End-Tidal Carbon Dioxide Measurement during Pediatric Polysomnography: Signal Quality, Association with Apnea Severity, and Prediction of Neurobehavioral Outcomes

'Personalized medicine': phenotyping pediatric obstructive sleep apnea

PURPOSE OF REVIEW

Obstructive sleep apnea (OSA) is common in children. Phenotyping pediatric OSA has a crucial role in personalized diagnosis and treatment to improve outcomes for this population. This review sets forth a clinical approach that allows for phenotyping pediatric OSA.

RECENT FINDINGS

The emerging concept of phenotyping pediatric OSA is based on identifying a primary cause, which leads to a more precise understanding of the pathogenesis in any individual patient. Phenotyping enables treatment focusing on the primary cause, but does not exclude the need for supplemental management strategies based on other recognizable traits. The identification of pediatric OSA phenotypes (POP) relies on observable characteristics with significant prevalence. This review will concentrate on the most important phenotypes seen in clinical practice: pediatric OSA with craniofacial abnormalities (POPCA); OSA with upper airway disease (POPUAD); OSA with obesity (POPO), and OSA associated with neuromuscular disease (POPNED).

SUMMARY

Phenotyping pediatric OSA is a form of personalized medicine. By identifying clinical subtypes, individualized treatment plans can be devised in order to choose therapies that are associated with predictable responses. Moreover, it is rare that a therapeutic modality is devoid of possible complications; knowledge of the phenotype being treated can enable early intervention should those occur. Finally, all of the aforementioned phenotypes require personalized support incorporating individualized care plans so as to optimize the quality of life and overall sleep health of children with OSA.

The effect of anesthesia without opioid on perioperative opioid demand in children with severe obstructive sleep apnea (OSA) for adenotonsillectomies — single-center retrospective observational study

Background

Children with severe obstructive sleep apnea (OSA) carry a higher risk of respiratory complications after adenotonsillectomy. Their altered sensitivity to opioids may be a significant contributor to respiratory morbidity. The purpose of this study was to identify how anesthesia without opioids affects perioperative opioid demand and postoperative course.

Methods

A chart review of children with severe OSA (apnea hypoxia index; AHI ≥ 10) undergoing adenotonsillectomies was performed. Comorbidities and perioperative medications were documented. Perioperative opioid doses within 48 h of procedure were calculated as morphine equivalents (mcg/kg). Pain scores, rescue medications, and postoperative complications in PICU and non-PICU settings were also documented. Anesthesia without opioid and with opioid groups were compared.

Results

The analysis included 225 children. A significantly higher percentage of children received no postoperative opioids in the anesthesia without opioid group compared to those with opioid (46 of 88 children vs. 43 of 137; P < 0.05). The incidence of severe postoperative pain between the two groups was not different in PICU (P = 0.88) or non-PICU setting (P = 0.84). Perioperative opioid administration was significantly lower in anesthesia without opioid (median, Q1, Q3: 0.0, 0.0, 83.0) compared to with opioid (144.4, 72.5, 222.2; P < 0.01). Anesthesia without opioid was one of the independent factors to achieve perioperative opioid avoidance (<50mcg/kg).

Conclusions

Anesthesia without opioid for children with severe OSA for tonsillectomy significantly reduced perioperative demand for opioid and did not affect the occurrence of severe pain. Anesthesia without opioid is an effective strategy to minimalize opioid demand perioperatively for children with severe OSA for tonsillectomy.

Perioperative respiratory adverse events during ambulatory anesthesia in obese children

Obesity is one of the most common clinical conditions in the pediatric population with an increasing prevalence ranging from 20 to 30% worldwide. It is well known that during ambulatory anesthesia, obese children are more prone to develop perioperative respiratory adverse events (PRAEs) associated with obesity. To avoid or at least minimize these adverse effects, a thorough preoperative assessment should be undertaken as well as consideration of specific anesthetic approaches such as preoxygenation before induction of anesthesia and optimizing drug dosing. The use of short-acting opioid and nonopioid analgesics and the frequent implementation of regional anesthesia should also be included. Noninvasive airway management, protective mechanical ventilation, and complete reversion of neuromuscular blockade and awake extubation also proved to be beneficial in preventing PRAEs. During the postoperative period, continuous monitoring of oxygenation and ventilation is mandatory in obese children. In the current review, we sought to provide recommendations that might help to reduce the severity of perioperative respiratory adverse events in obese children, which could be of particular importance for reducing the rate of unplanned hospitalizations and ultimately improving the overall postoperative recovery.

