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Objectives: Hyoid expansion is a novel procedure that was developed to widen and stabilize the lateral walls of the hypopharynx in order to improve obstructive sleep apnea. This study was conducted to evaluate the safety, efficacy and feasibility of hyoid expansion., Study Design: A prospective, non-randomized multicenter pilot study with a follow-up of 6 months was conducted., Method: An implantable device (the Air-Frame system) was used to surgically expand the hyoid bone. Subjective and objective outcome measures were evaluated., Results: The procedure was successfully performed in all patients without technical adverse events. There were three clinical adverse events, and tolerance was good. Although there was a significant improvement in snoring and excessive daytime sleepiness, there was no objective improvement of the apnea-hypopnea index as measured by polysomnography., Conclusion: Hyoid expansion did not provide objective improvement of obstructive outcome measures in patients with obstructive sleep apnea syndrome.

Nightly interventions, prevalent to on-call situations, can have negative consequences for those involved. We investigated if intervention-free-on-call-nights would also mean disturbance-free-sleep for people on-call. 16 healthy sleepers spent three nights in the laboratory: after a habituation night, reference and on-call night were counterbalanced. Subjects were instructed to react to a sound, presented at unpredictable moments during the night. Participants were unaware of the fact that the sound would never be presented. These vigilance instructions resulted in more subjective wake after sleep onset (WASO), lower subjective sleep efficiency and significantly lower experienced sleep quality. Objectively, a longer sleep onset, an increased amount of WASO and significantly lower sleep efficiency were observed. During deep sleep, significantly more beta activity was recorded. Apart from real nightly interventions increased vigilance during the night causes sleep to be less efficient and less qualitative as shown by an increase in wake-activity and a distorted sleep perception., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Despite a long history of interest in emotion regulation as well as in the mechanisms that regulate sleep, the relationship between emotion regulation and sleep is not yet well understood. The present study investigated whether "an experiential approach"-defined by coping through affectively acknowledging, understanding, and expressing actual emotional experience and affective feeling about a situation-compared with a "cognitive analytical approach"-defined by the cognitive analysis of the causes, meanings and implications of the situation for the own self-would buffer the impact of an emotional failure experience on (1) emotional experience and (2) sleep structure assessed by EEG polysomnography. Twenty-eight healthy volunteers participated in this study. A direct comparison of the two emotion regulation strategies revealed that participants who were instructed to apply an experiential approach showed less fragmentation of sleep than participants who were instructed to apply an analytical approach. The use of an experiential approach resulted in a longer sleep time, higher sleep efficiency, fewer awakenings, less % time awake, and fewer minutes wake after sleep onset. Implications of the differential effects of these two forms of emotion regulation on sleep are discussed., (PsycINFO Database Record (c) 2012 APA, all rights reserved.)

Objectives/hypothesis: Previous feasibility studies have shown that electrical stimulation of the hypoglossal nerve can improve obstructive sleep apnea (OSA). The current study examined the safety and preliminary effectiveness of a second generation device, the Upper Airway Stimulation (UAS) system, and identified baseline predictors for therapy success., Study Design: Two consecutive open prospective studies., Methods: UAS systems were implanted in patients with moderate to severe OSA who failed or were intolerant of continuous positive airway pressure (CPAP). The study was conducted in 2 parts. In part 1, patients were enrolled with broad selection criteria. Apnea hypopnea index (AHI) was collected using laboratory-based polysomnography at preimplant and postimplant visits. Epworth Sleepiness Scale (ESS) and Functional Outcomes of Sleep Questionnaire (FOSQ) were also collected. In part 2, patients were enrolled using selection criteria derived from the experience in part 1., Results: In part 1, 20 of 22 enrolled patients (two exited the study) were examined for factors predictive of therapy response. Responders had both a body mass index ≤32 and AHI ≤50 (P < .05) and did not have complete concentric palatal collapse. Part 2 patients (n = 8) were selected using responder criteria and showed an improvement on AHI from baseline, from 38.9 ± 9.8 to 10.0 ± 11.0 (P < .01) at 6 months postimplant. Both ESS and FOSQ improved significantly in part 1 and 2 subjects., Conclusions: The current study has demonstrated that therapy with upper airway stimulation is safe and efficacious in a select group of patients with moderate to severe OSA who cannot or will not use CPAP as primary treatment., (Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc.)

Mandibular advancement devices (MADs) represent the main non-continuous positive airway pressure (non-CPAP) therapy for patients with obstructive sleep apnoea (OSA). The aim of the European Respiratory Society Task Force was to review the evidence in favour of MAD therapy. Effects of tongue-retaining devices are not included in this report. Custom-made MADs reduce apnoea/hypopnoea index (AHI) and daytime sleepiness compared with placebo devices. CPAP more effectively diminishes AHI, while increasing data suggest fairly similar outcomes in relation to symptoms and cardiovascular health from these treatments. Patients often prefer MADs to CPAP. Milder cases and patients with a proven increase in upper airway size as a result of mandibular advancement are most likely to experience treatment success with MADs. A custom-made device titrated from an initial 50% of maximum mandibular advancement has been recommended. More research is needed to define the patients who will benefit from MAD treatment compared with CPAP, in terms of the effects on sleep-disordered breathing and on other diseases related to OSA. In conclusion, MADs are recommended for patients with mild to moderate OSA (Recommendation Level A) and for those who do not tolerate CPAP. The treatment must be followed up and the device adjusted or exchanged in relation to the outcome.

