الفهرس 
Review of LiteratureOnly 14 pages are availabe for public view
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Abstract
Sleep disordered breathing (SDB), a common underdiagnosed sequela of sickle cell disease (SCD) has been linked to the frequency of vaso-occlusive crises, cardiac abnormalities and central nervous system events. The aim of this work was to determine the frequency of SDB in patients with SCD and its association to SCD-related complications.
After having the approval of research ethics committee center at Ain Shams University Hospitals and after obtaining an informed written or oral parental consent from all participants or their parents, this cross sectional study started as 30 patients with confirmed sickle cell disease aging 6-18 years old were subjected to the following assessments; detailed medical history taking with emphasis on transfusion history, history of disease complications, chelation therapy and hydroxyurea therapy, clinical examination with special account on neurological deficits and laboratory investigation especially hemoglobin electrophoresis analysis and Markers of hemolysis. They were also evaluated using overnight polysomnography after completing the modified STOP-Bang questionnaire. Transcranial Doppler (TCD) and assessment of tricuspid regurgitation velocity (TRV) were performed.
Our results showed that sixty percent of our study cohort suffered SDB at AHI cutoff point of ≥ 1 and 20% at a cutoff point of ≥ 5. On the other hand, out of six patients with moderate to severe OSA, four had adenotonsiller hypertrophy.
Assessment of SDB in our study was done using the modified STOP bang questionnaire (SBQ) and polysomnography (PSG). The modified STOP-Bang questionnaire was demonstrated to have excellent sensitivity, but modest specificity in detecting OSA .Additionally, pediatric polysomnography is expensive and not commonly available in areas without specialized pediatric centers. Using this questionnaire, we found that fifty percent of our study sample had intermediate to high risk of OSA; we demonstrated that higher scores on the modified STOP-Bang questionnaire were associated with SDB found on the overnight PSG study.
In the setting of the polysomnogram sleep study, the mean sleep efficiency in our study cohort was 75.87% with REM duration ranged from 0 to 1.09 hours and mean REM latency of 2.04 hours which indicated poor sleep quality in our patients.
During evaluation of the risk of cerebrovascular events in our study cohort we found that in contrast to moderate and severe risk groups, none of the low-risk group in our study had abnormal TCD flow velocities, and also we found higher TCD velocities in patients with moderate to severe OSA (AHI > 5) using polysomnography, this links the risk of OSA to stroke in the SCD population. Also, during evaluation of the risk of pulmonary hypertension in our study sample, we found a significant positive correlation between OSA and the tricuspid regurgitation velocity.
Limitations to our work include the cross-sectional nature of the study, the use of a convenience and small sample size. It is possible that a larger sample size would have resulted in more significant associations and would have allowed a multivariate analysis of potential risk factors for SDB. A larger prospective study is needed to confirm these findings.
CONCLUSION
The prevalence of obstructive sleep apnea was high in children with sickle cell disease in our center and was associated with increasing risk of pulmonary hypertension and transcranial Doppler alterations. This underlines the importance of screening for OSA in all children with SCD.