• Safety and Health at Work
• /
• v.13 no.2
• /
• pp.148-154
• /
• 2022

Background: Bus driving is a mentally demanding activity that requires prolonged attention to ensure safety. The aim of the study was to assess mental fatigue caused by driving a public bus and to find a profile of workers at higher risk. Methods: We evaluated changes of critical flicker fusion (CFF) (index of central arousal) and heart rate variability (HRV) (index of autonomic balance) in a 6-hour driving shift on a real route, in 31 professional bus drivers, and we tested the influence of personal factors such as sleep quality, BMI, and age. Paired t-test was used to test differences of CFF and HRV between both initial and final phase of driving, while multiple linear regression tested the influence of personal variables on the indexes of mental fatigue. Results: Results showed that CFF significantly decreased after 6 hours of bus driving (41.91 Hz, sd 3.31 vs. 41.15 Hz, sd 3.15; p = 0.041), and heart rate significantly decreased in the final phase of driving, with respect to the initial phase (85 vs. 78 bpm, p = 0.027). Increasing age (beta = -0.729, p = 0.022), risk of obstructive sleep apnea syndrome (beta = -0.530, p = 0.04), and diurnal sleepiness (beta = -0.406, p = 0.017) showed a significant effect on influencing mental fatigue. Conclusion: Elderly drivers at higher risk of sleep disorders are more prone to mental fatigue, when exposed to driving activity. Monitoring indexes of central arousal and autonomic balance, coupled with the use of structured questionnaires can represent a useful strategy to detect profile of workers at higher risk of mental fatigue in such duty.

• The korean journal of orthodontics
• /
• v.38 no.3
• /
• pp.202-213
• /
• 2008

Objective: The purpose of this study was to compare the cephalometric measurements of obese and non-obese Korean male patients with obstructive sleep apnea syndrome (OSA). Methods: Eighty-seven adults who had visited the Sleep Disorder Clinic Center in Keimyung University, Daegu, Korea were examined and evaluated with polysomnography (PSG) and lateral cephalogram. They were divided into 4 groups (non-obese simple snorers, obese simple snorers, non-obese OSA patients, obese OSA patients) according to AHI (Apnea-Hypopnea Index) and BMI (Body Mass Index). Results: The obese OSA group had the highest AHI among the 4 groups. The non-obese OSA group had a significantly steeper mandibular angle and shorter tongue length than the obese OSA group. The hyoid bone of the obese OSA group was positioned anterior and inferior as compared with the non-obese OSA group. Multiple regression analysis showed that tongue length in the obese OSA group and retroposition of hyoid bone in the non-obese OSA group were significant determinants for the severity of AHI. Conclusions: From a cephalometric point of view, the obese and non-obese pateints with OSA may be characterized by different pathogeneses. Therefore, they have to be managed by individualized treatment. For the obese OSA patients, weight control must be advised as a first choice and for the non-obese OSA patients, oral appliance, nasal CPAP, UPPP and others could be chosen according to the obstructive sites.

• Clinical and Experimental Pediatrics
• /
• v.45 no.3
• /
• pp.383-389
• /
• 2002

We experienced a case of partial DiGeorge syndrome in a $35^{＋5}$ week premature female infant presented with micrognathia, fish-shaped mouth, beaked nose, nasal regurgitation, obstructive sleep apnea, velopharyngeal insufficiency and late onset hypocalcemic seizures. The chromosome 22q11 microdeletion was found by the FISH method. The lab findings showed serum calcium level of 4.4 mg/dL, ionized calcium level of 0.49 mg/dL, phosphorous level of 7.5 mg/dL, magnesium level of 1.3 mg/dL and PTH-RIA level of <1 pq/mL. Initial treatment was done with 10% calcium gluconate infusion and magnesium sulfate followed by oral calcium gluconate and low phosphorousformula milk feeding. The serum calcium level was normalized in 6 days. Nasal regurgitation, desaturation with obstructive sleep apnea continued. T-cell functions & numbers(CD 3, CD 4, CD 8)were decreased but Ig G/A/M levels were normal. No visible signs of thymus shadow were seen in either chest X-ray & chest MRI. Electrocardiography and echocardiography showed normal heart. Kidney ultrasonographby showed right side mild hydronephrosis. Neurosonography was normal but EEG showed electrical partial seizure. Hearing assessment by BERA showed mild to moderate hearing impairment. Velopharyngoplasty is scheduled for further treatment. A brief review of literature was made.

