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Biomedical subjects

Sean M Caples

Publications and source records attributed to Sean M Caples.

14 recordsLinked to original sources
PubMed2006

Testosterone use in men and its effects on bone health. A systematic review and meta-analysis of randomized placebo-controlled trials.

CONTEXT: Androgen-deficient men are at increased risk of osteoporosis. The extent to which testosterone can prevent and treat osteoporosis in men remains unclear. OBJECTIVE AND DESIGN: We performed a systematic review and meta-analysis of randomized placebo-controlled trials in men to estimate the effect of testosterone use on bone health outcomes. DATA SOURCES: The review encompassed librarian-designed search strategies using MEDLINE (1966 to March 2005), EMBASE (1988 to March 2005), and Cochrane CENTRAL (inception to March 2005); a review of reference lists from included studies; and content expert files. DATA COLLECTION: Independently and in duplicate, we assessed the methodological quality of the eligible trials and collected data on bone mineral density and bone fractures at the longest point of complete follow-up. DATA SYNTHESIS: We included eight trials enrolling 365 patients. Two trials followed patients for more than 1 yr. Meta-analysis of these trials showed that, compared with placebo, im testosterone was associated with an 8% (95% confidence interval, 4%, 13%) gain in lumbar bone mineral density and transdermal testosterone had no significant impact. Testosterone use was associated with a nonsignificant 4% (95% confidence interval, -2%, 9%) gain in femoral neck bone mineral density with unexplained differences in results across trials (26% of these differences were not explained by chance alone). No trials measured or reported the effect of testosterone on fractures. CONCLUSIONS: Intramuscular testosterone moderately increased lumbar bone density in men; the results on femoral neck bone density are inconclusive. Without bone fracture data, the available trials offer weak and indirect inferences about the clinical efficacy of testosterone on osteoporosis prevention and treatment in men.

Bone Density↗
PubMed2005

Coccidioidomycosis in patients with hematologic malignancies.

BACKGROUND: An endemic fungal infection of the desert southwestern United States, coccidioidomycosis is generally a self-limited illness in healthy persons. Immunosuppressed persons who contract coccidioidomycosis, however, are at increased risk for disseminated infection. METHODS: We conducted a retrospective review of patients with coccidioidomycosis and hematologic malignancy or bone marrow disease. RESULTS: Fifty-five patients were identified. The most common underlying malignancies were non-Hodgkin lymphoma and chronic lymphocytic leukemia. Extrathoracic (or disseminated) infection was observed in 12 patients (22%). Fifteen patients (27%) died with active coccidioidomycosis. Treatment of the hematologic disease with corticosteroids or antineoplastic chemotherapy increased the risk of death. CONCLUSION: To date, this is the largest case series of patients with hematologic malignancy and coccidioidomycosis. In persons with hematologic malignancy, coccidioidomycosis can be a severe illness with a high risk for disseminated infection and death.

Adrenal Cortex Hormones↗
PubMed2005

Therapy Insight: interactions between atrial fibrillation and obstructive sleep apnea.

Atrial fibrillation (AF) and obesity are coinciding epidemics. Obstructive sleep apnea (OSA) correlates directly with obesity and is highly prevalent among middle-aged adults. Emerging evidence supports a strong association between AF and OSA. The rate of AF among patients with OSA is low but is nevertheless higher than that in the general population. The prevalence of OSA among patients with AF is strikingly high-at least 32% and possibly as high as 49%-although differences in the AF populations studied and the criteria used to diagnose OSA have prevented more accurate measurement of this rate. Data in focused populations at risk of AF show that OSA increases the frequency and recurrence of AF. These findings cannot, however, be reliably generalized to the larger OSA population. Although the available information is limited, treatment of OSA, particularly with continuous positive airway pressure, seems to substantially reduce the frequency of AF. If true, this approach would provide a safe and noninvasive therapy for some patients with AF. Randomized controlled trials are necessary to rigorously answer this question. Many data have been obtained from studies with focuses other than the direct relationship between OSA and AF. Studies carefully designed to investigate the relevant issues are now needed.

Atrial Fibrillation↗
PubMed2005

Cardiopulmonary consequences of obstructive sleep apnea.