Proper body support plays an import role in the recuperation of our body during sleep. Therefore, this study uses an automatically adapting bedding system that optimises spinal alignment throughout the night by altering the stiffness of eight comfort zones. The aim is to investigate the influence of such a dynamic sleep environment on objective and subjective sleep parameters. The bedding system contains 165 sensors that measure mattress indentation. It also includes eight actuators that control the comfort zones. Based on the measured mattress indentation, body movements and posture changes are detected. Control of spinal alignment is established by fitting personalized human models in the measured indentation. A total of 11 normal sleepers participated in this study. Sleep experiments were performed in a sleep laboratory where subjects slept three nights: a first night for adaptation, a reference night and an active support night (in counterbalanced order). Polysomnographic measurements were recorded during the nights, combined with questionnaires aiming at assessing subjective information. Subjective information on sleep quality, daytime quality and perceived number of awakenings shows significant improvements during the active support (ACS) night. Objective results showed a trend towards increased slow wave sleep. On the other hand, it was noticed that % N1-sleep was significantly increased during ACS night, while % N2-sleep was significantly decreased. No prolonged N1 periods were found during or immediately after steering.

Cognitive hyperarousal, resulting in enhanced cognitive activation, has been cited as an important contributor to the development and preservation of insomnia. To further understand this process, our study examined the effects of acutely-induced pre-sleep cognitive hyperarousal on sleep onset processes in healthy volunteers. Following an adaptation night, 15 subjects slept two nights in our sleep laboratory: one reference night and another one with cognitive arousal induction, in a counterbalanced order. In the cognitive arousal condition, subjects worked through half an hour of cognitive tasks without interference of an emotional component prior to retiring to bed. Objective sleep onset latency was significantly prolonged in the cognitive arousal condition compared to the reference condition. Significantly more high frequency activity was recorded during the first and second deep-sleep period. Moreover, differences in heart rate and proximal temperature during and after sleep onset were observed in the nights after the cognitive induction. Pre-sleep cognitive activation successfully induced a significant cognitive load and activation in our subjects to influence subsequent sleep (onset) processes., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Ergonomic sleep studies benefit from long-term monitoring in the home environment to cope with daily variations and habituation effects. Polysomnography allows to asses sleep accurately, but is costly, time-consuming and possibly disturbing for the sleeper. Actigraphy is cheap and user friendly, but for many studies lacks accuracy and detailed information. This proof-of-concept study investigates Least-Squares Support Vector Machines as a tool for automatic sleep stage classification (Wake-N1-Rem to N2-N3 separation), using automatic trainingset-specific filtered features as derived from three easy to register signals, namely heart rate, breathing rate and movement. The algorithms are trained and validated using 20 nights out of a 600 night database from over 100 different healthy persons. Different training and test set strategies were analyzed leading to different results. The more person-specific the training nights to the test nights, the better the classification accuracy as validated against the hypnograms scored by experts from the full polysomnograms. In the limit of complete person-specific training, the accuracy of the algorithm on the test set reached 94%. This means that this algorithm could serve its use in long-term monitoring sleep studies in the home environment, especially when prior person-specific polysomnographic training is performed.

As the medical community and the general public have become more aware of the relationships among snoring, excessive daytime sleepiness, cardiovascular and metabolic disease, and obstructive sleep apnoea (OSA), physicians are seeing an increasing number of patients with these problems. In internal medicine high prevalences of sleep related-breathing disorders have been reported, with a high likelihood to develop chronic complications. The coincidence of OSA with alteration of one or more systems produces mutual potentiation of their negative effects. Polysomnography plays a prominent role in the evaluation of sleep disorders and diagnosing OSA, since the disorder cannot be correctly suspected on the basis of interview and physical examination alone. Increased awareness of the atypical presentation of OSA in different patient populations is warranted. Appropriate treatment can prevent burden to the patients and development of serious complications, including sudden death in sleep. These interactions illustrate the multidisciplinary nature of sleep medicine, above all in the field of diagnostics and therapy.

In view of the high prevalence and the relevant impairment of patients with obstructive sleep apnoea syndrome (OSAS) lots of methods are offered which promise definitive cures for or relevant improvement of OSAS. This report summarises the efficacy of alternative treatment options in OSAS. An interdisciplinary European Respiratory Society task force evaluated the scientific literature according to the standards of evidence-based medicine. Evidence supports the use of mandibular advancement devices in mild to moderate OSAS. Maxillomandibular osteotomy seems to be as efficient as continuous positive airway pressure (CPAP) in patients who refuse conservative treatment. Distraction osteogenesis is usefully applied in congenital micrognathia or midface hypoplasia. There is a trend towards improvment after weight reduction. Positional therapy is clearly inferior to CPAP and long-term compliance is poor. Drugs, nasal dilators and apnoea triggered muscle stimulation cannot be recommended as effective treatments of OSAS at the moment. Nasal surgery, radiofrequency tonsil reduction, tongue base surgery, uvulopalatal flap, laser midline glossectomy, tongue suspension and genioglossus advancement cannot be recommended as single interventions. Uvulopalatopharyngoplasty, pillar implants and hyoid suspension should only be considered in selected patients and potential benefits should be weighed against the risk of long-term side-effects. Multilevel surgery is only a salvage procedure for OSA patients.

