These practice parameters are an update of the previously-published recommendations regarding the indications for polysomnography and related procedures in the diagnosis of sleep disorders. Diagnostic categories include the following: sleep related breathing disorders, other respiratory disorders, narcolepsy, parasomnias, sleep related seizure disorders, restless legs syndrome, periodic limb movement sleep disorder, depression with insomnia, and circadian rhythm sleep disorders. Polysomnography is routinely indicated for the diagnosis of sleep related breathing disorders; for continuous positive airway pressure (CPAP) titration in patients with sleep related breathing disorders; for the assessment of treatment results in some cases; with a multiple sleep latency test in the evaluation of suspected narcolepsy; in evaluating sleep related behaviors that are violent or otherwise potentially injurious to the patient or others; and in certain atypical or unusual parasomnias. Polysomnography may be indicated in patients with neuromuscular disorders and sleep related symptoms; to assist in the diagnosis of paroxysmal arousals or other sleep disruptions thought to be seizure related; in a presumed parasomnia or sleep related seizure disorder that does not respond to conventional therapy; or when there is a strong clinical suspicion of periodic limb movement sleep disorder. Polysomnography is not routinely indicated to diagnose chronic lung disease; in cases of typical, uncomplicated, and noninjurious parasomnias when the diagnosis is clearly delineated; for patients with seizures who have no specific complaints consistent with a sleep disorder; to diagnose or treat restless legs syndrome; for the diagnosis of circadian rhythm sleep disorders; or to establish a diagnosis of depression.

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Practice parameters for the indications for polysomnography and related procedures: an update for 2005.

Introduction:This guideline establishes clinical practice recommendations for the diagnosis of obstructive sleep apnea (OSA) in adults and is intended for use in conjunction with other American Aca...

Clinical practice guideline for diagnostic testing for adult obstructive sleep apnea: An American academy of sleep medicine clinical practice guideline

The forced oscillation technique in clinical practice: methodology, recommendations and future developments. E. Oostveen, D. MacLeod, H. Lorino, R. Farre´ , Z. Hantos, K. Desager, F. Marchal, on behalf of the ERS Task Force on Respiratory Impedance Measurements. #ERS Journals Ltd 2003. ABSTRACT: The forced oscillation technique (FOT) is a noninvasivemethod with which to measure respiratory mechanics. FOT employs small-amplitude pressure oscillations superimposed on the normal breathing and therefore has the advantage over conventional lung function techniques that it does not require the performance of respiratory manoeuvres. The present European Respiratory Society Task Force Report describes the basic prin- ciple of the technique and gives guidelines for the application and interpretation of FOT as a routine lung function test in the clinical setting, for both adult and paediatric populations. FOT data, especially those measured at the lower frequencies, are sensitive to airway obstruction, but do not discriminate between obstructive and restrictive lung disorders. There is no consensus regarding the sensitivity of FOT for bronchodilation testing in adults. Values of respiratory resistance have proved sensitive to bronchodilation in children, although the reported cutoff levels remain to be cone rmed in future studies. Forced oscillation technique is a reliable method in the assessment of bronchial hyper- responsiveness in adults and children. Moreover, in contrast with spirometry where a deep inspiration is needed,forced oscillation techniquedoes not modifytheairway smooth muscle tone. Forced oscillation technique has been shown to be as sensitive as spirometry in detecting impairments of lung function due to smoking or exposure to occupational hazards. Together with the minimalrequirement for the subject 9s cooperation, this makes forced oscillation technique an ideal lung function test for epidemiological and e eld studies. Novel applications of forced oscillation technique in the clinical setting include the monitoring of respiratory mechanics during mechanical ventilation and sleep.

https://erj.ersjournals.com/content/erj/22/6/1026.full.pdf

The forced oscillation technique in clinical practice: methodology, recommendations and future developments

Travel to a high altitude requires that the human body acclimatize to hypobaric hypoxia. Failure to acclimatize results in three common but preventable maladies known collectively as high-altitude illness: acute mountain sickness (AMS), high-altitude cerebral edema (HACE), and high-altitude pulmonary edema (HAPE). Capillary leakage in the brain (AMS/HACE) or lungs (HAPE) accounts for these syndromes. The morbidity and mortality associated with high-altitude illness are significant and unfortunate, given they are preventable. Practitioners working in or advising those traveling to a high altitude must be familiar with the early recognition of symptoms, prompt and appropriate therapy, and proper preventative measures for high-altitude illness.

High-altitude illness.

