Impact of PTSD and Obstructive Sleep Apnea on Cognition in Older Adult Veterans.

Background: Posttraumatic stress disorder (PTSD) and obstructive sleep apnea (OSA) are highly prevalent and comorbid among older adult male veterans. Both PTSD and OSA are independently associated with cognitive deficits in older adults, but little research regarding the impact of comorbid PTSD and OSA among older adults exists. Purpose: The current study aimed to examine the independent and interactive effects of PTSD and OSA on cognitive functioning in older adult veterans. Study Sample: Older adult male veterans with (n = 106) and without PTSD (n = 69), ranging in age from 55 to 89 (M = 63.35). Data Collection: Participants underwent polysomnography evaluation to assess severity of OSA symptoms and comprehensive neuropsychological evaluation to assess cognitive functioning in 3 domains: attention and processing speed, learning and memory, and executive functioning. Results: Multiple regression analyses showed that the interaction between PTSD and OSA did not predict cognitive performance. However, PTSD significantly predicted poorer attention and processing speed, and increased OSA severity predicted poorer learning and memory. Conclusions: While PTSD and OSA did not have a synergistic detrimental impact on cognition, each independently predicted poorer cognitive functioning within certain domains, suggesting that older adults with these comorbid conditions may experience a wider array of cognitive difficulties.

Fatigue and sleepiness determine respiratory quality of life among veterans evaluated for sleep apnea.

BACKGROUND: In those with symptoms indicative of obstructive sleep apnea (OSA), respiratory-specific health-related quality of life (HRQL) may be an important patient-centered outcome. The aim of this study was to assess the associations between sleepiness, fatigue, and impaired general and respiratory-specific HRQL among persons with suspected OSA. METHODS: We evaluated military veterans consecutively referred for suspected OSA with sleep studies yielding apnea-hypopnea index (AHI) values. They also completed the sleepiness (Epworth Sleepiness Scale [ESS]), and fatigue (Fatigue Severity Scale [FSS]) questionnaires, as well as two HRQL instruments (the generic Short-Form SF-12v2 yielding the Physical Component Scale [PCS] and the respiratory-specific Airways Questionnaire [AQ]-20R). Multiple linear regression tested the associations between ESS and FSS (standardized as Z scores for scaling comparability) with AQ-20R, accounting for AHI, SF-12v2-PCS and comorbid respiratory conditions other than OSA. RESULTS: We studied 1578 veterans (median age 61.1 [IQR 16.8] years; 93.9% males). Of these, 823 (52%) met AHI criteria for moderate to severe OSA (AHI ≥15/h). The majority reported excessive daytime sleepiness (53%; median ESS 11 [IQR 9]) or fatigue (61%; median FSS 42 [IQR 23]). The median AQ-20R was 4 [IQR 1-8]. Controlling for AHI, SF-12v2-PCS, respiratory co-morbid conditions, body mass index, and demographics, both ESS and FSS were significantly associated with poorer AQ-20R: for each; ESS, 1.6 points (95% CI 1.4-1.9), and for FSS, 2.5 points (95% CI, 2.3-2.7). CONCLUSIONS: Greater daytime sleepiness and fatigue are associated with poorer respiratory-specific HRQL, over and above the effects of OSA, respiratory comorbidity, and generic physical HRQL.

Identifying Meningitis During an Anthrax Mass Casualty Incident: Systematic Review of Systemic Anthrax Since 1880.

