children treated with tracheostomy for sleep related breathing disorders benefit from polysomnography as part of the evaluation prior to decannulation. These children should be followed clinically after decannulation to assess for recurrence of symptoms of sleep related breathing disorders. (Option) 15. Polysomnography is indicated in the following respiratory disorders only if there is a clinical suspicion for an accompanying sleep related breathing disorder: chronic asthma, cystic fibrosis, pulmonary hypertension, bronchopulmonary dysplasia, or chest wall abnormality such as kyphoscoliosis. (Option) RECOMMENDATIONS AGAINST PSG USE: 16. Nap (abbreviated) polysomnography is not recommended for the evaluation of obstructive sleep apnea syndrome in children. (Option) 17. Children considered for treatment with supplemental oxygen do not routinely require polysomnography for management of oxygen therapy. (Option)

CONCLUSIONS

Current evidence in the field of pediatric sleep medicine indicates that PSG has clinical utility in the diagnosis and management of sleep related breathing disorders. The accurate diagnosis of SRBD in the pediatric population is best accomplished by integration of polysomnographic findings with clinical evaluation.

An anesthetic management protocol to decrease respiratory complications after adenotonsillectomy in children with severe sleep apnea

BACKGROUND

A high incidence of respiratory morbidity after adenotonsillectomy is reported in children with obstructive sleep apnea syndrome (OSAS). In an effort to decrease this morbidity, we implemented perioperative guidelines recommending an adjustment in the administration of opioids, dexamethasone, and atropine in children with OSAS who demonstrated recurrent episodes of profound hypoxemia during the perioperative sleep study.

METHODS

We performed a retrospective review and compared results with historic data from 2001. The primary outcome variable was a major respiratory medical intervention (MMI(Respiratory)). The severity of OSAS was classified with the McGill Oximetry Scoring (MOS) system, and our focus was on those children demonstrating repetitive desaturation <80% (MOS4).

RESULTS

The medical records of 292 children who underwent adenotonsillectomy between October 2002 and February 2006 met the inclusion criteria and 97 had been assigned MOS4. Eleven children (11.3%) required an MMI(Respiratory). In 2001, 8 children (29.6%), assigned MOS4, required an MMI(Respiratory). Comparing the new and old guidelines, the adjusted odds ratio for MMI(Respiratory) in MOS4 was 0.30 (95% CI: 0.10-0.85). The key elements achieving this reduction in MMI(Respiratory) were dexamethasone administration and a reduced opioid dosage. In 2002 to 2006, the intraoperative opioid dose, expressed in morphine equivalents, administered to the MOS4 group was 0.10 mg . kg(-1) (0.06-0.12 mg . kg(-1)), and the postoperative morphine dose was 0.02 mg . kg(-1) (0-0.07 mg . kg(-1)). Both doses were lower than the ones administered to the concurrent comparison group, P values <0.001.

CONCLUSIONS

A change in practice that included a dexamethasone administration and a reduction in opioid administration to children with profound recurrent hypoxia reduced the incidence of MMI(Respiratory) by >50%.

Perioperative management of children with obstructive sleep apnea

Obstructive sleep apnea syndrome (OSA) affects 1%-3% of children. Children with OSA can present for all types of surgical and diagnostic procedures requiring anesthesia, with adenotonsillectomy being the most common surgical treatment for OSA in the pediatric age group. Thus, it is imperative that the anesthesiologist be familiar with the potential anesthetic complications and immediate postoperative problems associated with OSA. The significant implications that the presence of OSA imposes on perioperative care have been recognized by national medical professional societies. The American Academy of Pediatrics published a clinical practice guideline for pediatric OSA in 2002, and cited an increased risk of anesthetic complications, though specific anesthetic issues were not addressed. In 2006, the American Society of Anesthesiologists published a practice guideline for perioperative management of patients with OSA that noted the pediatric-related risk factor of obesity, and the increased perioperative risk associated with adenotonsillectomy in children younger than 3 yr. However, management of OSA in children younger than 1 yr-of-age was excluded from the guideline, as were other issues related specifically to the pediatric patient. Hence, many questions remain regarding the perioperative care of the child with OSA. In this review, we examine the literature on pediatric OSA, discuss its pathophysiology, current treatment options, and recognized approaches to perioperative management of these young and potentially high-risk patients.