• Sleep Medicine and Psychophysiology
• /
• v.27 no.2
• /
• pp.56-66
• /
• 2020

Objectives: In this study, the clinical characteristics of OSA patients and the quality of life before and after CPAP use were compared to determine the degree of improvement in quality of life according to CPAP use. Methods: Age, sex, height, weight, body mass index, Epworth Sleepiness Scale, Modified Mallampatti Score, Montreal Cognitive Assessment-Korean, and Pittsburgh Sleep Quality Index were compared between men and women through medical records. To understand the degree of improvement in quality of life resulting from use of CPAP, a personal telephone call was made to compare the VAS scores for quality of life before and after CPAP use. Results: In height (HT) (Z = -4.525, p < 0.001), weight (BW) (Z = -2.844, p < 0.05), sleep quality (PSQI) (Z = -2.671, p < 0.05), and arousal index (AI) (Z = -2.105, p < 0.05), there was a difference between men and women (p < 0.05). There was no difference in the remaining variables. Cross-analysis (Chi-square test) confirmed a difference between severity and sex of OSA. It has been found that there is no statistically significant order in size according to level-specific severity of OSA for PreCPAP QOL, PostCPAP QOL, CPAPUse Months, and CPAP4Hr/d (%) (p > 0.05). The difference between AHI before and after CPAP was 36.48 ± 21.54 (t = 11.609, p < 0.001) and the difference between QOL before and after CPAP was -25.43 ± 22.06 (t = -7.901, p < 0.001), both of which were significant (p < 0.001). Conclusion: Among OSA patients, there were differences in height (HT), weight (BW), sleep quality (PSQI), arousal index (AI), and severity of OSA between men and women, but the quality of life before and after CPAP was different. However, there was no difference between men and women in quality of life before and after CPAP. In addition, quality of life in OSA patients improved after using CPAP.

• Sleep Medicine and Psychophysiology
• /
• v.9 no.1
• /
• pp.24-33
• /
• 2002

Objectives: Nasal continuous positive airway pressure (CPAP) corrected elevated blood pressure (BP) in some studies of obstructive sleep apnea syndrome (OSAS) but not in others. Such inconsistent results in previous studies might be due to differences in factors influencing the effects of CPAP on BP. The factors referred to include BP monitoring techniques, the characteristics of subjects, and method of CPAP application. Therefore, we evaluated the effects of one night CPAP application on BP and heart rate (HR) reactivity using non-invasive beat-to-beat BP measurement in normotensive and hypertensive subjects with OSAS. Methods: Finger arterial BP and oxygen saturation monitoring with nocturnal polysomnography were performed on 10 OSAS patients (mean age $52.2{\pm}12.4\;years$; 9 males, 1 female; respiratory disturbance index (RDI)>5) for one baseline night and another CPAP night. Beat-to-beat measurement of BP and HR was done with finger arterial BP monitor ($Finapres^{(R)}$) and mean arterial oxygen saturation ($SaO_2$) was also measured at 2-second intervals for both nights. We compared the mean values of cardiovascular and respiratory variables between baseline and CPAP nights using Wilcoxon signed ranks test. Delta ($\Delta$) BP, defined as the subtracted value of CPAP night BP from baseline night BP, was correlated with age, body mass index (BMI), baseline night values of BP, BP variability, HR, HR variability, mean $SaO_2$ and respiratory disturbance index (RDI), and CPAP night values of TWT% (total wake time%) and CPAP pressure, using Spearman's correlation. Results: 1) Although increase of mean $SaO_2$ (p<.01) and decrease of RDI (p<.01) were observed on the CPAP night, there were no significant differences in other variables between two nights. 2) However, delta BP tended to increase or decease depending on BP values of the baseline night and age. Delta systolic BP and baseline systolic BP showed a significant positive correlation (p<.01), but delta diastolic BP and baseline diastolic BP did not show a significant correlation except for a positive correlation in wake stage (p<.01). Delta diastolic BP and age showed a significant negative correlation (p<.05) during all stages except for REM stage, but delta systolic BP and age did not. 3) Delta systolic and diastolic BPs did not significantly correlate with other factors, such as BMI, baseline night values of BP variability, HR, HR variability, mean SaO2 and RDI, and CPAP night values of TWT% and CPAP pressure, except for a positive correlation of delta diastolic pressure and TWT% of CPAP night (p<.01). Conclusions: We observed that systolic BP and diastolic BP tended to decrease, increase or remain still in accordance with the systolic BP level of baseline night and aging. We suggest that BP reactivity by CPAP be dealt with as a complex phenomenon rather than a simple undifferentiated BP decrease.

