[Argentine consensus on sleep-related respiratory disorders]. / Consenso Argentino de trastornos respiratorios vinculados al sueño.

Due to the increased interest of the medical community in sleep disorders an experts meeting was called to establish common criteria for diagnosis, treatment and management of these disorders. Adult prevalence of sleep apnea/hypopnea syndrome (SA/HS) is about 2-4% and increases in the elderly. Snoring and excessive daytime somnolence (EDS) are habitual symptoms. Increased risk to cardiovascular disorders and traffic accidents are the major complications. Increased upper airways resistance syndrome is a recently described syndrome which also involves EDS. A standardized questionnaire was developed and its use was recommended in order to evaluate patients with respiratory sleep disorders (RSD). Polysomnography was established as gold standard in the diagnosis of RSD. Minimal requirement of split night studies and screening studies was also standardized and specific indications were summarized. Medical treatment of obesity in relationship to RSD was analyzed. Nasal continuous positive airways pressure (CPAP) was established as the first choice treatment of SA/HS. Titration of CPAP was standardized. Oral appliances with mandibular advancement could be considered in the treatment of snoring patients without SA/HS and in patients with increased upper airways resistance syndrome. Uvulopalatopharingoplasty can only be performed in snoring patients in whom the presence of SA/HS has been dismissed by polysomnography. Management of patients must include periodic clinical control. EDS must be determined by Epworth test. In order to evaluate CPAP compliance the use of time-controlled devices is highly recommended.

Sleep fragmentation: comparison of two definitions of short arousals during sleep in OSAS patients.

The measurement of arousals during sleep is useful to quantify sleep fragmentation. The criteria for electroencephalography (EEG) arousals defined by the American Sleep Disorders Association (ASDA) have recently been criticized because of lack of interobserver agreement. The authors have adopted a scoring method that associates the increase in chin electromyography (EMG) with the occurrence of an alpha-rhythm in all sleep stages (Université Catholique de Louvain (UCL) definition of arousals). The aim of the present study was to compare the two scoring definitions in terms of agreement and repeatability and the time taken for scoring in patients with obstructive sleep apnoea syndrome (OSAS) of varying severity. Two readers using both ASDA and UCL definitions scored twenty polysomnographies (PSGs) each on two occasions. The PSGs were chosen retrospectively to represent a wide range of arousal index (from 6-82) in OSAS patients. There was no difference in the arousal indices between readers and between scoring methods. The mean+/-SD difference between the two definitions (the bias) was 1.1+/-3.76 (95% confidence interval: -0.66-2.86). There was a strong linear relationship between the arousal index scored with the two definitions (r=0.981, p<0.001). Mean+/-SD scoring duration was significantly shorter for UCL than for ASDA definitions (18.5+/-5.4 versus 25.3+/-6.6 min, p<0.001). In conclusion, it has been found that in obstructive sleep apnoea syndrome patients, the American Sleep Disorders Association and Université Catholique de Louvain definitions were comparable in terms of agreement and repeatability.

CPAP treatment does not affect glucose-insulin metabolism in sleep apneic patients.

Objective: We investigated glucose metabolism and insulin resistance in non-obese and moderately overweight sleep apnea patients, as well as their response to nasal CPAP treatment.Methods: A group of subjects with glucose intolerance was screened for sleep disordered breathing by clinical interview and ambulatory recordings. Ten subjects were found to have untreated sleep apnea and were asked to participate in further investigation. This included nocturnal polysomnography, oral glucose tolerance test and indirect calorimetry. Subjects then had calibration of nasal CPAP with polysomnography. Two months after start of treatment, all subjects were restudied as at baseline. In parallel, six obstructive sleep apnea syndrome (OSAS) subjects, diagnosed through the sleep clinic, were matched for gender, age and oxygen desaturation index with the other group, and had a euglycemic hyperinsulinemic clamp at baseline and after 2 months of nasal CPAP.Results: The first ten patients showed no change in total glucose oxidation, glucose oxidation by weight or by fat free mass, or insulin energetic expenditure, despite nocturnal usage of nasal CPAP. Similarly, when comparing baseline to the treatment at 2 months, the six OSAS patients had no change in mean glycemia, insulin, C peptide and hemoglobin (Hgb) A1C measurements. No difference in the amount of glucose infused during the duration of the clamp was noted either.Conclusion: Our data do not support the existence of a significant relationship between glucose and insulin metabolism and obstructive sleep apnea. Obesity, when present, is the important variable.

Consenso Argentino de trastornos respiratorios vinculados al sueño. / [Argentine consensus on sleep-related respiratory disorders]

Due to the increased interest of the medical community in sleep disorders an experts meeting was called to establish common criteria for diagnosis, treatment and management of these disorders. Adult prevalence of sleep apnea/hypopnea syndrome (SA/HS) is about 2-4

and increases in the elderly. Snoring and excessive daytime somnolence (EDS) are habitual symptoms. Increased risk to cardiovascular disorders and traffic accidents are the major complications. Increased upper airways resistance syndrome is a recently described syndrome which also involves EDS. A standardized questionnaire was developed and its use was recommended in order to evaluate patients with respiratory sleep disorders (RSD). Polysomnography was established as gold standard in the diagnosis of RSD. Minimal requirement of split night studies and screening studies was also standardized and specific indications were summarized. Medical treatment of obesity in relationship to RSD was analyzed. Nasal continuous positive airways pressure (CPAP) was established as the first choice treatment of SA/HS. Titration of CPAP was standardized. Oral appliances with mandibular advancement could be considered in the treatment of snoring patients without SA/HS and in patients with increased upper airways resistance syndrome. Uvulopalatopharingoplasty can only be performed in snoring patients in whom the presence of SA/HS has been dismissed by polysomnography. Management of patients must include periodic clinical control. EDS must be determined by Epworth test. In order to evaluate CPAP compliance the use of time-controlled devices is highly recommended.

Upper airway imaging in sleep apnoea syndrome: clinical applications.

Symptoms of habitual snoring and excessive daytime sleepiness are extremely common in the general population, and have poor predictive value in identifying patients with "true" sleep-related disordered breathing. The upper airways are the main anatomical site responsible for snoring and sleep apnoea; therefore, their examination via different means has been quite extensively assessed. Clinical examination may point to severe micrognathia or retrognathia, grossly hypertrophied tonsils, obvious macroglossia, and oedema and inflammation of the uvula and soft palate. A recently proposed model is promising, but has not been validated independently yet. Endoscopic investigations have been performed in awake as well as in sleeping patients, with the pharynx in relaxed or active states; their predictive value remains poor, both for diagnostic purposes and for identifying patients that may benefit from surgery. Radiographic and magnetic resonance imaging techniques have permitted a detailed understanding of the process of narrowing and collapse of the upper airways. Unfortunately, these techniques do not perform any better than the ones previously cited as clinically efficient tools for diagnosis in the population of patients suspected of sleep-related breathing disorders. In conclusion, clinical examination of the upper airways remains part of the clinical evaluation of patients suspected of sleep-related disordered breathing. Other imaging techniques may be used for research purposes, but do not yet seem to be worth including in the routine assessment of this population.