Metoprolol for the Prevention of Acute Exacerbations of COPD.

BACKGROUND: Observational studies suggest that beta-blockers may reduce the risk of exacerbations and death in patients with moderate or severe chronic obstructive pulmonary disease (COPD), but these findings have not been confirmed in randomized trials. METHODS: In this prospective, randomized trial, we assigned patients between the ages of 40 and 85 years who had COPD to receive either a beta-blocker (extended-release metoprolol) or placebo. All the patients had a clinical history of COPD, along with moderate airflow limitation and an increased risk of exacerbations, as evidenced by a history of exacerbations during the previous year or the prescribed use of supplemental oxygen. We excluded patients who were already taking a beta-blocker or who had an established indication for the use of such drugs. The primary end point was the time until the first exacerbation of COPD during the treatment period, which ranged from 336 to 350 days, depending on the adjusted dose of metoprolol. RESULTS: A total of 532 patients underwent randomization. The mean (±SD) age of the patients was 65.0±7.8 years; the mean forced expiratory volume in 1 second (FEV1) was 41.1±16.3% of the predicted value. The trial was stopped early because of futility with respect to the primary end point and safety concerns. There was no significant between-group difference in the median time until the first exacerbation, which was 202 days in the metoprolol group and 222 days in the placebo group (hazard ratio for metoprolol vs. placebo, 1.05; 95% confidence interval [CI], 0.84 to 1.32; P = 0.66). Metoprolol was associated with a higher risk of exacerbation leading to hospitalization (hazard ratio, 1.91; 95% CI, 1.29 to 2.83). The frequency of side effects that were possibly related to metoprolol was similar in the two groups, as was the overall rate of nonrespiratory serious adverse events. During the treatment period, there were 11 deaths in the metoprolol group and 5 in the placebo group. CONCLUSIONS: Among patients with moderate or severe COPD who did not have an established indication for beta-blocker use, the time until the first COPD exacerbation was similar in the metoprolol group and the placebo group. Hospitalization for exacerbation was more common among the patients treated with metoprolol. (Funded by the Department of Defense; BLOCK COPD ClinicalTrials.gov number, NCT02587351.).

Continuous positive airway pressure usage in hospitalized patients with known obstructive sleep apnea: discrepancy between admission pressure settings and laboratory-determined settings.

PURPOSE: The aim of this study was to determine the frequency and predictors of correctly initiated continuous positive airway pressure (CPAP) settings on the initial night of hospitalization in patients with known obstructive sleep apnea-hypopnea syndrome (OSAHS). METHODS: Hospital records of all patients who underwent an outpatient therapeutic polysomnogram (PSG) at our institution between January 2005 and December 2010 were retrospectively reviewed. Data collected included initial CPAP settings on hospital admission, latency to hospitalization (from sleep study), hospital length of stay, demographic variables, and PSG variables. RESULTS: One hundred seventy subjects were included in the analysis: 51 % were male, average age (±SD) was 55.3 ± 13.7 years, and body mass index was 43.7 ± 10.4 kg/m2. OSAHS was generally severe (apnea-hypopnea index (AHI) 52.8 ± 37.3 event/h). Mean CPAP setting during in-laboratory titration was 11.1 ± 3.1 cm H2O and during the first night of hospitalization was 9.5 ± 2.8 cm H2O (p < 0.0001). Of 170 subjects, only 71 (42 %) received the correct laboratory-derived CPAP setting on the first night of hospitalization. In a multivariable logistic regression analysis, higher body mass index (BMI), lower CPAP level determined during PSG, and shorter latency (months) between PSG and hospitalization were associated with receiving the correct CPAP setting during the first night of hospitalization: Each 1 kg/m2 increase in BMI was associated with a 7 % increase odds of receiving the correct CPAP setting during the first night of hospitalization (OR 1.07, 95 % CI 1.02-1.12), while each 1 cm H2O increase in CPAP during PSG and each 1 month longer latency between PSG and hospitalization was associated with a 15 and 7 %, respectively, decrease in the odds of receiving the correct CPAP setting during the first night of hospitalization (CPAP OR 0.85, 95 % CI 0.74-0.97 and latency OR 0.93, 95 % CI 0.90-0.97). There was no in-hospital mortality, and correct CPAP settings did not affect hospital length of stay. CONCLUSIONS: Among patients admitted to the hospital, a correct, laboratory-derived CPAP setting is infrequently prescribed during the first night of hospitalization. Predictors for correctly ordering CPAP include latency from the time of in-laboratory CPAP titration, BMI, and laboratory-derived CPAP level.

