• Sleep Medicine and Psychophysiology
• /
• v.7 no.1
• /
• pp.27-33
• /
• 2000

Objectives: The sensitivity and accuracy of thermistor airflow signal has been debated. The purposes of this study were to compare apnea-hypopnea index(AHI) detected from a conventional thermistor signal and a nasal pressure transducer of airflow(NPT), to evaluate the value of NPT for the diagnosis of upper airway resistance syndrome(UARS), and to measure airway pressure fluctuations which produced respiratory arousals in UARS by naso-oro-esophageal manometer catheter. The subjects were 30 patients with obstructive sleep apnea syndrome [mild(540), 10), and 6 UARS patients. Airway resistance arousal in this study was defined as arousals which were not associated with apnea or hypopnea of thermistor signal, but showed significant decrease of nasal airflow pressure just before arousal and a prompt recovery of nasal airflow pressure after arousal. The airway pressure fluctuations were measured during 260 airway resistance arousals observed in 10 patients with OSAS, 2 with UARS. Results: Mean AHIs of patients with OSAS were 33.4 by thermistor and 48.4 by NPT. The AHIs of mild, moderate and severe OSAS groups were 10.2, 32.1, 65.4 respectively by thermistor and 23.1, 45.9, 76.4 by NPT. The mean AHI of patients with UARS was 3.2 by thermistor and 10.8 by NPT. The mean AHI of patients with nonspecific arousals was 2.7 by thermistor and 4.4 by NPT. The mean airway pressure changes during respiratory arousals of different groups were $8.7\;cmH_2O$ in mild OSAS, $11.4\;cmH_2O$ in moderate OSAS, $24.7\;cmH_2O$ in severe OSAS and $6.6\;cmH_2O$ in UARS. Conclusion: The nasal pressure transducer of airflow was more sensitive and accurate for assessing respiratory disturbances of patients with OSAS and was extremely helpful for the diagnosis of UARS without esophageal pressure monitoring. From the results, we would like to propose carefully the NPT diagnostic criteria for sleep disordered breathing as follows: NPT-AHI 5-15 $\rightarrow$ UARS, 15-35 $\rightarrow$ mild OSAS, 35-55 $\rightarrow$ moderate OSAS and >55 $\rightarrow$ severe OSAS.

• Journal of Oral Medicine and Pain
• /
• v.38 no.2
• /
• pp.203-213
• /
• 2013

Objecives : The purpose of the study was to evaluate treatment outcome of mandibular advancement device(MAD) in obstructive sleep apnea (OSA) patients using full night polysomnography and cephalometry. Methods : Twenty-seven OSA patients were confirmed by full night, lab-attended polysomnography. Cephalometric examinations were conducted to obtain SNA, ANB, $AH{\bot}MP$, AH-C3, SPT, PNS-U, NAS, SOAS, MOAS, and HAS. Mandibular advancement devices (MADs) were fabricated and delivered for all subjects. After acclimation period of MAD, the second polysomnographic examinations were conducted in the same manner. Polysomnographic variables were compared between before and after MAD placement. Also, correlation coefficients were calculated between apnea-hypopnea index (AHI) and each item of cephalometric parameters. Results : There were significant improvements in total AHI, lowest $SpO_2$, and total arousal index after MAD therapy. Also, there were significant improvements in NREM $SpO_2$ and NREM AHI, but not in REM $SpO_2$ and REM AHI with MAD. Stratifying the sleep stage, there were significant decrease in stage I and significant increases in stage II and REM, but change in stage III was not significant. SNA and SOAS were significantly correlated with total AHI and NAS was significantly correlated with supine AHI. ANB was significantly associate with the effect of MAD. Conclusions : MAD is an effective treatment in OSA patients comparing polysomnographic variables before and after treatment. Cephalometric examination can be useful to evaluate OSA patients and predict treatment outcome of MAD.

