Cardiac Implications of Adenotonsillar Hypertrophy and Obstructive Sleep Apnea in Pediatric Patients: A Comprehensive Systematic Review

This review investigates the relationship between pediatric obstructive sleep apnea, often associated with adenotonsillar hypertrophy, and cardiovascular health, particularly pulmonary hypertension. We conducted a comprehensive literature search using electronic databases, including Medline Pub-Med, Scopus, and the Web of Science. The study analyzed a total of 230 articles and screened 48 articles, with 20 included in the final analysis, involving 2429 children. The PRISMA flowchart visually illustrates the selection process, and the ROBINS-E and -I tools help ensure the reliability and validity of the evidence produced by these studies. These studies explored various aspects, including the severity of obstructive sleep apnea, cardiac anomalies, cardiac stress markers, risk factors for pulmonary hypertension, and the impact of adenoidectomy and tonsillectomy on cardiac function. The research found that adenotonsillar hypertrophy and obstructive sleep apnea are significant risk factors for cardiovascular complications, especially pulmonary hypertension, in children. Adenoidectomy and tonsillectomy may provide effective treatments. Following adenoidectomy in relation to obstructive sleep apnea, there appears to be a reduction in mean pulmonary artery pressure during echocardiographic examination. However, the efficacy of these procedures can vary based on the severity of obstructive sleep apnea and individual cardiac conditions. The study also identified concerns regarding data bias. The authors emphasize the need for well-designed clinical studies, including both healthy patients with adenotonsillar hypertrophy and vulnerable children with genetic disorders, to ensure that clinical decisions are based on solid scientific evidence.

Low incidence of pulmonary hypertension in children with suspected obstructive sleep apnea: A prospective observational study

OBJECTIVES

Pulmonary hypertension (PH) secondary to obstructive sleep apnea (OSA) is an uncommon but serious perioperative risk factor in children undergoing surgery for adenotonsillar hypertrophy. Routine pre-operative echocardiography is commonly requested if severe OSA is suspected. We investigated the incidence of PH in children with suspected OSA and explored the association between PH and OSA severity.

METHODS

A prospective study of children aged 1-13 years with suspected OSA admitted for overnight oximetry (OO) and echocardiography at a pediatric referral hospital in Cape Town, South Africa from 2018 to 2019. OSA severity was defined by McGill Oximetry Score (MOS): MOS 1-2 (mild-moderate) and MOS 3-4 (severe). PH was defined as mean pulmonary arterial pressure (mPAP) ≥20 mmHg estimated on echocardiographic criteria. Children with congenital heart disease, underlying cardio-respiratory or genetic disorders, and severe obesity were excluded.

RESULTS

One hundred and seventy children median age 3.8 years (IQR 2.7-6.4) were enrolled and 103 (60%) were female. Twenty-two (14%) had a BMIz >1.0 and 99 (59%) had tonsillar enlargement grade 3/4. One hundred and twenty-two (71%) and 48 (28%) children had mild-moderate and severe OSA, respectively. Echocardiographic assessment for PH was successful in 160 (94%) children of which eight (5%) had PH with mPAP 20.8 mmHg (SD 0.9): six with mild-moderate OSA and two with severe OSA. No significant difference in mPAP and other echocardiographic indices was observed in children with mild-moderate (16.1 mmHg; SD 2.4) and severe OSA (15.7 mmHg; SD 2.1). Similarly, no clinical and OSA severity differences were observed in children with and without PH.

CONCLUSION

PH is uncommon in children with uncomplicated OSA and there is no association of PH with severity of OSA measured by OO. Routine echocardiographic screening for PH in children with clinical symptoms of OSA without co-morbidity is unwarranted.

Prevalence of pulmonary hypertension in children with adenoid or adenotonsillar hypertrophy: A meta-analysis

OBJECTIVE

Adenoid or adenotonsillar hypertrophy (AATH) adversely affects cardiovascular function, leading to pulmonary hypertension (PH). This meta-analysis of observational studies aimed to estimate the prevalence of PH in children with AATH.

