Identification of obstructive sleep apnea in patients who snore

[Analysis of Snoring in Patients with Obstructive Sleep Apnea (OSA) by Polysomnography and LEOSound]

INTRODUCTION

Snoring was monitored in patients with obstructive sleep apnea (OSA) using the LEOSound-Monitor and simultaneously polysomnographic (PSG) recording. In obstructive apneas snoring is normally apparent after apnea termination and the beginning of ventilation. We wanted to know how often obstructive apneas are terminated by ventilation in combination with snoring.

METHODS AND INTENTION

In 40 patients with OSA (AHI > 15/h) simultaneous polysomnographic recordings were performed amongst long-term respiratory sound monitoring using the LEOSound monitor. Patients' average age was 57±11 years. Average weight was 100±19 kg by a mean body mass index (BMI) of 33±7 kg/m². 12 out of 40 recordings had to be rejected for further analysis because of artifacts. Snoring recorded by polysomnography was compared with snoring monitored by LEOSound.

RESULTS

3778 obstructive apnea episodes were monitored. LEOSound identified snoring in 1921 (51,0%), polysomnography in 2229 (58,8%) obstructive apneas. Only in one patient there was a higher difference in snoring episodes between PSG and LEOSound.

DISCUSSION

In nearly 60% of obstructive apnea events we found snoring during apnea-terminating hyperpnoea. LEOSound is a good diagnostic tool to monitor snoring. It is necessary to clarify why only 60% of all obstructive events/hyperpnoea develop snoring. From a pathophysiological point of view opening of collapsed upper airway should lead in a very high percentage to turbulences in airstream and committed snoring.

[Analysis of Snoring in Patients with Obstructive Sleep Apnea (OSA) by Polysomnography and LEOSound]

INTRODUCTION

 Snoring was monitored in patients with obstructive sleep apnea (OSA) using the LEOSound-Monitor and simultaneously polysomnographic (PSG) recording. In obstructive apneas snoring is normally apparent after apnea termination and the beginning of ventilation. We wanted to know how often obstructive apneas are terminated by ventilation in combination with snoring.

METHODS AND INTENTION

 In 40 patients with OSA (AHI > 15/h) simultaneous polysomnographic recordings were performed amongst long-term respiratory sound monitoring using the LEOSound monitor. Patients' average age was 57 ± 11 years. Average weight was 100 ± 19 kg by a mean body  mass  index (BMI) of 33 ± 7 kg/m². 12 out of 40 recordings had to be rejected for further analysis because of artifacts. Snoring recorded by polysomnography was compared with snoring monitored by LEOSound.

RESULTS

 3778 obstructive apnea episodes were monitored. LEOSound identified snoring in 1921 (51,0 %), polysomnography in 2229 (58,8 %) obstructive apneas. Only in one patient there was a higher difference in snoring episodes between PSG and LEOSound.

DISCUSSION

 In nearly 60 % of obstructive apnea events we found snoring during apnea-terminating hyperpnoea. LEOSound is a good diagnostic tool to monitor snoring. It is necessary to clarify why only 60 % of all obstructive events/hyperpnoea develop snoring. From a pathophysiological point of view opening of collapsed upper airway should lead in a very high percentage to turbulences in airstream and committed snoring.

Obstructive sleep apnea syndrome: natural history, diagnosis, and emerging treatment options

Sleep apnea is an entity characterized by repetitive upper airway obstruction resulting in nocturnal hypoxia and sleep fragmentation. It is estimated that 2%-4% of the middle-aged population has sleep apnea with a predilection in men relative to women. Risk factors of sleep apnea include obesity, gender, age, menopause, familial factors, craniofacial abnormalities, and alcohol. Sleep apnea has been increasingly recognized as a major health burden associated with hypertension and increased risk of cardiovascular disease and death. Increased airway collapsibility and derangement in ventilatory control responses are the major pathological features of this disorder. Polysomnography (PSG) is the gold-standard method for diagnosis of sleep apnea and assessment of sleep apnea severity; however, portable sleep monitoring has a diagnostic role in the setting of high pretest probability sleep apnea in the absence of significant comorbidity. Positive pressure therapy is the mainstay therapy of sleep apnea. Other treatment modalities, such as upper airway surgery or oral appliances, may be used for the treatment of sleep apnea in select cases. In this review, we focus on describing the sleep apnea definition, risk factor profile, underlying pathophysiologic mechanisms, associated adverse consequences, diagnostic modalities, and treatment strategies.