Adenotonsillectomy in the context of obstructive sleep apnoea

Adenotonsillectomy (T&A) is a common surgical procedure. Its frequency is highest in the paediatric age range and its most common current indication is obstructive sleep apnoea (OSA). Sleep studies are used to document the presence and severity of OSA. This review will focus on indications for and complications of T&A in the context of the age range and setting where this surgery is undertaken for OSA in children.

The snoring child

Snoring is a common manifestation of obstructive sleep apnea and represents one end of the spectrum of sleep-related breathing disorders. Children with primary snoring initially may develop OSAS later, so inquiring about symptoms of OSAS should be part of each visit. Obstructive sleep apnea can result in serious cardiovascular and metabolic consequences and neurocognitive deficits. Adenotonsillar hypertrophy remains the most common cause of OSA although the rising prevalence of obesity is of increasing importance. Polysomnography remains the gold standard in the diagnoses of OSAS and in assessing the risks associated with surgery. Most children with OSAS can be treated with adenotonsillectomy in the ambulatory surgery center. However, there are children at risk for severe OSAS and for postoperative complications, who will need PICU care. In addition to adenotonsillectomy, OSAS can be treated successfully in referral centers with other surgical approaches and by the use of positive airway pressure. Children with obesity-related OSAS often require CPAP or BPAP for control of OSAS.

Adenotonsillectomy for Obstructive Sleep Apnea in Children: Outcome Evaluated by Pre- and Postoperative Polysomnography

OBJECTIVE

To evaluate the outcome of adenotonsillectomy for obstructive sleep apnea (OSA) in children using objective data from polysomnography supplemented by subjective proxy reports from the OSA-18 quality of life instrument.

STUDY DESIGN

Prospective cohort study.

METHODS

Children 3 to 14 years of age with OSA diagnosed principally on the basis of polysomnography as having an obstructive apnea/hypopnea index (AHI) of 5 or greater underwent adenotonsillectomy. OSA was classified as mild (AHI > or = 5 < 10), moderate (AHI > or = 10 < 20), or severe (AHI > or =20). Children enrolled in the study also had postoperative polysomnography 3 to 6 months after surgery. Caregivers completed the OSA-18 survey before surgery and within 6 months after surgery. Pearson correlation was used to compare the pre- and postoperative AHI values with the pre- and postoperative OSA-18 total scores. SAS procedures (SAS Corp., Cary, NC) were used for statistical analyses. A P value less than or equal to .05 was considered significant.

RESULTS

The study population included 79 healthy children, 40 of who were male. The mean age was 6.3 (range, 3.0-14.0) years. Only tonsillar size was correlated significantly with a high preoperative AHI. For all children, the preoperative AHI value was higher than the postoperative value. The mean preoperative AHI for the study population was 27.5, whereas the mean postoperative AHI was 3.5. This change was highly significant (P < .001). The percentage of children with normal polysomnography parameters after adenotonsillectomy ranged from 71% to 90% as a function of the criteria used to define OSA. It was highest when an obstructive apnea index less than 1 was used and lowest when an AHI less than 1 was used to define resolution of OSA. Overnight respiratory parameters after adenotonsillectomy were normal for all children with mild OSA. Three (12%) children with moderate preoperative OSA, and 13 (36%) children with severe preoperative OSA had persistent OSA after adenotonsillectomy. Resolution of OSA occurred in all children with a preoperative AHI less than or equal to 10 and in 73% of children with a preoperative AHI greater than 10. The mean total OSA-18 score and the mean scores for all domains showed significant improvement after surgery (P < .001). The preoperative AHI values had a fair correlation with the preoperative total OSA-18 scores (r = 0.28), but postoperative AHI values had a poor correlation with the postoperative total OSA-18 scores (r = 0.16). Caregivers reported snoring some, most, or all of the time in 22 (28%) children; this group included all children with persistent OSA.

CONCLUSIONS

Adenotonsillectomy for OSA results in a dramatic improvement in respiratory parameters as measured by polysomnography in the majority of healthy children. Quality of life also improves significantly after adenotonsillectomy for OSA in children. However, the correlation between improvements in respiratory parameters and improvements in quality of life is poor. Severe preoperative OSA is associated with persistence of OSA after adenotonsillectomy. Postoperative reports of symptoms such as snoring and witnessed apneas correlate well with persistence of OSA after adenotonsillectomy.