METHODS

A meta-analysis was performed by searching the PubMed, EMBASE, and Cochrane Central Register of Controlled Trials databases from their inception to 1 July 2021, for all studies that extracted data about PH prevalence in children with AATH. PH prevalence was calculated for each included study and as a pooled estimate with a 95% confidence interval.

RESULTS

A total of eight studies were included in this analysis. The pooled prevalence of PH in children with AATH was 35.0% (95% CI [18.0%, 52.0%]). The subgroup analysis demonstrated that the prevalence of PH in children with adenotonsillar hypertrophy was higher than that with adenoid hypertrophy with or without tonsillar hypertrophy (39.0%, 95% CI [14.0%, 65.0%] vs. 22.0%, 95% CI [17.0%, 28.0%], respectively). The prevalence derived from the prospective and cross-sectional studies were 45.0% (95% CI [13.0%, 76.0%]) and 20.0% (95% CI [14.0%, 25.0%]), respectively. America and Africa had lower prevalence rates than Asia (24.0%, 95% CI [1.0%, 46.0%], 27.0%, 95% CI [17.0%, 38.0%], and 48.0%, 95% CI [-2.0%, 98.0%]), respectively. The prevalence of studies with diagnostic criterion (a mean pulmonary artery pressure higher than 20 mmHg) was 50.0% (95% CI [6.0%, 94.0%]). The pooled prevalence of studies with diagnostic criterion (a mean pulmonary artery pressure higher than 25 mmHg) was 25.0% (95% CI [13.0%, 36.0%]).

CONCLUSION

The meta-analysis showed a prevalence of PH in children with AATH of 35.0%, demonstrating that this condition is a frequent complication of AATH. To better understand its clinical impact, more prospective evaluations are urgently needed.

Prevalence of Pulmonary Hypertension in Pediatric Patients With Obstructive Sleep Apnea and a Cardiology Evaluation: A Retrospective Analysis

STUDY OBJECTIVES

Pulmonary hypertension (PH) has been reported as a serious complication of obstructive sleep apnea (OSA) in children; however, estimated prevalence rates vary widely (zero to 85%). The purpose of this study is to determine the prevalence of PH in children with OSA and identify factors that may predict an increased PH risk in children with OSA.

METHODS

A retrospective review of all pediatric beneficiaries (88,058) in the San Antonio Military Health System with a diagnosis of OSA and a clinical evaluation by a pediatric cardiologist. OSA severity and nadir oxygen saturation were recorded from overnight polysomnography. Reason for referral, comorbid disorders, echocardiogram results, and cardiac diagnoses were obtained from cardiology records.

RESULTS

OSA was identified in 2,020 pediatric patients (2.3%). A pediatric cardiology consultation was reported for 296 patients with OSA. After excluding 95 patients for incorrect OSA diagnoses, incomplete data, or OSA treatment before cardiology evaluation, 163 patients were included in the final analysis. A diagnosis of PH was found in 3 patients with OSA (1.8%). Two of these patients had obesity, and all three had comorbid cardiac disorders.

CONCLUSIONS

Prevalence of PH in pediatric patients with OSA is low and none of the patients with PH had severe OSA. Current guidelines recommend PH screening in patients with severe OSA, yet OSA severity may not accurately predict risk. Factors evaluated in this study did not demonstrate an increased PH risk; additional research is necessary to improve screening in pediatric patients with OSA.

CITATION

Burns AT, Hansen SL, Turner ZS, Aden JK, Black AB, Hsu DP. Prevalence of pulmonary hypertension in pediatric patients with obstructive sleep apnea and a cardiology evaluation: a retrospective analysis. J Clin Sleep Med. 2019;15(8):1081-1087.

