Continuous Positive Pressure Therapy Research Articles

Predictors of optimum continous positive airway pressure level in obstructive sleep apnoea patients

Background: Obstructive sleep apnoea (OSA) is a breathing disorder during sleep which leads to life-threatening events. The recommended treatment for moderate to severe OSA is continuous positive pressure therapy (CPAP). Aim: To predict the optimal CPAP level in OSA. Methodology: This was a cross sectional observational study, carried out in pulmonary medicine department at a tertiary referral centre in South India. Twenty patients were recruited in the study over a period of 6 months. All patients in study group underwent CPAP titration with optimal or good titration over a full night polysomnography. Results: We correlated the optimal CPAP level with demographic, anthropometric and polysomnographic variables, which showed a trend of association between body mass index (BMI), neck circumference, apnoea hypopnoea index (AHI), oxygen desaturation index (ODI) and severity of OSA with optimal CPAP level Conclusion: No statistically significant association was observed between demographic, clinical, anthropometric and polysomnographic variables with optimal CPAP level.

Metabolic Profile Correction in Patients with Obstructive Sleep Apnea Depends on the Duration of CPAP Therapy Sessions

Obstructive sleep apnea (OSA) is a common, heterogeneous chronic disease with sleep fragmentation, metabolic and cardiovascular disorders. Continuous Positive Air Pressure (CPAP) therapy is the primary treatment for patients with OSA. However, the effects of long-term CPAP therapy with night sessions > 6 hours remain poorly understood. The aim of the study was to study the effects of different durations of night sessions of CPAP therapy on the “metabolic profile” of patients with severe OSA. Materials and methods. In a retrospective case-control study comparing two CPAP-therapy regimens by matching pairs from among patients with verified severe OSA (apnea-hypopnea index> 30/h), arterial hypertension, obesity of I-II degrees according to the WHO classification (1997), signed informed consent, 2 groups of 18 people each were formed, comparable in age, anthropometric and somnographic indicators, using CPAP therapy 4-6 hours / night and more than 6 hours / night, respectively. Patients received CPAP therapy for a year, visits were carried out at 3, 6 and 12 months. The severity of sleep apnea was verified during nighttime computed somnography (CSG) on WatchPAT-200 hardware (ItamarMedical, Israel) with original software zzzPATTMSW ver. 5.1.77.7 (ItamarMedical, Israel) by registering the main respiratory polygraphic characteristics from 11.00 PM to 7:30 AM. The optimal therapeutic level of CPAP therapy was titrated at home using devices for automatic selection of therapeutic pressure (PR System One REMstar Auto CPAP Machine with A-Flex (Philips Respironics, USA)) within 7 days after the diagnostic study. To assess the compliance of OSA patients at 3-6-12 months of CPAP-therapy, we used the original compliance analysis program Encore Pro v.2.14 (Philips Respironics, USA). Results. With the initial comparability of the groups, by the 3rd month of therapy, patients with CPAP > 6 h/night showed a statistically significant advantage over the patients with 4-6 h CPAP-therapy in ESS, neck circumference and testosterone. By the 6th month, statistically significant differences of BMI, VAI, leptin, oral glucose tolerance test, fasting insulin, HOMA-IR, lipid metabolism (HDL, LDL, triglycerides, Apo-B) appeared. By the 12th month of therapy, the CPAP group > 6 h/night had a statistically significant advantage in waist circumference, fasting blood glucose and uric acid. Differences between groups at control points persisted throughout the observation period. Conclusions. Long-term home-based CPAP therapy with sessions > 6 h/night has an advantage over therapy with sessions 4-6 h/night in achieving a rapid and pronounced improvement in metabolic profile and hormonal levels in patients with severe OSA.