Characteristics of Children Likely to Have Spontaneous Resolution of Obstructive Sleep Apnea: Results from the Childhood Adenotonsillectomy Trial (CHAT)

OBJECTIVE

To evaluate if cardiopulmonary coupling (CPC) calculated sleep quality (SQI) may have a role in identifying children that may benefit from other intervention than early adenotonsillectomy (eAT) in management of obstructive sleep apnea (OSA).

METHODS

A secondary analysis of electrocardiogram-signals (ECG) and oxygen saturation-data (SpO₂) collected during polysomnography-studies in the prospective multicenter Childhood Adenotonsillectomy Trial (CHAT) to calculate CPC-SQI and apnea hypopnea index (AHI) was executed. In the CHAT, children 5-9 years with OSA without prolonged oxyhemoglobin desaturations were randomly assigned to adenotonsillectomy (eAT) or watchful waiting with supportive care (WWSC). The primary outcomes were to document change in attention and executive function evaluated with the Developmental Neuropsychological Assessment (NEPSY). In our analysis, children in the WWSC-group with spontaneous resolution of OSA (AHI_Obstructive < 1.0) and high-sleep quality (SQI ≥ 75) after 7-months were compared with children that showed residual OSA.

RESULTS

Of the 227 children randomized to WWSC, 203 children had available data at both baseline and 7-month follow-up. The group that showed resolution of OSA at month 7 (n = 43, 21%) were significantly more likely to have high baseline SQI 79.96 [CI_95% 75.05, 84.86] vs. 72.44 [CI_95% 69.50, 75.39], p = 0.005, mild OSA AHI_Obstructive 4.01 [CI_95% 2.34, 5.68] vs. 6.52 [CI_95% 5.47, 7.57], p= 0.005, higher NEPSY-attention-executive function score 106.22 [CI_95% 101.67, 110.77] vs. 101.14 [CI_95% 98.58, 103.72], p = 0.038 and better quality of life according to parents 83.74 [CI_95% 78.95, 88.54] vs. 77.51 [74.49, 80.53], p = 0.015. The groups did not differ when clinically evaluated by Mallampati score, Friedman palate position or sleep related questionnaires.

CONCLUSIONS

Children that showed resolution of OSA were more likely to have high-SQI and mild OSA, be healthy-weight and have better attention and executive function and quality of life at baseline. As this simple method to evaluate sleep quality and OSA is based on analyzing signals that are simple to collect, the method is practical for sleep-testing, over multiple nights and on multiple occasions. This method may assist physicians and parents to determine the most appropriate therapy for their child as some children may benefit from WWSC rather than interventions. If the parameters can be used to plan care a priori, this would provide a fundamental shift in how childhood OSA is diagnosed and managed.

The Effect of Adenotonsillectomy on Children's Behavior and Cognitive Performance with Obstructive Sleep Apnea Syndrome: State of the Art