Perioperative Complications of Adenotonsillectomy in Children with Obstructive Sleep Apnea Syndrome

We evaluated the rate of complications experienced by children who undergo adenotonsillectomy for obstructive sleep apnea syndrome (OSAS), the safety of a standard anesthetic protocol for these children, and preoperative predictors of complications. Sixty-one children with OSAS, confirmed by polysomnography, and 21 children with recurrent tonsillitis were anesthetized using a standard protocol before adenotonsillectomy (ages 2-16 yr, ASA 1-3). The number of complications and medical interventions in the perioperative period were recorded and correlated with the presence and severity of OSAS. Children with OSAS had more respiratory complications per operation than non-OSAS children (5.7 vs 2.9, P < 0.0001). Supraglottic obstruction, breath holding, and desaturation on anesthetic induction and emergence were the most common complications. Increased severity of OSAS, low weight, and young age are correlated with an increased rate of complications. Medical intervention was necessary in more children with OSAS during recovery and emergence than in the non-OSAS group (17/61 vs 1/21, P < 0.05). Both groups of children had similar opioid requirements and time to discharge from the recovery room. These findings suggest that children with OSAS are at risk for respiratory complications after adenotonsillectomy, but that these complications do not prolong the time to discharge.

Pediatric Sleep-Related Breathing Disorders and Restless Legs Syndrome

Sleep-related breathing disorders and restless legs syndrome have traditionally been felt to affect primarily adults. Recent research suggests that these conditions are surprisingly common in children as well, and that clinical manifestations may differ considerably from those seen in adults. This review summarizes the clinical characteristics, epidemiology, pathophysiology, and treatment of sleep-related breathing disorders and restless legs syndrome in children. Particular emphasis is placed on recent research and on how the presentation and treatment of these conditions are different in children compared with adults.

Obstructive Sleep Apnea Syndrome in Children

Obstructive sleep apnea syndrome is characterized by recurrent episodes of partial or complete obstruction of the upper airway during sleep. This results in the disruption of normal ventilation and sleep patterns. The symptoms, polysomnographic findings, pathophysiology, and treatment of obstructive sleep apnea syndrome are significantly different in children from those seen in adults.

Sleep and breathing on the first night after adenotonsillectomy for obstructive sleep apnea

Adenotonsillectomy (T&A) has established effectiveness for the treatment of obstructive sleep apnea (OSA). However, more than 20% of children with OSA have respiratory compromise requiring medical intervention in the postoperative period. The reasons for this complication are not well-defined. We aimed to compare the nature and severity of sleep-disordered breathing in children with mild and severe OSA on the first night following adenotonsillectomy. Ten children were classified into groups of mild and severe OSA, based on preoperative testing. On the first night after T&A, they underwent polysomnography, including electroencephalograph, submental electromyography, bilateral electro-oculograms, monitoring of respiratory movements, heart rate, ECG, and oxygen saturation. Sleep-disordered breathing was assessed by the apnea-hypopnea index, the SaO(2) nadir, and the desaturation index, including dips in saturation below 90% (DI(90)). Sleep quality was assessed by sleep efficiency, time spent in each sleep state, and respiratory arousal index. Obstructive events occurred postoperatively in all children, but were more frequent in those with severe OSA preoperatively: the median (interquartile range) mixed/obstructive apnea/hypopnea indicies were 6.9 (2.2-9.8) events/hr and 21.5 (15.1-112.1) events/hr for the mild OSA group and the severe OSA group, respectively (P = 0.009). Obstructive events were the major cause of desaturation during sleep postoperatively. Sleep quality was severely disrupted in both groups, with reductions in both slow-wave sleep and rapid eye movement sleep. In conclusion, despite removal of obstructing lymphoid tissue, upper airway obstruction occurred on the first postoperative night in children with OSA. This study is the first to demonstrate the mechanism of respiratory compromise after adenotonsillectomy, a common postoperative complication in children with severe OSA.

