Can CPAP Therapy in Pediatric OSA Ever Be Stopped?

Abstract

Study Objectives:

Continuous positive airway pressure (CPAP) has been increasingly used in children with obstructive sleep apnea (OSA), though it is unclear whether it can ever be ceased. We describe the clinical, demographic, and polysomnographic (PSG) characteristics of a cohort of children with OSA who were successfully weaned off CPAP.

Methods:

From a pediatric cohort on CPAP for OSA at the Queensland Children’s Hospital between January 2016 and December 2017, a subgroup of children who were taken off CPAP were retrospectively studied.

Results:

CPAP therapy was stopped for 53 children over a 2-year period; 29 of these were excluded from analysis due to change to bilevel support (n = 2), transition to adult care (n = 12), or cessation due to poor adherence (n = 15). A total of 24 children [median (interquartile range, IQR) age 4.1 years (1.0–10.5); 18 males] were successfully weaned off CPAP therapy based on improvement in clinical and PSG parameters; and were included in the analysis. These children had a median (IQR) apnea-hypopnea index (AHI) of 9.8 (5.7–46.0) at CPAP initiation, which improved to 3.3 (0.4–2.2) at CPAP cessation after a median (IQR) duration of 1.0 (0.5–2.0) year. The reasons for CPAP cessation included improved symptoms and/or PSG parameters with time (n = 11); improvement after airway surgery (n = 7), and improvement of body mass index (n = 2). In four children, CPAP therapy was ceased after initial trial due to low physician perceived clinical benefit.

Conclusions:

This is the first study describing the characteristics of children and likely reasons for successful CPAP cessation. Children on CPAP should be regularly screened for ongoing CPAP need.

Citation:

King Z, Josee-Leclerc M, Wales P, Masters IB, Kapur N. Can CPAP therapy in pediatric OSA ever be stopped? J Clin Sleep Med. 2019;15(11):1609–1612.

BRIEF SUMMARY

Current Knowledge/Study Rationale: Continuous positive airway pressure (CPAP) has been increasingly used in treatment of pediatric obstructive sleep apnea not resolved by surgical airway intervention. It is unclear what proportion of children can be successfully taken off CPAP and the factors that govern this cessation.

Study Impact: This is one of the first studies to describe a cohort of children who are able to successfully wean off CPAP therapy. It suggests ongoing screening plays an important role in those on established therapy, as a small proportion of children can successfully be weaned.

INTRODUCTION

Continuous positive airway pressure (CPAP) is initiated in children with obstructive sleep apnea (OSA) and subsequent sleep disturbance resistant to surgical therapy or when intervention is not feasible. CPAP is widely used throughout the world in pediatric populations for OSA and/or related conditions.

OSA affects 5.7% of Australian children.¹ The condition has two peak periods, the first in children aged 2 to 8 years and the second during adolescence.² This number is expected to rise as the obesity epidemic continues to worsen. The benefits of CPAP are well recognized in the literature.³ However, there are no published data on the indications to cease CPAP in children or the clinical course of patients while on this mode of therapy. Furthermore, there also appears to be a poor understanding of how many patients cease or discontinue therapy. Studies in adults have reported immediate recurrence of clinical and PSG-based sleep- disordered breathing with intermittent cessation of well-established CPAP therapy,^4–6 though most report less severe PSG parameters on cessation.⁷

This is also based on the premise that single PSG analysis is deemed adequate for diagnosis of OSA,⁶ and interstudy variability is low.⁸ These data, when extrapolated into the pediatric population, fail to address the pediatric-specific changes with growth likely effecting risk of airway obstruction including changes in tone, airway caliber, and amount of lymphoid tissue. Because of the absence of any data on incidence of and factors associated with successful weaning and cessation of CPAP therapy in children, no recommendations are available on the long-term pressure support weaning strategies in this cohort, despite the increasing use of this modality. This is likely to result in unnecessary prolongation of therapy. The aim of this study is to investigate factors associated with successful cessation of CPAP therapy in a cohort of children with OSA.