Obstructive Sleep Apnea and Pulmonary Hypertension in Children

Obstructive sleep apnea (OSA) is a common pediatric breathing disorder, affecting 1-5% of all children. Pulmonary hypertension (PH), a severe complication of OSA, is associated with significant morbidity and mortality. Despite this important relationship between OSA and PH, there is sparse literature addressing this subject in children. This review will examine the putative relationship between OSA and PH, synthesize the available literature in children, and suggest a reasonable approach, despite limited data, for clinicians. We conclude that available evidence suggests many children with OSA have evidence of PH (estimates ranging from 0% to 85%) and vice versa (estimates ranging from 6% to 24%). Furthermore, previous studies demonstrate that treatment of the OSA, either with surgery or non-invasive ventilation, ameliorates pulmonary artery pressures to the extent of cure in a substantial number of cases. Future studies are required to better delineate the true co-occurrence of these diseases and help predict which patients are at greater risk for this serious complication. Clinicians who maintain a healthy vigilance for this important interaction of disease states will likely recognize opportunities to intervene and improve prognoses in these patients.

Transcervical ultrasonographic examination of palatine tonsil size and its correlation with age, gender and body-mass index in healthy children

OBJECTIVE

Our aim was to assess the palatine tonsil size with transcervical ultrasonography in healthy children and to analyze whether the palatine tonsil size is correlated with age, gender and body-mass index (BMI).

METHODS

This series consisted of 680 healthy children (340 females, 340 males) who underwent transcervical ultrasonography for evaluation of palatine tonsil size. A total of seventeen age groups (range: 1-17 years) comprised of 40 children (20 females, 20 males) were constituted. Demographic data including gender, height, weight and BMI were noted. Correlation between baseline descriptive data and tonsil volume was investigated.

RESULTS

The average age was 102.51 ± 59.24 months (range: 12 to 204) and body-mass index was 17.50-5.16 kg/m2 (min: 12.4-max:25.8). The average tonsil volume was 1819.5-2023.5 mm³ (min:601, max: 4007). The tonsil volume did not differ significantly between females and males (p = 0.108). However, there was a significant difference between tonsil volumes of various age groups (p < 0.001). Tonsil size seemed to be greater in parallel with advancement of age (p < 0.001) and increased BMI (p < 0.001).

CONCLUSION

Transcervical ultrasonography can be an accurate, safe, cheap, non-invasive and accessible measure for evaluation of the size of tonsils objectively. There were strongly positive correlations between age, BMI and palatine tonsil size in healthy children and variability with respect to descriptive characteristics must be considered during diagnostic procedures and preoperative evaluation.

ADVANCES IN KNOWLEDGE

In our study, we suggest that transcervical ultrasonography can be an accurate, safe, cheap, non-invasive and accessible measure for evaluation of the size of tonsils. There were positive correlations between age, BMI and palatine tonsil size in healthy children.

A novel method for evaluation of oxidative stress in children with OSA

OBJECTIVES

To evaluate the role of adenotonsillar hypertrophy and the outcomes of adenotonsillectomy (AT) on oxidative stress for obstructive sleep apnea (OSA) in children using a new method; thiol/disulfide homeostasis.

METHODS

The study is consisted of 45 children with OSA and 38 healthy control subjects with similar age and sex. Children 3-12 years of age with OSA, defined as having an apnea/hypopnea index (AHI) of 5 or more in an overnight polysomnography, underwent adenotonsillectomy. OSA was classified as mild (1 ≤ AHI<10), moderate (10 ≤ AHI<20) or severe (AHI≥20). Venous blood samples were taken preoperatively and one month after surgery. The blood levels of thiol/disulfide homeostasis were assessed and compared between patients and control group, before and after adenotonsillectomy.

RESULTS

Body mass index (BMI), mean age and gender distribution were similar between the study and control groups. Statistically significant higher disulfide levels and ratios were found in the study group compared to the control group; in patients with moderate to severe OSA compared to mild OSA; in the preoperative period compared to postoperative period (p < 0.001, for all).

CONCLUSIONS

The current study provides preliminary evidence between oxidative stress and OSA in children with adenotonsillar. Adenotonsillectomy for OSA may result in a dramatic improvement in oxidative stress as measured by thiol/disulfide homeostasis.

CD4(+)T-lymphocyte subsets in nonobese children with obstructive sleep apnea syndrome

BACKGROUND

To characterize the distribution of both tonsillar and circulating CD4(+)T-lymphocyte subsets, and to explore their clinical relevance in nonobese children with obstructive sleep apnea syndrome (OSAS).