(1) Background: This systematic review was designed to analyze adenotonsillectomy’s role in treating behavioural disorders and sleep-related quality of life in pediatric OSAS. (2) Methods: Papers that report pre-operative and post-operative outcomes by using the Epworth sleepiness scale, OSA-18, NEPSY, Conners’ rating scale, BRIEF, PSQ-SRBD, PedsQL and CBCL. We performed a comprehensive review of English papers published during the last 20 years regarding behavioural disorders in OSAS patients and adenotonsillectomy. (3) Results: We included 11 studies reporting behavioral outcomes and sleep related quality of life after surgery. We investigated changes in behavior and cognitive outcomes after AT, and we found significant improvements of the scores post-AT in almost all studies. After comparing the AT group and control group, only one study had no difference that reached significance at one year post-AT. In another study, it did not show any significant improvement in terms of all behavioural and cognitive outcomes. The questionnaires on sleep-related quality of life after AT (PSQ-SRBD or ESS or OSA-18 or KOSA) may improve with positive changes in sleep parameters (AHI, ODI and SpO2). Furthermore, there is a significantly higher decrease in OSAS symptoms than the pre-AT baseline score. (4) Conclusion: Future studies should pay more attention to characterizing patient populations as well as rapid surgical treatments through existing criteria.

Phenotypic variance in pediatric obstructive sleep apnea

It is crucial that clinicians understand what underpins the considerable phenotypic variance in pediatric obstructive sleep apnea syndrome (OSAS), if they are to implement individually tailored phenotype-based approaches to diagnosis and management. This review summarizes the current literature on how disease severity, comorbidities, genetic and environmental/lifestyle factors interact to determine the overall OSAS phenotype. The first part discusses the impact of these factors on OSAS-related morbidity in the context of otherwise healthy children, whilst the second half details children with complex conditions, particularly focusing on the anatomical and functional abnormalities predisposing to upper airway obstruction unique to each condition. One can then understand the need for a multidimensional assessment strategy for pediatric OSAS; one that incorporates the history, physical examination, sleep study results, and biomarkers to enable precise stratification, so vital for effective determination of the timing and the nature of the therapeutic interventions required.

Childhood Obesity and Respiratory Diseases: Which Link?

Prevalence of childhood obesity is progressively increasing, reaching worldwide levels of 5.6% in girls and of 7.8% in boys. Several evidences showed that obesity is a major preventable risk factor and disease modifier of some respiratory conditions such as asthma and Obstructive Sleep Apnea Syndrome (OSAS). Co-occurrence of asthma and obesity may be due to common pathogenetic factors including exposure to air pollutants and tobacco smoking, Western diet, and low Vitamin D levels. Lung growth and dysanapsis phenomenon in asthmatic obese children play a role in impaired respiratory function which appears to be different than in adults. Genes involved in both asthma and obesity have been identified, though a gene-by-environment interaction has not been properly investigated yet. The identification of modifiable environmental factors influencing gene expression through epigenetic mechanisms may change the natural history of both diseases. Another important pediatric respiratory condition associated with obesity is Sleep-Disordered Breathing (SDB), especially Obstructive Sleep Apnea Syndrome (OSAS). OSAS and obesity are linked by a bidirectional causality, where the effects of one affect the other. The factors most involved in the association between OSAS and obesity are oxidative stress, systemic inflammation, and gut microbiota. In OSAS pathogenesis, obesity's role appears to be mainly due to mechanical factors leading to an increase of respiratory work at night-time. However, a causal link between obesity-related inflammatory state and OSAS pathogenesis still needs to be properly confirmed. To prevent obesity and its complications, family education and precocious lifestyle changes are critical. A healthy diet may lead to an improved quality of life in obese children suffering from respiratory diseases. The present review aimed to investigate the links between obesity, asthma and OSAS, focusing on the available evidence and looking for future research fields.

Oxidative Stress and Inflammation Biomarker Expression in Obstructive Sleep Apnea Patients

Obstructive Sleep Apnea Syndrome (OSAS) is a respiratory sleep disorder characterised by repeated episodes of partial or complete obstruction of the upper airway during the night. This obstruction usually occurs with a reduction (hypopnea) or complete cessation (apnea) of the airflow in the upper airways with the persistence of thoracic-diaphragmatic respiratory movements. During the hypopnea/apnea events, poor alveolar ventilation reduces the oxygen saturation in the arterial blood (SaO₂) and a gradual increase in the partial arterial pressure of carbon dioxide (PaCO₂). The direct consequence of the intermittent hypoxia is an oxidative imbalance, with reactive oxygen species production and the inflammatory cascade’s activation with pro and anti-inflammatory cytokines growth. Tumour necrosis factors, inflammatory cytokines (IL2, IL4, IL6), lipid peroxidation, and cell-free DNA have been found to increase in OSAS patients. However, even though different risk-related markers have been described and analysed in the literature, it has not yet been clarified whether specified inflammatory bio-markers better correlates with OSAS diagnosis and its clinical evolution/comorbidities. We perform a scientific literature review to discuss inflammatory and oxidative stress biomarkers currently tested in OSAS patients and their correlation with the disease’s severity and treatment.

