Predictors of Obstructive Sleep Apnea on Polysomnography after a Technically Inadequate or Normal Home Sleep Test.

STUDY OBJECTIVES: Home sleep testing (HST) is an accepted alternative to polysomnography (PSG) for diagnosing obstructive sleep apnea (OSA) in high-risk populations. Clinical guidelines recommend PSG in cases where the HST is technically inadequate (TI) or fails to establish the diagnosis of OSA in patients with high pretest probability. This retrospective study evaluated predictors of OSA on PSG within patients who had a TI or normal HST. METHODS: Electronic medical records were reviewed on 1,157 patients referred for HST at our sleep center. Two hundred thirty-eight patients had a TI or normal HST with subsequent PSG. Age, BMI, Epworth score, HST result, and PSG-based apnea-hypopnea index (AHI) were abstracted. RESULTS: Two hundred thirty-eight consecutive patients with either a normal HST (n = 127) or TI HST (n = 111) underwent subsequent PSG. Of 127 who had a normal HST, 76% had a normal PSG and 24% had OSA (23 mild, 6 moderate, 1 severe). Of 111 who had a TI HST, 29% had a normal PSG and 71% had OSA (43 mild, 19 moderate, 17 severe). Individuals younger than 50 years old with a normal HST were more likely to have a normal PSG. Older age predicted diagnosis of OSA on PSG among individuals with a TI HST. CONCLUSION: In this retrospective analysis of a clinical sample, when the HST is interpreted as normal in a younger patient population, the subsequent PSG is likewise normal in majority of the patients, although significant OSA is sometimes discovered. When a HST is read as TI, the majority of patients have OSA.

Clinical control in the dual diagnosis of obstructive sleep apnea syndrome and rhinitis: a prospective analysis.

BACKGROUND: Obstructive sleep apnea syndrome (OSAS) and allergic rhinitis (AR) are common coexisting disorders. Upper airway, specifically nasal resistance, is thought to increase during exacerbations of AR and nonallergic rhinitis (NAR), as well as in OSAS. The study objective was to determine if a correlation exists between clinical control of rhinitis and OSAS. METHODS: This prospective study followed 43 patients with concurrent OSAS and AR or NAR. OSAS was diagnosed by polysomnography, and AR or NAR was diagnosed by history, skin testing, serum-specific IgE, and total IgE levels. Measurements of control of OSAS included the Epworth Sleepiness Scale (ESS) survey and compliance with continuous positive airway pressure (CPAP) device. Measurements of rhinitis control included Assessment of Nasal Symptom Severity and Assessment of Nonnasal Symptom Severity (NSS refers to both) and Global Assessment of Nasal and Nonnasal Symptom Severity surveys (GSS). Higher NSS scores correlate with more rhinitis symptoms, whereas higher GSS scores correlate with less symptoms. RESULTS: All patients completed the study. There was a positive correlation between ESS and NSS scores (p < 0.001), inverse correlation between ESS and GSS scores (p < 0.001), inverse correlation between CPAP compliance and NSS scores (p < 0.001), and positive correlation between CPAP compliance and GSS scores (p < 0.001). There was no statistically significant difference between the AR, NAR, and AR/NAR groups. CONCLUSION: Our study showed a statistically significant positive correlation between clinical control of rhinitis symptoms and clinical control of OSAS. This study emphasizes the importance of achieving concurrent optimal control of both OSAS and AR/NAR.

Development of transcriptomic biomarker signature in human saliva to detect lung cancer.

Lung cancer is the leading cause of cancer death for both men and women worldwide. Since most of the symptoms found for lung cancer are nonspecific, diagnosis is mostly done at late and progressed stage with the consecutive poor therapy outcome. Effective early detection techniques are sorely needed. The emerging field of salivary diagnostics could provide scientifically credible, easy-to-use, non-invasive and cost-effective detection methods. Recent advances have allowed us to develop discriminatory salivary biomarkers for a variety of diseases from oral to systematic diseases. In this study, salivary transcriptomes of lung cancer patients were profiled and led to the discovery and pre-validation of seven highly discriminatory transcriptomic salivary biomarkers (BRAF, CCNI, EGRF, FGF19, FRS2, GREB1, and LZTS1). The logistic regression model combining five of the mRNA biomarkers (CCNI, EGFR, FGF19, FRS2, and GREB1) could differentiate lung cancer patients from normal control subjects, yielding AUC value of 0.925 with 93.75 % sensitivity and 82.81 % specificity in the pre-validation sample set. These salivary mRNA biomarkers possess the discriminatory power for the detection of lung cancer. This report provides the proof of concept of salivary biomarkers for the non-invasive detection of the systematic disease. These results poised the salivary biomarkers for the initiation of a multi-center validation in a definitive clinical context.