Impact of CPAP treatment for a short period in moderate-to-severe OSAS patients: a randomized double-blind clinical trial

IntroductionObesity is the most frequent reversible agravating factor of obstructive sleep apnea syndrome, with physical activity very important for its control. Continuous positive air pressure during sleep is the “gold standard” treatment for obstructive sleep apnea syndrome. Objectivewe aimed to investigate if the use of continuous positive air pressure for a short period (7 days), would improve sleep quality, daytime sleepiness, and the disposition for physical activity. MethodsEighty obstructive sleep apnea syndrome patients were randomly assigned as follows: group I – continuous positive air pressure with a steady pressure of 4 cm H2O; group II – ideal therapeutic pressure. After filling out the questionnaires related to the studied variables (International physical activity questionnaire long-form, Epworth sleepiness scale, Pittsburgh sleep quality index), patients underwent a baseline pulmonary function test and continuous positive air pressure titration. After continuous positive air pressure therapy for 4≥ hours a night for 7 consecutive days, patients returned and filled out new (International physical activity questionnaire long-form, Epworth sleepiness scale, Pittsburgh sleep quality index) forms. New spirometry was carried out. Results39 patients completed the study. The mean age was 52 ± 11 years old and 28 patients (71.79%) were obese. Both groups were similar for all variables studied at baseline. After Continuous positive air pressure use, patients of group II presented more significant improvements (p < 0.05) for sleep quality and diurnal sleepiness. Time spent with physical activities did not change. Spirometric data were at normal range at baseline. Solely the variable FEF 25%–75% was significantly enhanced (p < 0.05) in group II. ConclusionContinuous positive air pressure therapy for 1 week, with ideal pressure, improves daytime sleepiness and sleep quality, enhances pulmonary function, but does not change the mean time spent with physical activities.

Sleep apnea: Tracking effects of a first session of CPAP therapy by means of Granger causality

Connectivity between physiological networks is an issue of particular importance for understanding the complex interaction brain-heart. In the present study, this interaction was analyzed in polysomnography recordings of 28 patients diagnosed with obstructive sleep apnea (OSA) and compared with a group of 10 control subjects. Electroencephalography and electrocardiography signals from these polysomnography time series were characterized employing Granger causality computation to measure the directed connectivity among five brain waves and three spectral subbands of heart rate variability. Polysomnography data from OSA patients were recorded before and during a first session of continuous positive air pressure (CPAP) therapy in a split-night study. Results showed that CPAP therapy allowed the recovery of inner brain connectivities, mainly in subsystems involving the theta wave. In addition, differences between control and OSA patients were established in connections that involve lower frequency ranges of heart rate variability. This information can be potentially useful in the initial diagnosis of OSA, and determine the role of cardiac activity in sleep dynamics based on the use of three subbands of heart rate variability.

Beyond heart health: Consequences of obstructive sleep apnea.

Obstructive sleep apnea (OSA) is a serious condition associated with impaired quality of life, depression, drowsy driving and motor vehicle accidents, metabolic disease, and cognitive decline. The mechanisms accounting for OSA and metabolic disease include hypoxia, sleep fragmentation, and systemic inflammation. OSA appears to advance cognitive decline, and the relationship between the 2 conditions may be bidirectional. Treatment of patients with continuous positive air pressure therapy improves many of the impaired outcomes associated with OSA. Greater awareness, screening, and treatment of patients with OSA can reduce the negative consequences associated with OSA.

Rational antihypertensive therapy in patients with obstructive sleep apnea

Background. The relationship between obstructive sleep apnea (OSA) and hypertension (AH) is well known. In numerous studies it was found that obstructive sleep apnea was an independent predictor of the development of resistant AH (RAH), and the severity of apnea was directly correlated with the severity of RAH with the exception of the such confounders as age, obesity, sex. The purpose of this publication is to present a new strategy and modern approaches of drug and non-drug therapy of resistant hypertension in patients with OAS with the possibility of their implementation in real clinical practice. Conclusion. Currently, for a practitioner, the therapy of the patient with OSA and RAH is a serious clinical problem. A new rational therapeutic strategy for the treatment of such patients includes a combination of three-component drug therapy and non-drug continuous positive air pressure therapy (CPAP therapy). A reasonable duration of CPAP therapy should exceed 12 weeks. The proposed strategy for the treatment of patients with OAS+RAH has the highest efficiency of achieving blood pressure levels and significantly reduces the risks of fatal cardiovascular events.

Long-term Effect of Continuous Positive Air Pressure Therapy on Intraocular Pressure in Patients with Primary Open-angle Glaucoma with Obstructive Sleep Apnea.

