Investigators observed that children with sickle cell disease (SCD) may be at increased risk of comorbid events related to sleep-related breathing disorder (SDS).
Findings from a team of researchers at Udine University Hospital in Italy indicated that progression from the common pediatric sickle cell-associated sleep disorder could include hypoxemia, obstructive sleep apnea (OSA), and severe cardiovascular or neurological sequelae.
The study focuses on the epidemiology, clinical presentation, complications, and management of sleep-related breathing disorders in children with sickle cell disease. Investigators reviewed a total of 190 research papers on sleep-disordered breathing in children with sickle cell anemia published between 2000 and 2020, and narrowed the selection to include 62 studies in their analysis.
There are 11 studies that reported comparable polysomnography (PSG) results. All selected studies showed that children with sickle cell anemia had significantly lower median oxygen saturation and lower minimum oxygen saturation during sleep compared to healthy control groups.
None of the patients with sickle cell anemia from the 11 studies had a previous OSA history (men 470, 45%, mean age 10.2 years, range 1-18), calculated mean overnight SpO2 was 95.8% ( 95% CI, 95.6-95.9), with a mean nadir SpO2 of 88.0% (95% CI, 87.8-88.2%) and a mean AHI of 3.6 (95% CI, 3.4-3.8).
Greater and longer-lasting nocturnal desaturation and hypercapnia were found in pediatric patients with sickle cell anemia than in children without sickle cell anemia with OSA. Overnight PSG results are generally stable or improve slightly in the medium to long term.
A single study looked at 100 children with sickle cell anemia using a specific sleep questionnaire, regardless of sleep-related breathing difficulties, and found that 19 children had a positive sleep apnea screening score. 7 patients were diagnosed with OSA and 10 patients underwent PSG.
Investigators found 11 publications that focus on possible treatments for sleep disorders in children with sickle cell disease. This included 6 studies examining the clinical effects of tonsillectomy and adenoidectomy (T&A); 2 studies on the Hounsfield Unit (HU); and 3 studies on night oxygen.
All interventions showed a significant increase in mean nocturnal SpO2 (MD, 2069; 95% CI, 2.01-3.36; I2 = 0%). Relatively. Oxygen supplementation had a slightly increased performance (MD 2.98; 95% CI, 2.08-3.88).
The effect was even more pronounced with nadir SpO2 (MD 5.84; 95% CI 4.41-7.28; I2 = 32%). The reduction in the apnea-hypopnea index (AHI) was significant in all interventions (MD, -6.7; 95% CI, -11.27 to 2.12; I2 = 92%).
Results and implications
Ultimately, the researchers of this cumulative study found that children with sickle cell anemia often suffer from sleep-related breathing disorder, which can correlate with various other complications that include neurological, cognitive, cardiovascular, and pulmonary aspects.
Children with OSA are at greater risk of neurological events such as seizures, but not stroke. The specific relationship between OSA and cerebrovascular complications is indeterminate, but chronic hypoxemia is associated with a higher incidence of central nervous system events.
The results support the hypothesis that interventions aimed at alleviating sleep-related breathing disorders and nighttime hypoxemia through T&A and supplemental oxygen therapy result in significant reductions in TCD rates. However, the clinical implications are still unclear.
Although the evidence is limited, there is no apparent impact on the incidence of VOCs and acute coronary syndrome. Nocturnal home oxygen appears to be safe overnight for children with sickle cell anemia and severe hypoxemia, but due to the lack of high quality data, no conclusions can be drawn about the impact of this measure on long-term clinical outcomes.
“Prospective and sufficiently informative studies are needed to further investigate the relationship between SDS and neurological, cardiovascular and pulmonary complications in children with SCD,” the investigators wrote. “And to evaluate the clinical effect and the long-term safety profile of possible therapeutic interventions.”
The study, “The Stress of Breathing Sleep Disorders in Children with Sickle Cell Anemia” was published in the journal Pediatric Pulmonology.