Contralateral decubitus positioning enhances computed tomographic angiographic evaluation of pulmonary vasculature in a patient with a pulmonary arteriovenous malformation.

Computed tomographic pulmonary angiography has become the diagnostic procedure of choice in patients suspected of having a pulmonary embolus. However, intrapulmonary shunting of blood in a variety of pathologic conditions can cause suboptimal opacification of the pulmonary arterial circulation and result in a suboptimal or even nondiagnostic study. Radiologists should be aware of these conditions and be familiar with positioning techniques to minimize such shunting. We report a patient suspected of having pulmonary embolism, in whom a preexisting unilateral arteriovenous malformation prevented adequate evaluation of the pulmonary circulation. Positioning the patient in the contralateral decubitus position significantly enhanced image quality.

Prevalence of comorbid obstructive sleep apnea and metabolic syndrome: syndrome Z and maxillofacial surgery implications.

PURPOSE: To determine the prevalence of the recently identified syndrome Z (SZ), which is the co-occurrence of obstructive sleep apnea (OSA; hypoxia, systemic and pulmonary hypertension, nocturnal arrhythmias) and metabolic syndrome (MetS; increased abdominal girth, hypertriglyceridemia, decreased high-density lipoprotein, hypertension, increased fasting glucose), which places the surgical patient at heightened risk of perioperative complications (myocardial infarction, stroke, pneumonia, wound infection). MATERIALS AND METHODS: Electronic medical records of 296 male veterans were assessed for the presence of SZ using the American Academy of Sleep Medicine definition of OSA and a modified Adult Treatment Panel III definition of MetS, where obesity was defined by a body mass index of at least 30 kg/m(2) rather than by waist circumference. RESULTS: SZ was diagnosed in 59% of patients. These individuals commonly exhibited severe OSA and least commonly mild OSA. The more severe the OSA, the more likely (60%) that patients manifested moderate (4 risk markers) or severe (5 risk markers) MetS. Furthermore, with increasing apnea-hypopnea index values, the more severe were the MetS elements. CONCLUSIONS: The results of this study demonstrate the high prevalence rate of MetS in patients with OSA seeking treatment. Given the risk of perioperative complications, it is suggested that all patients scheduled for maxillofacial surgical procedures to treat OSA be evaluated for SZ.

Anxiety during respirator use: comparison of two respirator types.

Anxiety may interfere with proper respirator use. This study directly compares the effect of two types of respirators--elastomeric half-face mask with dual-cartridges (HFM) and N95 filtering facepiece--on anxiety levels. Twelve volunteers with normal or mildly impaired respiratory conditions performed a series of simulated work tasks using the HFM and N95 on different days. The State-Trait Anxiety Inventory (STAI) measured state anxiety (SA) before and during respirator use. STAI also measured trait anxiety (TA), a stable personal characteristic. The effect of the respirator was measured as the difference between SA pre-use and during use. Work with HFM was associated with an increase in SA (2.92 units, p < .01), whereas work with the N95 had no observed effect. Anxiety should be considered in the selection of the best respirator for a user. Impact on anxiety should be considered for respirator design and certification purposes, particularly if the device is to be widely used in workplace and community settings.

Respirator impact on work task performance.