ABSTRACTPurposePrevalence of glaucoma is higher in obstructive sleep apnea (OSA) patients. The gold standard technique to treat OSA is continuous positive airway pressure (CPAP) therapy. The influence of long-term CPAP therapy on intraocular pressure (IOP), blood pressure, ocular perfusion pressure (OPP), and glaucoma progression in primary open-angle glaucoma (POAG) patients was evaluated.DesignProspective study.Materials and methodsIn this study, we enrolled 12 eyes from six POAG patients aged >35 years, with newly diagnosed OSA and with indication for CPAP therapy. The CPAP was performed for 12 months. We monitored the IOP every 3 months. Visual field was determined at baseline and 12 months.ResultsThe mean IOP after CPAP therapy for 12 months was significantly higher than the mean baseline IOP (average IOP 3 months before CPAP therapy) (19.08 ± 3.47 vs 17.83 ± 2.88 mm Hg; p = 0.006). The IOP rising rate was 0.69 ± 0.47/years (p = 0.138) before CPAP therapy and increased to 1.13 ± 0.47/years (p = 0.016) after CPAP therapy. The OPP after 12 months of CPAP was significantly lower than the baseline (42.21 ± 5.29 vs 45.24 ± 7.09 mm Hg; p = 0.06). Results showed that the pattern standard deviation (PSD) value of 24-2 short wavelength automated perimetry (SWAP) visual field was reduced from 5.34 ± 3.92 to 4.77 ± 3.73 (p = 0.025). Antiglaucoma medication was administered to a patient due to increased IOP without glaucoma progression evidence.ConclusionThe POAG and OSA patients demonstrated significant IOP rising after CPAP therapy but did not show progression of glaucomatous damage. Mean deviation (MD), PSD, and visual field index (VFI) were not significantly different after CPAP therapy.PrécisProspective study of POAG and OSA patients demonstrated significant IOP rising after CPAP therapy for a year. The study did not show progression of glaucomatous damage.How to cite this articleHirunpatravong P, Kasemsup T, Ayudhya WN, et al. Long-term Effect of Continuous Positive Air Pressure Therapy on Intraocular Pressure in Patients with Primary Open-angle Glaucoma with Obstructive Sleep Apnea. J Curr Glaucoma Pract 2019;13(3):94–98.

Obstructive Sleep Apnea: From Intermittent Hypoxia to Cardiovascular Complications via Blood Platelets.

Obstructive sleep apnea is a chronic condition characterized by recurrent episodes of apneas or hypopneas during sleep leading to intermittent hypoxemia and arousals. The prevalence of the sleep disordered breathing is estimated that almost 50% of men and 24% of women suffer from moderate to severe form of the disorder. Snoring, collapse of upper airways and intermittent hypoxia are main causes of smoldering systemic inflammation in patients suffering from obstructive sleep apnea. The systematic inflammation is considered one of the key mechanisms leading to significant cardiovascular complications. Blood platelets, formerly not even recognized as cells, are currently gaining attention as crucial players in the immune continuum. Platelet surface is endowed with receptors characteristic for cells classically belonging to the immune system, which enables them to recognize pathogens, immune complexes, and interact in a homo- and heterotypic aggregates. Platelets participate in the process of transcellular production of bioactive lipids by delivering both specific enzymes and substrate molecules. Despite their lack of nucleus, platelets synthetize proteins in a stimuli-dependent manner. Atherosclerosis and consequent cardiovascular complications result from disruption in homeostasis of both of the platelet roles: blood coagulation and inflammatory processes modulation. Platelet parameters, routinely evaluated as a part of complete blood count test, were proposed as markers of cardiovascular comorbidity in patients with obstructive sleep apnea. Platelets were found to be excessively activated in this group of patients, especially in obese subjects. Persistent activation results in enhanced spontaneous aggregability and change in cytokine production. Platelet-lymphocyte ratio was suggested as an independent marker for cardiovascular disease in obstructive sleep apnea syndrome and continuous positive air pressure therapy was found to have an impact on platelet parameters and phenotype. In this literature review we summarize the current knowledge on the subject of platelets involvement in obstructive sleep apnea syndrome and consider the possible pathways in which they contribute to cardiovascular comorbidity.