METHODS

A total of 53 children who underwent tonsillectomy for either OSAS (n = 25) or primary snoring (PS, n = 28) were prospectively enrolled. Nineteen healthy children without any symptoms were recruited as controls. We quantified the frequencies of CD4(+)T-lymphocyte subpopulations using flow cytometry, serum-related cytokines using enzyme-linked immunosorbent assay, and key transcription factors using quantitative polymerase chain reaction (qPCR).

RESULTS

Tonsillar distributions of CD4(+)T-lymphocyte subsets were comparable in the OSAS and PS subjects. The peripheral Th17/Treg ratio was positively correlated to severity as measured by apnea/hypopnea index (AHI), serum C-reactive protein and hypoxia-inducible factor-1α mRNA in the OSAS children (P < 0.05). And AHI was independently associated with the peripheral Th17/Treg ratio (P < 0.05). Furthermore, the response to surgery was associated with a significant reversal of the Th17/Treg imbalance and a concomitant relief of the proinflammatory profile in the OSAS subjects.

CONCLUSION

Pediatric OSAS was associated with an altered Th17:Treg balance toward Th17 predominance. The changes in lymphocytic phenotypes that correlated with recurrent intermittent hypoxia in sleep apnea may contribute to the variance in systemic inflammation and downstream morbidities of pediatric OSAS.

A systematic review and meta-analysis of cohort studies of echocardiographic findings in OSA children after adenotonsilectomy

CONTEXT

There is evidence that OSA in children can be associated with acute and chronic effects on the cardiovascular system due to repetitive episodes of apnea and hypoxemia.

OBJECTIVE

To assess whether there is an association between OSA and echocardiographic findings in children and whether that association persists after adenotonsillectomy.

DATA SOURCES

A literature search was conducted based on PUBMED, EMBASE and LILACS.

STUDY SELECTION

Children with OSA and children who did not have OSA, who were aged ≤12 years.

DATA EXTRACTION

Two reviewers extracted data independently; the risk of bias was assessed by examining the selected sample, the recruitment method, completeness of follow up, and blinding.

RESULTS

Seven studies met all the inclusion criteria and methodological requirements. There was a significant difference with elevated mean pulmonary arterial pressure levels in OSA participants compared to those without OSA at preoperative assessment [mean difference (MD) 8.67; confidential interval (CI) 95% 6.09, 11.25]. OSA participants showed a statistically significant increased interventricular septum (IVS) thickness (mm) [MD 0.60; CI 95% 0.09, 1.11]; and right ventricular (RV) dimension (cm/m) [MD 0.19; CI 95% 0.10, 0.28]. There was also a significant increase in right ventricular (RV) dimension (cm/m) [MD 0.10; CI 95% 0.05, 0.14] in OSA children.

CONCLUSION

There is moderate quality evidence regarding possible association between OSA and right heart repercussions. More prognosis studies are needed, to allow the combination of results in a meta-analysis.

Relationship between obstructive sleep apnea-specific symptoms and cardiac function before and after adenotonsillectomy in children with adenotonsillar hypertrophy

OBJECTIVE

The aim of our study was to investigate subclinical cardiac disturbances in patients with symptoms due to adenotonsillar hypertrophy (ATH) and the impact of adenotonsillectomy (AT) using conventional and novel echocardiographic measures.

MATERIAL AND METHODS

Thirty patients with grade 3 or 4 ATH (mean age: 7.86 ± 3.83 years; 10 females) and 30 healthy, age- and sex-matched volunteers (mean age, 8 ± 2.77; 14 females) were enrolled in the study. In addition to conventional two-dimensional and Doppler echocardiographic parameters, tissue Doppler parameters, including myocardial performance indices (MPIs) of both the right (RV) and left ventricle (LV), were studied. The severity of obstructive sleep apnea (OSA) was determined using the OSA-18 health quality questionnaire. The OSA-18 questionnaire and echocardiographic examination were repeated after AT in patients with ATH.