Polysomnography in children scheduled for adenotonsillectomy

OBJECTIVE

Several studies suggest that a reliable diagnosis of childhood sleep-disordered breathing (SDB) requires polysomnography (PSG). We compared clinical and PSG-based diagnoses in children scheduled for adenotonsillectomy (AT). Parent responses on a validated Pediatric Sleep Questionnaire were used to determine which symptoms could help identify children with clinical diagnoses of SDB but normal PSG.

STUDY DESIGN AND SETTING

Thirty-four children aged 5.0 to 12.9 years and scheduled for AT to treat clinically diagnosed sleep-disordered breathing underwent laboratory-based PSG. Results were scored by 3 different criteria: 1) >1 obstructive apnea (2 breaths or longer) per hour of sleep; 2) >5 apneas or hypopneas per hour of sleep; or 3) >1 apnea, hypopnea, or respiratory event-related arousal per hour of sleep.

RESULTS

Depending on the criterion used, the PSG documented SDB from a minimum of 18/34 subjects (53%, for criterion I) to as many as 30/34 subjects (88%, for criterion III). Among symptoms studied, absence of daytime mouth breathing and habitual snoring were most helpful in identification of children who had no evidence of SDB on PSG, by criterion I (Chi-square, P < 0.05). The absence of other common symptoms, such as "loud snoring" or "trouble breathing" at night, were not helpful.

CONCLUSION

Children with clinical diagnoses of SDB may not consistently meet PSG criteria for this disorder. Questions about daytime mouth breathing and habitual snoring might help clinicians recognize children who would not have SDB on objective testing.

SIGNIFICANCE

Clinical identification of SDB confirmable on PSG could be improved. However, available outcome data do not yet clarify whether clinical or PSG criteria best identify children likely to suffer morbidity from SDB.

EBM RATING

C.

Upper airway dynamic responses in children with the obstructive sleep apnea syndrome

Normal children have a smaller upper airway than adults, but, nevertheless, snore less and have less apnea. We have previously shown that normal children have an upper airway that is resistant to collapse during sleep. We hypothesized that this resistance to collapse is due to preservation of upper airway neuromotor responses during sleep. Furthermore, we hypothesized that upper airway responses would be diminished in children with the obstructive sleep apnea syndrome (OSAS). We therefore compared the upper airway pressure-flow relationship during sleep between children with OSAS and controls. Measurements were made by correlating maximal inspiratory airflow with the level of nasal pressure applied via a mask. Neuromotor upper airway activation was assessed by evaluating the upper airway response to 1) hypercapnia and 2) intermittent, acute negative pressure. We found that children with OSAS had no significant response to either hypercapnia or negative pressure during sleep, compared with the normal children. After treatment of OSAS by tonsillectomy and adenoidectomy, there was a trend for normalization of upper airway responses. We conclude that upper airway dynamic responses are decreased in children with OSAS but recover after treatment. We speculate that the pharyngeal airway neuromotor responses present in normal children are a compensatory response for a relatively narrow upper airway. Further, we speculate that this compensatory response is lacking in children with OSAS, most likely due to either habituation to chronic respiratory abnormalities during sleep or to mechanical damage to the upper airway.

Age-associated issues in preoperative evaluation, testing, and planning: pediatrics

The author has reviewed recent developments in preoperative assessment and testing, emphasizing issues that are of greatest concern in pediatric patients. Attention to these areas during the process of preoperative preparation and appropriate communication of conditions that may contribute to increased peri-operative risk will provide greater predictability for families, surgeons, and operating room staff. This predictability is an important component to improved patient or family satisfaction and operating room efficiency.

Obstructive sleep apnea in children: do intranasal corticosteroids help?

Obstructive sleep apnea (OSA) is a common condition of childhood, and is associated with significant morbidity. Prevalence of the condition peaks during early childhood, due in part to adenoidal and tonsillar enlargement within a small pharyngeal space. The lymphoid tissues regress after 10 years of age, in the context of ongoing bony growth, and there is an associated fall in the prevalence of OSA. Obstruction of the nasopharynx by adenoidal enlargement promotes pharyngeal airway collapse during sleep, and the presence of large tonsils contributes to airway obstruction. Administration of systemic corticosteroids leads to a reduction in the size of lymphoid tissues due to anti-inflammatory and lympholytic effects. However, a short course of systemic prednisone has been demonstrated not to have a significant effect on adenoidal size or the severity of OSA, and adverse effects preclude the long-term use of this therapy. Intranasal corticosteroids are effective in relieving nasal obstruction in allergic rhinitis, and allergic sensitization is more prevalent among children who snore than among those who do not snore. Intranasal corticosteroids have also been demonstrated to reduce adenoidal size, independent of the individual's atopic status. There is preliminary evidence of an improvement in the severity of OSA in children treated with intranasal corticosteroids, but further studies are needed before such therapy can be routinely recommended. Prescribing clinicians should take into account the potential benefits to the patient, the age of the child, the presence of comorbidities such as allergic rhinitis, the agent used, and the dose and duration of treatment when considering such therapy.