• Sleep Medicine and Psychophysiology
• /
• v.9 no.1
• /
• pp.34-40
• /
• 2002

Objectives: The gold standard for diagnosing obstructive sleep apnea syndrome (OSAS) is nocturnal polysomnography (NPSG). This is rather expensive and somewhat inconvenient, however, and consequently simpler and cheaper alternatives to NPSG have been proposed. Oximetry is appealing because of its widespread availability and ease of application. In this study, we have evaluated whether oximetry alone can be used to diagnose or screen OSAS. The diagnostic performance of an analysis algorithm using arterial oxygen saturation ($SaO_2$) base on 'dip index', mean of $SaO_2$, and CT90 (the percentage of time spent at $SaO_2$<90%) was compared with that of NPSG. Methods: Fifty-six patients referred for NPSG to the Division of Sleep Studies at Seoul National University Hospital, were randomly selected. For each patient, NPSG with oximetry was carried out. We obtained three variables from the oximetry data such as the dip index most linearly correlated with respiratory disturbance index (RDI) from NPSG, mean $SaO_2$, and CT90 with diagnosis from NPSG. In each case, sensitivity, specificity and positive and negative predictive values of oximetry data were calculated. Results: Thirty-nine patients out of fifty-six patients were diagnosed as OSAS with NPSG. Mean RDI was 17.5, mean $SaO_2$ was 94.9%, and mean CT90 was 5.1%. The dip index [4%-4sec] was most linearly correlated with RDI (r=0.861). With dip index [4%-4sec]${\geq}2$ as diagnostic criteria, we obtained sensitivity of 0.95, specificity of 0.71, positive predictive value of 0.88, and negative predictive value of 0.86. Using mean $SaO_2{\leq}97%$, we obtained sensitivity of 0.95, specificity of 0.41, positive predictive value of 0.79, and negative predictive value of 0.78. Using $CT90{\geq}5%$, we obtained sensitivity of 0.28, specificity of 1.00, positive predictive value of 1.00, and negative predictive value of 0.38. Conclusions: The dip index [4%-4sec] and mean $SaO_2{\leq}97%$ obtained from nocturnal oximetry data are helpful in diagnosis of OSAS. CT90${\leq}$5% can be also used in excluding OSAS.