TcCO2 changes correlate with partial obstruction in children suspected of sleep disordered breathing

INTRODUCTION

Pediatric sleep disordered breathing (SDB) is characterized by long periods of partial upper airway obstruction (UAO) with low apnea-hypopnea indices (AHI). By measuring snoring and stertor, Sonomat studies allow quantification of these periods of partial UAO.

AIM

To determine whether transcutaneous CO₂ (TcCO₂ ) levels correlate with increasing levels of partial UAO and to examine patterns of ΔTcCo₂ in the transitions from (a) wakefulness to sleep and (b) non-rapid eye movement (NREM) to rapid eye movement (REM) sleep.

METHODS

This was a retrospective review of sleep studies in seven asymptomatic controls aged 7 to 12 years and 62 symptomatic children with suspected SDB and no comorbidities, aged 2 to 13 years. Both groups underwent overnight polysomnography, including continuous TcCO₂ , at one of two pediatric hospitals in Sydney. Changes in carbon dioxide levels between wake to NREM (sleep onset) and NREM to REM sleep were evaluated using an all-night TcCO₂ trace time-linked to a hypnogram. Paired Sonomat recordings were used to quantify periods of UAO in the symptomatic group.

RESULTS

The ΔTcCO₂ at sleep onset was greater in SDB children than controls and ΔTcCO₂ with sleep onset correlated with the duration of partial obstruction (r = .60; P < .0001). Children with an increase in TcCO₂ from NREM to REM had a higher number of snoring and stertor events compared to those in whom TcCO₂ decreased from NREM to REM (91 vs 30 events/h; P = < .0001).

CONCLUSIONS

In children without comorbidities, the measurement of TcCO₂ during sleep correlates with indicators of partial obstruction.

The Effect of Tonsillectomy and Adenoidectomy on Isolated Sleep Associated Hypoventilation in Children

OBJECTIVE

Sleep associated hypoventilation (SAH) is diagnosed when more than 25% of total sleep time (%TST) is spent with end tidal carbon dioxide (EtCO₂ ) > 50 mmHg. SAH in children occurs as a single entity or combined with obstructive sleep apnea. Outcomes of surgical treatment for isolated SAH in children have not been reported.

METHODS

The medical charts of children who were diagnosed with isolated SAH and did not have OSA at a tertiary children's hospital between January 2013 and December 2019 were reviewed. Data collection included information on history and physical examination, past medical history, polysomnography (PSG) findings, and surgical management.

RESULTS

Seventeen children (10 male, 7 female, age range: 3-14 years) were diagnosed with isolated SAH. Comorbid conditions included asthma in four children, Down syndrome in one, and seizure in two. Eight children were normal weight, four were overweight, and five were obese. Children did not have obstructive or central sleep apnea. Three children (18%) had persistent SAH as documented by PSG. All normal weight children had resolution of SAH whereas two obese children and one overweight child had residual SAH. %TST with CO₂ > 50 mmHg after upper airway surgery (3.4% ± 1.6%) was significantly less than that of before TA (59.1% ± 5.5%) (P < .001).

CONCLUSIONS

The majority of children with isolated SAH had normalization of hypercapnia after TA. Further studies in larger groups of children are needed to identify the risk factors for residual isolated SAH after TA.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:E1380-E1382, 2021.