Self-reported short sleep duration and frequent snoring in pregnancy: impact on glucose metabolism

OBJECTIVE

We sought to evaluate the impact of short sleep duration (SSD) and frequent snoring (FS) on glucose metabolism during pregnancy.

STUDY DESIGN

We conducted a prospective cohort study of healthy nulliparas who participated in a sleep survey study. SSD was defined as <7 hours of sleep per night and FS, as snoring >or=3 nights per week. Outcomes included 1-hour oral glucose tolerance results and the presence of gestational diabetes mellitus (GDM). Univariate and multivariate analyses were performed.

RESULTS

A total of 189 women participated; 48% reported an SSD and 18.5% reported FS. SSD and FS were associated with higher oral glucose tolerance values: SSD (116 +/- 31 vs 105 +/- 23; P = .008) and FS (118 +/- 34 vs 108 +/- 25; P = .04). Both SSD (10.2% vs 1.1%; P = .008) and FS (14.3% vs 3.3%; P = .009) were associated with a higher incidence of GDM. Even after controlling for potential confounders, SSD and FS remained associated with GDM.

CONCLUSION

SSD and FS are associated with glucose intolerance in pregnancy.

A two-tier screening model using quality-of-life measures and pulse oximetry to screen adults with sleep-disordered breathing

PURPOSE

Using quality-of-life measures and pulse oximetry, this study developed a two-tiered prediction algorithm with an aim to prioritize sleep-disordered breathing patients for polysomnography.

METHODS

Data from 355 patients were evaluated to obtain their clinical information, Chinese version of Epworth sleepiness scale, and snore outcomes survey scores against respiratory disturbance index (RDI). In the first-tier screening, receiver-operating characteristics were calculated with an initial strategy of choosing optimal prediction sensitivity. The second-tier strategy investigated the association between pulse oximetry data (desaturation index of 3%) against RDI to optimize prediction specificity.

RESULTS

The "SOS score of 55 and ESS score of 9" was the optimal combination that yielded the highest sensitivity (0.603) in the first-tier screening. The strategy can includ 94.93% possible patients (probability = 0.6) with positive predictive value of 0.997. The area under the curve (AUC) was 0.88 (p < 0.001). Desaturation index of 3% would optimized specificity (0.966, probability = 0.5) in the second-tier screening to exclude 54% of innocent patients, with negative predictive values of 0.93 and AUC of 0.951 (p < 0.001). The two-tier screening model jointly excluded 4.8% of innocent subjects and prioritized 40% of severe patients for polysomnography.

CONCLUSIONS

The prediction model is sufficiently accurate and feasible for large-scale population screening.

Severity of obstructive sleep apnea: correlation with clinical examination and patient perception

OBJECTIVE

To correlate clinical history, patient self-perception of obstructive sleep apnea, and physical examination with the severity of OSA.

METHODS

One hundred and two consecutive patients were prospectively enrolled over a 6-month period. All patients underwent a comprehensive history and clinical examination, nasopharyngoscopy, and an overnight-attended polysomnogram.

RESULTS

There were 65 males and 37 females with a mean age of 50.2 +/- 11.3 years (range, 24 to 76 years). The mean apnea-hypopnea index (AHI) was 37.9 +/- 27.7 (range, 0.7 to 111.2). There was a strong correlation between patient self-perception of OSA severity and AHI (r = 0.499, P < 0.0001), and the correlation with AI was 0.577 (P < 0.0001). OSA severity strongly correlated with Friedman Tongue Position grade, (r = 0.389, P < 0.0001), Friedman clinical staging, (r = 0.331, P = 0.0007). Of significance, only 6.9% of patients with mild OSA had a >50% collapse of the base of tongue region, as compared to 65.9% of patients with severe OSA.