• Sleep Medicine and Psychophysiology
• /
• v.3 no.2
• /
• pp.32-42
• /
• 1996

Objectives : Upper airway resistance syndrome(UARS) is a sleep-related breathing disorder characterized by abnormal negative intrathoracic pressure during sleep. Abnormally increased negative intrathoracic pressure results in microarousal and sleep fragmentation which underlay UARS-associated complaints of daytime fatigue and sleepiness. Although daytime dysfunction in patients with UARS is comparable to that of sleep apnea syndrome, UARS has been relatively unnoticed in clinical setting. That is why UARS is apt to be excluded in diagnosing of sleep-related breathing disorders since its respiratory disturbance index and arterial oxygen saturation are within normal limits. The current study presents a summary of clinical and polysomnographic characteristics found in patients with UARS. The present study aims (1) to explore characteristics of patients diagnosed with UARS, (2) to characterize the polysomnographic findings of UARS patients, and (3) to enhance the understanding of UARS through those clinical and laboratory characteristics. Methods : This was a retrospective study of 20 UARS patients (male 15, female 5) and 30 obstructive sleep apnea (OSA) patients (male 21, female 9) at the Stanford Sleep Disorders Clinic. We diagnosed patients as having UARS when they met critenia, RDI < 5 characteristic findings of an elevated esophageal pressure($<-10\;cmH_2O$), frequent arousals secondary to an elevated esophageal pressure, and symptoms of daytime fatigue and sleepiness. We used polysomnographic value, which is standardized by Williams et al(1974), as normal control. Statiotical test were done with student t-tests. Results : (1) Mean age of UARS was $41.0\;{\pm}\;14.8$ years and OSA was $50.9\;{\pm}\;12.0$ years. UARS subject was significantly younger than OSA subject (p<0.05). (2) The total score of Epworth Sleepiness Scale (ESS) was UARS $9.7\;{\pm}\;6.3$ and OSAS $11.2\;{\pm}\;6.3$. There was no significant difference between two groups. (3) The mean body mass index was UARS $28.1\;{\pm}\;5.7\;kg/m^2$ and OSAS $32.9\;{\pm}\;7.0\;kg/m^2$. UARS had significantly lower meen body man index than OSAS subjects (p<0.05). (4) The polysomnographic parameters of UARS were not significantly different from those of OSA except RDI(p<0.001), $SaO_2$ (p<0.001) and slow wave sleep latency (p<0.05). (5) Compared with normal control, Total sleep time in UARS subjects was significantly shorter (p<0.001), sleep efficiency index was significantly lower (p<0.001), total awakening percentage was significantly higher (p<0.001), and sleep stage 1 (p<0.001) were significantly higher. (6) OSA patients showed poor sleep quality and distinct abnormal sleep architectures compared with normal control. Conclusions : Conclusions from the above results are as follows : (1) UARS patients were younger and had lower body mass index when umpared with OSA patients. (2) The quality of sleep and sleep architectures of the UARS and OSA patients are significantly different from those of normal control. (3) ESS scores and awakening frequencies of UARS are similar with those of OSA, suggesting that daytime dysfunction of UARS patients may be comparable to those of OSA patients. (4) The RDI and the $SaO_2$ which are important indicators in diagnosing sleep-related breathing disorders, of UARS subjects are close to normal value. (5) According to the the above results, we unclude that despite the absence of $SaO_2$ drops and the absence of an elevated number of apnea and hypopnea, subjects developed clinical complaints which were associated with laborious breathing, elevated Pes nadir, and frequently snoring. (6) Accordingly, we suggest including LIARS in the differential diagnosis list when sleep related breathing disorder is suspected clinically and overnight polysomnographic findings except snoring and frequent microarousal are within normal limits.