Normal human sleep comprises two states—rapid eye movement (REM) and non–REM (NREM) sleep— that alternate cyclically across a sleep episode. State characteristics are well defined: NREM sleep includes a variably synchronous cortical electroencephalogram (EEG; including sleep spindles, Kcomplexes, and slow waves) associated with low muscle tonus and minimal psychological activity; the REM sleep EEG is desynchronized, muscles are atonic, and dreaming is typical. A nightly pattern of sleep in mature humans sleeping on a regular schedule includes several reliable characteristics: Sleep begins in NREM and progresses through deeper NREM stages (stages 2, 3, and 4 using the classic definitions, or stages N2 and N3 using the updated definitions) before the first episode of REM sleep occurs approximately 80 to 100 minutes later. Thereafter, NREM sleep and REM sleep cycle with a period of approximately 90 minutes. NREM stages 3 and 4 (or stage N3) concentrate in the early NREM cycles, and REM sleep episodes lengthen across the night. Age-related changes are also predictable: Newborn humans enter REM sleep (called active sleep) before NREM (called quiet sleep) and have a shorter sleep cycle (approximately 50 minutes); coherent sleep stages emerge as the brain matures during the first year. At birth, active sleep is approximately 50% of total sleep and declines over the first 2 years to approximately 20% to 25%. NREM sleep slow waves are not present at birth but emerge in the first 2 years. Slow-wave sleep (stages 3 and 4) decreases across adolescence by 40% from preteen years and continues a slower decline into old age, particularly in men and less so in women. REM sleep as a percentage of total sleep is approximately 20% to 25% across childhood, adolescence, adulthood, and into old age except in dementia. Other factors predictably alter sleep, such as previous sleep-wake history (e.g., homeostatic load), phase of the circadian timing system, ambient temperature, drugs, and sleep disorders. A clear appreciation of the normal characteristics of sleep provides a strong background and template for understanding clinical conditions in which “normal” characteristics are altered, as well as for interpreting certain consequences of sleep disorders. In this chapter, the normal young adult sleep pattern is described as a working baseline pattern. Normative changes due to aging and other factors are described with that background in mind. Several major sleep disorders are highlighted by their differences from the normative pattern.

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Chapter 2 - Normal Human Sleep : An Overview

Nasal obstruction has frequently been mentioned as a possible risk factor in obstructive sleep apnoea syndrome (OSAS). Over a 2-yr period, 541 unselected consecutive snorers referred for suspected breathing disorders during sleep were included to undergo posterior rhinomanometry. In addition cephalometric landmarks and body mass index (BMI) were obtained. Polysomnography was used to determine the number of abnormal respiratory events that occurred during sleep. OSAS was defined as 15 episodes, or more, of apnoea or hypopnoea per hour of sleep (AHI). Of the 541 consecutive snorers 528 underwent nasal resistance measurement by posterior rhinomanometry (failure rate: 2.4%). Patients with OSAS (259 patients) had higher nasal resistance than patients without OSAS (2.6+/-1.6 hPa x L x s(-1) versus 2.2+/-1.0 hPa x L x s(-1), respectively, p<0.005). A stepwise multiple regression analysis showed that BMI, male sex, nasal resistance, and cephalometric parameters were contributing factors to the AHI. The r2-value of the multiple regression analysis was 0.183. Nasal resistance contributed 2.3% of the variance (p<0.0001), whereas mandibular plane-hyoid distance, BMI, male sex and age contributed 6.2%, 4.6%, 3% and 1.3% of the variance, respectively. To conclude, daytime nasal obstruction is an independent risk factor for OSAS.

https://erj.ersjournals.com/content/erj/16/4/639.full.pdf

Nasal obstruction as a risk factor for sleep apnoea syndrome

Constant vs. automatic continuous positive airway pressure therapy: home evaluation.

Prevalence of Sleep-Disordered Breathing in Patients on a Heart Transplant Waiting List

We evaluated pulmonary function abnormalities associated with the sleep apnea syndrome (SAS) in 170 habitual snorers without SAS (n = 62, apnea-hypopnea index [AHI] or = 30). The three groups were similar regarding obesity (BMI approximately 30 kg.m-2) and smoking history (approximately 20 pack-years). Pulmonary function was assessed by spirometry, forced oscillation mechanics, and gas exchange studies. Forced expiratory flows decreased as the SAS severity increased (p < 0.001, p < 0.02, and p < 0.05 for FEF50, FEV1, and FEV1/VC, respectively). Multiple regression analysis showed that the correlation between FEV50 and the AHI persisted when smoking history was taken into account (p < 0.05), suggesting that SAS may be an independent risk factor for small airway disease. A highly significant correlation was found between specific respiratory conductance (sGrs) and the AHI (p < 0.0001). In a multiple regression analysis (p < 0.0001), variables that influenced sGrs were distal airway obstruction as assessed by FEV50 (p < 0.05), morphological upper airway abnormalities as assessed by cephalometric parameters (p < 0.02), and the AHI (p < 0.0005). SAS appears to be highly correlated to lower and upper airway obstruction, as demonstrated by a reduction in specific respiratory conductance, which adds to the increase in breathing load due to obesity.

Françoise Goldenberg

Papers

Nasal obstruction as a risk factor for sleep apnoea syndrome

Constant vs. automatic continuous positive airway pressure therapy: home evaluation.

Prevalence of Sleep-Disordered Breathing in Patients on a Heart Transplant Waiting List

Pulmonary Function in Obese Snorers with or without Sleep Apnea Syndrome

Sleep fragmentation as a risk factor for hypertension in middle-aged nonapneic snorers.