CONCLUSION

There is good correlation between clinical examination parameters and the severity of OSA. An algorithm for surgical treatment of OSA should acknowledge both the site of obstruction and the severity of disease.

[Sleep-related breathing disorders. Sleep anamnesis questionnaire and determination of clinical results within the framework of staged diagnostics]

Sleep-related breathing disorders (SBAS) affect approximately 8% of the population of middle aged adults. At the age of 20 years, approximately 10% of the population snore, while at the age of 60 about 50% of men snore. Some 9% of middle aged women and 24% of middle aged men have an apnea hypopnea index (AHI) of >5 (number of nocturnal apnea and hypopnea per hour of sleep). Sleep apnea hypopnea syndrome is found in 2% of the women and 4% of the men, i.e. they have an AHI>5 associated with daytime sleepiness. Forms, check lists, summaries and patient-readable questionnaires have proved helpful in the evaluation of SBAS.

Screening for obstructive sleep apnea: an evidence-based analysis

Sleep disordered breathing is a spectrum of diseases that includes snoring, upper airway resistance syndrome, and obstructive sleep apnea (OSA). Obstructive sleep apnea is a common sleep disorder and is estimated to have an incidence of 24% in men and 9% in women. However, many authors believe that up to 93% of women and 82% of men with moderate to severe OSA remain undiagnosed. There is a strong link between sleep disordered breathing and hypertension, believed to be due to sleep fragmentation, intermittent hypoxemia, and increased sympathetic tone, which results in a higher mortality and morbidity rate among these patients. It is therefore desirable to attempt to diagnose all patients with OSA, to institute early treatment intervention, and to prevent development of cardiovascular complications. The gold standard for diagnosing OSA remains the attended overnight level I polysomnogram. However, in view of the limited resources, including limited number of recording beds, high cost, long waiting lists, and labor requirements, many authors have explored the use of clinical predictors or questionnaires that may help to identify higher-risk patients. Screening devices in the form of single or multiple channel monitoring systems have also been introduced and may represent an alternative method to diagnose OSA. The ideal screening device should be cheap, readily accessible, easily used with minimal instructions, have no risk or side effects to the patient, and be safe and accurate. We review a variety of clinical predictive formulae and several screening devices available for the diagnosis of OSA.

Evaluación clínica del paciente con roncopatía

INTRODUCTION

Sleep disordered breathing patients usually undergo an ENT clinical examination before any therapeutic decision is taker. This clinical examination should be predictive about the occurrence of OSAS, reproductible and should determine the sites of obstruction in the upper airways. We have evaluated the clinical ENT examination and compared it with the bibliography in order to standardize it.

MATERIALS AND METHODS

We have done the same clinical ENT examination to 181 patients. 127 had a standar polysomnography.

RESULTS

The patient's mean age was 49.6 years, the mean BMI was 29.3 kg/m2. 92.7% had an abnormal palate, 4.5% a tonsilar hipertrophy, 66.5% high Modified Mallampati scores, 60.8% were clasiffied as Fujita IIb type and 39.2% had nasal obstruction.

CONCLUSIONS

Upper airway examination is important for the assessment of chronic snoring patients. Most of them have anatomical alterations that can be represented in visual scales to make it more reproductible. The obstruction area does not predict the severity of OSAS.

Acoustic pharyngometry patterns of snoring and obstructive sleep apnea patients

OBJECTIVE

Anatomic narrowing of the pharyngeal airway increases the relative negative pressure generated during inspiration, thus affecting the dynamic behavior of the upper airway. The aim of this work was to measure pharyngeal area in snoring patients with and without obstructive sleep apnea (OSA), as categorized by polysomnography and by acoustic pharyngometry, and to analyze the different curve patterns obtained from patients of both groups.