This study investigates the effect of mild physical activity before bedtime on the sleep pattern and heart rate during the night. Nine healthy subjects underwent a habituation night, a reference night, and a physical induction night. The physical induction night did not alter the sleep pattern. Physical activity before bedtime resulted in higher heart rate variance during slow-wave sleep. The low-frequency/high-frequency component (LF/HF) ratio during slow-wave sleep in the physical induction night was significantly higher than during the reference night. Increased mean heart rate and higher LF/HF ratio are related to decreased parasympathetic dominance. Exercise up to 1 h before bedtime thus seems to modify the quality of sleep.

Objectives: In Europe, the services provided for the investigation and management of obstructive sleep apnoea (OSA) varies from country to country. The aim of this questionnaire-based study was to investigate the current status of diagnostic pathways and therapeutic approaches applied in the treatment of OSA in Europe, qualification requirements of physicians involved in diagnosis and treatment of OSA, and reimbursement of these services., Methods: Two questionnaires were sent to 39 physicians in 22 countries in Europe. In order to standardize the responses, the questionnaire was accompanied by an example., Results: Sleep centers from 21 countries (38 physicians) participated. A broad consistency among countries with respect to the following was found: pathways included referral to sleep physicians/sleep laboratories, necessity for objective diagnosis (primarily by polysomnography), use of polygraphic methods, analysis of polysomnography (PSG), indications for positive airway pressure (PAP) therapy, application of standard continuous PAP (CPAP) therapy (100% with an CPAP/APAP ratio of 2.24:1), and the need (90.5%) and management of follow-up. Differences were apparent in reimbursement of the diagnostic procedures and follow-up, in the procedures for PAP titration from home APAP titration with portable sleep apnea monitoring (38.1%) up to hospital monitoring with PSG and APAP (85.7%), and in the qualification requirements of sleep physicians., Conclusions: Management of OSA in different European countries is similar except for reimbursement rules, qualification of sleep specialists and procedures for titration of the CPAP treatment. A European network (such as the one accomplished by the European Cooperation in Science and Technology [COST] B26 Action) could be helpful for implementing these findings into health-service research in order to standardize management in a cost effective perspective., (Copyright © 2010 Elsevier B.V. All rights reserved.)

Epidemiological studies provide strong evidence that obstructive sleep apnea (OSA) is associated with cardiovascular complications such as systemic hypertension, congestive heart failure, and atrial fibrillation. Successful OSA treatment with continuous positive airway pressure (CPAP) has resulted in coincident reductions in systemic hypertension, improvements in left ventricular systolic function, and reductions in sympathetic nervous activity. These data suggest that successful treatment of OSA may reduce cardiovascular morbidity in such patients. Although CPAP is the more successful treatment for OSA when used properly and consistently, its clinical success is often limited by poor patient and partner acceptance, which leads to suboptimal compliance. Oral appliances or upper airway surgeries are considered a second line of treatment for patients with mild to moderate OSA who do not comply with or refuse long-term CPAP treatment. Oral devices such as mandibular repositioning appliances were recently shown to improve arterial hypertension in OSA patients. Electrical stimulation of the hypoglossal nerve is a new investigational therapy for patients with moderate to severe OSA. This new treatment option, if proven effective, may provide cardiovascular benefits secondary to treating OSA.

This study combines concepts of bed design and sleep registrations to investigate how quality of spine support affects the manifestation of sleep in healthy subjects. Altogether, 17 normal sleepers (nine males, eight females; age 24.3±7.1 years) participated in an anthropometric screening, prior to the actual sleep experiments, during which personalised sleep system settings were determined according to individual body measures. Sleep systems (i.e. mattress and supporting structure) with an adjustable stiffness distribution were used. Subjects spent three nights of 8 h in bed in the sleep laboratory in a counterbalanced order (adaptation, personalised support and sagging support). During these nights, polysomnography was performed. Subjective sleep data were gathered by means of questionnaires. Results show that individual posture preferences are a determinant factor in the extent that subjects experience a negative effect while sleeping on a sagging sleep system. STATEMENT OF RELEVANCE: This study investigated how spine support affects sleep in healthy subjects, finding that the relationship between bedding and sleep quality is affected by individual anthropometry and sleep posture. In particular, results indicate that a sagging sleep system negatively affects sleep quality for people sleeping in a prone or lateral posture.