Long-term prediction of adherence to continuous positive air pressure therapy for the treatment of moderate/severe obstructive sleep apnea syndrome

BackgroundContinuous positive airway pressure (CPAP) therapy is a highly effective treatment for obstructive sleep apnea syndrome (OSAS). However, poor adherence is a limiting factor, and a significant proportion of patients are unable to tolerate CPAP. The aim of this study was to determine predictors of long-term non-compliance with CPAP. MethodsCPAP treatment was prescribed to all consecutive patients with moderate or severe OSAS (AHI ≥15 events/h) (n = 295) who underwent a full-night CPAP titration study at home between February 1, 2002 and December 1, 2016. Adherence was defined as CPAP use for at least 4 h per night and five days per week. Subjects had periodical follow-up visits including clinical and biochemical evaluation and assessment of adherence to CPAP. ResultsMedian follow-up observation was 74.8 (24.2/110.9) months. The percentage of OSAS patients adhering to CPAP was 41.4% (42.3% in males and 37.0% in females), and prevalence was significantly higher in severe OSAS than in moderate (51.8% vs. 22.1%; p < 0.001; respectively). At multivariate analysis, lower severity of OSAS (HR = 0.66; CI 95 0.46–0.94) p < 0.023), cigarette smoking (HR = 1.72; CI 95 1.13–2.61); p = 0.011), and previous cardiovascular events (HR = 1.95; CI 95 1.03–3.70; p = 0.04) were the only independent predictors of long-term non-adherence to CPAP after controlling for age, gender, and metabolic syndrome. ConclusionsIn our cohort of patients with moderate/severe OSAS who were prescribed CPAP therapy, long-term compliance to treatment was present in less than half of the patients. Adherence was positively associated with OSAS severity and negatively associated with cigarette smoking and previous cardiovascular events at baseline.

Application of Cognitive-Behavioral Therapy in Obstructive Sleep Apnea: Comparison of Combined Treatment, and CPAP Therapy on Executive Functions of the Brain

Sleep apnea disorder brings about negative effects to the quality of life of the people involved. Debilitation of cognitive functioning is one of the consequences of this condition. Scant researches have been carried out to explore the efficacy of cognitive therapy on mitigating clinical symptoms and cognitive functions of the brain. In our study we combined cognitive method and medical treatment. This research aims to compare the effectiveness of continuous positive air pressure (CPAP) therapy and cognitive-behavioral treatment (CBT) on improving mental cognitive functions in patients with sleep apnea disorder. Methods: The study population included all patients referred the Sleep Disorders Clinic in Tehran. The sample consisted of 45 people who were randomly placed into three groups of 15 people (CPAP, combined treatment, and control). All three groups were psychologically assessed prior to the intervention. Next, individuals in the cognitive-behavioral group underwent CPAP and 12 sessions of cognitive training, progressive muscle relaxation, mental visualization, and sleep hygiene. The other group went through CPAP therapy and the third group were assessed. After the intervention, All groups were assessed psychologically. Data collection instruments included Wisconsin cognitive software, simple Stroop, complex Stroop, continuous performance, polysomnography device, and CPAP devices. Results: The results indicated that both types of intervention can enhance cognitive functioning; however, a greater efficacy is obtained by combining the two methods compared with the exclusive application of medical treatment solely. Conclusion: We propose cognitive-behavioral therapy as a complement to medical treatment.