BACKGROUND: Bacillus anthracis, the causative agent of anthrax, is a potential bioterrorism agent. Anthrax meningitis is a common manifestation of B. anthracis infection, has high mortality, and requires more aggressive treatment than anthrax without meningitis. Its rapid identification and treatment are essential for successful management of an anthrax mass casualty incident. METHODS: Three hundred six published reports from 1880 through 2013 met predefined inclusion criteria. We calculated descriptive statistics for abstracted cases and conducted multivariable regression on separate derivation and validation cohorts to identify clinical diagnostic and prognostic factors for anthrax meningitis. RESULTS: One hundred thirty-two of 363 (36%) cases with systemic anthrax met anthrax meningitis criteria. Severe headache, altered mental status, meningeal signs, and other neurological signs at presentation independently predicted meningitis in the derivation cohort and were tested as a 4-item assessment tool for use during anthrax mass casualty incidents. Presence of any 1 factor on admission had a sensitivity for finding anthrax meningitis of 89% (83%) in the adult (pediatric) validation cohorts. Anthrax meningitis was unlikely in the absence of any of these signs or symptoms (likelihood ratio [LR]- = 0.12 [0.19] for adult [pediatric] cohorts), while presence of 2 or more made meningitis very likely (LR+ = 26.5 [30.0]). Survival of anthrax meningitis was predicted by treatment with a bactericidal agent (P = .005) and use of multiple antimicrobials (P = .01). CONCLUSIONS: We developed an evidence-based assessment tool for screening patients for meningitis during an anthrax mass casualty incident. Its use could improve both patient outcomes and resource allocation in such an event.

Diagnosis of obstructive sleep apnea in adults: a clinical practice guideline from theAmerican College of Physicians.

DESCRIPTION: The American College of Physicians (ACP) developed this guideline to present the evidence and provide clinical recommendations on the diagnosis of obstructive sleep apnea in adults. METHODS: This guideline is based on published literature on this topic that was identified by using MEDLINE (1966 through May 2013), the Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Reviews. Searches were limited to English-language publications. The clinical outcomes evaluated for this guideline included all-cause mortality, cardiovascular mortality, nonfatal cardiovascular disease, stroke, hypertension, type 2 diabetes, postsurgical outcomes, and quality of life. Sensitivities, specificities, and likelihood ratios were also assessed as outcomes of diagnostic tests. This guideline grades the evidence and recommendations by using ACP's clinical practice guidelines grading system. RECOMMENDATION 1: ACP recommends a sleep study for patients with unexplained daytime sleepiness. (Grade: weak recommendation, low-quality evidence). RECOMMENDATION 2: ACP recommends polysomnography for diagnostic testing in patients suspected of obstructive sleep apnea. ACP recommends portable sleep monitors in patients without serious comorbidities as an alternative to polysomnography when polysomnography is not available for diagnostic testing. (Grade: weak recommendation, moderate-quality evidence).

Centers for disease control and prevention expert panel meetings on prevention and treatment of anthrax in adults.

The Centers for Disease Control and Prevention convened panels of anthrax experts to review and update guidelines for anthrax postexposure prophylaxis and treatment. The panels included civilian and military anthrax experts and clinicians with experience treating anthrax patients. Specialties represented included internal medicine, pediatrics, obstetrics, infectious disease, emergency medicine, critical care, pulmonology, hematology, and nephrology. Panelists discussed recent patients with systemic anthrax; reviews of published, unpublished, and proprietary data regarding antimicrobial drugs and anthrax antitoxins; and critical care measures of potential benefit to patients with anthrax. This article updates antimicrobial postexposure prophylaxis and antimicrobial and antitoxin treatment options and describes potentially beneficial critical care measures for persons with anthrax, including clinical procedures for infected nonpregnant adults. Changes from previous guidelines include an expanded discussion of critical care and clinical procedures and additional antimicrobial choices, including preferred antimicrobial drug treatment for possible anthrax meningitis.

Management of obstructive sleep apnea in adults: A clinical practice guideline from the American College of Physicians.

DESCRIPTION: The American College of Physicians (ACP) developed this guideline to present the evidence and provide clinical recommendations on the management of obstructive sleep apnea (OSA) in adults. METHODS: This guideline is based on published literature from 1966 to September 2010 that was identified by using MEDLINE, the Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Reviews. A supplemental MEDLINE search identified additional articles through October 2012. Searches were limited to English-language publications. The clinical outcomes evaluated for this guideline included cardiovascular disease (such as heart failure, hypertension, stroke, and myocardial infarction), type 2 diabetes, death, sleep study measures (such as the Apnea-Hypopnea Index), measures of cardiovascular status (such as blood pressure), measures of diabetes status (such as hemoglobin A1c levels), and quality of life. This guideline grades the evidence and recommendations using ACP's clinical practice guidelines grading system. RECOMMENDATION 1: ACP recommends that all overweight and obese patients diagnosed with OSA should be encouraged to lose weight. (Grade: strong recommendation; low-quality evidence) RECOMMENDATION 2: ACP recommends continuous positive airway pressure treatment as initial therapy for patients diagnosed with OSA. (Grade: strong recommendation; moderate-quality evidence) RECOMMENDATION 3: ACP recommends mandibular advancement devices as an alternative therapy to continuous positive airway pressure treatment for patients diagnosed with OSA who prefer mandibular advancement devices or for those with adverse effects associated with continuous positive airway pressure treatment. (Grade: weak recommendation; low-quality evidence).

