Is mandatory screening for obstructive sleep apnea with polysomnography in all severely obese patients indicated?

Purpose  

The study aims to assess the risk factors for the presence and severity of obstructive sleep apnea (OSA) among severely obese patients evaluated for bariatric surgery.     

Validation of ApneaLink Ox™ for the diagnosis of obstructive sleep apnea

Objective

The aim of the study was to validate the automatic and manual analysis of ApneaLink Ox? (ALOX) in patients with suspected obstructive sleep apnea (OSA).

Methods

All patients with suspected OSA had a polysomnography (PSG) and an ALOX performed in the sleep laboratory. For automatic analysis, hypopnea was defined as a decrease in airflow ≥30 % of baseline for at least 10 s plus oxygen desaturation ≥3 or 4 %. While for the manual analysis, hypopnoea was considered when a reduction of airflow ≥30 % of ≥10 s plus oxygen desaturation ≥3 % or increase in cardiac rate ≥5 beats/min were identified or, when only a reduction of airflow ≥50 % was observed. OSA was defined as a respiratory disturbance index (RDI) ≥5. The apnea/hypopnea automatic index (AHI3-a, AHI4-a) and manual index were estimated. Receiver operating characteristics (ROC) analysis and the agreement between ALOX and PSG were performed.

Results

Fifty-five patients were included (38 men; mean age, 48.2; median, RDI 15.1; median BMI, 30 Kg/m²). The automatic analysis of ALOX under-estimated the RDI from PSG, mainly for the criterion of oxygen desaturation ≥4 % (AHI3-a–RDI, ?3.6?±?10.1; AHI4-a–RDI, ?6.5?±?10.9, p?<?0.05). The autoscoring from ALOX device showed a better performance when it was set up to identify hypopneas with an oxygen desaturation criterion of ≥3 % than when it was configured with an oxygen desaturation criterion of ≥4 % (area under the receiver operator curves, 0.87 vs. 0.84). Also, the manual analysis was found to be better than the autoscoring set up with an oxygen desaturation of ≥3 % (0.923 vs. 0.87). The manual analysis showed a good interobserver agreement for the classification of patients with or without OSA (k?=?0.81).

Conclusion

The AHI obtained automatically from the ApneaLink Ox? using oxygen desaturation ≥3 % as a criterion of hypopnea had a good performance to diagnose OSA. The manual scoring from ApneaLink Ox? was better than the automatic scoring to discriminate patients with OSA.     

Is portable monitoring for diagnosing obstructive sleep apnea syndrome suitable in elderly population?

Purpose

Obstructive sleep apnea syndrome (OSAS) is highly prevalent in the elderly. Unattended, at-home portable monitoring (PM) is a diagnostic alternative to polysomnography in adults with high clinical probability of OSAS. However, no studies have evaluated the diagnostic accuracy of PM in elderly population. The aim of our study was to evaluate the effectiveness of PM in elderly patients.

Methods

We selected patients aged over 65 years with suspected OSAS. Two-order randomized evaluations were performed: one night of at-home PM (PMhome) and one night of simultaneous PM and polysomnography (PSG) in the sleep lab (PSG+PM). We obtained three different apnea–hypopnea index (AHI): AHI from PSG (AHI PSG), AHI from at-home PM (AHI PMhome), and AHI from PM+PSG (AHI PM+PSG). Two technicians, blinded to the recording order, scored each sleep study.

Results

We studied a total of 43 patients. No difference between the AHI values for each of the different recordings was found (p?>?0.05). There was good correlation between AHI PSG and AHI PMhome (r?=?0.67) and AHI PSG+PM (r?=?0.84). The area under the receiver operator curve was above 0.83, indicating good sensitivity and a positive predictive value for AHI with cutoffs of 5, 15, and 30 and good specificity and negative predictive value for AHI values above 15. Correlation, accuracy, and agreement were greater when the recordings were made simultaneously.

Conclusions

PM was effective for diagnosing OSAS in the elderly and can be used as an alternative to PSG in elderly patients with a high clinical probability of OSAS.     

Validation of ApneaLink™ Plus for the diagnosis of sleep apnea

Purpose

The aim of this study is to evaluate the validation of ApneaLink? Plus (ALP) based on a large number of subjects in a prospective design.

Method

We recommended enrolling of 200 consecutive patients who had been referred because of habitual snoring or witnessed apnea during sleep. If consent was obtained, patients underwent standard polysomnography (PSG) and ALP evaluation simultaneously at the hospital (ALP_lab), and repeated ALP at home (ALP_home) within 1 month. The parameters of ALP were scored based on three different systems, Manual, Auto AASM, and Auto scoring systems.

Result

Among the 200 patients who were recommended for enrollment, 149 completed the study. Sensitivity was good for all three scoring systems, while specificity was poor for the Auto scoring system. The area under curve was highest for the manual scoring system and lowest for the auto scoring system, and increased as the apnea-hypopnea index (AHI) cutoff value increased from 5 to 30. Regarding agreement with PSG, the manual scoring system was most superior, followed by the Auto AASM, and Auto scoring systems. The degree of agreement between PSG and ALP was affected by sleep efficiency and the arousal index. Moderate agreement between PSG and ALP based on central apnea index was observed.