113 Is obstructive sleep apnea (OSA) a risk factor for the progression of thoracic aortic aneurysm (TAA)?

Introduction: Care of aortic aneurysms (AA) consists of regular imaging follow-up and managing cardiovascular risk factors. OSA has been proposed to be associated with accelerated expansion of abdominal AA in observational studies. The purpose of this ongoing study is to evaluate whether OSA has an influence on the progression of thoracic aortic aneurysm (TAA). Methods: In total, 340 people with known TAA are to be included in this prospective, observational study. In women the TAA is defined as aortic diameter > 39mm at the level of Sinus valsalvae and >42mm at the level of the ascending aorta. The values for men are >44mm and >46 mm, respectively. Each participant undergoes a home sleep study at baseline and at the 3-year follow-up. OSA is defined as Apnea-Hypopnea-Index (AHI) ≥ 5/h, and its severity classified into mild, moderate or severe according to the guidelines by the American Academy of Sleep Medicine (AASM). Each participant receives an annual TAA assessment by transthoracic echocardiography. The primary outcome is the yearly expansion rate of TAA in relation to OSA severity. The secondary outcomes encompass aortic events (ruptures, dissections), endovascular repairs and rapid progressions of TAA. Results: To date, 228 patients have been recruited, 20 patients have dropped out during follow-up and 5 have reached a secondary outcome (TAA surgery). Out of 203 still active participants, 148 have reached the first follow-up (1 year) and 88 the second one (2 years). In total, 12 patients were started on continuous positive air pressure therapy (CPAP) during follow-up - these were considered as a separate AHI category. The baseline characteristics are listed in table 1. The one-year progression rates were similar in all subgroups. After 2 years, the mean systolic TAA progression rate at Sinus valsalve (0.051 ± 0.107cm) was significantly greater in moderate-to-severe OSA (AHI≥15/h) than in participants with an AHI < 15/h (0.014 ± 0.098cm) or in the CPAP subgroup (-0.003 ± 0.055cm). A similar trend was observed for the ascending aorta. Conclusions: Moderate-to-severe OSA seems to increase the TAA expansion rate at the level of Sinus valsalvae, whereas CPAP seems to be an effective countermeasure. It might therefore be beneficial to routinely screen and treat for OSA in the management of TAA.Table 1Population CharacteristicsPopulation CharacteristicsFeatureTotal (203 participants)2nd follow-up at +2 years (88 partcipants)N%N%Males168(82.76%)74(84.09%)Smokers and Ex-Smokers117(57.64%)46(52.27%)Arterial Hypertension151(74.38%)62(70.46%)Diabetes Mellitus13(6.4%)6(6.81%)Adipositas36(17.73%)17(19.32%)Dyslipidemia115(56.65%)48(54.55%)Stroke28(13.79%)17(19.32%)Coronary Heart Disease46(22.66%)20(22.73%)Other know Aneurysms8(3.94%)2(2.27%)Chronic Obstructive Pulmonary Disease13(6.4%)5(5.68%)Atrial Fibrillation45(22.17%)20(22.73%)Renal Failure22(10.84%)11(12.50%)Family History of Vascular Incidents47(23.15%)28(31.82%)Family History of Aortic Aneurysms20(9.85%)8(0.09%)AHI < 577(37.93%)29(32.96%)AHI 5-1561(30.05%)27(30.68%)AHI 15-3040(19.7%)14(15.91%)AHI > 3025(12.32%)9(10.23%)CPAP12(5.91%)9(10.23%) Open table in a new tab

Application of Cognitive-behavioral Therapy in Obstructive Sleep Apnea: Comparison of CPAP Therapy and CBT on the Executive Functions of the Brain

Purpose: Sleep apnea disorder brings about negative effects to the quality of life of the people involved. Debilitation of cognitive functioning is one of the consequences of this condition. Scant researches have been carried out to explore the efficacy of cognitive therapy on mitigating clinical symptoms and cognitive functions of the brain. The novelty of the present study is in combining cognitive method and medical treatment. This research aims to compare the effectiveness of continuous positive air pressure (CPAP) therapy and cognitive-behavioral treatment (CBT) on improving mental cognitive functions in patients with sleep apnea. Methods: The study population included all patients referred to the Bahar Sleep Disorders Clinic in Tehran, Iran. The sample consisted of 45 people who were randomly placed into three groups of 15 people (CPAP therapy, cognitive behavioral therapy, and control groups). All three groups were psychologically assessed prior to the intervention. Next, individuals in the cognitive-behavioral group underwent 12 sessions of cognitive training, progressive muscle relaxation, mental visualization, and sleep hygiene. The other group went through CPAP therapy. After the intervention, both groups were assessed psychologically. Data collection instruments included Wisconsin cognitive software, simple Stroop, complex Stroop, continuous performance, polysomnography device, and CPAP devices. Results: The results indicated that both types of intervention can enhance cognitive functioning; however, a greater efficacy is obtained by combining the two methods compared with the exclusive application of medical treatment. Conclusion: The authors propose cognitive-behavioral therapy OSA as a complement to medical treatment.