Sleep fragmentation is a cause of impaired daytime performance. We have developed an algorithm for detection of nighttime awakenings based on heart rate. As much as 15 healthy normal sleepers, 23 +/- 3 years, participated in this study. The dataset contains 33 nights of polysomnographic (PSG) and electrocardiographic (ECG) measurements. After a habituation night, the subjects underwent a reference night without interventions, followed by some nights with interventions. These included noise, light, physical and cognitive interventions. Nighttime awakenings were subdivided in to awakenings (>15 s) and short awakenings (<15 s). The overall number of awakenings was 18.5 (+/-10.5) and short awakenings 13.2 (+/-10.5). The number of nighttime awakenings did not differ significantly between the reference and intervention nights; a repeated measures ANOVA resulted in a p value of 0.66 for awakenings and 0.57 for short awakenings. As much as 5 reference nights were used as training set, 28 as validation set. The algorithm detects the awakening periods with a sensitivity of 80.5% (confidence interval 77.9-82.9%). Heart rate is an adequate measure that allows for detection of nighttime awakenings and hence sleep quality.

Objectives: Snoring and obstructive sleep apnoea (OSA) result from upper airway (UA) collapse during sleep. Sleep endoscopy is a dynamic evaluation of the UA that can be used to determine the site(s) of collapse during respiratory events. This study evaluates the feasibility and outcome of sleep endoscopy in patients with OSA, compares the findings with the literature, and reviews the therapeutic advice given to patients., Methodology: A retrospective analysis was conducted of the data for 70 OSA patients in whom UA surgery was considered. Sleep endoscopy was performed after IV administration of midazolam and propofol. The UA was visualised and assessed for the location of UA flutter, narrowing or collapse. Feasibility and safety were evaluated retrospectively. Outcome data were described as type and pattern of flutter and/or collapse. Treatment advice given to the patients was reviewed., Results: Sleep endoscopy showed monolevel palatal collapse in 31.9%, monolevel tongue/hypopharyngeal collapse in 27.8% and multilevel collapse in 31.9% of patients. In 5.6% of patients, no collapse was found. In all patients except 2, reliable assessment proved possible of the site(s) of obstruction. No side effects were reported., Conclusion: Sleep endoscopy is feasible and safe in daily practice when sedation is performed by an anaesthesiologist and can be used to locate the site of collapse in the UA. Sleep endoscopy findings in our study sample, as well as in the literature, differ according to the content of the study sample and the method of sedation. Treatment advice may differ from sleep endoscopy findings since other factors such as age and patient preferences need to be considered.

Objectives: Surgical treatment of obstructive sleep apnea (OSA) caused by hypopharyngeal collapse of the upper airway can be considered in patients who are intolerant to continuous positive airway pressure (CPAP). The present procedures addressing the hypopharynx are invasive and have substantial morbidity and limited efficacy., Methods: Ten patients (mean age, 44 years) with moderate to severe OSA, ie, an apnea-hypopnea index (AHI) between 15 and 50, with CPAP intolerance were included in a prospective, nonrandomized, multicenter study to evaluate the feasibility, safety, and efficacy of a novel tongue advancement procedure. The procedure consists of the implantation of a tissue anchor in the tongue base and an adjustment spool at the mandible. Titration of this tissue anchor results in advancement of the tongue and a patent upper airway., Results: The mean AHI decreased from 22.8 at baseline to 11.8 at the 6-month follow-up (p = 0.007). The Epworth Sleepiness Scale score decreased from 11.4 at baseline to 7.7 at the 6-month follow-up (p = 0.094), and the snoring score decreased from 7.5 at baseline to 3.9 at the 6-month follow-up (p = 0.005). Four technical adverse events were noted, and 1 clinical adverse event occurred., Conclusions: Adjustable tongue advancement is a feasible and relatively safe way to reduce the AHI and snoring in selected patients with moderate to severe OSA and CPAP intolerance. Technical improvements and refinements to the procedure are ongoing.

Purpose: Several reports have demonstrated an association between glaucoma and obstructive sleep apnea (OSA), though the origin of this association remains unknown. In the present study, the influence of OSA and continuous positive airway pressure (CPAP) therapy on intraocular pressure (IOP) and ocular perfusion pressure (OPP) was examined., Methods: IOP, blood pressure, and pulse rate were measured every 2 hours during 24-hour sessions in 21 patients with newly diagnosed OSA. A first series of measurements was performed before CPAP therapy, and a second series was performed 1 month after the initiation of CPAP therapy. OPP was then calculated., Results: Baseline measurements showed a significant nycththemeral fluctuation in the average IOP, with the highest IOPs at night. After 1 month of CPAP therapy, the average IOP was significantly higher than baseline. The increase in overnight IOP was also significantly higher. A 24-hour IOP fluctuation of > or =8 mm Hg was found in 7 patients at baseline and in 12 patients during CPAP therapy. The mean difference between trough and peak IOP was 6.7 +/- 1.5 mm Hg at baseline and 9.0 +/- 2.0 mm Hg during CPAP therapy. Thirty minutes after CPAP cessation a significant decrease in IOP was recorded. There was a statistically significant decrease in mean OPP during CPAP therapy., Conclusions: Patients with OSA demonstrated significant 24-hour IOP fluctuations, with the highest values at night. CPAP therapy causes an additional IOP increase, especially at night. Regular screening of visual fields and the optic disc is warranted for all patients with OSA, especially those treated with CPAP.