Conclusion

ALP is an accurate and reliable device for the diagnosis of OSA. Manual scoring is recommended; however, Auto AASM is also acceptable. ALP detects central sleep apnea to a certain degree. Both sleep efficiency and the arousal index affect the results of ALP.

     

Evaluation of a portable recording device (ApneaLink?) for case selection of obstructive sleep apnea

Objective  This study was designed to assess the sensitivity and specificity of a portable sleep apnea recording device (ApneaLink™) using standard polysomnography (PSG) as a reference and to evaluate the possibility of using the ApneaLink™ as a case selection technique for patients with suspected obstructive sleep apnea (OSA). Materials and methods  Fifty patients (mean age 48.7 ± 12.6 years, 32 males) were recruited during a 4-week period. A simultaneous recording of both the standard in-laboratory PSG and an ambulatory level 4 sleep monitor (ApneaLink™) was performed during an overnight study for each patient. PSG sleep and respiratory events were scored manually according to standard criteria. ApneaLink™ data were analyzed either with the automated computerized algorithm provided by the manufacturer following the American Academy of Sleep Medicine standards (default setting DFAL) or The University of British Columbia Hospital sleep laboratory standards (alternative setting, ATAL). The ApneaLink respiratory disturbance indices (RDI), PSG apnea–hypopnea indices (AHI), and PSG oxygen desaturation index (ODI) were compared. Results  The mean PSG-AHI was 30.0 ± 25.8 events per hour. The means of DFAL-RDI and ATAL-RDI were 23.8 ± 21.9 events per hour and 29.5 ± 22.2 events per hour, respectively. Intraclass correlation coefficients were 0.958 between PSG-AHI and DFAL-RDI and 0.966 between PSG-AHI and ATAL-RDI. Receiver operator characteristic curves were constructed using a variety of PSG-AHI cutoff values (5, 10, 15, 20, and 30 events per hour). Optimal combinations of sensitivity and specificity for the various cutoffs were 97.7/66.7, 95.0/90.0, 87.5/88.9, 88.0/88.0, and 88.2/93.9, respectively for the default setting. The ApneaLink™ demonstrated the best agreement with laboratory PSG data at cutoffs of AHI ≥ 10. There were no significant differences among PSG-AHI, DFAL-RDI, and ATAL-RDI when all subjects were considered as one group. ODI at 2%, 3%, and 4% desaturation levels showed significant differences (p < 0.05) compared with PSG-AHI, DFAL-RDI, and ATAL-RDI for the entire group. Conclusion  The ApneaLink™ is an ambulatory sleep monitor that can detect OSA and/or hypopnea with acceptable reliability. The screening and diagnostic capability needs to be verified by further evaluation and manual scoring of the ApneaLink™. It could be a better choice than traditional oximetry in terms of recording respiratory events, although severity may be under- or overestimated.     

Validation of the WristOx 3100? oximeter for the diagnosis of sleep apnea/hypopnea syndrome

OBJECTIVE: To evaluate the diagnostic accuracy of the Nonin WristOx 3100 and its software (nVision 5.0) in patients with suspicion of sleep apnea/hypopnea syndrome (SAHS). METHODS: All participants (168) had the oximetry and polysomnography simultaneously. The two recordings were interpreted blindly. The software calculated: adjusted O(2) desaturation index [ADI]-mean number of O(2) desaturation per hour of total recording analyzed time of >/= 2%, 3%, 4%, 5%, and 6% (ADI2, 3, 4, 5, and 6) and AT90-accumulated time at SO(2) < 90%. The ADI2, 3, 4, 5, and 6 and the AT90 cutoff points that better discriminated between subjects with or without SAHS arose from the receiver operating characteristic curve analysis. The sensitivity (S), specificity (E), and positive and negative likelihood ratio (LR+, LR-) for the different thresholds for ADI were calculated. RESULTS: One hundred and fifty-four patients were included (119 men, mean age 51, median apnea/hypopnea index [AHI] 14, median body mass index [BMI] 28.3 kg/m(2)). The best cutoff points of ADI were: SAHS = AHI >/= 5: ADI2 > 19.3 (S 89%, E 94%, LR+ 15.5 LR- 0.11); SAHS =AHI >/= 10: ADI3 > 10.5 (S 88%, E 94%, LR+ 15 LR- 0.12); SAHS = AHI >/= 15: ADI3 > 13.4 (S 88%, E 90%, LR+ 8.9, LR- 0.14). AT90 had the lowest diagnosis accuracy. An ADI2 /= 5 and 10; S 100%, LR- 0) and ADI3 > 4.3 (AHI >/= 5 and 10) or 32 (AHI >/= 15) confirmed SAHS (E 100%). CONCLUSIONS: A negative oximetry defined as ADI2 /= 5 or 10 with a sensitivity and negative likelihood ratio of 100% and 0%, respectively. Furthermore, a positive oximetry defined as an ADI3 > 32 (SAHS = AHI >/= 15) had a specificity of 100% to confirm the pathology.     

