Turbulent Kinetic Energy of Flow during Inhale and Exhale to Characterize the Severity of Obstructive Sleep Apnea Patient

This paper aims to investigate and present the numerical investigation of airflow characteristics using Turbulent Kinetic Energy(TKE)to characterize the upper airway with obstructive sleep apnea(OSA)under inhale and exhale breathing conditions.The importance of TKE under both breathing conditions is that it showan accuratemethod in expressing the severity of flow in sleep disorder.Computational fluid dynamics simulate the upper airway’s airflow via steady-state Reynolds-averaged Navier-Stokes(RANS)with k–ωshear stress transport(SST)turbulencemodel.The three-dimensional(3D)airway model is created based on the CT scan images of an actual patient,meshed with 1.29 million elements using Materialise Interactive Medical Image Control System(MIMICS)and ANSYS software,respectively.High TKE were noticed around the region after the necking(smaller cross-sectional area)during the inhale and exhale breathing.The turbulent kinetic energy could be used as a valuablemeasure to identify the severity of OSA.This study is expected to provide a better understanding and clear visualization of the airflow characteristics during the inhale and exhale breathing in the upper airway of patients for medical practitioners in the OSA research field.

Relationship between metabolic syndrome and hypercapnia among obese patients with sleep apnea Relationship between metabolic syndrome and hypercapnia among obese patients with sleep apnea

BACKGROUND In the obese patient population,some patients have severe obstructive sleep apnea(OSA)with daytime hypoventilation.Such patients are generally identified on the basis of the presence or absence of daytime hypercapnia,and the condition is called obesity hypoventilation syndrome.However,mechanisms for such daytime hypoventilation remain unclear.AIM To investigate metabolic syndrome and daytime hypercapnia association based on hypercapnia prevalence in obese OSA patients in a nested case-control study.METHODS Consecutive obese patients(body mass index≥30 kg/m2)who underwent polysomnography due to suspected OSA were included.Among them,patients with severe OSA(apnea hypopnea index≥30/h)were divided into two groups according to the presence or absence of hypercapnia during wakefulness(arterial partial pressure of carbon dioxide≥or<45 Torr,respectively).The characteristics and clinical features of these two groups were compared.RESULTS Among 97 eligible patients,25 patients(25.8%)had daytime hypercapnia.There were no significant differences in age,gender,body mass index,apnea-hypopnea index,and Epworth Sleepiness Scale scores between the two groups.However,patients with hypercapnia had a significantly lower arterial partial pressure of oxygen level(75.8±8.2 torr vs 79.9±8.7 torr,P=0.042)and higher arterial partial pressure of carbon dioxide level(46.6±2.5 torr vs 41.0±2.9 torr,P<0.001).Additionally,patients with hypercapnia were more likely to have metabolic syndrome(72.0%vs 48.6%,P=0.043)and a higher metabolic score(the number of satisfied criteria of metabolic syndrome).In multivariate logistic regression analysis,the presence of metabolic syndrome was associated with the presence of hypercapnia(OR=2.85,95%CI:1.04-7.84,P=0.042).CONCLUSION Among obese patients with severe OSA,26%of patients had hypercapnia during wakefulness.The presence of metabolic syndrome was independently correlated with the presence of daytime hypercapnia.

Undiagnosed obstructive sleep apnea in hypertensive outpatients in primary care—Associations with sleep complaints, depressive symptoms and global perceived health

Objective: 1) To describe the prevalence of undiagnosed obstructive sleep apnea (OSA) and depressive symptoms in hypertensive men and women below 65 years of age, and 2) to describe the association of OSA to subjective sleep complaints, depressive symptoms and global perceived health. Design: Cross-sectional design focusing on nursing care outcomes of obstructive sleep apnea. Setting: Four primary care health centres in Sweden. PATIENTS: 411 consecutive patients (52% women), mean age 57.9 years (SD 5.9 years), with diagnosed hypertension (BP > 140/90). Main Outcome Measures: Prevalence of OSA and depressive symptoms, and association of OSA to sleep complaints, depressive symptoms and global perceived health. RESULTS: Mild, moderate and severe OSA was seen among 29%, 16% and 14% of patients, respectively. Depressive symptoms were seen in 16% of the total group, with a higher prevalence among men, compared to women, 21% vs. 12%. No differences were found regarding blood pressure, estimated sleep need, sleep sufficiency index, insomnia symptoms, daytime sleepiness or depressive symptoms with respect to different degrees of OSA. Apnea-hypopnea index was significantly associated to perceived health after adjustment for gender and comorbidities, but when depressive symptoms and non-restorative sleep were added to the model, 33% of the variance in global perceived health was explained. Conclusion: OSA is highly prevalent among patients with hypertension in primary care and does together with sleep complaints and depressive symptoms have a negative impact on global perceived health. Hypertensive patients without subjective sleep complaints or depressive symptoms may still have OSA.