Sleep-Disordered Breathing and Airway Assessment Using Polysomnography in Pediatric Patients With Craniofacial Disorders

Children with cleft and craniofacial conditions commonly present with concurrent airway anomalies, which often manifest as sleep disordered breathing. Craniofacial surgeons and members of the multidisciplinary team involved in the care of these patients should appreciate and understand the scope of airway pathology as well as the proper means of airway assessment. This review article details the prevalence and assessment of sleep disordered breathing in patients with craniofacial anomalies, with emphasis on indications, limitations, and interpretation of polysomnography.

Treatment of Obstructive Sleep Apnea in Children: Handling the Unknown with Precision

Treatment approaches to pediatric obstructive sleep apnea (OSA) have remarkably evolved over the last two decades. From an a priori assumption that surgical removal of enlarged upper airway lymphadenoid tissues (T&A) was curative in the vast majority of patients as the recommended first-line treatment for pediatric OSA, residual respiratory abnormalities are frequent. Children likely to manifest persistent OSA after T&A include those with severe OSA, obese or older children, those with concurrent asthma or allergic rhinitis, children with predisposing oropharyngeal or maxillomandibular factors, and patients with underlying medical conditions. Furthermore, selection anti-inflammatory therapy or orthodontic interventions may be preferable in milder cases. The treatment options for residual OSA after T&A encompass a large spectrum of approaches, which may be complementary, and clearly require multidisciplinary cooperation. Among these, continuous positive airway pressure (CPAP), combined anti-inflammatory agents, rapid maxillary expansion, and myofunctional therapy are all part of the armamentarium, albeit with currently low-grade evidence supporting their efficacy. In this context, there is urgent need for prospective evidence that will readily identify the correct candidate for a specific intervention, and thus enable some degree of scientifically based precision in the current one approach fits all model of pediatric OSA medical care.

Hypoventilation disproportionate to OSAS severity in children with Prader-Willi syndrome

OBJECTIVE

To test the hypothesis that children with Prader-Willi syndrome (PWS) and obstructive sleep apnoea syndrome (OSAS) have hypercapnia for higher proportion of total sleep time (TST) than non-syndromic children with similar obstructive apnoea-hypopnoea index (OAHI).

DESIGN

Cross-sectional study.

SETTING

Two tertiary care hospitals.

PATIENTS

Patients with PWS and non-syndromic children with snoring who underwent polygraphy and were of similar age, body mass index (BMI) z-score and OAHI.

MAIN OUTCOME MEASURE

The two groups were compared regarding %TST with transcutaneous CO₂ (PtcCO₂) >50 mm Hg. The interaction between PWS diagnosis and OSAS severity (OAHI <1 episode/h vs 1-5 episodes/h vs >5 episodes/h) regarding %TST with PtcCO₂ >50 mm Hg was tested using multiple linear regression.

RESULTS

48 children with PWS and 92 controls were included (median age 2.3 (range 0.2-14.1) years vs 2.2 (0.3-15.1) years; BMI z-score 0.7±1.9 vs 0.8±1.7; median OAHI 0.5 (0-29.5) episodes/h vs 0.5 (0-33.9) episodes/h; p>0.05). The two groups did not differ in %TST with PtcCO₂ >50 mm Hg (median 0% (0-100%) vs 0% (0-81.3%), respectively; p>0.05). However, the interaction between PWS and OSAS severity with respect to duration of hypoventilation was significant (p<0.01); the estimated mean differences of %TST with PtcCO₂ >50 mm Hg between children with PWS and controls for OAHI <1 episode/h, 1-5 episodes/h and >5 episodes/h were +0.2%, +1% and +33%, respectively.

CONCLUSION

Increasing severity of upper airway obstruction during sleep in children with PWS is accompanied by disproportionately longer periods of hypoventilation when compared with non-syndromic children with similar frequency of obstructive events.

Neurodevelopmental Outcomes at Two Years of Age for Premature Infants Diagnosed With Neonatal Obstructive Sleep Apnea

STUDY OBJECTIVES

Neurocognitive deficits have been shown in school-aged children with sleep apnea. The effect of obstructive sleep apnea (OSA) on the neurodevelopmental outcome of preterm infants is unknown.