METHODS

A dataset of all children younger than 18 years on CPAP therapy in Queensland from January 2016 to December 2017 was obtained through the Queensland Children Hospital’s sleep unit. This unit is the sole provider of CPAP for children throughout Queensland. One hundred fifty-two children were on CPAP therapy between January 2016 and December 2017 and 99 continued to be on CPAP therapy in September 2018, leaving 53 who had ceased CPAP therapy during the period. Of this cohort, those who ceased therapy due to nonadherence (n = 15), changed to bilevel positive airway pressure therapy (n = 2) or those transitioned to adult services (n = 12) were excluded from the final analysis. The data included for analysis were: patient demographics, clinical features, reasons for starting CPAP therapy including PSG parameters, and likely factors for ceasing CPAP therapy including PSG parameters. We usually recommend cessation of CPAP use for at least 3 days before the diagnostic / split CPAP check study in children where CPAP cessation is being envisioned.

Statistical Analyses

Statistical analysis was performed using the SPSS 22.0 software (IBM Corp., Armonk, New York, United States). Categorical variables were presented by frequencies and percentages, and differences were analyzed using the χ² test or Fisher exact test when required. Continuous variables are presented as mean and standard deviation, or median and interquartile range (IQR) when data were not normally distributed. Differences in continuous variables were analyzed using the t test, or their corresponding nonparametric tests. We defined statistical significance as a two-tailed P < .05.

RESULTS

Twenty-four children (18 males) with median (IQR) age of 4.1 (1.0–10.5) years successfully ceased CPAP therapy during the period and were included in the analysis. The median (IQR) apnea-hypopnea index (AHI) prior to commencement of CPAP was 9.8 (5.7–46.0) and improved to 3.3 (0.4–2.2) at cessation after a median usage duration of 12 months (Table 1). The median (IQR) obstructive apnea-hypopnea index prior to commencement of CPAP was 7.4 (4.1–38) and improved to 0.7 (0.1–2.2) at CPAP cessation.

Table 1.

Population demographics and indication for CPAP cessation.

The largest group of children (n = 11) reported improved symptoms and PSG parameters without any obvious intervention or clinical change. These children were classified as “outgrew.” Seven children improved after airway surgical intervention including adenotonsillectomy and two showed significant improvement in body mass index defined as a reduction in body mass index of at least 1 z-score (Table 1). In four children, a decision to discontinue CPAP therapy was based on clinical judgement and overnight oximetry without repeating a formal PSG.

The outgrew category was further subdivided into two categories. These included children who had previous surgery for OSA (eg, adenotonsillectomy) but did not have a resolution of symptoms and were deemed to require ongoing support, and those who had never had surgery (Table 2). All children with craniofacial abnormalities required surgery for correction of their OSA; two children with Down syndrome and one child with achondroplasia also outgrew their requirement for CPAP (Table 3).

Table 2.

Characteristics of children who “outgrew” CPAP need based on previous airway surgical intervention.

Table 3.

Indication of continuous positive airway pressure cessation in various etiologic categories.

As on December 2018, none of these 24 children were reinitiated on CPAP therapy. On clinical follow-up, 12 children had no reported ongoing snoring, 7 children reported occasional snoring, 3 reported snoring when unwell, and 1 reported occasional stridor in sleep. One child with restrictive chest wall because of hypophosphatasia experienced persistent snoring and mild OSA on a follow-up PSG and was awaiting adenotonsillectomy.

DISCUSSION

In 24 children with a range of severity of OSA, CPAP therapy could be successfully ceased after a median use of 1 year. A high proportion of these children improved with age without any obvious intervention, though in a sizeable number the improvement was associated with CPAP initiation airway either before or after surgical intervention. Surgical airway intervention was associated with the largest improvement in PSG parameters, and body mass index improvement with the least improvement.

To our knowledge, this is the first study to describe a cohort of children who were successfully weaned off CPAP therapy. Of these children, those who had surgical airway intervention (n = 7) were associated with the largest improvement in AHI (Table 1). This is in keeping with current literature that supports early surgical intervention, when clinically indicated, in children with OSA.⁹

The largest group was those who had some airway surgery (n = 13), either before (n = 6) or after (n = 7) initiating CPAP therapy. Of the 6 who required CPAP despite the surgical intervention, a repeat PSG was done at a median duration of 7 weeks postsurgery. This is in keeping with current practiced follow-up time. Although not clearly defined, there is some appreciation that OSA symptoms can take up to 8 weeks to resolve after adenotonsillectomy.¹⁰ It is possible but conjectural that improvement in airway caliber continues beyond the 6- to 8-week period postsurgery and some of these children may have had a repeat PSG too soon after the surgical procedure. There are also a group of children who may need CPAP support for a short period after the airway intervention. Adenotonsillectomy still remains the first line of treatment in children with large adenoid and/or tonsillar tissue, and is highly effective in eliminating the symptoms associated with obstructive sleep apnea, as well as improving the quality of life of the child.¹¹ The procedure has a success rate of 27.2% to 82.9% in children, with relatively low associated side effects.¹² Despite its effectiveness and popularity in treatment of OSA, there appears to be a lack of clearly defined follow-up guidelines for children receiving surgical intervention for OSA.