The association of subjective and objective sleep measures with chronic tinnitus.

STUDY OBJECTIVES: Poor sleep is a prevalent complaint in the population with chronic tinnitus, but the relationship between the two is not well-characterized. The objective of this study was to understand how subjective and objective measures of sleep compare in patients with or without chronic tinnitus. METHODS: This prospective cohort study included consecutive adult patients who presented to a sleep laboratory between January 19, 2017, and January 10, 2020. All patients underwent an in-laboratory nocturnal polysomnogram and filled out questionnaires including the Pittsburgh Sleep Quality Index (PSQI), Tinnitus Screener, and Tinnitus Handicap Inventory, among others. RESULTS: The study included 1,968 participants, out of which 284 (14.4%) reported chronic tinnitus. Patients with chronic tinnitus were younger (51.6 years vs 54.1 years; P < .05) and more likely female (16.4% vs 11.7%; P < .005). They demonstrated worse subjective sleep quality (PSQI: 11.3 vs 9.5; P < .0005) and increased sleepiness (Epworth Sleepiness Scale: 9.8 vs 8.6; P < .005). In the objective sleep parameters only the total sleep time was increased in chronic tinnitus (311.5 vs 294.5 minutes; P < .05) and total arousals were decreased (41.7 vs 47; P < .005). Sleep stage N3 was higher in those with chronic tinnitus (14.9% vs 13.0%; P < .05). In multivariable analyses, as PSQI increases the odds of chronic tinnitus increases. This effect was modified by age: In those younger than 55 years of age, the odds of the presence of chronic tinnitus was 1.10 (95% confidence interval, 1.03, 1.17) times higher as PSQI increased. CONCLUSIONS: Chronic tinnitus is associated with significant changes in qualitative sleep (higher PSQI) but no major differences in quantitative sleep measures were observed. CITATION: Weingarten JA, Islam A, Dubrovsky B, Gharanei M, Coelho DH. The association of subjective and objective sleep measures with chronic tinnitus. J Clin Sleep Med. 2024;20(3):399-405.

Pulmonary hypertension predicts higher mortality in patients admitted with severe COVID-19 infection.

Objective: Patients with underlying conditions are predicted to have worse outcomes with COVID-19. A strong association between baseline cardiovascular disease and COVID-19-related mortality has been shown by a number of studies. In the current retrospective study, we aim to identify whether patients with pulmonary hypertension have worse outcomes compared with patients without pulmonary hypertension. Methods: Data from patients of ⩾18 years of age with COVID was retrospectively collected and analyzed (n = 679). Patients who underwent transthoracic echocardiography, at the discretion of the medical team, were identified and the transthoracic echocardiography was reviewed for the presence of pulmonary hypertension. Patient health parameters and outcomes were measured and statistically analyzed. Results: Of 679 consecutive patients identified with a diagnosis of COVID-19, 57 underwent transthoracic echocardiography, 32 of which were found to have pulmonary hypertension. Patients who underwent transthoracic echocardiography had a significantly higher intensive care unit admission rate (73.7% versus 25.4%, p < 0.001) and increased presence of acute respiratory distress syndrome (63.2% versus 21.6%, p > 0.001). These patients had longer intensive care unit length of stay, longer mechanical ventilation time, longer hospital length of stay, and a significantly higher mortality rate when compared to those not undergoing transthoracic echocardiography (59.7% versus 32.3%, p < 0.001). Among patients who underwent transthoracic echocardiography, those with pulmonary hypertension had significantly higher mortality compared to those without pulmonary hypertension (80% versus 43.8%, p < 0.01). Conclusion: COVID-19 in patients with pulmonary hypertension was associated with high in-hospital mortality even when adjusted for confounding factors. A number of mechanisms have been proposed for the worse outcomes in patients with pulmonary hypertension and right ventricular dysfunction, including right ventricle overload and indirect pro-inflammatory cytokine storm. Further, large-scale studies are required to evaluate the impact of right ventricular dysfunction in COVID-19 patients and to elucidate the associated mechanisms.