METHODS

A retrospective chart review was performed for all preterm infants (< 37 weeks) who had neonatal polysomnography (PSG) and completed neurodevelopmental assessment with the Bayley Scales of Infant and Toddler Development, 3rd Edition, between 2006 to 2015 at Riley Hospital. Exclusion criteria included grade IV intraventricular hemorrhage, tracheostomy, cyanotic heart disease, severe retinopathy of prematurity, craniofacial anomalies, or central and mixed apnea on PSG. Sleep apnea was defined as an apnea-hypopnea index (AHI) > 1 event/h. Regression analyses were performed to find a relationship between PSG parameters and cognitive, language, and motor scores.

RESULTS

Fifteen patients (males: n = 10) were eligible for the study. Median postmenstrual age at the time of the PSG was 41 weeks (37-46). Median AHI for the cohort was 17.4 events/h (2.2-41.3). Median cognitive, language, and motor scores were 90 (65-125), 89 (65-121), and 91 (61-112), respectively. Mean end-tidal CO2 (median 47 mm Hg [25-60]) negatively correlated with cognitive scores (P = .01) but did not significantly correlate with language or motor scores. AHI was not associated with cognitive, language, or motor scores.

CONCLUSIONS

The median score for cognitive, language, and motor scores for preterm infants with neonatal OSA were within one standard deviation of the published norm. Mean end-tidal CO2, independent of AHI, may serve as a biomarker for predicting poor cognitive outcome in preterm infants with neonatal OSA.

COMMENTARY

A commentary on this article appears in this issue on page 1233.

Evaluation of MIh Scoring System in Diagnosis of Obstructive Sleep Apnea Syndrome

Background

The objective of the present study was to investigate whether the analysis of magnesium (Mg), high-sensitivity C-reactive protein (hsCRP), and ischemia-modified albumin (IMA) concentrations can be used as a non-invasive and convenient method for diagnosing obstructive sleep apnea syndrome (OSAS).

Material/Methods

After polysomnography, venous blood was collected from 33 patients with OSAS and 30 control individuals. Serum levels of Mg, hsCRP, and IMA were investigated. The relationship between these factors and apnea–hypopnea index (AHI) was analyzed using the Pearson correlation coefficient. The role of the factors was determined using a receiver operating characteristic (ROC) curve and multivariate logistic regression analysis.

Results

The levels of hsCRP and IMA were significantly higher in patients with OSAS than in control subjects, while the levels of Mg were lower (P<0.05 for all). A significant correlation was noted between serum IMA (r=0.614; P<0.001) and hsCRP (r=0.453; P<0.001) levels and the AHI. The ROC showed that serum Mg (AUC=0.74(0.62–0.85)), hsCRP (AUC=0.77(0.65–0.87)), and IMA (AUC=0.78(0.66–0.87)) levels could be used as markers to diagnose OSAS. Moreover, our new model, MIh, which is obtained by multivariate analysis, yielded an AUC value of 0.93 (0.83–0.98). Continuous positive airway pressure (CPAP) treatment reversed the changes in the serum levels of Mg, hsCRP, and IMA.

Conclusions

Patients with OSAS show reduced serum Mg levels and elevated serum hsCRP and IMA levels. These observed alterations can be reversed by CPAP treatment. A novel model, named MIh, may be a promising tool for OSAS diagnosis.

Tonsillectomy for Obstructive Sleep-Disordered Breathing: A Meta-analysis

CONTEXT

The effectiveness of tonsillectomy or adenotonsillectomy (hereafter, "tonsillectomy") for obstructive sleep-disordered breathing (OSDB) compared with watchful waiting with supportive care is poorly understood.

OBJECTIVE

To compare sleep, cognitive or behavioral, and health outcomes of tonsillectomy versus watchful waiting with supportive care in children with OSDB.

DATA SOURCES

Medline, Embase, and the Cochrane Library.

STUDY SELECTION

Two investigators independently screened studies against predetermined criteria.