Ongoing research in obstructive sleep apnea (OSA) suggests strong associations with cardiopulmonary disorders. There is an abundance of studies describing physiological pathways in OSA that acutely impact the cardiovascular system. These mechanisms, if proven to carry over into the daytime hours, could form the basis for clinical disease. The challenge remains in disentangling these mechanistic processes from the many comorbid conditions often present in patients with OSA. Examples include male gender, obesity, and diabetes mellitus, all of which exert their own influence on the development of cardiopulmonary disease. This review discusses some of the physiological mechanisms associated with disordered breathing during sleep and explores putative cardiopulmonary disease associations.

Cardiovascular Diseases↗
PubMed2005

Noninvasive positive pressure ventilation in the intensive care unit: a concise review.

OBJECTIVE: To critically assess available high-level clinical studies regarding use of noninvasive positive pressure ventilation in varied intensive care unit settings. DATA SOURCE: Search of pertinent articles within Ovid MEDLINE from 1975 to 2005, CINAHL from 1982 to 2005, EMBASE from 1988 to 2005, and Web of Science from 1993 to 2005. STUDY SELECTION: Randomized, controlled clinical trials and cohort studies and observational studies the authors consider important or novel. DATA EXTRACTION/SYNTHESIS: Performed equally by both authors with the use of an Excel data spreadsheet. CONCLUSION: There is abundant level I evidence supporting the use of noninvasive positive pressure ventilation in such critical care settings as acute hypercapnic respiratory failure, particularly related to chronic obstructive pulmonary disease, and acute cardiogenic pulmonary edema. We also report on other clinical scenarios in which the data may be somewhat less compelling, but evidence favors a noninvasive positive pressure ventilation trial. Some well designed studies suggest that noninvasive positive pressure ventilation is not an appropriate intervention for patients who have failed endotracheal extubation.

Critical Care↗
PubMed2005

Influence of cardiac function and failure on sleep-disordered breathing: evidence for a causative role.

Heart failure is an increasingly common public health problem that is strongly linked to both central and obstructive sleep apnea, collectively referred to as sleep-disordered breathing. Much attention has been given to the deleterious effects of sleep-disordered breathing on the failing heart and potential mechanisms by which treatment of sleep-disordered breathing may result in improved cardiac performance and long-term outcomes. However, there is compelling evidence that cardiac dysfunction may contribute to sleep-disordered breathing. Although there is recognized overlap between pathophysiological mechanisms in central sleep apnea and obstructive sleep apnea, data supporting the role of cardiac function are certain forms of central sleep apnea are well established, whereas investigation into the relationship with obstructive sleep apnea is less mature but continues to evolve. This review will examine experimental and observational data that explore possible pathophysiological mechanisms and potential targets for therapy in heart failure and sleep-disordered breathing.

Animals↗
PubMed2004

Association of atrial fibrillation and obstructive sleep apnea.

BACKGROUND: Obstructive sleep apnea (OSA) is associated with recurrent atrial fibrillation (AF) after electrocardioversion. OSA is highly prevalent in patients who are male, obese, and/or hypertensive, but its prevalence in patients with AF is unknown. METHODS AND RESULTS: We prospectively studied consecutive patients undergoing electrocardioversion for AF (n=151) and consecutive patients without past or current AF referred to a general cardiology practice (n=312). OSA was diagnosed with the Berlin questionnaire, which is validated to identify patients with OSA. We also assessed its accuracy compared with polysomnography in a sample of the study population. Groups were compared with the 2-tailed t, Wilcoxon, and chi2 tests. Logistic regression modeled the association of AF and OSA after adjustment for relevant covariates. Patients in each group had similar age, gender, body mass index, and rates of diabetes, hypertension, and congestive heart failure. The questionnaire performed with 0.86 sensitivity, 0.89 specificity, and 0.97 positive predictive value in our sample. The proportion of patients with OSA was significantly higher in the AF group than in the general cardiology group (49% versus 32%, P=0.0004). The adjusted odds ratio for the association between AF and OSA was 2.19 (95% CI 1.40 to 3.42, P=0.0006). CONCLUSIONS: The novel finding of this study is that a strong association exists between OSA and AF, such that OSA is strikingly more prevalent in patients with AF than in high-risk patients with multiple other cardiovascular diseases. The coinciding epidemics of obesity and AF underscore the clinical importance of these results.

Aged↗
PubMed2004

Ventilator-associated lung injury in patients without acute lung injury at the onset of mechanical ventilation.