OBJECTIVE: Respirators are used to maintain work performance and protect against inhaled toxins. The study compared the effects of two commonly used respirator classes--dual cartridge half face mask (HFM) and filtering face piece (N95)--upon work productivity. METHODS: 107 volunteers performed eight simulated work tasks when using the HFM and N95 respirators. Tasks included several body positions, exertion levels, and concentration requirements. Objective measures of accuracy and speed were developed for each task. Scores for each task were based on the subject's rank among all subjects. RESULTS: All subjects were capable of performing the tasks. There were no statistically significant differences between respirator types in either task performance metric. CONCLUSIONS: Productivity impact can be measured effectively and should be considered as part of respirator design testing and when selecting the optimal respirator for a worker.

Subjective response to respirator type: effect of disease status and gender.

OBJECTIVE: To assess the effect of respirator type and user characteristics (eg, health status) on the subjective response to respirator use. METHODS: The subjective responses for multiple domains were evaluated in 104 volunteers performing work tasks in a simulated work environment. Each used a dual cartridge half face mask and a filtering facepiece (N95) respirator. The study population was recruited to include four groups (normal respiratory status, mild asthma, chronic obstructive pulmonary disease, or chronic rhinitis). Mixed model regression analyses determined the effects of respirator type, disease, gender, and age. RESULTS: Half face mask produced more adverse subjective response than the N95 for most scales. There were significant interactions such that disease status modified the effect of respirator type. In general, women reported greater adverse ratings than did men. CONCLUSIONS: The effect of respirator type depends on disease status. Respirator design evaluation panels should include persons with mild respiratory disease.

Respirator physiologic impact in persons with mild respiratory disease.

OBJECTIVE: To assess whether mild respiratory disease affects physiologic adaptation to respirator use. METHODS: The study compared the respiratory effects of dual cartridge half face mask and filtering facepeice (N95) respirators while performing simulated-work tasks. Subjects with mild chronic obstructive pulmonary disease (n = 14), asthma (n = 42), chronic rhinitis (n = 17), and normal respiratory status (n = 24) were studied. Mixed model regression analyses determined the effects of respirator type, disease status, and the respirator-disease interactions. RESULTS: Respirator type significantly affected several physiologic measures. Respirator type effects differed among disease categories as shown by statistically significant interaction terms. Respiratory timing parameters were more affected than ventilatory volumes. In general, persons with asthma showed greater respirator-disease interactions than chronic obstructive pulmonary disease, rhinitis, or healthy subjects. CONCLUSIONS: The effects of respirator type differ according to the category of respiratory disease.

Multidomain subjective response to respirator use during simulated work.

OBJECTIVE: : Evaluate subjective tolerance to respirator use outside of traditional industrial settings by users including persons with mild respiratory impairment. METHODS: : The response to respirator use (half face mask dual cartridge and N95) was measured during eight types of work activities as well as in an exercise laboratory setting. The 43 research subjects included persons with mild respiratory impairments. Multiple domains of subjective response were evaluated. RESULTS: : Mixed model regression analyses assessing the effect of respirator type and task type showed: 1) most tolerated respirator use well; 2) half face mask respirators typically had greater adverse impact than N95 types; 3) multiple subjective outcomes, rather than only comfort/breathing impact, should be measured; and 4) rated subjective impact during work activities is less than in exercise laboratory settings. CONCLUSIONS: : The results suggest that respirator use may be feasible on a widespread basis if necessary in the face of epidemic or terror concerns.

Respirator physiological effects under simulated work conditions.

This study compared the physiological impacts of two respirator types in simulated work conditions. Fifty-six subjects included normal volunteers and persons with mild respiratory impairments (chronic rhinitis, mild COPD, and mild asthma). Respiratory parameters and electrocardiogram were measured using respiratory inductive plethysmography while performing eight work tasks involving low to moderate exertion using two respirators: (1) a dual cartridge half face mask (HFM) respirator, and (2) the N95. Mixed model regression analyses evaluating the effect of task and respirator type showed that task affected tidal volume, minute ventilation, breathing frequency and heart rate; all were greater in heavier tasks. Although respirator type did not affect respiratory volume parameters and flow rates, the HFM led to increase in the inspiratory time, reduction of the expiratory time, and increase in the duty cycle in comparison with the N95. The magnitude of differences was relatively small. The results suggest that most individuals, including persons with mild respiratory impairments, will physiologically tolerate either type of respirator at low to moderate exertion tasks. However, because effective protection depends on proper use, differences in subjective effect may have greater impact than physiological differences. Using respirators may be feasible on a widespread basis if necessary for maintaining essential services in the face of widespread concern about an infectious or terrorist threat.