METHODS

We examined 50 snorers who were divided into 2 groups matched for age, gender, and body mass index.

RESULTS

Mean Apnea Index (AI) in nonapneic snorers (group 1) was 4, and mean pharyngeal area was 2.41 cm(2). In snoring patients with OSA (group 2), mean AI was 25.9 with a mean pharyngeal area of 1.589 cm(2) (P < 0.001). In both groups, the dependent variable (AI) can be predicted from a linear relation with the independent variable (pharyngeal area) with normality and constant variance tests passed. In group 1, the resulting curve can be 1 of 2 types depending on the relative area of the pharyngeal segment to the velopharyngeal area. In group 2, the curve pattern can be categorized into 3 patterns depending on the possible pathology of pharyngeal obstruction.

CONCLUSION

The acoustic reflection technique is reproducible, noninvasive, and free from potential side effects. The good correlation between AI and pharyngeal area adds to the potential of acoustic pharyngometry. Careful study of the pharyngeal cross-sectional area and curve topography may give a good idea about the site of upper airway obstruction.

Obstructive sleep apnea syndrome in ambulatory surgical patients

Obstructive sleep apnea in the ambulatory surgery setting has become a more significant concern in recent years because its Identification and recognition are a critical part of preoperative patients' risk assessment. The types of surgeries that can be performed on an outpatient basis have increased and include many specialty procedures that previously were performed on an inpatient basis only. Ambulatory surgery has proven to be a cost-effective alternative for patients and physicians; however, patients in this setting often have complex surgical histories. Perioperative nurses must provide a more integrated approach to patient assessment to recognize, identify, plan, and implement a course of safe care for patients with obstructive sleep apnea. Reviewing patients' histories can help nurses identify symptoms of obstructive sleep apnea, allowing them to alert the surgical team of special requirements. Ambulatory patients with identified obstructive sleep apnea will require a planned course of care. Ambulatory care facilities should have a policy in place to ensure that safe care will be provided to patients for the entire perioperative course.

Lung volume dependence of pharyngeal cross-sectional area by acoustic pharyngometry

Pharyngeal size and the dynamic behavior of the pharynx may be important factors in the modulation of pharyngeal airflow. There are two measures of pharyngeal function: changes in pharyngeal area with lung volume and changes in pharyngeal area in response to externally applied positive pressure. Both measurements have been used for the assessment of pharyngeal function, and both reflect pharyngeal "floppiness." The aim of the present study was to examine the relationship between pharyngeal cross-sectional area, using acoustic reflection technique, and different lung volumes (tidal volume, inspiratory reserve volume, and expiratory reserve volume), to determine whether there are differences in mechanical properties of the pharynx of normal volunteers in response to changes in intrapharyngeal pressure. The acoustic technique was used to assess the pharyngeal cross-sectional area of 40 healthy volunteers (29 men and 11 women) at tidal volume, inspiratory reserve volume, and expiratory reserve volume. In men, the mean pharyngeal area at tidal volume was 3.191 cm2, the mean pharyngeal area at inspiratory reserve volume was 2.976 cm2, and the mean pharyngeal area at expiratory reserve volume was 2.975 cm2. In women, the corresponding pharyngeal area measurements were 2.832, 2.484, and 2.492 cm2. Statistical analysis of results showed that men have a larger pharyngeal cross-sectional area and the pharyngeal airways of men and women act in a similar manner in response to changes in intrapharyngeal pressure, with men having a greater change. Examination of the pharyngeal compliance by acoustic pharyngometry adds to the potential of this technique as a tool for the evaluation of the pharyngeal airway in terms of area and dynamic behavior assessment. This may be of relevance in promotion of the development of upper airway assessment in patients with obstructive sleep apnea.

Accuracy of terminology and methodology in economic analyses in otolaryngology

OBJECTIVE

Economic studies increasingly guide health care resource allocation decisions. Because rigorous adherence to accepted definitions and research techniques is critical to ensure accuracy, we evaluated the terminology and methods of otolaryngology economic analyses.