Modeling the effects of obstructive sleep apnea and hypertension in Vietnam veterans with PTSD.

PURPOSE: The present work aimed to extend models suggesting that obstructive sleep apnea (OSA) is associated with worse cognitive performance in community-dwelling older adults. We hypothesized that in addition to indices of OSA severity, hypertension is associated with worse cognitive performance in such adults. METHODS: The PTSD Apnea Clinical Study recruited 120 community-dwelling, male veterans diagnosed with PTSD, ages 55 and older. The Rey Auditory Verbal Learning Test (RAVLT) and Color-Word Interference Test (CWIT) were measures of auditory verbal memory and executive function, respectively. Apnea-hypopnea index (AHI), minimum and mean pulse oximeter oxygen saturation (min SpO(2), mean SpO(2)) indicators were determined during standard overnight polysomnography. Multivariate linear regression and receiver operating characteristic (ROC) curve analyses were performed. RESULTS: In regression models, AHI (ß = -4.099; p < 0.01) and hypertension (ß = -4.500; p < 0.05) predicted RAVLT; hypertension alone (ß = 9.146; p < 0.01) predicted CWIT. ROC analyses selected min SpO(2) cut-points of 85% for RAVLT (κ = 0.27; χ² = 8.23, p < 0.01) and 80% for CWIT (κ = 0.25; χ² = 12.65, p < 0.01). Min SpO(2) cut-points and hypertension were significant when added simultaneously in a regression model for RAVLT (min SpO(2), ß = 4.452; p < 0.05; hypertension, ß = -4.332; p < 0.05), and in separate models for CWIT (min SpO(2), ß = -8.286; p < 0.05; hypertension, ß = -8.993; p < 0.01). CONCLUSIONS: OSA severity and presence of self-reported hypertension are associated with poor auditory verbal memory and executive function in older adults.

Systematic review: safety and efficacy of extended-duration antiviral chemoprophylaxis against pandemic and seasonal influenza.

BACKGROUND: Neuraminidase inhibitors (NAIs) are stockpiled internationally for extended use in an influenza pandemic. PURPOSE: To evaluate the safety and efficacy of extended-duration (>4 weeks) NAI chemoprophylaxis against influenza. DATA SOURCES: Studies published in any language through 11 June 2009 identified by searching 10 electronic databases and 3 trial registries. STUDY SELECTION: Randomized, placebo-controlled, double-blind human trials of extended-duration NAI chemoprophylaxis that reported outcomes of laboratory-confirmed influenza or adverse events. DATA EXTRACTION: 2 reviewers independently assessed study quality and abstracted information from eligible studies. DATA SYNTHESIS: Of 1876 potentially relevant citations, 7 trials involving 7021 unique participants met inclusion criteria. Data were pooled by using random-effects models. Chemoprophylaxis with NAIs decreased the frequency of symptomatic influenza (relative risk [RR], 0.26 [95% CI, 0.18 to 0.37]; risk difference [RD], -3.9 percentage points [CI, -5.8 to -1.9 percentage points]) but not asymptomatic influenza (RR, 1.03 [CI, 0.81 to 1.30]; RD, -0.4 percentage point [CI, -1.6 to 0.9 percentage point]). Adverse effects were not increased overall among NAI recipients (RR, 1.01 [CI, 0.94 to 1.08]; RD, 0.1 percentage point [CI, -0.2 to 0.4 percentage point]), but nausea and vomiting were more common among those who took oseltamivir (RR, 1.48 [CI, 1.86 to 2.33]; RD, 1.7 percentage points [CI, 0.6 to 2.9 percentage points]). Prevention of influenza did not statistically significantly differ between zanamivir and oseltamivir. LIMITATIONS: All trials were industry-sponsored. No study was powered to detect rare adverse events, and none included diverse racial groups, children, immunocompromised patients, or individuals who received live attenuated influenza virus vaccine. CONCLUSION: Extended-duration zanamivir and oseltamivir chemoprophylaxis seems to be highly efficacious for preventing symptomatic influenza among immunocompetent white and Japanese adults. Extended-duration oseltamivir is associated with increased nausea and vomiting. Safety and efficacy in several subpopulations that might receive extended-duration influenza chemoprophylaxis are unknown.