• Korean Journal of Clinical Laboratory Science
• /
• v.48 no.3
• /
• pp.255-261
• /
• 2016

The purpose of this study was to investigate the relationship between excessive daytime sleepiness (EDS) and blood pressure (BP) in patients with obstructive sleep apnea-hypopnea (OSAH). Patients were classified into four groups based on their severity of polysomnographic data: the snoring group (n=108)-characterized by Apnea-Hypopnea Index (AHI<5); the mild OSA group (n=186)-AHI $5{\leq}AHI$<15; the moderate OSA group (n=179)- AHI $15{\leq}AHI$<30; and the severe OSA group (n=233)-$AHI{\geq}30$. On the same night of polysomnography (PSG), BP levels were measured before sleeping (bedtime BP) and immediately after waking up on the following morning (morning BP). EDS was recognized as ESS (epworth sleepiness scale)${\geq}9$. The differences and correlations between BP and PSG parameters in the EDS and non-EDS groups of OSAH patients were analyzed. MAP was positively correlated with BMI, AHI, and total arousal (r=0.099, r=0.142, r=0.135, p<0.01, p<0.01, p<0.01), while negatively correlated with mean $SaO_2$ (r=-0.258, p<0.01). The EDS group had overall younger population ($47.2{\pm}11.3$ vs $50.3{\pm}11.4$, p=0.023), higher DBP (both bedtime and morning, $83.1{\pm}9.7$ vs $81.4{\pm}8.8$ and $86.4{\pm}9.2$ vs $83.6{\pm}9.7$)(p=0.031, p=0.047), and higher SBP (both bedtime and morning, $126.7{\pm}11.2$ vs $123.4{\pm}12.4$, $128.9{\pm}12.4$ vs $125.3{\pm}12.9$)(p=0.021, p=0.021) than compared with the non-EDS group. In hypertensive OSAH patients, patients with EDS were also younger and had higher total arousal number, as well as higher morning and bedtime DBP and SBP than compared with the non-EDS group (p<0.005, p=0.008, p<0.001 and p<0.001). EDS in OSAHS patients is a special phenotype characterized by younger age, higher DBP, more severe desaturation, and hypertension.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.38
• /
• pp.47.1-47.8
• /
• 2016

Background: The paradigm of tonsillectomy has shifted from a treatment of recurrent throat infection to one of multi-discipline management modalities of sleep-disordered breathing (SDB). While tonsillectomy as a treatment for throat problems has been performed almost exclusively by otorhinolaryngologists, tonsillectomy as a part of the armamentarium for the multifactorial, multidisciplinary therapy of sleep-disordered breathing needs a new introduction to those involved in treating SDB patients. This study has its purpose in sharing a series of tonsillectomies performed at the Seoul National University Dental Hospital for the treatment and prevention of SDB in adult patients. Methods: Total of 78 patients underwent tonsillectomy at the Seoul National University Dental Hospital from 1996 to 2015, and 23 of them who were operated by a single surgeon (Prof. Jin-Young Choi) were included in the study. Through retrospective chart review, the purpose of tonsillectomy, concomitant procedures, grade of tonsillar hypertrophy, surgical outcome, and complications were evaluated. Results: Twenty-one patients diagnosed with SDB received multiple surgical procedures (uvulopalatal flap, uvulopalatopharyngoplasty, genioglossus advancement genioplasty, tongue base reduction, etc.) along with tonsillectomy. Two patients received mandibular setback orthognathic surgery with concomitant tonsillectomy in anticipation of postoperative airway compromise. All patients showed improvement in symptoms such as snoring and apneic events during sleep. Conclusions: When only throat infections were considered, tonsillectomy was a procedure rather unfamiliar to oral and maxillofacial surgeons. With a shift of primary indication from recurrent throat infections to SDB and emerging technological and procedural breakthroughs, simpler and safer tonsillectomy has become a major tool in the multidisciplinary treatment modality for SDB.

• Tuberculosis and Respiratory Diseases
• /
• v.60 no.1
• /
• pp.76-82
• /
• 2006

Background : The objective of this study was to understand sleep-related problems, and to determine whether the sleep questionnaires is a clinically useful method in patients who need polysomnography. Methods : Subjects were patients who performed polysomnography and who asked to answer a sleep questionnaires at the Sleep Disorders Clinic of St. Paul's Hospital, Catholic University of Korea. Baseline characteristics, past medical illness, behaviors during sleep-wake cycle, snoring, sleep-disordered breathing and symptoms of daytime sleepiness were analyzed to compare with data of polysomnography. Results : The study population included 1081 patients(849 men, 232 female), and their mean age was $44.2{\pm}12.8years$. Among these patients, 38.9% had an apnea-hypopnea index(AHI)<5, 27.9% had $5{\leq}AHI<20$, 13.2% had $20{\leq}AHI<40$, and 20.0% had $40{\leq}AHI$. The main problems for visiting our clinic were snoring(91.7%), sleep apnea(74.5%), excessive daytime sleepiness(8.0%), insomnia(4.3%), bruxism(1.1%) and attention deficit(0.5%). The mean value of frequency of interruptions of sleep was 1.6 and the most common reason was urination(46.3%). Epworth Sleepiness Scale(ESS) had a weak correlation with AHI(r=0.209, p<0.01). When we performed analysis of sleep questionnaires, there were significant differences in the mean values of AHI according to the severity of symptoms including snoring, daytime sleepiness, taking a nap and arousal state after wake(p<0.05). Conclusion : On the basis of statistical analysis of sleep questionnaires, the severity of subjective symptoms such as ESS, snoring, daytime sleepiness and arousal state after wake correlated with the AHI significantly. Therefore the sleep questionnaires can be useful instruments for prediction of the severity of sleep disorder, especially sleep-disordered breathing.