The Critical Role of the Adipocytokine NOV in Obstructive Sleep Apnea Induced Cardiometabolic Dysfunction: A Review.

Obstructive sleep apnea (OSA) is highly prevalent and associated with oxidative stress, chronic inflammation, and adverse cardiovascular consequences. The comorbid condition of obesity remains epidemic. Both obesity and OSA are highly comorbid in patients with cardiovascular disease including atrial fibrillation, resistant hypertension, congestive heart failure, and coronary artery disease. Patients with these preexisting cardiovascular conditions should be screened for OSA with a low threshold to treat, even if OSA severity is mild. Nephroblastoma overexpressed (NOV/CCN3) protein has been identified in multiple chronic inflammatory states, most notably in obesity and more recently in OSA, even in the absence of obesity. As such, NOV may represent an important biomarker for oxidative stress in OSA and may lead to a deeper understanding of the relationship between OSA and its clinical sequelae.

Cost-Effectiveness of Continuous Positive Airway Pressure Therapy Versus Other Treatments of Obstructive Sleep Apnea.

Obstructive sleep apnea (OSA) is a common disorder that is increasing in prevalence, both in the United States and worldwide. Continuous positive airway pressure (CPAP), the gold-standard treatment for OSA, is cost-effective from both a payer and societal perspective. Alternative treatments of OSA, including oral appliance therapy, various surgeries, and hypoglossal nerve stimulation have also been evaluated from a cost-effectiveness perspective although results are less consistent. Some studies directly compare these alternative therapies with CPAP. This review will discuss the available literature for cost-effectiveness analysis in the treatment of OSA.

The Association of Nephroblastoma Overexpressed (NOV) and Endothelial Progenitor Cells with Oxidative Stress in Obstructive Sleep Apnea.

OBJECTIVE: Obstructive sleep apnea (OSA) is a sleep disorder characterized by intermittent hypoxia, chronic inflammation, and oxidative stress and is associated with cardiometabolic disease. Several biological substrates have been associated with OSA such as nephroblastoma overexpressed (NOV), endothelial progenitor cells (EPC), and circulating endothelial cells (CEC). Few studies have looked at the association of NOV with OSA while the EPC/CEC relationships with OSA are unclear. In this study, we hypothesize that (1) NOV is associated with the severity of OSA independent of BMI, identifying a protein that may play a role in the biogenesis of OSA complications, and (2) EPCs and CECs are also associated with the severity of OSA and are biomarkers of endothelial dysfunction in OSA. METHODS: 61 subjects underwent overnight polysomnography (PSG), clinical evaluation, and blood analysis for NOV, EPC, CEC, interleukin 6 (IL-6), and other potential biomarkers. RESULTS: NOV and EPCs were independently associated with the oxygen desaturation index (ODI) after adjusting for potential confounders including body mass index (BMI), age, and sex (NOV p = 0.032; EPC p = 0.001). EPC was also independently associated with AHI after adjusting for BMI, age, and sex (p = 0.017). IL-6 was independently associated with AHI, but not with ODI. CONCLUSION: NOV and EPC levels correlate with the degree of OSA independent of BMI, indicating that these biomarkers could potentially further elucidate the relationship between OSA patients and their risk of the subsequent development of cardiovascular disease.