Efficacy of pursed-lips breathing: a breathing pattern retraining strategy for dyspnea reduction.

PURPOSE: Breathing pattern retraining is frequently used for exertional dyspnea relief in adults with moderate to severe chronic obstructive pulmonary disease. However, there is contradictory evidence to support its use. The study objective was to compare 2 programs of prolonging expiratory time (pursed-lips breathing and expiratory muscle training) on dyspnea and functional performance. METHODS: A randomized, controlled design was used for the pilot study. Subjects recruited from the outpatient pulmonary clinic of a university-affiliated Veteran Affairs healthcare center were randomized to: 1) pursed-lips breathing, 2) expiratory muscle training, or 3) control. Changes over time in dyspnea [modified Borg after 6-minute walk distance (6MWD) and Shortness of Breath Questionnaire] and functional performance (Human Activity Profile and physical function scale of Short Form 36-item Health Survey) were assessed with a multilevel modeling procedure. Weekly laboratory visits for training were accompanied by structured verbal, written, and audiovisual instruction. RESULTS: Forty subjects with chronic obstructive pulmonary disease [age = 65 +/- 9 (mean +/- standard deviation) years, forced expiratory volume 1 second/forced vital capacity % = 46 +/- 10, forced expiratory volume 1 second % predicted = 39 +/- 13, body mass index = 26 +/- 6 kg/m, inspiratory muscle strength = 69 +/- 22 cm H2O, and expiratory muscle strength (PEmax) = 102 +/- 29 cm H2O] were enrolled. No significant Group x Time difference was present for PEmax (P = .93). Significant reductions for the modified Borg scale after 6MWD (P = .05) and physical function (P = .02) from baseline to 12 weeks were only present for pursed-lips breathing. CONCLUSION: Pursed-lips breathing provided sustained improvement in exertional dyspnea and physical function.

Idiopathic pulmonary fibrosis: evaluation with positron emission tomography.

BACKGROUND: The pathogenesis of interstitial lung disease remains under investigation, but may be related to increased inflammatory or cellular activity. This activity may be detectable with physiologic imaging. OBJECTIVES: We investigated the role of physiologic imaging using (18)F-2-fluoro-2-deoxy-D-glucose ((18)FDG)-positron emission tomography (PET) scans in idiopathic pulmonary fibrosis (IPF). METHODS: Seven male patients with histologically confirmed IPF underwent (18)FDG-PET scans. Scans were analyzed qualitatively and interpreted as positive or negative. Patients also underwent pulmonary function tests and computed tomography (CT) scans. RESULTS: The average total lung capacity was 71 +/- 22% predicted (mean +/- SD) and diffusing capacity for carbon monoxide was 44 +/- 14% predicted. All had changes consistent with IPF on chest CT and 2 patients had ground glass attenuation. Six of seven patients (86%) had a positive (18)FDG-PET scan. Changes in the (18)FDG-PET scan were seen in 1 patient corresponding to changes in clinical status. CONCLUSIONS: Our findings suggest that (18)FDG-PET scans may be helpful in the evaluation of IPF. Increased activity suggests active disease and changes in response to therapy.

Usefulness of the human activity profile, a functional performance measure, in people with chronic obstructive pulmonary disease.