Children with severe OSAS who have adenotonsillectomy in the morning are less likely to have postoperative desaturation than those operated in the afternoon

PURPOSE

To determine, in a subset of children previously reported, if the time of day when adenotonsillectomy for severe obstructive sleep apnea syndrome (OSAS) was performed affected the incidence of postoperative respiratory complications.

CLINICAL FEATURES

Children having adenotonsillectomy were included if they had a polysomnographic diagnosis of severe OSAS within six months prior to operation. Patients who met the inclusion criteria were grouped by the occurrence of postoperative desaturation into a saturated (SAT) and desaturated (deSAT) group. The charts of children in group deSAT were reviewed. The clock time of the surgical procedure was recorded and categorized as morning (AM) or afternoon (PM).

RESULTS

Eighty-eight patients met the inclusion criteria. There were 31 girls and 57 boys. The mean +/- SD age (yr) and weight (kg) were 4.6 +/- 2.9 yr and 20.8 +/- 14.5 kg respectively. There were 63 children in the SAT group and 25 in the deSAT group. Differences in age, weight and gender were not significant. The preoperative oxygen saturation (SaO2) nadir for the SAT and deSAT groups was 80.8 +/- 10.2% and 67.6 +/- 17.5% (P < 0.05) respectively. The preoperative obstructive apnea and hypopnea index was 15.8 +/- 10.2 and 35.7 +/- 34.6 events.hr(-1) (P < 0.05), respectively. Surgery in 63 (71.6%) children was performed in the AM. Univariate logistic regression identified PM surgery [odds ratio (OR) 4.6, 95% confidence interval (CI) 1.7 to 12.6, P = 0.002] and a preoperative SaO2 nadir < 80% (OR 3.6, 95% CI 1.4 to 9.4, P = 0.009) as risk factors predicting postadenotonsillectomy desaturation.

CONCLUSION

Children with severe OSAS whose surgery is performed in the AM are less likely to desaturate following adenotonsillectomy than children whose surgery is performed in the PM.

Complications of adenotonsillectomy in children with OSAS younger than 2 years of age

The most common sleep disorder in children is obstructive sleep apnea syndrome (OSAS). The majority of children with OSAS improve following tonsillectomy and adenoidectomy (T&A). T&A as an outpatient procedure in children is very common. Young age in considered risk factors for postoperative respiratory complications. The purpose of this study is to analyze our experience with postoperative T&A complications in patients younger than 2 years of age. A total of 39 T&A were performed in children younger than 2 years of age. OSAS diagnosis was confirmed by overnight polysomnography (PSG). All the patients were hospitalized and monitored by overnight pulse oximetry monitoring. Post-operatively there was marked improvement in respiratory function in all the patients comparing pre- and post-operative nadir oxygen saturation (P<0.05). Complications were documented in seven patients (20%). Five of the complications occurred in children older than 1 year of age. Bleeding occurred in two patients (5.7%). Three patients (8.6%) had dehydration, one patient (2.9%) had hypercarbia and one patient had laryngospasm. In this study there was a low incidence of peri- and post- operative respiratory complications in children younger than 2 years of age who undergo T&A for OSAS. Identification of OSAS severity may be an important factor in determining the risk of T&A in a young child.

Obstructive sleep apnea in children: an update

The diagnosis of obstructive sleep apnea in children requires clinical suspicion supplemented with the use of specific diagnostic tests. Polysomnography remains the key to diagnosis, and helps to assess the need for treatment, the risk for perioperative respiratory compromise, and the likelihood of persistent OSAS after treatment. Adenotonsillectomy is the mainstay of treatment, although children with complex medical conditions that affect upper airway anatomy and tone may require additional treatment.