Polysomnographic findings of obstructive sleep apnea in children with adenotonsillar hypertrophy

Serous Background: There are few studies assessing the clinical manifestations of sleep breathing disorders and polysomnograms in several pediatric age ranges. This studied aimed to assess polysomnography results such as apnea-hypopnea index, mean oxygen saturation and sleep efficiency in children presenting with airway obstruction and adenotonsillar hypertrophy complaints, and to establish whether they are correlated to age and sex. Methods: A retrospective study with children of both sexes, aged between 2 and 12 years, with clinically suspected obstructive sleep apnea syndrome and adenotonsillar hypertrophy, who underwent polysomnography before surgery. The children were allocated to groups according to their age range (Group I: 2 to 4 years old;Group II: 5 to 8 years old;Group III: 9 to 12 years old). Apnea-hypopnea index, mean oxygen saturation and sleep efficiency data were compared between sexes and among the three groups (Student’s t test, p < 0.05). Results: Of 167 children studied by polysomnography, 76.6% were of school age and 67% were male. For all studied age ranges, there was no difference between sexes for the investigated parameters (body mass index, apnea-hypopnea index, mean oxygen saturation and sleep efficiency). As regards mean oxygen saturation, Group I showed the lowest value (89.9 ± 6.2). Apnea-hypopnea indexes were higher in male children aged between 2 and 4 years (9.9 ± 5.2). Group III had the lowest sleep efficiency (84.1 ± 9.2). Conclusion: There was a predilection of more severe cases of obstructive sleep apnea syndrome for children younger than four years, shown by higher apnea-hypopnea index per hour and lower mean oxygen saturation in this age range.

A 7-year-old boy with recurrent cyanosis and tachypnea:A case report

BACKGROUND Brain tumors are the most common solid tumors in children and comprise 25%of all malignancies in children.Common presentations include headache,nausea and vomiting,gait abnormality,papilledema,and epileptic seizure;however,some symptoms can be very insidious,with atypical and misleading manifestations.CASE SUMMARY Here,we report a 7-year-old boy who presented with recurrent cyanosis and tachypnea after exercise for 2 years.His body mass index was 26.43 kg/m2.Hepatosplenomegaly,blood gas analysis,biochemical parameters,chest computed tomography scan,and echocardiograph suggested type II respiratory failure,pulmonary heart disease,and mild liver injury.Non-invasive breathing support,antibiotics,and anti-heart failure therapy were given.The patient’s pulse oxygen saturation increased to over 95%when he was awake but dropped to 50%-60%,accompanied by cyanosis,during sleep while receiving high-flow nasal cannula oxygen.Sleep-related breathing disorder was suspected.In the intensive care unit,however,polysomnography was unavailable.Brain magnetic resonance imaging revealed a space-occupying(cerebellum and brainstem)lesion,which was later confirmed to be pleomorphic xanthoastrocytoma by surgery and histopathology by tissue biopsy.CONCLUSION When treating patients with cyanosis and tachypnea,a broad differential diagnosis should be considered,including brain tumor.

Subjective sleepiness in heart failure patients with sleep-related breathing disorder

Background Previous studies show that sleep-related breathing disorder （SRBD） is common in patients with heart failure （HF） and is associated with increased mortality. This study aimed to determine whether there was significant difference of subjective daytime sleepiness between HF patients with and without SRBD. Methods We enrolled, prospectively, 195 consecutive HF patients with left ventricular ejection fractions （LVEF） ≤45% and all subjects underwent polysomnography to measure the sleep structure between 2005 and 2008. Patients were then assigned to those with SRBD including obstructive and central sleep apnea （apnea-hypopnea index （AHI） ≥5/hour of sleep） and those without SRBD （AHI 〈5/hour） according to the sleep study. The subjective sleepiness was assessed with Epworth sleepiness scale （ESS）. Results Among 195 HF patients, the prevalence of obstructive sleep apnea （OSA） was 53% and of central sleep apnea （CSA） was 27%. There was no significant difference of ESS scores between patients without SRBD （NSA） and with SRBD （NSA vs OSA： 6.7±0.6 vs 7.6±0.4, P=0.105 and NSA vs CSA： 6.7±0.6 vs 7.4±K）.5, P=0.235, respectively）, indicating that SRBD patients had no more subjective daytime sleepiness. Compared with NSA, patients with SRBD had increased arousal index （Arl） （NSA vs OSA： 14.1±1.4 vs 26.3 ±1.5, P〈0.001 and NSAvs CSA： 14.1±1.4 vs 31.3±3.5, P 〈0.001, respectively）, more awake number after sleep onset （NSA vs OSA： 19.2±1.5 vs 26.2±1.4, P=0.01 and NSA vs CSA： 19.2±1.5 vs 36.9±4.4, P 〈0.001, respectively）, and reduced proportion of slow-wave sleep （SWS） （NSA vs OSA： 13.8±1.7 vs 9.3±0.7, P=0.024 and NSA vs CSA： 13.8±1.7 vs 8.9±0.9, P=0.024, respectively）. Conclusions OSA and CSA remain common in patients with HF on optimal contemporary therapy. Patients with both HF and SRBD have no significant subjective daytime sleepiness compared with patients without SRBD, despite of significantly increased awake number, arousal and decreased proportion of deep sleep stages. It is not a credible way and means to exclude SRBD in patients with HF according to the absence of subjective daytime sleepiness.

Chinese children＇s respiratory diseases in 60 years

This year marks the 60th anniversary of the founding of the People＇s Republic of China. On this occasion,it is worthy to recall the past and look towards the future in order to do a better job in research and control of children＇s respiratory diseases.