Fluid Response Evaluation in Sepsis Hypotension and Shock: A Randomized Clinical Trial.

BACKGROUND: Fluid and vasopressor management in septic shock remains controversial. In this randomized controlled trial, we evaluated the efficacy of dynamic measures (stroke volume change during passive leg raise) to guide resuscitation and improve patient outcome. RESEARCH QUESTION: Will resuscitation that is guided by dynamic assessments of fluid responsiveness in patients with septic shock improve patient outcomes? STUDY DESIGN AND METHODS: We conducted a prospective, multicenter, randomized clinical trial at 13 hospitals in the United States and United Kingdom. Patients presented to EDs with sepsis that was associated hypotension and anticipated ICU admission. Intervention arm patients were assessed for fluid responsiveness before clinically driven fluid bolus or increase in vasopressors occurred. The protocol included reassessment and therapy as indicated by the passive leg raise result. The control arm received usual care. The primary clinical outcome was positive fluid balance at 72 hours or ICU discharge, whichever occurred first. RESULTS: In modified intent-to-treat analysis that included 83 intervention and 41 usual care eligible patients, fluid balance at 72 hours or ICU discharge was significantly lower (-1.37 L favoring the intervention arm; 0.65 ± 2.85 L intervention arm vs 2.02 ± 3.44 L usual care arm; P = .021. Fewer patients required renal replacement therapy (5.1% vs 17.5%; P = .04) or mechanical ventilation (17.7% vs 34.1%; P = .04) in the intervention arm compared with usual care. In the all-randomized intent-to-treat population (102 intervention, 48 usual care), there were no significant differences in safety signals. INTERPRETATION: Physiologically informed fluid and vasopressor resuscitation with the use of the passive leg raise-induced stroke volume change to guide management of septic shock is safe and demonstrated lower net fluid balance and reductions in the risk of renal and respiratory failure. Dynamic assessments to guide fluid administration may improve outcomes for patients with septic shock compared with usual care. CLINICAL TRIAL REGISTRATION: NCT02837731.

Quantification of single-breath underestimation of lung volume in emphysema.

The extent to which a single breath measurement represents available gas dilutional as well as compressible thoracic volume in emphysema patients has not been quantified. We therefore measured single breath (TLCSB) and rebreathe helium dilution (TLCRB), and plethysmographic lung volume (TLCpleth), in fifty-five outpatients with clinical and radiographic emphysema, and in twenty-one normal controls. Among emphysema patients, TLCSB increasingly underestimated both TLCpleth and TLCRB as FEV1% predicted decreased (p for interaction=0.001 for both) by a mean of 1.7 l for TLCRB (p<0.001) and 2.2l for TLCpleth (p<0.001). In contrast, TLCRB underestimated TLCpleth by a mean of 0.5l (p<0.001) regardless of FEV1% (p for interaction=0.25). TLCSB, TLCRB, and TLCpleth showed strong agreement among normal subjects. We conclude that TLCSB underestimates available gas dilutional and compressible lung volume as physiologic emphysema severity increases. In contrast, TLCRB and TLCpleth show closer agreement which is unaffected by physiologic emphysema severity.

Positive Expiratory Pressure Therapy With And Without Oscillation And Hospital Length Of Stay For Acute Exacerbation Of Chronic Obstructive Pulmonary Disease.