• Korean Journal of Psychosomatic Medicine
• /
• v.10 no.1
• /
• pp.37-47
• /
• 2002

Objective : Previous studies have suggested an association between sleep-related breathing disorder (SRBD) and several psychological problems, and there were increasing recognition of the link. The purpose of this study is to evaluate the characteristic profiles of MMPI and SCL-90-R in patients with SRBD. Methods : This study consisted of 80 SRBD patients(73 men, 7 women) referred from Sleep Disorder Clinic of Dong-A University Hospital, Busan, Korea. Basic informations including demographic findings and physical examination were collected. Subjects completed the Epworth Sleepiness Scale(ESS), Minnesota Multiphasic Personality Inventory(MMPI), and Symptom Check List-90-Revision (SCL-90-R) prior to standard overnight polysomnography that was performed at hospital sleep laboratory. SRBD was divided into two groups of primary snoring(PS) and obstructive sleep apnea(OSA) according to polysomnographic findings. Results : SRBD showed significant elevation rate of Hs, D, and Hy scales of MMPI and SOM scale of SCL-90-R, which exceeded the rate expected in normal individuals(>5%, 2SD). On comparison of clinical scales of SCL-90-R, OSA group had significantly greater mean score than that of PS group in terms of O-C, DEP, PAR, GSI(p<0.05), SOM and PST(p<0.01). OSA group also showed significantly higher elevation rate in Hs scale of MMPI and SOM scale of SCL-90-R than that of PS. Among OSA group, three scales of MMPI(D, Pt, Si) and three scales of SCL-90-R(ANX, PAR, PSDI) had significant correlation with some PSG variables including total sleep time and sleep efficiency. Among PS group, two scales of MMPI(Hy and Pt), elevation rate of MMPI scales and three scales of SCL-90-R(I-S, PAR, PSDI) had significant correlation with some PSG variables including sleep efficiency, sleep latency and REM sleep percent. Conclusion : The above results suggest that SRBD show neurotic profiles in MMPI and SCL-90-R. This study also clearly indicates that PS group are suffered from clinically meaningful psychiatric symptoms, which are quantitatively lessened but qualitatively similar as compared to that of OSA group.

• Journal of Biomedical Engineering Research
• /
• v.29 no.4
• /
• pp.323-328
• /
• 2008

A patient with respiratory disorders such as a sleep apnea is increasing as the obese patient increase on the modern society. Positive Airway Pressure (PAP) devices are used in curing patient with respiratory disorders and turn out to be efficacious for patients of 75%. However, these devices are required for evaluating their performance to improve their performance by the mechanical breathing simulator. Recently, the mechanical breathing simulator was studied by the real time feedback control. However, the mechanical breathing simulator by an open loop control was specially required in order to analyze the effect of flow rate and pressure after operating the breathing auxiliary devices. Therefore the aims of this study were to make the mechanical breathing simulator by a piston motion and a valve function from the characteristic test of valve and motor, and to duplicate the flow rate and pressure profiles of some breathing patterns: normal and three disorder patterns. The mechanical simulator is composed cylinder, valve, ball screw and the motor. Also, the characteristic test of the motor and the valve were accomplished in order to define the relationship between the characteristics of simulator and the breathing profiles. Then, the flow rate and pressure profile of human breathing patterns were duplicated by the control of motor and valve. The result showed that the simulator reasonably duplicated the characteristics of human patterns: normal, obstructive sleep apnea (OSA), mild hypopnea with snore and mouth expiration patterns. However, we need to improve this simulator in detail and to validate this method for other patterns.