Effect of Suvorexant vs Placebo on Total Daytime Sleep Hours in Shift Workers: A Randomized Clinical Trial.

Importance: Many shift workers have difficulty sleeping during the daytime owing to an inappropriately timed circadian drive for wakefulness. Objective: To determine whether a dual hypocretin receptor antagonist would enable shift workers to have more daytime sleep. Design, Setting, and Participants: This double-blind, placebo-controlled randomized clinical trial included 2 weeks of baseline data and 3 weeks of intervention data, from March 2016 to December 2018. Individuals were recruited through poster advertisements in the broader San Francisco Bay area in California. From an initial voluntary recruitment cohort of 38 shift workers, 19 individuals with self-reported difficulty sleeping during the daytime following night work shift were included. Data were analyzed from Janaury to March 2019. Interventions: 1 week of 10 mg suvorexant or placebo, titrated upward to 20 mg suvorexant or placebo for 2 additional weeks. Main Outcomes and Measures: Objective (ie, actigraphy) and subjective (ie, sleep logs) measures of sleep. Results: Among 19 participants who completed the study (mean [SD] age, 37.7 [11.1] years; 13 [68%] men), 8 participants (42%) were assigned to the suvorexant group and 11 participants (58%) were assigned to the placebo group. Compared with individuals in the placebo group, individuals in the suvorexant group increased their objective total sleep time by a mean (SE) of 1.04 (0.53) hours (P = .05) at the end of 1 week of 10-mg doses and by 2.16 (0.75) hours (P = .004) by the end of the 2 weeks of 20-mg doses. Subjective sleep was similarly improved as, compared with the placebo group, individuals in the suvorexant group increased their subjective total sleep time by a mean (SE) of 2.08 (0.47) hours (P < .001) at the end of 1 week of 10-mg doses and by 2.97 (0.56) hours (P < .001) by the end of the 2 weeks of 20-mg doses. Physician ratings of daytime sleep aligned with these measures, as there was no change in the placebo group and a much improved change in the suvorexant group. No adverse events were reported in the suvorexant group. Conclusions and Relevance: This pilot study found that the use of a dual hypocretin receptor antagonist in shift workers under real-world conditions resulted in more than 2 extra hours of daytime sleep per episode. Future research should confirm this pilot finding in a larger sample size and examine whether, over the long term, use of this medication has a concomitant improvement in medical and psychiatric health as well as workplace performance and safety. Trial Registration: ClinicalTrials.gov Identifier: NCT02491788.

Tuberculosis in liver transplant recipients: a systematic review and meta-analysis of individual patient data.

Mycobacterium tuberculosis (MTB) causes substantial morbidity and mortality in liver transplant recipients. We examined the efficacy of isoniazid latent Mycobacterium tuberculosis infection (LTBI) treatment in liver transplant recipients and reviewed systematically all cases of active MTB infection in this population. We found 7 studies that evaluated LTBI treatment and 139 cases of active MTB infection in liver transplant recipients. Isoniazid LTBI treatment was associated with reduced MTB reactivation in transplant patients with latent MTB risk factors (0.0% versus 8.2%, P = 0.02), and isoniazid-related hepatotoxicity occurred in 6% of treated patients, with no reported deaths. The prevalence of active MTB infection in transplant recipients was 1.3%. Nearly half of all recipients with active MTB infection had an identifiable pretransplant MTB risk factor. Among recipients who developed active MTB infection, extrapulmonary involvement was common (67%), including multiorgan disease (27%). The short-term mortality rate was 31%. Surviving patients were more likely to have received 3 or more drugs for MTB induction therapy (P = 0.003) and to have been diagnosed within 1 month of symptom onset (P = 0.01) and were less likely to have multiorgan disease (P = 0.01) or to have experienced episodes of acute transplant rejection (P = 0.02). Compared with the general population, liver transplant recipients have an 18-fold increase in the prevalence of active MTB infection and a 4-fold increase in the case-fatality rate. For high-risk transplant candidates, isoniazid appears safe and is probably effective at reducing MTB reactivation. All liver transplant candidates should receive a tuberculin skin test, and isoniazid LTBI treatment should be given to patients with a positive skin test result or MTB pretransplant risk factors, barring a specific contraindication. Liver Transpl 15:894-906, 2009. (c) 2009 AASLD.