Mandibular advancement devices (MADs) have emerged as a popular alternative for the treatment of sleep-disordered breathing. These devices bring the mandibula forward in order to increase upper airway (UA) volume and prevent total UA collapse during sleep. However, the precise mechanism of action appears to be quite complex and is not yet completely understood; this might explain interindividual variation in treatment success. We examined whether an UA model, that combines imaging techniques and computational fluid dynamics (CFD), allows for a prediction of the treatment outcome with MADs. Ten patients that were treated with a custom-made mandibular advancement device (MAD), underwent split-night polysomnography. The morning after the sleep study, a low radiation dose CT scan was scheduled with and without the MAD. The CT examinations allowed for a comparison between the change in UA volume and the anatomical characteristics through the conversion to three-dimensional computer models. Furthermore, the change in UA resistance could be calculated through flow simulations with CFD. Boundary conditions for the model such as mass flow rate and pressure distributions were obtained during the split-night polysomnography. Therefore, the flow modeling was based on a patient specific geometry and patient specific boundary conditions. The results indicated that a decrease in UA resistance and an increase in UA volume correlate with both a clinical and an objective improvement. The results of this pilot study suggest that the outcome of MAD treatment can be predicted using the described UA model.

Objective and Background: Existence of an increased oxidative stress has been confirmed in patients with acute exacerbation of COPD. This study aims to examine the extent and time-course of antioxidant defence in patients with an acute exacerbation of COPD in comparison with stable patients., Methods: Twelve patients with acute exacerbation were studied at admission, and then 24 h and 48 h following admission and at discharge. The antioxidants assessed were the endogenous antioxidants: glutathione peroxidase, superoxide dismutase, oxidized and reduced glutathione, albumin and exogenous antioxidants: alpha-tocopherol and retinol. Trolox equivalent antioxidant capacity as a marker of antioxidant status was also measured., Results: There was an increase in glutathione peroxidase and superoxide dismutase 48 h after admission (P<0.05). Alpha-tocopherol was the lowest 24 h after admission and increased significantly at discharge (P<0.05)., Conclusions: There is an increase in antioxidant defence during acute exacerbation of COPD reaching a maximum at 48 h after admission. This rise in the antioxidant defence is not sufficient to prevent depletion of non-enzymatic antioxidants such as alpha-tocopherol.

Objectives: We studied structural and functional cardiac alterations in obstructive sleep apnea (OSA), their relationship to the severity of OSA, and the effects of treatment with continuous positive airway pressure (CPAP)., Background: Obstructive sleep apnea may influence the cardiac function by several mechanisms in the awake patient., Methods: Left and right ventricular morphology and function were studied using echocardiography before and after treatment with CPAP in symptomatic patients (Epworth sleepiness score, 10 +/- 4.8) with severe OSA (apnea-hypopnea index [AHI], 42 +/- 24). The patients (n = 43, 32 men) had no known cardiac disease and were obese (body mass index, 31.6 +/- 5.4 kg/m2). The same echocardiographic parameters were studied in age-matched overweight patients (n = 40; body mass index, 26.4 +/- 2.3 kg/m2)., Results: The patients were hypertensive (systolic blood pressure, 153 +/- 25 mm Hg), with a higher resting heart rate (77 +/- 10 beats/min, p = 0.008) compared with age-matched control patients (n = 40). There was right ventricular dilatation, hypertrophic interventricular septum, reduced left ventricular stroke volume, tissue Doppler-determined systolic and diastolic velocities of the left and right ventricle, and normal pulmonary artery pressure. The structural and functional parameters were significantly associated with AHI (p < 0.004). Multiple stepwise regression showed the interventricular septum thickness, right ventricular free wall, and mitral annulus tissue Doppler systolic velocities to be predictive of a higher AHI (p < 0.001). Six months after treatment with CPAP, significant improvements were observed in the symptoms and hemodynamics, as well as left and right ventricular morphology and function., Conclusions: The structural and functional consequences of OSA on the heart are influenced by the severity of AHI. These effects are reversible if the apneic episodes are abolished.