• Tuberculosis and Respiratory Diseases
• /
• v.58 no.3
• /
• pp.295-298
• /
• 2005

We report a case of a 48-year-old man with a paradoxic upper airway obstruction and central sleep apnea that developed after an anterior cervical spinal fusion. Nine months before being admitted to this hospital, he was diagnosed with a herniated intervertebral disc between the 5th and 6th cervical spine, and the first operation was carried out. Two months later, a pseudoarthrosis has developed and a second operation, an anterior interbody fusion of the C5 and C6 using autogenous strut bone graft, was performed. After the second operation, he began to complain of snoring, excessive daytime sleepiness, insomnia, and a bizarre sound heard near the upper airway during breathing. Nasopharyngoscope and magnetic resonance imaging disclosed a paradoxical narrowing of the nasopharynx during expiration. On the overnight polysomnography, the apnea index was 8.7/h (central apnea, 7.0/h; obstructive apnea, 1.7/h). Nasal continuous positive airway pressure was applied, but he complained of pressure-intolerance, and laser-assisted uvulopalatoplasty was then performed. Two months after surgery, clinical symptoms as well as the apneas had improved markedly. We suggest that this paradoxic upper airway obstruction might be associated with the anterior cervical spinal surgery even though the mechanism is unclear. This case also emphasizes that an upper airway obstruction can contribute to the development of central sleep apnea.

• Tuberculosis and Respiratory Diseases
• /
• v.62 no.5
• /
• pp.382-388
• /
• 2007

Background: The cognitive function is impaired in patients with hypoxemic chronic obstructive pulmonary disease (COPD). However, there are conflicting results regarding the cognitive function in patients with non-hypoxemic COPD. COPD patients also have sleep disorders. This study examined the cognitive function in non-hypoxemic COPD patients, and nocturnal sleep was assessed in COPD patients with a cognitive dysfunction. Methods: Twenty-eight COPD patients (mean age, 70.7 years) with an oxygen saturation > 90%, and 33 healthy control subjects (mean age, 69.5 years) who had visited for a routine check-up were selected. The neurocognitive tests were performed using the Korean version of the Consortium to Establish a Registry for Alzheimer's Disease (CERAD-K) Neuropsychological Battery. Results: The scores of the word list recall test (p=0.03) and the word list recognition test (p=0.006) in the COPD group were significantly lower than those in the control group. Nine patients showed a significantly impaired cognitive function. Seven of these underwent polysomnography, which revealed apnea-hypopnea indices ${\geq}$ five per hour in five patients. The median oxygen desaturation index and median limb movement index were 3.6/h and 38.6/h, respectively. Conclusion: These results suggest that the verbal memory function is impaired in non-hypoxemic COPD patients. Six out of seven COPD patients with an impaired cognitive function had sleep disorders of sleep apnea and/or periodic limb movements during sleep.

• Sleep Medicine and Psychophysiology
• /
• v.11 no.1
• /
• pp.22-28
• /
• 2004

Objective: The purpose of this study is to investigate the prevalence rate of OSA in subjects whose main sleep complaint is insomnia and to find differential factors of OSA in these insomniac subjects. Method: We reviewed the medical records and polysomnographic findings of patients referred to the Sleep Laboratory at Seoul National University Hospital from January 1996 to December 2002. Four-hundred and seventy subjects complained of insomnia as their main sleep problem (235 males and 235 females, mean age $53.6{\pm}12.4\;years$). First, we investigated the prevalence rate of OSA in these insomniac patients. Second, we compared the clinical and demographic characteristics of the OSA-associated group with those of the non-associated group. Third, we examined whether the degree or presence of differential factors within the OSA group correlate with severity of OSA, as determined by the respiratory disturbance index (RDI). Results: Among 470 insomniac subjects, 125 subjects (26.6%) were diagnosed as OSA by nocturnal polysomnography. OSA-associated subjects were significantly older ($58.4{\pm}12.3\;years$ vs. $51.8{\pm}11.2\;years$, p<0.01), and had significantly higher body mass index (BMI) ($23.4{\pm}3.3\;kg/m^2$ vs. $22.5{\pm}3.1\;kg/m^2$, p=0.44) than non-associated subjects. The OSA-associated group had more subjects with male gender (64.0% vs. 44.9%, p<0.01), hypertension (20.0% vs. 9.3%, p<0.01) or snoring (96.0% vs. 63.5%, p<0.01). Within the OSA-associated group, age had a significant positive correlation with RDI (p=0.01). Conclusion: We found that a considerable portion of patients complaining of insomnia as their main sleep problem were diagnosed as OSA. Snoring, old age, male gender, obesity, and comorbid hypertension were found to be differential factors of OSA in insomniac patients. We suggest that diagnostic efforts including nocturnal polysomnography are needed for insomniac patients with any of the above risk factors of OSA.