Does drug-induced sleep endoscopy change the treatment concept of patients with snoring and obstructive sleep apnea?

Purpose

Success rates of non-ventilation therapies for sleep disordered breathing (SDB) remain hardly acceptable. Drug-induced sleep endoscopy (DISE) tends to show the level and mechanism of obstruction and helps to specify therapy individually. Therefore, increasing success rates are expected. The objective of this study is to detect whether locations of treatment recommendations given after DISE are different to those made after clinical basic ENT (ear, nose, throat) examination (CBE).

Methods

This study included patients with obstructive sleep apnea (OSA) and primary snoring who wish or require an alternative therapy to the gold standard, continuous positive airway pressure (CPAP). After CBE, a theoretical treatment recommendation was given comprising surgery (possible surgical target: soft palate, tonsils, tongue base, epiglottis) and mandibular advancement splints (MAS) or both. A second ENT specialist conducted a DISE and independently recommended a second therapy concept without knowing the first one. A third person compared both theoretical locations of treatment recommendations (CBE vs. DISE).

Results

A total of 97 patients (eight female and 89 male, age 30–85 years, AHI 1.9–88.6/h, body mass index [BMI] 20.3–36.3 kg/m²) received two therapy recommendations. Regarding surgical options only, 63.9% of the examined patients got a different recommendation in at least one of four levels. If MAS was included, a change was found in 78.4% of the patients. Subdivided into each type of intervention, the following changes were found in the therapy concept: 24.7% (n?=?24/97) soft palate, 12.4% (n?=?12/97) tonsils, 33.0% (n?=?32/97) tongue base, 27.8% (n?=?27/97) epiglottis, 38.1% (n?=?37/97) MAS.

Conclusions

DISE shows a relevant influence on the location of treatment recommendation. Thus, a change in success rates of non-CPAP therapy in OSA and snoring appears possible.     

Do patients with obstructive sleep apnea wake up with headaches?

BACKGROUND: There is a controversy regarding the association of obstructive sleep apnea (OSA) and morning headaches. This study investigates whether this relationship exists. METHODS: This is a retrospective study of 80 consecutive patients with OSA who underwent sleep polysomnography from December 1996 to March 1997. Patients were interviewed about their headache history. Headaches were classified according to International Headache Society criteria and the severity graded by the Chronic Pain Index. Headache characteristics were compared with those of 22 control patients with periodic limb movement disorder. Headache response to continuous positive airway pressure or uvulopalatopharyngoplasty in the patients with OSA was also assessed. RESULTS: Forty-eight (60%) patients had headaches in the year prior to study. Twenty-five of the 48 patients had headaches that did not fit any category. Of these 25 patients, 23 (48% of total group) reported awakening headaches. These awakening headaches were significantly more common in the OSA group compared with the periodic limb movement disorder group, 9 (41%) of whom had headaches, none of which occurred on awakening. The proportion of common types of headaches in both groups was similar. The awakening headaches were brief (shorter than 30 minutes), and their occurrence and severity correlated with OSA severity. Of the 29 patients with OSA who were treated with continuous positive airway pressure or uvulopalatopharyngoplasty, awakening headaches improved by a mean of 80% compared with minimal improvement of migraine, tension, and cervicogenic headaches. CONCLUSIONS: Awakening headaches are associated with OSA. These headaches are of brief duration, and their occurrence and severity increase with increasing OSA severity. Treatment of OSA with continuous positive airway pressure or uvulopalatopharyngoplasty can reduce these headaches.     

Are the adverse effects of body position in patients with obstructive sleep apnea dependent on sleep stage?

Purpose  

The purpose of the study was to determine if the adverse effect of body position on obstructive sleep apnea (OSA) is worsened during rapid eye movement (REM) sleep and if patients with OSA decrease the time spent supine during REM sleep.     

Is the severity of obstructive sleep apnea or the magnitude of respiratory effort associated with gastroesophageal reflux?

TO THE EDITOR In a tecent issue of World Journal of Gastroenterology,Demeter et al.[1],reported that in patients having both gastro-esophageal reflux disease(GERD)and obstructive sleep apnea(OSA),there was a positive correlation between endoscopic findings of GERD and the number of apneas and hypopneas per hour,namely apnea hypopnea index.     

Can obstructive sleep apnea be a cause of in-stent thrombosis?

We present the case of a 45-year-old patient readmitted to Central University Hospital at 3 a.m. for acute retrosternal chest pain associated with ST-segment elevation in lead I, aVL, V1–V6 in standard 12-lead ECG performed on admission in emergency department. Coronary angiography revealed late in-stent thrombosis in left anterior descending artery. According to the new universal definition of myocardial infarction patient was finally recognized acute ST-segment elevation myocardial infarction type 4b with additional diagnosis of severe obstructive sleep apnea and overweight.