Treatment of obstructive sleep apnea in children: do we really know how?

Obstructive sleep apnea syndrome (OSAS) is a frequent, albeit underdiagnosed problem in children. If left untreated, OSAS may lead to substantial morbidities affecting multiple target organs and systems. The immediate consequences of OSAS in children include behavioral disturbance and learning deficits, pulmonary hypertension, as well as compromised somatic growth. However, if not treated promptly and early in the course of the disease, OSAS may also impose long-term adverse effects on neurocognitive and cardiovascular function, thereby providing a strong rationale for effective treatment of this condition. This review provides a detailed description of the current treatment modalities for pediatric OSAS, and uncovers the potential limitations of the available data on these issues. Furthermore, we postulate that OSAS will persist relatively often after tonsillectomy and adenoidectomy, and that critical studies need to be conducted to identify such patients and refine the clinical management algorithm for pediatric OSAS.

Effects of OSA, inhalational anesthesia, and fentanyl on the airway and ventilation of children

To assess effects of anesthesia and opioids, we studied 13 children with obstructive sleep apnea (OSA, age 4.0 +/- 2.2 yr, mean +/- SD) and 24 age-matched control subjects (5.8 +/- 4.0 yr). Apnea indexes of children with OSA were 29.4 +/- 18 h-1, median 30 h-1. Under inhalational anesthetic, closing pressure at the mask was 2.2 +/- 6.9 vs. -14.7 +/- 7.8 cmH2O, OSA vs. control (P < 0.001). After intubation, spontaneous ventilation was 115.5 +/- 56.9 vs. 158.7 +/- 81.6 ml x kg-1 small middle dot min-1, OSA vs. control (P = 0.02), despite elevated PCO2 (49.3 vs. 42.1 Torr, OSA vs. control, P < 0.001). Minute ventilation fell after fentanyl (0.5 microg/kg iv), with central apnea in 6 of 13 OSA cases vs. 1 of 23 control subjects (P < 0.001). Consistent with the finding of reduced spontaneous ventilation, apnea was most likely when end-tidal CO2 exceeded 50 Torr during spontaneous breathing under anesthetic. Thus children with OSA had depressed spontaneous ventilation under anesthesia, and opioids precipitated apnea in almost 50% of children with OSA who were intubated but breathing spontaneously under inhalational anesthesia.

Technical report: diagnosis and management of childhood obstructive sleep apnea syndrome

OBJECTIVE

This technical report describes the procedures involved in developing the recommendations of the Subcommittee on Obstructive Sleep Apnea Syndrome in children. The group of primary interest for this report was otherwise healthy children older than 1 year who might have adenotonsillar hypertrophy or obesity as underlying risk factors of obstructive sleep apnea syndrome (OSAS). The goals of the committee were to enhance the primary care clinician's ability to recognize OSAS, identify the most appropriate procedure for diagnosis of OSAS, identify risks associated with pediatric OSAS, and evaluate management options for OSAS.

METHODS

A literature search was initially conducted for the years 1966-1999 and then updated to include 2000. The search was limited to English language literature concerning children older than 2 and younger than 18 years. Titles and abstracts were reviewed for relevance, and committee members reviewed in detail any possibly appropriate articles to determine eligibility for inclusion. Additional articles were obtained by a review of literature and committee members' files. Committee members compiled evidence tables and met to review and discuss the literature that was collected.

RESULTS

A total of 2115 titles were reviewed, of which 113 provided relevant original data for analysis. These articles were mainly case series and cross-sectional studies; overall, very few methodologically strong cohort studies or randomized, controlled trials concerning OSAS have been published. In addition, a minority of studies satisfactorily differentiated primary snoring from true OSAS. Reports of the prevalence of habitual snoring in children ranged from 3.2% to 12.1%, and estimates of OSAS ranged from 0.7% to 10.3%; these studies were too heterogeneous for data pooling. Children with sleep-disordered breathing are at increased risk for hyperactivity and learning problems. The combined odds ratio for neurobehavioral abnormalities in snoring children compared with controls is 2.93 (95% confidence interval: 2.23-3.83). A number of case series have documented decreased somatic growth in children with OSAS; right ventricular dysfunction and systemic hypertension also have been reported in children with OSAS. However, the risk growth and cardiovascular problems cannot be quantified from the published literature. Overnight polysomnography (PSG) is recognized as the gold standard for diagnosis of OSAS, and there are currently no satisfactory alternatives. The diagnostic accuracy of symptom questionnaires and other purely clinical approaches is low. Pulse oximetry appears to be specific but insensitive. Other methods, including audiotaping or videotaping and nap or home overnight PSG, remain investigational. Adenotonsillectomy is curative in 75% to 100% of children with OSAS, including those who are obese. Up to 27% of children undergoing adenotonsillectomy for OSAS have postoperative respiratory complications, but estimates are varied. Risk factors for persistent OSAS after adenotonsillectomy include continued snoring and a high apnea-hypopnea index on the preoperative PSG.

