Pathophysiologic considerations for the interactions between obstructive sleep apnea and sickle hemoglobinopathies

Sleep Behaviour in Sickle Cell Disease: A Systematic Review and Meta-Analysis

Background/Objectives: There is a high prevalence of sleep behaviour disorders, as well as sleep disordered breathing (SDB), in individuals living with sickle cell disease (SCD). SDB has been systematically reviewed; therefore, this systematic review and meta-analysis focused on sleep behaviour. Methods: The comprehensive literature search, following PRISMA reporting guidelines, included all languages, conference proceedings and published theses from inception through February 2022. We identified 31 studies, with most of the research being conducted in North America, using polysomnography, actigraphy and questionnaires/diaries in paediatric SCD cohorts. Results: Total sleep time (TST) decreased, while sleep onset latency (SOL) increased with age. TST was higher on self-reported sleep diary measures and lower on polysomnography (PSG) and actigraphy assessments. SOL was lowest during PSG and highest in actigraphy. The discrepancy between sleep measures might be due to the overestimation of sleep behaviour by parents. In six studies, TST and SOL were compared between people living with SCD and healthy controls; in four, TST was longer in those living with SCD while it was shorter in two. Meta-analyses on the effect of TST and SOL were limited due to publication bias, with heterogeneity between the studies, in part related to measurement differences. No significant differences were found. Conclusions: The scarcity of case-control studies and significant heterogeneity in findings likely attributable to variations in sleep assessment methodologies. Gaps in the literature should be addressed.

Nocturnal Pain Crises in an Adult with Sickle Cell Disease

Sickle cell disease is the most common genetic hemoglobinopathy worldwide, characterized by a single-nucleotide mutation that predisposes to hemoglobin polymerization and erythrocyte sickling in hypoxic states. This report describes a 62-year-old male obese patient with a history of sickle cell disease, who presented with worsening nocturnal pain crises without any apparent triggering factor. A thorough evaluation at the outpatient department revealed obstructive sleep apnea. Airway obstruction or decreased respiratory effort during sleep may induce hypoventilation and hypoxia in the context of sleep-disordered breathing, with severe cardiopulmonary complications. Sleep-disordered breathing is considered common in children with sickle cell disease, but the prevalence in adults has not been sufficiently documented. Our patient responded favorably to treatment with continuous positive airway pressure during sleep, showing complete resolution of his symptoms. Timely diagnosis and management are fundamental to improve outcomes and prevent severe complications.

Adenotonsillar Hypertrophy in Pre-School Children with Sickle Cell Disease and Diagnostic Accuracy of the Sleep Disturbance Scale for Children

Introduction  Adenotonsillar hypertrophy is more common in children with sickle cell disease, and can lead to sleep-disordered breathing.

Objectives  To determine the frequency of adenotonsillar hypertrophy in pre-school children with sickle cell disease and assess the diagnostic accuracy of the sleep-disordered breathing subscale in the Sleep Disturbance Scale for Children.

Method  Observational study with a group of 48 children with sickle cell disease and a control group of 35 children without the disease. The children underwent oropharingoscopy and video nasal endoscopy. The parents and/or guardians answered the questions of the subscale.

Results  Adenotonsillar hypertrophy was observed in 25% of the children in the study group, and in 20% of the children in the control group, with no statistical difference between the groups. The subscale score ranged from 3 to 11 in both groups. There was a statistical significance in the study group. The average was 4.79 (standard deviation [SD] ± 2.50), with 4.19 (SD ± 1.72) among the children without adenotonsillar hypertrophy, and 6.5 (SD ± 3.40) among the children with adenotonsillar hypertrophy. There was also a statistical significance in the control group. The average was 5.23 (SD ± 2.81), with 4.44 (SD ± 2.2) among the children without adenotonsillar hypertrophy, and 7.87 (SD ± 2.89) among the children with adenotonsillar hypertrophy.

Conclusion  Adenotonsillar hypertrophy was not associated with sickle cell disease in pre-school children. The subscale of sleep-disordered breathing in the Sleep Disturbance Scale for Children was a useful tool for the diagnostic suspicion of adenotonsillar hypertrophy in children in this age group.

Hydroxyurea treatment effect on children with sickle cell disease and obstructive sleep apnea

BACKGROUND

While hydroxyurea is the mainstay of treatment for many of the comorbidities associated with sickle cell disease, its effect on obstructive sleep apnea has not been fully investigated. The purpose of this project is to help characterize the effects of hydroxyurea on obstructive sleep apnea in children with sickle cell disease and determine its therapeutic role in the condition.

METHODS

Chart review was conducted on two pediatric patients with sickle cell disease who experienced resolution of obstructive sleep apnea following hydroxyurea administration.

RESULTS

After undergoing approximately 11 months of hydroxyurea therapy, sleep apnea symptoms improved and obstructive sleep apnea resolution was confirmed by repeat polysomnography in both cases. This resolution was largely secondary to a reduction in the obstructive component of the apnea hypopnea index, highlighting a previously unreported association.

CONCLUSIONS

As adenotonsillectomy is associated with significant risks in patients with sickle cell disease, it appears reasonable to consider a period of observation for improvement of obstructive sleep apnea following hydroxyurea administration rather than directly proceeding with surgery.

Wheezing in children with sickle cell disease

PURPOSE OF REVIEW

The purpose of this article is to provide a comprehensive review of wheezing in sickle cell disease (SCD), including epidemiology, pathophysiology, associations between wheezing and SCD morbidity and finally the clinical approach to evaluation and management of individuals with SCD who wheeze.

RECENT FINDINGS

Wheezing is common in SCD and in some individuals represents an intrinsic component of SCD-related lung disease rather than asthma. Emerging data suggest that, regardless of the cause, individuals with SCD and with recurrent wheezing are at increased risk for subsequent morbidity and premature mortality. We believe individuals who acutely wheeze and have respiratory symptoms should be managed with a beta agonist and short-term treatment of oral steroids, typically less than 3 days to attenuate rebound vaso-occlusive disease. For those who wheeze and have a history or examination associated with atopy, we consider asthma treatment and monitoring per National Heart, Lung and Blood Institute asthma guidelines.

SUMMARY

Wheezing in SCD should be treated aggressively both in the acute setting and with controller medications. Prospective SCD-specific clinical trials will be necessary to address whether anti-inflammatory asthma therapies (leukotriene antagonists, inhaled corticosteroids) can safely mitigate the sequelae of wheezing in SCD.