Recommendations for modeling disaster responses in public health and medicine: a position paper of the society for medical decision making.

PURPOSE: Mathematical and simulation models are increasingly used to plan for and evaluate health sector responses to disasters, yet no clear consensus exists regarding best practices for the design, conduct, and reporting of such models. The authors examined a large selection of published health sector disaster response models to generate a set of best practice guidelines for such models. METHODS: . The authors reviewed a spectrum of published disaster response models addressing public health or health care delivery, focusing in particular on the type of disaster and response decisions considered, decision makers targeted, choice of outcomes evaluated, modeling methodology, and reporting format. They developed initial recommendations for best practices for creating and reporting such models and refined these guidelines after soliciting feedback from response modeling experts and from members of the Society for Medical Decision Making. RESULTS: . The authors propose 6 recommendations for model construction and reporting, inspired by the most exemplary models: health sector disaster response models should address real-world problems, be designed for maximum usability by response planners, strike the appropriate balance between simplicity and complexity, include appropriate outcomes that extend beyond those considered in traditional cost-effectiveness analyses, and be designed to evaluate the many uncertainties inherent in disaster response. Finally, good model reporting is particularly critical for disaster response models. CONCLUSIONS: . Quantitative models are critical tools for planning effective health sector responses to disasters. The proposed recommendations can increase the applicability and interpretability of future models, thereby improving strategic, tactical, and operational aspects of preparedness planning and response.

Mycobacterium tuberculosis infection in transplant recipients: early diagnosis and treatment of resistant tuberculosis.

PURPOSE OF REVIEW: To provide a better understanding and summarize recent advances in the diagnosis and treatment of Mycobacterium tuberculosis (MTB) infection in solid organ transplant (SOT) candidates and recipients. RECENT FINDINGS: Despite advances in SOT medicine, MTB causes substantial morbidity and mortality in SOT recipients, with reported prevalence rates of 0.4-6%. The primary source of posttransplant MTB is reactivation of pretransplant latent MTB infection. The short-term mortality rate in SOT recipients with drug-susceptible active MTB is 30%. In immunocompromised persons with extensively drug-resistant MTB, the mortality rate approaches 100%. Clinical presentation is often atypical with more than half of SOT recipients presenting with extrapulmonary or disseminated disease. Pretransplant latent MTB infection screening and treatment is the cornerstone for preventing reactivation and dissemination of active MTB posttransplant. Treatment of active MTB in SOT recipients is problematic, given significant drug toxicity and interaction with immunosuppressive agents. SUMMARY: A high degree of suspicion for latent and active MTB infection in SOT candidates and recipients is warranted to establish a timely diagnosis and initiate life-saving appropriate therapy.

Modeling the logistics of response to anthrax bioterrorism.