RESULTS

The total OSA-18 scores for the control, preoperative, and postoperative groups were 39.56 ± 19.98, 80.63 ± 22.32, and 44.10 ± 20.31, respectively. Conventional parameters were not different among the groups. The mean pulmonary artery pressure estimated using the Mahan formula was increased in the ATH group compared with that in the control group (21.72 ± 4.25 vs. 12.43 ± 3.83, respectively; p<0.001) and significantly improved after AT (21.72 ± 4.25 vs. 16.09 ± 4.53; p<0.001). The RV MPI was significantly different between the control and ATH groups (0.322 ± 0.052 vs. 0.383 ± 0.079, respectively; p=0.001). Both the LV and RV MPI significantly improved (0.515 ± 0.066 vs. 0.434 ± 0.052, p<0.001; and 0.383 ± 0.079 vs. 0.316 ± 0.058, p=0.018, respectively) after surgery for ATH.

CONCLUSIONS

Our study revealed that the patients with OSA-specific symptoms due to ATH had higher pulmonary artery pressure and impaired RV function according to novel echocardiographic parameters. Surgery for ATH seems to have an important effect on both LV and RV function.

Prevalence and associated factors of pulmonary hypertension in Kenyan children with adenoid or adenotonsillar hypertrophy

OBJECTIVES

Adenotonsillar hypertrophy is a common condition in childhood, whose serious complications of pulmonary hypertension and cor pulmonale are devastating but local prevalence is unknown. This study determined the prevalence and associated factors of pulmonary hypertension in children with adenoid or adenotonsillar hypertrophy at Kenyatta National Hospital, Kenya.

METHODS

This was a cross sectional hospital based survey conducted among children below 12 years of age with clinical and radiological adenoid hypertrophy attending the ear, nose and throat (ENT) outpatient clinic and general pediatric wards. Doppler echocardiography was used to determine pulmonary hypertension defined as a mean pulmonary arterial pressure (mPAP) of ≥ 25 mm Hg using the Chemla equation. Children with mPAP of ≥ 25 mm Hg were compared to those with lower pressures and clinical and radiological factors associated with pulmonary hypertension determined using multivariate logistic regression analysis.

RESULTS

Of the 123 eligible children in the study, 27 had pulmonary hypertension giving a prevalence of 21.9% (95% CI 14.64%-29.27%). Independent factors associated with pulmonary hypertension included nasal obstruction (OR=3.0 [95% CI 1.08-8.44] p=0.035) and hyperactivity on history (OR=0.2 [95% CI 0.07-0.59] p=0.003) and adenoid-nasopharyngeal ratio (ANR) >0.825 on lateral neck radiography (OR=5.0 [95% CI 1.01-24.37] p=0.048).

CONCLUSION

One in five children with adenoid or adenotonsillar hypertrophy had pulmonary hypertension with a 3-fold and 5-fold increased odds in those with nasal obstruction on history and ANR >0.825 on lateral neck radiography respectively and an 80% reduced odds in reportedly hyperactive children.

Reversal of pulmonary hypertension in children after adenoidectomy or adenotonsillectomy

INTRODUCTION

Adenotonsillar hypertrophy is a common condition in pediatric patients with upper respiratory airways complaints, and pulmonary arterial hypertension (PAH) may be one complication of that condition.

OBJECTIVES

To study the occurrence of PAH (mean pulmonary artery pressure higher than or equal to 25 mmHg) in a group of children with adenotonsillar hypertrophy and upper respiratory complaints (snoring or oral breathing), and to verify the pulmonary arterial pressure (PAP) changes after adenotonsillectomy.

STUDY DESIGN

Case-control prospective study.

SETTINGS

Study conducted at São Lucas Hospital, approaching both public and private sector.

SUBJECT AND METHODS

Thirty-three pediatric patients with adenotonsillar hypertrophy and evidence of obstructive upper airways complaints were treated with adenotonsillectomy. All 33 patients underwent echocardiogram before and after the surgery with determination of the pulmonary arterial pressure (PAP), through either the tricuspid regurgitation or artery linear flow acceleration time estimation. Similar determinations were performed in 10 normal non operated controls.