Three-dimensional evaluation of upper airway in patients with obstructive sleep apnea syndrome during oral appliance therapy.

Obstructive sleep apnea syndrome (OSAS) represents a frequent and common respiratory disease characterized by repeated episodes of complete and/or partial obstruction of upper airways during sleep, normally associated with reduction of oxygen saturation in blood. The oral appliances (OAs) are considered to be an effective treatment modality thanks to the upper airway enlargement. Lateral cephalometry has been used for the 2-dimensional evaluation of upper airway form with several limits. We obtained an accurate 3-dimensional (3D) volume analyses with cone beam computed tomography (CBCT) scans to confirm the effects of OA on the upper airway in patients with OSAS. Ten Italian patients with moderate or severe OSA (3 males and 7 females, 53.4 ± 11.3 years of age, and BMI 24.5 ± 2.7), who cannot tolerate continuous positive air pressure therapy and rejected a surgical approach, were treated with non-adjustable customized OAs and evaluated with CBCT and polysomnography. Upper airway form was examined in the presence and absence of OA and the volume was measured and compared in 2 different areas. Specific planes have been considered to match the data and calculate the benefit obtained with therapy. Nine out of ten patients showed an improvement of total upper airway volume and an improvement in apnea-hypopnea index. Volume increased both in the posterior soft palate region and in the posterior tongue region. In the inferior area, we observed greater differences. 3D image reconstruction accurately confirmed morphological changes in the upper airway during OA therapy. The use of this 3D evaluation is expected to improve the results of OA therapy in the future.

First night of CPAP: impact on memory consolidation attention and subjective experience

ObjectiveNeurocognitive deficits are common and serious consequences of obstructive sleep apnea (OSA). Currently, the gold standard treatment is continuous positive air pressure (CPAP) therapy, although the clinical responses to this intervention can be variable. This study examined the effect of one night of CPAP therapy on sleep-dependent memory consolidation, attention, and vigilance as well as subjective experience. MethodsFifteen healthy controls and 29 patients with obstructive sleep apnea of whom 14 underwent a full-night CPAP titration completed the psychomotor vigilance test (PVT) and motor sequence learning task (MST) in the evening and the morning after undergoing overnight polysomnography. All participants also completed subjective evaluations of sleep quality. ResultsParticipants with OSA showed significantly less overnight improvement on the MST compared to controls without OSA, independent of whether or not they had received CPAP treatment, while there was no significant difference between the untreated OSA and CPAP-treated patients. Within the OSA group, only those receiving CPAP exhibited faster reaction times on the PVT in the morning. Compared to untreated OSA patients, they also felt subjectively more rested and reported that they slept better. ConclusionOur results demonstrate an instant augmentation of subjective experience and, based on PVT results, attention and vigilance after one night of CPAP, but a lack of an effect on offline sleep-dependent motor memory consolidation. This dissociation may be explained by different brain structures underlying these processes, some of which might require longer continued adherence to CPAP to generate an effect.

The effect of continuous positive air pressure (CPAP) on nightmares in patients with posttraumatic stress disorder (PTSD) and obstructive sleep apnea (OSA).

Post-Traumatic Stress Disorder (PTSD) is increasingly prevalent among Veterans characterized by recurrent nightmare and disrupted sleep. Veterans with PTSD also have a high prevalence of obstructive sleep apnea (OSA) and untreated OSA worsens the sleep-related symptoms of PTSD. In our study, we hypothesized that among PTSD-afflicted Veterans with OSA, CPAP therapy may reduce the frequency of nightmares and a better CPAP compliance may be associated with increased symptom improvement. We retrospectively reviewed medical records to identify OSA patients treated in a VA medical center who also carried a diagnosis of PTSD (n = 69). Data about patient characteristics and polysomnographic findings were extracted. Repeated-measures t-tests were performed, comparing mean nightmare frequency and Epworth sleepiness score (ESS) before and after CPAP treatment. Multiple linear regressions were done to identify factors predicting CPAP compliance. A logistic regression analysis was also done to estimate the odds of subjective improvement in PTSD symptoms with CPAP. CPAP therapy reduced the mean ESS from 14.62 to 8.52 (p < 0.001) and the mean number of nightmares per week from 10.32 to 5.26 (p < 0.01). Reduced nightmare frequency after CPAP treatment was best predicted by CPAP compliance (p < 0.001). Every 10% increase in CPAP compliance almost doubled the odds of benefitting by CPAP (odds ratio = 1.92, 95% CI = 1.47-2.5). In Veterans with PTSD and OSA, CPAP therapy reduces PTSD-associated nightmares and improves overall PTSD symptoms. We recommend that all PTSD patients should be screened clinically for symptoms of OSA and receive CPAP treatment whenever possible to improve PTSD symptoms.