Values for body surface area (BSA) are commonly used in medicine, particularly to calculate doses of chemotherapeutic agents and index cardiac output. Various BSA formulas have been developed over the years. The DuBois and DuBois (Arch Intern Med 1916;17:863-71) BSA equation is the most widely used, although derived from only 9 subjects. More recently, Mosteller (N Engl J Med 1987;317:1098) produced a simple formula, [weight (kg) x height (cm)/3600](1/2), which could be easily remembered and evaluated on a pocket calculator, but validation data in adults are rare. The purpose of the present study was to examine the BSA based on Mosteller's formula in normal-weight (body mass index [BMI], 20-24.9 kg/m(2)), overweight (BMI, 25-29.9 kg/m(2)), and obese (BMI, >/=30 kg/m(2)) adults (>18 years old) in comparison with other empirically derived formulas (DuBois and DuBois, Boyd [The growth of the surface area of the human body. Minneapolis: University of Minnesota Press; 1935], Gehan and George [Cancer Chemother Rep 1970;54:225-35], US Environmental Protection Agency [Development of statistical distributions or ranges of standard factors used in exposure assessments Washington, EPA/600/8-85-010. Office of Health and Environmental Assessment; 1985), Haycock et al [J Pediatr 1978;93:62-6], Mattar [Crit Care Med 1989;17:846-7], Livingston and Scott [Am J Physiol Endocrinol Metab 2001;281:E586-91]) and with the new 3-dimensional-derived formula of Yu et al (Appl Ergon. 2003;34:273-8). One thousand eight hundred sixty-eight patients were evaluated (397 normal weight [BMI, 23 +/- 1 kg/m(2); age, 50 +/- 14 years; M/F, 289/108], 714 overweight [BMI, 27 +/- 1 kg/m(2); age, 52 +/- 11 years; M/F, 594/120], and 757 obese [BMI, 36 +/- 6 kg/m(2); age, 53 +/- 11 years; M/F, 543/215]). The overall BSA was 2.04 +/- 0.24 m(2): 1.81 +/- 0.19 m(2) in normal-weight, 1.99 +/- 0.16 m(2) in overweight, and 2.21 +/- 0.22 m(2) in obese subjects. These values were significantly higher in overweight and obese patients compared with the values using the DuBois-DuBois formula (overall, 2.00 +/- 0.22 m(2), P < .01; normal weight, 1.81 +/- 0.19 m(2), P = .93; overweight, 1.97 +/- 0.16 m(2), P < .01; obese, 2.14 +/- 0.21 m(2), P < .001). We could show an excellent correlation between the results obtained from each formula, with all correlations of 0.97 or higher (between 0.971 and 0.999). Body surface area prediction with the commonly used DuBois formula underestimated BSA in obese patients by as much as 3% (male) to 5% (female). Based on the formula of Yu et al, however, BSA is overestimated when these traditional formulas are used. Although Mosteller's formula is recommended based on its simplicity and suitability for laboratory and clinical work in adults, accuracy studies in whites with 3-dimensional one-pass whole-body scanning are needed.

Background and Aim of the Work: Many sarcoidosis patients suffer from fatigue and sleep disturbances. Recently, it was demonstrated that obstructive sleep apnea (OSA) is rather common in sarcoidosis. Moreover, sheet intolerance and painful legs are frequently reported in sarcoidosis patients. These symptoms might interfere with sleep quality., Methods: In order to determine the relationship between objective and subjective sleep disturbance full polysomnography, including leg EMG analysis, was performed in 46 chronic sarcoidosis patients indicating awakening unrefreshed in the morning., Results: In 20 (44%) patients OSA activity [60% with PLM (n=12), 40% without (n = 8)] was demonstrated, while in 7 patients (15%) significant PLM without OSA were found. In 19 patients (42%) no OSA or PLM activity was present. Moreover restless legs (RLS) were reported by 52% of the patients (45% in OSA; 71% in PLM; 47% in others). Distribution of sleep stages and sleep fragmentation was comparable in all groups. In a healthy snoring control group (n = 102) a prevalence of PLM was found in 13.7% (17.8% in men; 3.4% in women), while RLS were only reported by 1.4% (men) and 6.9% (women)., Conclusions: Sleep disturbance (OSA and/or PLM) and RLS were demonstrated in more than half of the studied sarcoidosis patients. A high prevalence of RLS or PLM (primary and secondary) has not been reported before in sarcoidosis. Further studies are needed to establish whether RLS, OSA and/or PLM might contribute to fatigue and whether fatigue complaints improve after treatment of RLS/PLM/OSA.

We report on a patient with Marfan's syndrome, with coexistent obstructive sleep hypopnea (OSH) and restrictive lung disease, complicated by respiratory insufficiency, who was successfully treated with nasal intermittent positive airway pressure (NIPPV) and oxygen. NIPPV therapy turned out to be effective on arterial gas exchange and well tolerated. Moreover, progressive dilatation of the aortic root was attenuated during NIPPV, but could, however, not be reversed. We hypothetized that (at least partially) a decrease of nocturnal intrathoracic pressures could explain this.