• Annual Conference of KIPS
• /
• 2024.10a
• /
• pp.692-695
• /
• 2024

폐쇄성 수면 무호흡증(Obstructive Sleep Apnea, OSA)은 수면 중 상기도의 폐쇄로 호흡 저하 및 중단이 발생하는 질환이다. 약물 유도 수면내시경(Drug-induced sleep endoscopy, DISE)은 이러한 상기도의 폐쇄 위치를 파악하는 데 사용되며, VOTE(Velum, Oropharynx, Tongue base, Epiglottis) scoring을 통해 DISE 결과를 판독한다. 하지만 VOTE scoring은 의료진이 주관적으로 각 해부학적 위치의 폐쇄 정도를 판단하기 때문에, 의료진의 해석에 따라 진단 결과가 달라질 수 있으며, 이로 인한 판독자간 판독 불일치가 상당하다. 따라서 본 연구는 딥러닝 모델을 활용하여 DISE 영상에서 VOTE 영역을 자동으로 분류하고 상기도의 완전폐쇄 여부를 예측하고자 한다. 연구개(V), 연구개 완전폐쇄(V degree 2), 구인두-혀 기저부-후두덮개(OTE), 구인두-혀 기저부-후두덮개 완전폐쇄(OTE degree 2), 왜곡(X) 총 5가지 클래스로 분류하였다. 이러한 분류 체계는 상기도의 부위별 폐쇄를 더 정확하고 체계적으로 예측할 수 있게 해 준다. 이를위해 13명의 환자로부터 수집된 DISE 영상 데이터셋과 임상 정보를 기반으로 ResNet, DenseNet, VGG, EfficientNet과 같은 딥러닝 모델을 구현하고 성능을 비교했다. 그 결과 EfficientNet 모델이 80%의 정확도로 가장 뛰어난 성능을 보였다. 향후 연구에서는 DISE 영상에서 상기도 폐쇄 양상을 더욱 세분화하여 분석하고자 한다.

• Clinical and Experimental Pediatrics
• /
• v.57 no.11
• /
• pp.484-488
• /
• 2014

Purpose: Chronic upper airway obstruction causes hypoxemic pulmonary vasoconstriction, which may lead to right ventricle (RV) dysfunction. Adenotonsillar hypertrophy (ATH) is the most common cause of upper airway obstruction in children. Therefore, we aimed to evaluate RV function in children with ATH. Methods: Twenty-one children (male/female, 15/6; mean age, $92.3{\pm}39.0$ months; age range, 4-15 years) with ATH and 21 healthy age- and gender-matched controls were included in this study. Tricuspid annular plane systolic excursion and RV myocardial performance index were measured by transthoracic echocardiography. Further, the plasma level of N-terminal of probrain natriuretic peptide (NT-proBNP), an indicator of RV function, was determined. Results: The snoring-tiredness during daytime-observed apnea-high blood pressure (STOP) questionnaire was completed by the patients' parents, and loud snoring was noted in the ATH group. The plasma NT-proBNP level was significantly higher in the ATH group than that in the controls ($66.44{\pm}37.63pg/mL$ vs. $27.85{\pm}8.89pg/mL$, P=0.001). The echocardiographic parameters were not significantly different between the groups. Conclusion: We were unable to confirm the significance of echocardiographic evidence of RV dysfunction in the management of children with ATH. However, the plasma NT-proBNP level was significantly higher in the ATH group than that in the control, suggesting that chronic airway obstruction in children may carry a risk for cardiac dysfunction. Therefore, more patients should be examined using transthoracic echocardiography. In addition, pediatricians and otolaryngologists should consider cardiologic aspects during the management of children with severe ATH.

• Korean Journal of Clinical Laboratory Science
• /
• v.51 no.2
• /
• pp.191-197
• /
• 2019

Although auto-adjusting positive airway pressure (APAP) titration at home has several advantages over a CPAP titration in terms of convenience and time saving, there are still concerns as to whether it will show corresponding accuracy when compared to laboratory-based polysomnography (PSG) and CPAP titration. To obtain more evidence supporting home-based auto-titration, APAP titration was performed at home for patients who were presented with OSA on laboratory-based diagnostic PSG followed by CPAP titration. A total of 79 patients were included in the study. They all underwent split-night PSG with CPAP titration, and APAP titration for more than 7 days. The patients with successful titration at both situations were selected. The optimal pressure and apnea-hypopnea index (AHI) of CPAP and APAP titration were compared. The optimal pressure for CPAP and APAP titration were $7.0{\pm}1.8cmH_2O$ and $7.6{\pm}1.6cmH_2O$ (P<0.001), whereas the corresponding AHI were $1.3{\pm}1.5/h$ and $3.0{\pm}1.7/h$ (P<0.001). As a result, the achievement rates of optimal pressure for CPAP and APAP titration were 96.2% and 94.9% (r=-0.045, P=0.688), respectively. The results of this study did not differ with regard to the optimal pressure between CPAP and APAP titration. Overall, CPAP and APAP titrations should be chosen depending on a required situation.