CONCLUSIONS

OSAS is common in children and is associated with significant sequelae. Overnight PSG is currently the only reliable diagnostic modality that can differentiate OSAS from primary snoring. However, the PSG criteria for OSAS have not been definitively validated, and it is not clear that primary snoring without PSG-defined OSAS is benign. Adenotonsillectomy is the first-line treatment for OSAS but requires careful postoperative monitoring because of the high risk of respiratory complications. Adenotonsillectomy is usually curative, but children with persistent snoring (and perhaps with severely abnormal preoperative PSG results) should have PSG repeated postoperatively.

Perioperative management issues in pediatric patients

Recent developments in perioperative practice, emphasizing issues that are of greatest concern in pediatric patients, are reviewed in this article. Many areas bear further evaluation in the evolving field of perioperative medicine: Effective techniques of psychologic preparation for children and their parents in an era in which the family rarely encounters the hospital environment before the day of surgery Application of newer intraoperative anesthetics, such as new narcotics and muscle relaxants, to shorten PACU and pediatric ICU stay while maintaining safety and comfort Critical evaluation of current methods of pain management to optimize comfort, while minimizing cost of such management in an increasingly cost-conscious health care environment The recent advent of a process for credentialing pediatric anesthesia fellowship programs, which requires a research component, bodes well for the prospect of finding answers to some of these questions.

Pediatric obstructive sleep apnea syndrome

Pediatric obstructive sleep apnea occurs in about 2% of children, and manifests as snoring, difficulty breathing, and witnessed apneic spells. Daytime symptoms include excessive sleepiness with poor performance and behavior problems. Severe forms may be associated with failure-to-thrive or death. The gold standard diagnostic procedure is overnight polysomnography and is indicated in high-risk patients. While most pediatric patients with obstructive sleep apnea can be treated with tonsillectomy and adenoidectomy; uvulopalatopharyngoplasty, tracheotomy, or other procedures are sometimes indicated. Nonsurgical treatment with continuous positive airway pressure is used in some children. Postoperative management in high-risk children includes careful perioperative monitoring and postoperative polysomnography.

Sleep apnea treatment improves seizure control in children with neurodevelopmental disorders

Seizure disorder and sleep apnea are common chronic disorders in children, but the relationship between sleep apnea and seizure control has not been studied in the pediatric population. This retrospective review included nine children with neurodevelopmental disorders who had well-documented sleep apneic episodes and seizure disorders. Seizure frequency was reduced in five patients (56%) in the first 12 months after sleep apnea treatment without changes in their antiepileptic medications. Sleep apnea can be one of the seizure precipitants in children with epilepsy. This study indicates the importance of identifying sleep apnea when treating children with intractable epilepsy, particularly in those who are at high risk.

Obstructive sleep apnoea syndrome in children

Obstructive sleep apnoea syndrome in children is a complex disorder characterised by repeated nocturnal episodes of increased upper airway resistive load. It is most commonly associated with adenotonsillar hypertrophy and more children are now presenting for adenotonsillectomy. These children may pose different anaesthetic problems to those having surgery for recurrent infection alone and anaesthetic morbidity and mortality has been reported. In addition, due to the varied symptomatology of the condition, children with unrecognised obstructive sleep apnoea syndrome may present for incidental surgery. This is of importance as patients with undiagnosed obstructive sleep apnoea syndrome may experience additional peri-operative morbidity when undergoing incidental surgery. This article aims to review the aetiology, pathophysiology, clinical presentation and anaesthetic management of children with obstructive sleep apnoea syndrome.