RESULTS

Pulmonary hypertension was verified 12 (36%) of the 33 patients with adenotonsillar hypertrophy. Adenoidectomy or adenotonsillectomy was associated to a significant 27% decrease in mean PAP (27 ± 2.8 to 20 ± 5.1 mmHg, p<0.001) and to a non significant 26% decrease in systolic PAP (35 ± 6.2 mmHg to 25 ± 0.5 mmHg, p=0.243). The PAP values in children with no pulmonary hypertension were not changed after the surgery.

CONCLUSIONS

In children with pulmonary hypertension associated to adenotonsillar hypertrophy, the adenotonsillectomy decreased PAP to normal values in all patients.

The association between sleep apnea and young adults with hypertension

OBJECTIVES/HYPOTHESIS

To study the association between sleep apnea and hypertension in a younger age group than previously studied, adding upper airway sizes at endoscopy as important compounding variables not often included in the past.

STUDY DESIGN

Case control.

METHODS

We analyzed data on sleep-disordered breathing (based on polysomnography tests), body mass index (BMI), neck circumference, upper airway endoscopy sizes, and habitus and health history in 120 hypertensive and 120 nonhypertensive participants in a clinic-based setting. Independent t test, χ(2) , multivariate analysis, and binary logistic regression models were used for case-control comparison.

RESULTS

The mean age of the participants was 27 years; 67.5% were male. The incidence and severity of sleep apnea were significantly higher in the hypertensive than the control subjects. Persons with hypertension had an OR of 2.7 times of having comorbid sleep apnea than patients without hypertension (95% confidence interval [CI] 1.2-6.1). Persons with sleep apnea (AHI [apnea-hypopnea index] ≥ 5) had an OR of 2.76 (95% CI 1.57-4.86), and persons with severe sleep apnea (AHI ≥ 30) had an OR 7.94 (95% CI 4.21-15.33) for having hypertension than did persons without sleep apnea. Although adjustments for the compounding factors, particularly BMI, decreased the OR to a large degree, subjects with severe sleep apnea were still 72% more likely to have hypertension than subjects without sleep apnea.

CONCLUSIONS

Sleep apnea is related to hypertension in young adults aged 18 to 40 years. The association was more pronounced with the increasing severity of sleep apnea. Screening for sleep apnea should be considered in young adults with hypertension.

Predicting complications after adenotonsillectomy in children 3 years old and younger

OBJECTIVES

To identify risk factors for complications in the first 24h after surgery in the young (<4 years old) adenotonsillectomy patient.

METHODS

A retrospective chart review was performed at a tertiary care children's hospital. Consecutive records of all children of age 3 years and younger undergoing adenotonsillectomy over a 5 year period were included in the study. The main outcomes measured were total and airway complications occurring on post-operative days 0-1.

RESULTS

993 patients were included in the study. The mean age was 2.94 years old. Witnessed apneas (74.1%) and snoring (59.2%) were the most frequent pre-operative symptoms. 700 children were admitted with a mean length-of-stay of 1.22 days (0-9 days) and a mean time-to-oral intake of 0.28 days (0-4 days) among those patients admitted. The total number of complications was 102 in 98 patients (9.9%). There were 35 complications on post-operative days (POD) 0-1 (3.5%), and 23 of those were airway-related (2.3%). With regard to all complications on POD 0-1, significant predictors were nasal obstruction, gastroesophageal reflux disease, prematurity and a history of cardiovascular anomalies. Significant predictors of airway complications on POD 0-1 were younger age (1-2 years old), larger adenoid size, nasal obstruction, and a history of cardiovascular anomalies.

CONCLUSIONS

Knowing the stated risk factors for complications in the early post-operative period after adenotonsillectomy in the younger pediatric patient can help select certain patients for closer monitoring. Specifically, children aged 1-2 years old with a history of nasal obstruction from large adenoids, gastroesophageal reflux disease, prematurity, and/or cardiovascular anomalies appear to be at higher risk for early complications and should warrant closer observation.