A pilot study of an in-vitro bovine trachea model of the effect of continuous positive airway pressure breathing on airway surface liquid

BackgroundContinuous positive air pressure (CPAP) users frequently report troublesome symptoms of airway dryness and nasal congestion. Clinical investigations have demonstrated that supplementary humidification reduces these symptoms but the reason for their occurrence remains unexplained. Investigations using human computational air-conditioning models are unable to reproduce or quantify the apparent airway drying experienced during CPAP therapy. The purpose of this study was to determine whether augmented air pressures change overall mucosal airway surface liquid (ASL) water supply and, if so, the extent of this effect.MethodIn an original in vitro experimental set up, maximal ASL supply was determined in whole bovine trachea when exposed to simulated tidal breathing stresses over a range of air pressures.ResultsAt ambient pressure, the maximal supply of ASL was found to compare well to previously published data (31.2 μl/cm2.hr). CPAP pressures from 5 cm H2O above ambient were found to reduce ASL supply by 22%. Statistical analysis (n = 8) showed a significant difference existed between the ambient and CPAP results (p < 0.0001), and that there was no significant variation between all pressurized results (p = 0.716).ConclusionsThese findings provide preliminary data that ASL supply is reduced by CPAP therapy which may explain the airway drying symptoms associated with this therapy.

The impact of sleep apnea treatment on carbohydrate metabolism in patients with acromegaly

Sleep Apnea is highly prevalent and may contribute to insulin resistance in patients with acromegaly. The primary aim of this study was to assess the impact of sleep apnea treatment with a continuous positive air pressure (CPAP) device on insulin resistance evaluated by hyperinsulinemic euglycemic clamp (HEC). A prospective, randomized, open label, placebo-controlled, crossover study was performed at a tertiary outpatient pituitary center. Twelve acromegalic subjects on somatostatin analogs (SA) with a recent diagnosis of moderate to severe sleep apnea were randomized to CPAP therapy or to nasal dilator adhesive (NDA) with placebo effect for 3 months and then crossed over for another 3 months period without washout. Assessment of HEC, mathematical insulin resistance indexes (HOMA, HOMA2 and QUICKI), GH, IGF-1, HbA1c and free fat acids were performed. A significant reduction on insulin resistance was demonstrated by HEC at the end of the study in patients on CPAP (HEC, pre- and post-CPAP: 4.27 vs. 6.10 mg/Kg/min, P = 0.032). This reduction was not observed in NDA group (HEC, pre- and post-adhesive: 5.53 vs. 5.19 mg/Kg/min, P = 0.455). There was no significant difference on HbA1c or on peripheral insulin resistance indexes in both treatments. CPAP promoted a significant increase on peripheral insulin sensitivity in acromegalic patients with moderate to severe sleep apnea on SA use. Our results support the concept that sleep apnea plays an important role on glucose metabolism. Insulin resistance indexes were unable to detect this finding.

Parotid abscess in a patient with obstructive sleep apnea treated with continuous positive airway pressure therapy

Continuous positive pressure therapy (CPAP) is a mainstay of treatment of obstructive sleep apnea (OSA). A CPAP device pressurizes room air and blows it through a nasal or oronasal mask into the patient’s airway, preventing the dynamic collapse of the airway soft tissue structures. In order to apply a sufficient pressure, there has to be a seal between the CPAP mask and the patient’s facial structures. Most complications of CPAP therapy are related to a mask interface (skin abrasion, leakage) or dryness of the inspired air (nasal/throat dryness, nasal congestion, rhinorrhea) [1]. We report a case of a man with OSA who, once started with CPAP, developed worsening of the preexisting parotic sialoadenitis that eventually led to parotid abscess formation and required removal of the gland.