Introduction: Pharmacologic management of acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is well-established. Our aim in the current study is to determine if therapy with a positive expiratory pressure (PEP) device with or without an oscillatory mechanism (OM) in addition to standard care results in a reduction in hospital length of stay (LOS) among patients hospitalized for AECOPD. Methods: Two studies were performed and are reported here. Study 1: Patients admitted with AECOPD and sputum production were enrolled in a prospective trial comparing PEP therapy versus Oscillatory PEP (OPEP) therapy. Study 2: A retrospective historical cohort, matched in a 2 to 1 manner by age, gender, and season of admission, was compared with the prospectively collected data to determine the effect of PEP ± OM versus standard care on hospital LOS. Results: In the prospective trial (Study 1; 91 subjects), median hospital LOS was 3.2 (95% CI 3.0-4.3) days in the OPEP group and 4.8 (95% CI 3.9-6.1) days in the PEP group (p=0.16). In fully adjusted models comparing the prospective trial data with the retrospective cohort (Study 2; 182 subjects), cases had a median hospital LOS of 4.2 days (95% CI 3.8-5.1) versus 5.2 days (95% CI 4.4-6.0) in controls, consistent with a shorter hospital LOS with adjunctive PEP±OM therapy versus standard care (p=0.04). Conclusion: Adjunctive therapy with a PEP device versus standard care may reduce hospital LOS in patients admitted for AECOPD. Although the addition of an OM component to PEP therapy suggests a further reduction in hospital LOS, comprehensive multicenter randomized controlled trials are needed to confirm these findings. Clinical trial registration number: NCT03094806.

Oxidized HDL, Adipokines, and Endothelial Dysfunction: A Potential Biomarker Profile for Cardiovascular Risk in Women with Obesity.

OBJECTIVE: High BMI predicts adverse cardiovascular outcomes and positively correlates with increased levels of adipokines. The relationship among BMI, IL-6, TNFα, adiponectin, and oxidized high-density lipoprotein (Ox-HDL) with circulating endothelial cells (CECs) and endothelial progenitor cells (EPCs) has not been well studied. Elevated CEC levels have been described in both humans and mice with obesity and diabetes. Ox-HDL has been shown to be a potent driver of adipogenesis in vivo and in vitro. In this study, elevated BMI was examined in 2 groups of women studied in Brooklyn, New York, and Huntington, West Virginia, respectively. METHODS: Twenty-six females with obesity and five lean controls without overt cardiovascular disease were enrolled, 13 from Huntington and 13 from Brooklyn. Cytokine levels, EPCs, and CECs were determined. RESULTS: Females with obesity had elevated levels of leptin, IL-6, and Ox-HDL, increased CEC levels, and decreased EPC and adiponectin levels (all P < 0.01). The Ox-HDL levels were higher in women from Brooklyn versus Huntington (P < 0.01), possibly from higher TNFα levels in Brooklyn or higher adiponectin levels in Huntington. Seventy-five percent of the variance in Ox-HDL levels could be predicted in this population (P < 0.01). CONCLUSIONS: This study reveals a unique inflammatory biomarker profile in females with obesity.

The association of NOV/CCN3 with obstructive sleep apnea (OSA): preliminary evidence of a novel biomarker in OSA.

Obstructive sleep apnea (OSA) has a strong association with cardiovascular and metabolic abnormalities, although the mechanism driving this association is not well established. NOV/CCN3, a multifunctional extracellular matrix protein, may play a mechanistic and/or prognostic role in these associations. We hypothesized that patients with OSA, which primarily affects obese individuals, will have increased levels of NOV, and that NOV can serve as a biomarker in patients to predict OSA as well as metabolic and cardiac risk. Ten morbidly obese and 10 healthy lean subjects underwent overnight polysomnography (PSG) and clinical evaluation. Blood samples were analyzed for NOV levels, adiponectin and IL-6. OSA was found in nine obese subjects and three lean subjects. NOV levels were significantly higher in the OSA vs. no OSA group (2.1 ± 0.9 vs. 1.3 ± 0.8, p < 0.03). NOV levels were significantly higher in the obese vs. lean group (2.2 ± 0.3 vs. 1.4 ± 0.2-fold change, p < 0.03). Among lean subjects, NOV levels were significantly higher in the OSA vs. no OSA group (2.1 ± 0.9 vs. 1.0 ± 0.4, p < 0.05). NOV and AHI were positively correlated (ρ = 0.49, p = 0.033). IL-6 and adiponectin differences in obese vs. lean and OSA vs. no OSA were consistent with an inflammatory phenotype in obese subjects and OSA subjects. NOV is a novel biomarker of the presence and severity of OSA and a potential marker of future cardiovascular and metabolic disease in OSA patients.