BACKGROUND: A bioterrorism attack with an agent such as anthrax will require rapid deployment of medical and pharmaceutical supplies to exposed individuals. How should such a logistical system be organized? How much capacity should be built into each element of the bioterrorism response supply chain? METHODS: The authors developed a compartmental model to evaluate the costs and benefits of various strategies for preattack stockpiling and postattack distribution and dispensing of medical and pharmaceutical supplies, as well as the benefits of rapid attack detection. RESULTS: The authors show how the model can be used to address a broad range of logistical questions as well as related, nonlogistical questions (e.g., the cost-effectiveness of strategies to improve patient adherence to antibiotic regimens). They generate several key insights about appropriate strategies for local communities. First, stockpiling large local inventories of medical and pharmaceutical supplies is unlikely to be the most effective means of reducing mortality from an attack, given the availability of national and regional supplies. Instead, communities should create sufficient capacity for dispensing prophylactic antibiotics in the event of a large-scale bioterror attack. Second, improved surveillance systems can significantly reduce deaths from such an attack but only if the local community has sufficient antibiotic-dispensing capacity. Third, mortality from such an attack is significantly affected by the number of unexposed individuals seeking prophylaxis and treatment. Fourth, full adherence to treatment regimens is critical for reducing expected mortality. CONCLUSIONS: Effective preparation for response to potential bioterror attacks can avert deaths in the event of an attack. Models such as this one can help communities more effectively prepare for response to potential bioterror attacks.

Use of blood biomarkers to screen for obstructive sleep apnea.

PURPOSE: Obstructive sleep apnea (OSA) is a highly prevalent disorder associated with increased risk for cardiovascular disease, diabetes, and other chronic conditions. Unfortunately, up to 90% of individuals with OSA remain without a diagnosis or therapy. We assess the relationship between OSA and blood biomarkers, and test the hypothesis that combinations of markers provide a characteristic OSA signature with diagnostic screening value. This validation study was conducted in an independent cohort in order to replicate findings from a prior feasibility study. PATIENTS AND METHODS: This multicenter prospective study consecutively enrolled adult male subjects with clinically suspected OSA. All subjects underwent overnight sleep studies. An asymptomatic control group was also obtained. Five biomarkers were tested: glycated hemoglobin (HbA1c), C-reactive protein (CRP), uric acid, erythropoietin (EPO), and interleukin-6 (IL-6). RESULTS: The study enrolled 264 subjects. The combination of HbA1c+CRP+EPO (area under the curve 0.78) was superior to the Epworth Sleepiness Scale (ESS; 0.53) and STOP-Bang (0.70) questionnaires. In non-obese subjects, the combination of biomarkers (0.75) was superior to body mass index (BMI; 0.61). Sensitivity and specificity results, respectively, were: HbA1c+CRP+EPO (81% and 60%), ESS (78% and 19%), STOP-Bang (75% and 52%), BMI (81% and 56%), and BMI in non-obese patients (81% and 38%). CONCLUSION: We verify our hypothesis and replicate our prior feasibility findings that OSA is associated with a characteristic signature cluster of biomarker changes in men. Concurrent elevations of HbA1c, CRP, and EPO levels should generate a high suspicion of OSA and may have utility as an OSA screening tool. Biomarker combinations correlate with OSA severity and, therefore, may assist sleep centers in identifying and triaging higher risk patients for sleep study diagnosis and treatment.

Inhalational, gastrointestinal, and cutaneous anthrax in children: a systematic review of cases: 1900 to 2005.

OBJECTIVE: To systematically review all published case reports of children with anthrax to evaluate the predictors of disease progression and mortality. DATA SOURCES: Fourteen selected journal indexes (1900-1966), MEDLINE (1966-2005), and the bibliographies of all retrieved articles. STUDY SELECTION: Case reports (any language) of anthrax in persons younger than 18 years published between January 1, 1900, and December 31, 2005. Main Exposures Cases with symptoms and culture or Gram stain or autopsy evidence of anthrax infection. MAIN OUTCOME MEASURES: Disease progression, treatment responses, and mortality. RESULTS: Of 2499 potentially relevant articles, 73 case reports of pediatric anthrax (5 inhalational cases, 22 gastrointestinal cases, 37 cutaneous cases, 6 cases of primary meningoencephalitis, and 3 atypical cases) met the inclusion criteria. Only 10% of the patients were younger than 2 years, and 24% were girls. Of the few children with inhalational anthrax, none had nonheadache neurologic symptoms, a key finding that distinguishes adult inhalational anthrax from more common illnesses, such as influenza. Overall, observed mortality was 60% (3 of 5) for inhalational anthrax, 65% (13 of 20) for gastrointestinal anthrax, 14% (5 of 37) for cutaneous anthrax, and 100% (6 of 6) for primary meningoencephalitis. Nineteen of the 30 children (63%) who received penicillin-based antibiotics survived, and 9 of the 11 children (82%) who received anthrax antiserum survived. CONCLUSIONS: The clinical presentation of children with anthrax is varied. The mortality rate is high in children with inhalational anthrax, gastrointestinal anthrax, and anthrax meningoencephalitis. Rapid diagnosis and effective treatment of anthrax in children requires recognition of the broad spectrum of clinical presentations of pediatric anthrax.