Continuous positive airway pressure (CPAP) improves idiopathic central sleep apnea (ICSA), but the mechanisms are not completely understood. It has been demonstrated that some ICSA patients have an increased CO2 drive, expressed by the hypercapnic ventilatory response (HCVR). The aim of our study was to evaluate whether CPAP can decrease the HCVR in successfully treated ICSA patients. Also the central apnea mean duration (CMD) was studied. Nine patients were evaluated. Their apnea-hypopnea index at baseline was high, but decreased from 50 +/- 5 to 8 +/- 3, during 5 +/- 1 cm H2O CPAP. After one month CPAP high values were still found for HCVR (2.69 +/- 0.23 L.min-1.mmHg-1 at baseline, 2.71 +/- 0.33 L.min-1.mmHg-1 after CPAP). Sleep quality was only improved by a decrease in the arousal index (from 29 +/- 12 to 6 +/- 1 a night) (p = 0.04). Daytime arterial O2 partial pressure (PaO2) increased from 73 +/- 4 mmHg to 85 +/- 3 mmHg (p = 0.02), whereas daytime arterial CO2 partial pressure (PaCO2) remained unchanged (from 41 +/- 1 mmHg to 40 +/- 1 mmHg). CMD was 21 +/- 6 s before and 13 +/- 1 s after CPAP (p = 0.05). The presence of hypersomnolence decreased from in 89% to in 33% of the patients. It is concluded that CPAP treatment can induce a subjective and objective improvement in ICSA patients, with improved sleep-related respiratory indices, daytime PaO2, but without a change in CO2 drive. High chemical drives seem to be the cause and not the consequence of sleep disordered breathing and persist after treatment.

We report a case of a 73-year-old woman with chronic respiratory failure in association with syringohydromyelia and sleep apnea. She was initially intubated and mechanically ventilated. Weaning from the ventilator was only successful after nasal intermittent positive airway pressure therapy was started. A normalization of arterial blood gas exchange could be achieved., (Copyright 2002 S. Karger AG, Basel)

Sleep complaints are frequently reported by patients with Marfan and Ehlers-Danlos syndrome (EDS). We examined the exact nature of sleep complaints in these patients. A representative sample of Marfan and EDS patients responded to a general sleep questionnaire, including the Epworth Sleepiness Scale (ESS) and the Medical Outcomes Study Short-Form 36 (SF-36) health-related quality of life (QOL) questionnaire. Fifteen Marfan patients and 9 EDS patients were evaluated and compared to 24 healthy controls, matched for age, sex and body mass index. Maintaining sleep was frequently disturbed in Marfan (40%, p < 0.04) as well as in EDS patients (56%, p < 0.01). Sleep apnea was exclusively reported by Marfan patients (27%, p = 0.03). Periodic limb movements were much more reported in EDS (67%, p = 0.02) than in Marfan (27%, p = 0.25) compared to controls (8%). Pain and back complaints were highly presented in both groups, but most pronounced in EDS patients (47% in Marfan versus 77% in EDS). No differences for the scores in the ESS were found. For all SF-36 questionnaire items, scores were much lower in patient groups, except for emotional problems. We found that sleep complaints were not rare in Marfan and EDS patients and correlated well with different QOL items. Our study calls for greater attention to the presence of apnea, pain and periodic limb movements in these patients.

Background: It was shown in normals that an important decrease in upper airway resistance can be obtained with continuous positive airway pressure (CPAP). It was suggested that lung inflation in patients with sleep apnea syndrome (SAS) could also be a mechanism of action of CPAP., Objective: In the present study we wanted to evaluate the effects of nocturnal CPAP on the daytime lung function pattern in patients with SAS., Methods: We measured arterial blood gases and possible changes in static lung volumes in 57 SAS patients (37 with normal lung function, 10 with COPD and 10 with restrictive lung disease) after at least one month of CPAP therapy., Results: A significant increase in PaO(2) (from 79 to 84 mm Hg, p = 0.01) and a decrease in AaDO(2) (from 23 +/- 1 to 16 +/- 1, p < 0.01) was only observed in SAS patients with normal lung function. This improved gas exchange was parallelled by a small but non significant change in the FRC (from 96.5 +/- 3.2 to 105.4 +/- 3.7%pred, p = 0.07) and TLC (from 101.3 +/- 1.7 to 104.1 +/- 1.4%pred, p = 0.15). Similar changes in TLC and FRC were also observed in SAS patients with obstructive and restrictive lung disease., Conclusions: Chronic nocturnal CPAP therapy can improve daytime gas exchange and may influence lung inflation during the daytime. The small changes seem to be a functional effect but of no clinical relevance., (Copyright 2001 S. Karger AG, Basel)

Many patients with sarcoidosis suffer from persistent constitutional symptoms such as fatigue and general weakness, even though physiological measures of disease activity returned within normal limits. The following case report demonstrates a sarcoidosis patient with recurring fatigue caused by an obstructive sleep apnea syndrome developed during the course of the disease., (Copyright 2000 S. Karger AG, Basel.)

A survey performed in 100 CPAP users indicated that irritation of the face, a painful nose and nasal obstruction were among the most frequently mentioned complaints in chronic CPAP users. In 132 normocapnic SAS patients a significant improvement of PaO2 was shown, with a decrease of the alveolo-arterial oxygen difference. This improved gas exchange was parallelled by a significant increase in the FRC and TLC. Maybe a modulation in force of the respiratory muscles may be involved. These data were more pronounced in obstructive sleep apnea than in central sleep apnea. In 50 chronic CPAP users we could show a lower AHI immediately after CPAP withdrawal after a previous prolonged treatment. These findings may support the insufflation theory as a mechanism of action of CPAP. Traditionally, mechanical splinting of the upper airway has been considered as the dominant mechanism of action. Other mechanisms like changes in regulation of breathing and decrease of the pharyngeal edema may be involved as well.