High-frequency percussive ventilation in cardiac surgery patients failing mechanical conventional ventilation.

OBJECTIVES: Failure of mechanical conventional ventilation (MCV) after cardiac surgery portends a dismal prognosis, with extracorporeal membrane oxygenation frequently utilized as a salvage therapy. We describe our experience with high-frequency percussive ventilation (HFPV) as a rescue therapy for hypoxaemia refractory to MCV after cardiac surgery. METHODS: In a 6-year retrospective analysis from 2009 to 2015, we identified 16 subjects who required HFPV after cardiac surgery. Data regarding demographics, intraoperative details, postoperative ventilatory settings including length of time on HFPV and postoperative outcomes were collected. The primary outcome was improvement in oxygenation as measured by pre- and post-HFPV partial pressures of oxygen (pO2) and ratio of pO2 to fraction of inspired oxygen (P/F ratio). RESULTS: Sixteen patients required HFPV after cardiac surgery. Operative procedures included coronary artery bypass surgery (n = 6), aortic aneurysm or dissection repair (n = 5), valve with bypass surgery (n = 2), aortic valve replacement (n = 2) and extracorporeal membrane oxygenation (n = 1). Median pO2 increased from 61 to 149.5 mmHg (P < 0.001) and the median P/F ratio improved from 62 to 169 (P < 0.001). The improvement in pO2 and P/F ratio was durable at 24 h whether the patient was returned to MCV (n = 4) or remained on HFPV (n = 12) with pO2 and P/F ratio increasing from 61 to 104 mmHg (P < 0.001) and from 62 to 193.5 (P < 0.001), respectively. Survival to discharge was 81%. CONCLUSIONS: In our cohort of cardiac surgical patients, HFPV was successfully utilized as a rescue therapy, obviating the need for extracorporeal membrane oxygenation. Although further studies are warranted, HFPV should be considered in cardiac surgical patients failing MCV.

Polysomnographic Measurement of Sleep Duration and Bodily Pain Perception in the Sleep Heart Health Study.

STUDY OBJECTIVES: To determine whether total sleep time (TST) and specific sleep stage duration are associated with bodily pain perception and whether sex, age, or subjective sleepiness modifies this relationship. METHODS: Data from adults ages 39-90 y (n = 5,199) who took part in the Sleep Heart Health Study Exam 1 were analyzed. TST, rapid eye movement (REM) sleep time, and slow wave sleep (SWS) time were measured by unattended, in-home nocturnal polysomnography. Bodily pain perception was measured via the Short Form-36 questionnaire bodily pain component. We used logistic regression to examine associations between total and individual sleep stage durations and bodily pain perception controlling for age, sex, race, body mass index, apnea-hypopnea index, antidepressant use, and important cardiovascular conditions (smoking [pack-years], history of diabetes, and history of percutaneous coronary intervention and/or coronary artery bypass graft). RESULTS: In the fully adjusted model, REM sleep time and SWS time were not associated with "moderate to severe pain," whereas TST was: Each 1-h decrement in TST was associated with a 7% increased odds of "moderate to severe pain" (odds ratio 1.07, 95% confidence interval 1.002, 1.14). Due to modification of the association between SWS time and "moderate to severe pain" by sex (P for interaction = 0.01), we performed analyses stratified by sex: Each 1-h decrement in SWS time was associated with a 20% higher odds of "moderate to severe pain" among men (odds ratio 1.20, 95% confidence interval 1.03-1.42) whereas an association was not observed among women. CONCLUSIONS: Shorter TST among all subjects and shorter SWS time in men was associated with "moderate to severe pain." REM sleep time was not associated with bodily pain perception in this cohort.

Do pulmonary function tests improve risk stratification before cardiothoracic surgery?