Systematic review: a century of inhalational anthrax cases from 1900 to 2005.

BACKGROUND: Mortality from inhalational anthrax during the 2001 U.S. attack was substantially lower than that reported historically. PURPOSE: To systematically review all published inhalational anthrax case reports to evaluate the predictors of disease progression and mortality. DATA SOURCES: MEDLINE (1966-2005), 14 selected journal indexes (1900-1966), and bibliographies of all retrieved articles. STUDY SELECTION: Case reports (in any language) between 1900 and 2005 that met predefined criteria. DATA EXTRACTION: Two authors (1 author for non-English-language reports) independently abstracted patient data. DATA SYNTHESIS: The authors found 106 reports of 82 cases of inhalational anthrax. Mortality was statistically significantly lower for patients receiving antibiotics or anthrax antiserum during the prodromal phase of disease, multidrug antibiotic regimens, or pleural fluid drainage. Patients in the 2001 U.S. attack were less likely to die than historical anthrax case-patients (45% vs. 92%; P < 0.001) and were more likely to receive antibiotics during the prodromal phase (64% vs. 13%; P < 0.001), multidrug regimens (91% vs. 50%; P = 0.027), or pleural fluid drainage (73% vs. 11%; P < 0.001). Patients who progressed to the fulminant phase had a mortality rate of 97% (regardless of the treatment they received), and all patients with anthrax meningoencephalitis died. LIMITATIONS: This was a retrospective case review of previously published heterogeneous reports. CONCLUSIONS: Despite advances in supportive care, fulminant-phase inhalational anthrax is usually fatal. Initiation of antibiotic or anthrax antiserum therapy during the prodromal phase is associated with markedly improved survival, although other aspects of care, differences in clinical circumstances, or unreported factors may contribute to this observed reduction in mortality. Efforts to improve early diagnosis and timely initiation of appropriate antibiotics are critical to reducing mortality.

Does untreated obstructive sleep apnea cause secondary erythrocytosis?

BACKGROUND: The current literature suggests a relationship between obstructive sleep apnea (OSA) severity and hematocrit. However, the degree that OSA contributes to clinically significant erythrocytosis is uncertain. The aim of this study is to evaluate this association in a large study sample controlling for multiple confounders. METHODS: We evaluated consecutive subjects with suspected untreated OSA using multivariate analysis to test the associations between apnea-hypopnea index (AHI) and hematocrit. Subjects were evaluated with sleep studies, comprehensive sleep questionnaires, and detailed electronic medical record reviews to document their medical comorbidities, and demographic and laboratory information. RESULTS: 1604 consecutive veterans (age 57.6 ± 13.4 years, 92% male) were included in the analysis with 77.4% diagnosed with OSA. However, few included subjects (1.6%) had clinical erythrocytosis. OSA severity defined by AHI was not associated with hematocrit or clinically significant erythrocytosis. Rather, awake oxygen saturation (-0.17 points, p < 0.001) and mean nocturnal oxygen saturation (-0.08 points, p = 0.04) were inversely proportional to hematocrit (per standardized Z-score). Other factors including active tobacco, increased alcohol ingestion and exogenous testosterone therapy were associated with higher hematocrit. Although AHI was not predictive of erythrocytosis, having severe OSA was predictive of nocturnal hypoxemia (adjusted OR 7.4, p < 0.001). CONCLUSIONS: Hematocrit levels and presence of erythrocytosis appear not associated with OSA severity, but rather with hypoxemia as measured by awake and to a lesser extent mean nocturnal oxygen saturation. Nocturnal oximetry may provide diagnostic utility in the evaluation of unexplained secondary polycythemia and polysomongraphy may be warranted in those with unexplained nocturnal hypoxemia and erythrocytosis.