DATA EXTRACTION

Two investigators independently extracted key data. Investigators independently assessed study risk of bias and the strength of the evidence of the body of literature. Investigators synthesized data qualitatively and meta-analyzed apnea-hypopnea index (AHI) scores.

RESULTS

We included 11 studies. Relative to watchful waiting, most studies reported better sleep-related outcomes in children who had a tonsillectomy. In 5 studies including children with polysomnography-confirmed OSDB, AHI scores improved more in children receiving tonsillectomy versus surgery. A meta-analysis of 3 studies showed a 4.8-point improvement in the AHI in children who underwent tonsillectomy compared with no surgery. Sleep-related quality of life and negative behaviors (eg, anxiety and emotional lability) also improved more among children who had a tonsillectomy. Changes in executive function were not significantly different. The length of follow-up in studies was generally <12 months.

LIMITATIONS

Few studies fully categorized populations in terms of severity of OSDB; outcome measures were heterogeneous; and the durability of outcomes beyond 12 months is not known.

CONCLUSIONS

Tonsillectomy can produce short-term improvement in sleep outcomes compared with no surgery in children with OSDB. Understanding of longer-term outcomes or effects in subpopulations is lacking.

Oxygen and carbon dioxide monitoring during sleep

Monitoring of oxygen and carbon dioxide (CO₂) is of crucial importance during sleep-disordered breathing in order to assess the consequences of respiratory events on gas exchange. Pulse oximetry (SpO₂) is a simple and cheap method that is used routinely for the recording of oxygen levels and the diagnosis of hypoxemia. CO₂ recording is necessary for the diagnosis of alveolar hypoventilation and can be performed by means of the end-tidal (PetCO₂) or transcutaneous CO₂ (PtcCO₂). However, the monitoring of CO₂ is not performed on a routine basis due to the lack of simple, cheap and reliable CO₂ monitors. This short review summarizes some technical aspects of gas exchange recording during sleep in children before discussing the different definitions of alveolar hypoventilation and the importance of CO₂ recording.

Polysomnography results in pediatric patients with mild obstructive sleep apnea: Adenotonsillectomy vs. watchful waiting

OBJECTIVE

There is a lack of consensus and a paucity of data regarding how to best treat pediatric patients with mild obstructive sleep apnea. The objective of our study was to compare outcomes following adenotonsillectomy vs. observation in children with mild obstructive sleep apnea based on polysomnography results.

METHODS

A retrospective chart review was performed on children ages 9 months to 9 years with 2 or more polysomnograms completed at a tertiary care academic center. Children diagnosed with mild obstructive sleep apnea (obstructive apnea-hypopnea index 1-5) on polysomnography performed from 1999 to 2013 were included. Patients underwent adenotonsillectomy or watchful waiting for obstructive sleep apnea. The primary outcome was the change in apnea-hypopnea index.

RESULTS

There were 62 patients who met inclusion criteria for the study; 19 of the 62 patients were obese, while 15 had a craniofacial syndrome or hypotonia. Eighteen patients underwent adenotonsillectomy for mild obstructive sleep apnea while 44 were observed. The mean apnea-hypopnea index of patients after adenotonsillectomy improved from 3.50 (95% Confidence Interval [CI] 2.97-4.03) to 2.69 (95% CI 1.48-3.90), while the mean apnea-hypopnea index of the observation group worsened from 3.09 (95% CI 2.76-3.42) to 5.18 (95% CI 2.46-7.90). Between-group analysis showed significant improvement in the surgery group (p=0.03), with a persistent improvement on multivariate analysis adjusting for baseline apnea-hypopnea index (p=0.05). This difference was seen mostly in non-obese, non-syndromic children (p=0.04). There was no significant difference between groups amongst obese (p=0.25) and syndromic (p=0.36) patients.

CONCLUSIONS

Adenotonsillectomy leads to a significant improvement in apnea-hypopnea index on follow-up polysomnography over an observational approach, especially in non-obese, non-syndromic children. A prospective, randomized trial is necessary to help determine appropriate treatment strategies for pediatric mild obstructive sleep apnea.