Obese obstructive sleep apnea patients with tonsil hypertrophy submitted to tonsillectomy

The physiopathology of obstructive sleep apnea-hypopnea syndrome (OSAHS) is multifactorial and obesity has been shown to be one of the main factors correlated with its occurrence. In obese patients with anatomical alterations of the upper airways it is often difficult to predict success for surgical correction since obesity is a limiting factor. Therefore, the aim of the present study was to evaluate the results of tonsillectomy in a specific group of patients, i.e., obese OSAHS patients with tonsil hypertrophy. Seven OSAHS patients with moderate obesity with obstructive palatine tonsil hypertrophy were submitted to tonsillectomy. All patients were submitted to pre- and postoperative appraisal of body mass index, otorhinolaryngology examination and polysomnography. Patients' average age was 36.4 +/- 10.3 years and average preoperative body mass index was 36.6 +/- 6.3 kg/m(2). Postoperative weight did not differ significantly from preoperative weight (P = 0.27). Average preoperative apnea and hypopnea index (AHI) was 81 +/- 26/h and postoperative AHI was 23 +/- 18/h (P = 0.0005). Average preoperative minimum oxyhemoglobin saturation (SaO2 min) was 69 +/- 14% and the postoperative value was 83 +/- 3% (P = 0.038). In relation to AHI, 6 (86%) of the 7 patients studied showed a reduction of 50% in relation to preoperative level and of these, 4 (57%) presented AHI of less than 20%. Only one patient presented a reduction of less than 50% in AHI, but even so showed improved SaO2 min. Tonsillectomy treatment for OSAHS in obese patients with obstructive palatine tonsil hypertrophy caused a significant reduction in AHI, with improvement in SaO2 min. This procedure could be eventually considered as an option of treatment for obese OSAHS patients with significant tonsil hypertrophy when continuous positive air pressure therapy is not possible as the first choice of treatment.

Risk factors for obstructive sleep apnea in adults.

OBSTRUCTIVE SLEEP APNEA (OSA) is a sleep disorder characterized by intermittent complete and partial airway collapse, resulting in frequent episodes of apnea and hypopnea. The breathing pauses cause acute adverse effects, including oxyhemoglobin desaturation, fluctuations in blood pressure and heart rate, increased sympathetic activity, cortical arousal, and sleep fragmentation. The condition has received increasing attention during the past 3 decades. Until 1981, the only effective treatment for OSA was tracheostomy. The advent of continuous positive air pressure therapy, an effective noninvasive treatment, was a turning point, and clinical interest began to increase in tandem with the accumulation of research linking OSA to cognitive, behavioral, cardiovascular, and cerebrovascular morbidities (FIGURE). Findings from large population studies in different countries during the last decade have contributed to a better understanding of the epidemiology of OSA. In most population studies, OSA status has been indicated by the frequency of apnea and hypopnea events per hour of sleep (apnea-hypopnea index) as determined by polysomnography (a continuous overnight recording of sleep, breathing, and cardiac parameters). The apnea-hypopnea index cutpoints of 5, 15, and 30 (with or without daytime sleepiness) are commonly used to indicate mild, moderate, and severe OSA, respectively. These studies have demonstrated that OSA is highly prevalent in adults (TABLE). Approximately 1 in 5 adults has at least mild OSA and 1 in 15 adults has OSA of moderate or worse severity. In the United States, 75% to 80% of OSA cases that could benefit from treatment remain undiagnosed. Associations of OSA with serious morbidity have raised concern that untreated OSA is a substantial but underappreciated public health threat. Primary care physicians are currently being encouraged to be alert to OSA symptoms of disruptive snoring, breathing pauses, and excessive daytime sleepiness in their patients. It is important that physicians also recognize that not all OSA patients are “Pickwickian” (ie, male, obese, sleepy, snoring, and middle-aged), a stereotype that emerged from clinical observations of the highly selective patient populations observed in earlier years. The goal of this article is to review recent findings from populationbased epidemiology studies on risk factors for OSA in adults.