Those who were considered to have truly outgrown their requirements (n = 5, Table 2) are those who had improved with no observable or documented reason for improvement other than age and had no previous airway surgery. This group was observed to commence CPAP therapy at a later age (median 6.7 years) and remained on treatment longer (median 2.2 years). This group of children are beyond the first peak incidence of OSA symptoms (age 2 to 5 years, in relation to adenotonsillar tissue being at maximal growth in relation to the upper airway¹³) and were not considered to have likely clinical benefit from surgical intervention. Improvement of upper airway tone combined with widening of the upper airway with age may have relieved the obstructive symptoms in some of these children.¹⁴ Pediatric OSA is a distinct entity from adult OSA, highlighted by differences in reasons for upper airway obstruction, response to surgery, and growth-related improvement in airway caliber, making extrapolation from adult literature unreliable.

In the group that improved without any obvious intervention, although there were no consistent findings that helped the physician decide on a trial without CPAP therapy, some parents reported absence of snoring during nights when CPAP therapy was inadvertently not used for various reasons such as sleepovers or travel. Two parents also self-tested taking the child off CPAP therapy to determine whether if he or she was still snoring and reported no snoring.

In two children, improved clinical and PSG parameters were directly attributed to weight loss. Obesity affects OSA symptomatology by both mechanical (fatty infiltrates within the upper airway and accumulation of abdominal visceral fat impacting diaphragmatic descent¹⁵) and behavioral aspects (worsening daytime sleepiness, impacting physical activity and worsening obesity¹⁶). This finding is consistent with current literature suggesting weight loss improves OSA symptoms.¹⁷

CPAP therapy has been reported to have negative adverse effects, including nasal and pharyngeal dryness and claustrophobia associated with the mask as well as social anxiety or embarrassment associated with using the mask.¹⁸ CPAP usage is also associated with abnormal facial growth, such as retrusion of the midface, counter-clockwise rotation of the palatal plane, and upper incisor flaring.¹⁹ Commencement and continuation of CPAP in children should be thoroughly evaluated by the clinician. When indicated, cessation of treatment should occur if the child is thought to no longer have a clinical benefit. This is especially relevant in the younger age group, as in our cohort, where PSG monitoring should be considered at a more frequent interval to help screen for this. Based on the median usage of 12 months in our cohort, PSG monitoring should be considered at least annually, and even more frequently when clinically indicated.

Our study was limited because of its retrospective design, single center data, and inability to compare the group taken off CPAP with those who continued to be on CPAP, to help predict the factors associated with a successful wean. We also used only selective PSG data available from the report and did not reanalyze the complete study. Success in our study was measured by improvement in AHI, which is only one of the many components in diagnosing sleep-disordered breathing. Many children still had residual OSA, albeit mild, when CPAP therapy was ceased. It is also possible that some children who were continued on CPAP therapy may have outgrown the clinical need for this and hence not included in this study, though regular clinical follow up and PSG tests would make this less likely. Despite these limitations, this is the first description of a cohort of children in whom CPAP therapy was successfully ceased. Inclusion of all principles of its analysis may prevent CPAP prescription in some children or allow for a shorter prescription time of CPAP therapy.

CONCLUSIONS

There appears to be insufficient literature on indication and timing of CPAP cessation in children. The long-term benefit of CPAP in children is also unclear, especially in the severe and treatment-resistant cases. This study suggests that ongoing screening plays an important role in treatment of OSA, as some children can successfully be weaned off CPAP therapy after a course of treatment. In routine CPAP check studies, diagnostic analysis without CPAP should be included in selected cases to screen for possible clinical improvement.

DISCLOSURE STATEMENT

Work for this study was performed at Queensland Children’s Hospital. All authors have seen and have approved this manuscript. The authors report no conflicts of interest.

ABBREVIATIONS

AHI

apnea-hypopnea index

CPAP

continuous positive airway pressure

IQR

interquartile range

OSA

obstructive sleep apnea

PSG

polysomnography