Snoring is a common phenomenon and a primary symptom in obstructive sleep apnea syndrome, a sleep-related breathing disorder in which neuropsychological function is reported to be impaired. The first purpose of the present study was to compare cognitive and motor function in 25 heavy nonapneic snorers and 26 sleep apneics. As the basis for impairments in heavy nonapneic snorers is still unclear, the influence of nighttime breathing disturbances and morning alertness, respectively, on daytime performance was evaluated too. Nonapneic snorers exhibit more slow wave sleep and tend to have fewer changes in sleep stage than sleep apnea patients, but values for other sleep variables are similar. Snorers also show comparable alertness. Deficits in immediate visual memory and in visuospatial reasoning are not found. However, there are some indications that snorers show decreased manual dexterity and eye-hand coordination for the nonpreferred hand and that they have deficits in focused attention. In addition, snorers may show difficulties in finger-tapping speed. These performance measures tend to be associated with reduced morning alertness, except for the score on focused attention which has a tendency to be related to the nocturnal breathing disturbances.

Neuropsychological functioning is reported to be impaired in patients suffering from obstructive sleep apnea syndrome (OSAS). This syndrome is characterized by nocturnal respiratory disturbances, blood oxygen desaturations, sleep fragmentation, and excessive daytime sleepiness. Opinions are divided concerning the exact relationship between the observed cognitive deficits, nocturnal hypoxia, sleep disruption, and impaired daytime alertness. In the present study, morning neuropsychological function of 26 moderate to severe middle-aged sleep apneics is compared to that of 22 primary insomniacs. There were no performance differences on a range of neuropsychological tests among the two patient groups. In addition, the data suggest that morning alertness impairment, which is closely associated with a lack of slow wave sleep (SWS) and rapid eye movement (REM) sleep, is of major importance in inducing poorer cognitive performance in patients with moderate to severe sleep apnea.

A patient with Marfan's syndrome and obstructive sleep hypopnea syndrome is reported. She had complained about insomnia, tiredness and hypersomnolence lasting 2 years. A complete nightly polysomnography revealed 94 obstructive hypopneas (the hypopnea index was 12.85) and no obstructive apneas. Presumably an increased laxity of the pharyngeal wall was responsible for the phenomenon. A therapy with CPAP was started, but was not tolerated by the patient. Oxygen therapy on the other hand turned out to be effective and well tolerated.

Respiratory control and instability in the breathing pattern during sleep. Unstable breathing during sleep plays an important role in the development of sleep related breathing disorders (SRBD). Periodic breathing, as a hallmark of this instability, is a common initiator of these disorders. In addition, structure and function of the upper airway are prone to intrinsic and extrinsic, congenital and acquired abnormalities which are as well responsible for the pathogenesis of SRBD.

Only a limited number of studies dealing with the epidemiology and therapy of central sleep apnea syndrome (CA) are available. The treatment strategies are poorly defined and not well evaluated. The aim of our present study was to treat selected CA patients with low dose acetazolamide (ACET) for a longer time period than has been done before. Previous studies were performed with high dose ACET provoking severe metabolic acidosis, not for more than 1 wk or only in obstructive apnea patients. Referred patients with suspicion of sleep-related breathing disorders (SRBD) were included in the study if, after a first selection night, their central apnea index (CAI) was > 5 or their apnea-hypopnea index (AHI) > 10 and their obstructive apnea index (OAI) < 5. Of 327 screened patients, 14 (4.3%) fulfilled these criteria. Patients were then treated with ACET (250 mg, 1 h before sleep): Polysomnography was repeated once after one single dose (N2) and twice after 1-mo chronic treatment without (N3) and with (N4) additional ACET administration. After each study night, arterial blood gases and chemical drive were measured. CAI (25.5 +/- 6.8 at N1) already decreased during N2 (13.8 +/- 5.2) and further during N3 (6.6 +/- 2.9) and N4 (6.8 +/- 2.8) p < 0.01). OAI remained unchanged. Total sleep time (TST) and sleep efficiency index (SEI) did not change significantly. The number of arousals decreased from 62 +/- 11 at N1 to 40 +/- 5 at N3 (p = 0.019).(ABSTRACT TRUNCATED AT 250 WORDS)

Careful analysis of the EEG in obstructive sleep apnea (OSA) patients according to the Rechtschaffen and Kales (R & K) criteria indicates that obstructive apneas (OA) are more frequently observed during stage 1 and 2 sleep than during slow wave sleep. However it is also obvious that OA can be recognised during R & K wakefulness stage (St W). The purpose of the present study was to see whether further partition of R & K St W could define a wakefulness stage during which no apneas occur. Ten patients with predominantly OSA were studied (OA-Index 20 +/- 5). Patients EEG were scored according to classic R & K and to modified criteria which further divided R & K St W. Three additional stages were defined (STW-a, STW-b, STW-c). The partitioning of STW of R & K allowed us to define a W-stage (STW-a) during which no apneas occur, and to identify alpha (STW-b) and drowsiness (STW-c) during which OA occur frequently.