OBJECTIVE: To assess the added value of pulmonary function tests (PFTs) and different classifications of chronic obstructive pulmonary disease (COPD) to the Society of Thoracic Surgeons (STS) risk model using a clinical definition of lung disease for predicting outcomes after cardiothoracic (CT) surgery. METHODS: We evaluated consecutive patients who underwent nonemergency cardiac surgery and underwent PFTs before CT surgery. We used the STS risk model 2.73 to estimate the postoperative risk for respiratory failure (RF; defined as the need for mechanical ventilation for ≥72 hours, or reintubation), prolonged postoperative stay (PPLS; defined as >14 days), and 30-day all-cause mortality. We plotted the receiver operating characteristics curve for STS score for each adverse event, and compared the resulting area under the curve (AUC) with the AUC after adding PFT parameters and COPD classifications. RESULTS: Of the 1412 patients with a calculated STS score, 751 underwent PFTs. The AUC of the STS score was 0.65 (95% confidence interval [CI], 0.55-0.74) for RF, 0.67 (95% CI, 0.6-0.74) for prolonged postoperative length of stay (PPLS), and 0.74 (95% CI, 0.6-0.87) for death. None of the PFT parameters or COPD classifications added to the predictive ability of STS for RF, PPLS, or 30-day mortality. CONCLUSIONS: Adding individual PFT parameters or different COPD classifications to STS score calculated using clinically based classification of lung disease did not improve model discrimination. Thus, routine preoperative PFTS may have limited clinical utility in patients undergoing CT surgery when the STS score is readily available.

Air travel: effects of sleep deprivation and jet lag.

Air travel is a common mode of transportation in today's society, particularly for individuals traveling long distances. Sleep disturbances associated with air travel frequently result in cognitive and physiologic impairments that may be detrimental to the traveler's experience and intent. A primary consequence of air travel is the development of acute sleep deprivation, which may result in reduced attention/vigilance, alteration in mood states, diminished memory processing, and alteration in executive function. Along with and contributing to acute sleep deprivation, circadian rhythm misalignment resulting in jet lag disorder (JLD) is frequently encountered by air travelers traversing multiple time zones. JLD is characterized by insomnia or excessive daytime sleepiness associated with physical or mental impairment associated with travel. This review focuses on the neurocognitive manifestations of acute sleep deprivation and the pathophysiology and treatment of JLD to provide the practicing clinician a greater understanding of the sleep abnormalities manifest in air travelers. Treatment recommendations for the traveler, including the use of light/melatonin therapy, sleep scheduling, and pharmacologic aids for both sleep and alertness, are provided.

A practical algorithmic approach to the diagnosis and management of solitary pulmonary nodules: part 1: radiologic characteristics and imaging modalities.

The solitary pulmonary nodule (SPN) is frequently encountered on chest imaging and poses an important diagnostic challenge to clinicians. The differential diagnosis is broad, ranging from benign granulomata and infectious processes to malignancy. Important concepts in the evaluation of SPNs include the definition, morphologic characteristics via appropriate imaging modalities, and the calculation of pretest probability of malignancy. Morphologic differentiation of SPN into solid or subsolid types is important in the choice of follow-up and further management. In this first part of a two-part series, we describe the morphologic characteristics and various imaging modalities available to further characterize SPN. In Part 2, we will describe the determination of pretest probability of malignancy and an algorithmic approach to the diagnosis of SPN.

A practical algorithmic approach to the diagnosis and management of solitary pulmonary nodules: part 2: pretest probability and algorithm.

In this second part of a two-part series, we describe an algorithmic approach to the diagnosis of the solitary pulmonary nodule (SPN). An essential aspect of the evaluation of SPN is determining the pretest probability of malignancy, taking into account the significant medical history and social habits of the individual patient, as well as morphologic characteristics of the nodule. Because pretest probability plays an important role in determining the next step in the evaluation, we describe various methods the physician may use to make this determination. Subsequently, we outline a simple yet comprehensive algorithm for diagnosing a SPN, with distinct pathways for the solid and subsolid SPN.