STUDY DESIGN

A total of 71 articles published from 1990 to 1999 in 6 peer-reviewed otolaryngology journals with terms such as "cost-effective" in their title or representing economic analyses were reviewed for terminology and use of established methodology guidelines.

RESULTS

Over half (35 of 66) of terms such as "cost-effective" were used incorrectly, and 60% of articles (39 of 64) confused "charge" and "cost" data. Eleven percent (7 of 64) of papers specified the perspective of their analysis. About half (17 of 30) reported a summary measure such as a cost-effectiveness ratio. Only one third (23 of 63) performed sensitivity analyses.

CONCLUSION

Adherence to accepted definitions and research methods is inconsistent, although we did note moderate improvements in making the distinction between costs and charges, defining of study perspective, and performing sensitivity analysis.

SIGNIFICANCE

Greater attention to both terminology and methodology can enhance the quality of economic analyses and ultimately improve certain resource allocation decisions.

Normal standard curve for acoustic pharyngometry

Pharyngeal size, compliance, and the dynamic behavior of the upper airway are important factors in the production of obstructive sleep apnea. Assessment of the upper airway for possible site(s) of obstruction is one of the keys to a successful management of the condition. Acoustic pharyngometry has the potential for localizing such sites, however, standardizing the operating technique and producing a standard normal curve is a prerequisite before exploring the potential of this equipment. A total number of 350 normal volunteers (271 males and 79 females) were examined by acoustic pharyngometry and a coefficient of variance of 5% to 7% was obtained from each of them. Mean and standard deviation of pharyngeal area at each point of X-axis (distance) was obtained and analyzed statistically to produce a general standard curve. Using special techniques during examination, the oropharyngeal junction and glottis were located, and thus a mapped acoustic pharyngogram was produced. Mean pharyngeal area was 3.194 cm(2) in males (SD 0.311) and 2.814 cm(2) in females (SD 0.331). Mean glottic area was 1.06 cm(2) in males (SD 0.119) and 0.936 cm(2) in females (SD 0.108). A minimal pharyngeal area is probably needed as a "golden standard" to evaluate patients with obstructive sleep apnea.

Clinical predictors of obstructive sleep apnea

OBJECTIVE

To identify physical findings that can be standardized to predict the presence and the severity of obstructive sleep apnea (OSA).

STUDY DESIGN

One hundred seventy-two patients who answered questionnaires with responses that suggested they might have OSA were included in this prospective study.

METHODS

All patients underwent a physical examination and polysomnography. The physical examination included the measurement of four parameters used by anesthesiologists to identify patients likely to have difficult intubation to determine if these same parameters predict OSA. We recorded modified Mallampati grade (MMP), tonsil size, and body mass index (BMI) and measured thyroid-mental distance (TMD) and hyoid-mental distance (HMD) in the study population.

RESULTS

When the physical findings were correlated singly with the respiratory disturbance index (RDI), we found that MMP (P < .001), tonsil size grading (P = .008), and BMI (P = .003) were reliable predictors of OSA. A greater correlation with OSA emerged when an "OSA score" was formulated by factoring the MMP, tonsil grade, and BMI grade (RDI = 7.816 x MMP + 3.988 x Tonsil Size + 4.675 x BMI - 7.544). A high score was not only predictive of OSA but also correlated well with OSA severity. Neither HMD nor TMD correlated with the severity of RDI.

CONCLUSIONS

An OSA score may help identify those patients who should have a full sleep evaluation.

Preoperative, intraoperative, and postoperative management of patients with obstructive sleep apnea syndrome

The patient with untreated, obstructive sleep apnea may present difficult or potentially life-threatening challenges to the surgical team. This is true even if the anticipated surgery is remote to the upper airway. Preoperative recognition of the obstructive apnea is essential as the first step in preventing potential complications. When recognized, intraoperative and postoperative initiative can result in a satisfactory outcome.