PURPOSE: To further evaluate the usefulness of the Human Activity Profile (HAP) as a functional performance measure for those with chronic obstructive pulmonary disease (COPD). METHODS: Phase 1. The sample consisted of 53 outpatients (51 male) with stable COPD (forced expiratory volume in 1 second% predicted (FEV1% pred) = 38 +/- 14 (mean +/- standard deviation) at a university-affiliated veterans affairs medical center. Variables were functional performance (HAP Maximal Activity Score [MAS], HAP Adjusted Activity Score [AAS]), dyspnea (modified Borg category-ratio scale and Shortness of Breath Questionnaire [SOBQ]), and exercise capacity (6-minute walk distance [6MWD]). Phase 2. The HAP was administered pre-post pulmonary rehabilitation in 48 (14 male) outpatients with stable COPD (FEV1% pred = 35 +/- 15) at an outpatient pulmonary rehabilitation program at a large private hospital. RESULTS: Phase 1. Scores for MAS and AAS were, respectively, 62 +/- 12 and 44 +/- 15. The 6MWD, modified Borg, and SOBQ were, respectively, 1055 +/- 372 ft, 4.1 +/- 1, and 64.4 +/- 22 ft. Correlations of the 6MWD and dyspnea scores with the AAS were strong and explained 40% of the AAS variation. Phase 2. The baseline MAS and AAS scores were 55 +/- 14 and 42 +/- 15, respectively, with 29/48 (60%) classified as "low fitness" on the basis of the AAS. Post-rehabilitation, there was significant improvement in the AAS score (48 +/- 13) and significant reduction for those classified as "low fitness." CONCLUSIONS: The utility of the HAP as a measure of functional performance improvement in COPD is supported by its relationship with both 6MWD and dyspnea and its responsiveness to pulmonary rehabilitation.

Pulmonary hypertension in men with thyrotoxicosis.

Thyrotoxicosis has a myriad of respiratory symptoms including dyspnea. Pulmonary hypertension may contribute to the respiratory symptoms of thyrotoxicosis, but is often unrecognized. We describe 3 male patients with thyrotoxicosis and associated pulmonary hypertension. Case reports of an additional 15 patients are also reviewed. In patients with thyrotoxicosis and pulmonary hypertension, treatment of thyrotoxicosis alone is associated with improvement in pulmonary hypertension. Previous reports have consisted of mostly female patients, but we report 3 men. When all cases are considered, the typical patient is female (10/14 = 71%), middle-aged (48 years), with mean pulmonary artery systolic pressures improving from 56 to 32 mm Hg with treatment. Autoantibodies were detected in 10/14 (71%) patients. The response to treatment (medical or surgical) of thyrotoxicosis supports the hypothesis that hyperthyroidism is either a cause of pulmonary hypertension, or a factor that may unmask pulmonary hypertension. Recognition is important since treatment and response are very different compared to other patients with pulmonary hypertension. This association may not be readily considered in men, since most reports have been of women.

Racial differences pertaining to a belief about lung cancer surgery: results of a multicenter survey.

BACKGROUND: Patients at the Philadelphia Veterans Affairs Medical Center frequently voice concern that air exposure during lung cancer surgery might cause tumor spread. Several African-American patients asserted that this belief was common in the African-American community. OBJECTIVE: To assess the prevalence of the belief that air exposure during lung cancer surgery might cause tumor spread and gauge the influence of this belief on the willingness of African-American and white patients to have lung cancer surgery. DESIGN: Prospective questionnaire survey. SETTING: Philadelphia Veterans Affairs Medical Center and University of Pennsylvania, Philadelphia, Pennsylvania; Los Angeles Veterans Affairs Medical Center, Los Angeles, California; and Medical University of South Carolina, Charleston, South Carolina. PATIENTS: 626 consecutive patients in pulmonary and lung cancer clinics. MEASUREMENTS: None. RESULTS: 38% of patients (61% of whom were African American and 29% of whom were white) stated that they believe air exposure at surgery causes tumor spread. The most significant predictor of belief was African-American race (odds ratio, 3.5 [95% CI, 1.9 to 6.5]), even after controlling for other relevant variables in a multivariable analysis. Nineteen percent of African Americans stated that this belief was a reason for opposing surgery, and 14% would not accept their physicians' assertion that the belief is false. These rates were also statistically significantly higher among African-American than white patients. CONCLUSIONS: Belief in accelerated tumor spread at surgery is prevalent among general pulmonary outpatients and lung cancer clinic patients facing lung surgery, particularly among African-American patients. Our findings may pertain to key racial disparities in lung cancer surgery and survival rates and suggest that culturally sensitive physician training or outreach programs directed at disparate beliefs and attitudes may help to address racial discrepancies in health care outcomes.