OBJECTIVE: Although ventilation with small tidal volumes is recommended in patients with established acute lung injury, most others receive highly variable tidal volume aimed in part at normalizing arterial blood gas values. We tested the hypothesis that acute lung injury, which develops after the initiation of mechanical ventilation, is associated with known risk factors for ventilator-induced lung injury such as ventilation with large tidal volume. DESIGN: Retrospective cohort study. SETTING: Four intensive care units in a tertiary referral center. PATIENTS: Patients who received invasive mechanical ventilation for > or = 48 hrs between January and December 2001. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The main outcome of interest, acute lung injury, was assessed by independent review of daily digital chest radiographs and arterial blood gases. Ventilator settings, hemodynamics, and acute lung injury risk factors were extracted from the Acute Physiology and Chronic Health Evaluation III database and the patients' medical records. Of 332 patients who did not have acute lung injury from the outset, 80 patients (24%) developed acute lung injury within the first 5 days of mechanical ventilation. When expressed per predicted body weight, women were ventilated with larger tidal volume than men (mean 11.4 vs. 10.4 mL/kg predicted body weight, p <.001) and tended to develop acute lung injury more often (29% vs. 20%, p =.068). In a multivariate analysis, the main risk factors associated with the development of acute lung injury were the use of large tidal volume (odds ratio 1.3 for each mL above 6 mL/kg predicted body weight, p <.001), transfusion of blood products (odds ratio, 3.0; p < 0.001), acidemia (pH < 7.35; odds ratio, 2.0; p =.032) and a history of restrictive lung disease (odds ratio, 3.6; p =.044). CONCLUSIONS: The association between the initial tidal volume and the development of acute lung injury suggests that ventilator-associated lung injury may be an important cause of this syndrome. Height and gender should be considered when setting up the ventilator. Strong consideration should be given to limiting large tidal volume, not only in patients with established acute lung injury but also in patients at risk for acute lung injury.

Aged↗
PubMed2004

Thoracic surgical procedures in patients with rheumatoid arthritis.

OBJECTIVE: Rheumatoid arthritis (RA) is associated with a variety of pleuropulmonary manifestations, some of which require surgical intervention. We investigated the spectrum of indications and results, as well as outcome associated with thoracic surgical procedures in rheumatoid patients. METHODS: Identification and retrospective review of medical records of 100 patients with RA at a tertiary-referral medical center undergoing thoracic surgical procedures over a 24-year period from January 1, 1976, to December 31, 1999. RESULTS: Sixty-four patients underwent surgical lung biopsy for localized lung lesions, 57 of which were nodules or masses; 24 lesions proved to be malignant. Surgical lung biopsy was undertaken in 40 patients for diffuse interstitial lung disease, 4 cases of which were found to be infectious. Five other patients underwent surgery for pleural disease, 3 of which proved to be benign pleuritis. CONCLUSION: Patients with rheumatoid disease undergo thoracic surgical procedures for a variety of indications, including benign and malignant localized lesions and pleural disease as well as diffuse parenchymal lung disease. The overall in-hospital mortality rate was low. However, the subgroup with diffuse interstitial lung disease was found to have a 20% in-hospital death rate following surgical lung biopsy.

Aged↗
PubMed2003

Obesity and obstructive sleep apnea.

There is a very high prevalence of OSA in obese individuals and a high prevalence of obesity in patients with OSA. The pathophysiology of OSA is intimately linked to obesity. Anatomic and functional considerations of the pharyngeal airway, the CNS, central obesity, and leptin likely interact in the development of OSA in obese individuals. OSA may itself predispose individuals to worsening obesity because of sleep deprivation, daytime somnolence, and disrupted metabolism. The diagnosis of OSA requires the clinician's awareness of its potential to cause a spectrum of acute and chronic neurocognitive, psychiatric, and nonspecific symptoms in patients who may be unaware that their sleep is disturbed. Symptoms and examination findings help predict which obese individuals have OSA, and polysomnography is the gold standard by which to make the diagnosis and assess the effects of treatment. Numerous disease states are associated with both OSA and obesity, and it is becoming clear that the relationships are mediated by complex interrelated mechanisms. Common diseases and disease mechanisms in OSA and obesity suggest that conditions related to obesity may be better managed if patients, particularly those who are morbidly obese, are evaluated and treated for previously undiagnosed OSA. OSA is cured in only specific cases with craniofacial or upper airway surgery, and the general application of UVP is not efficacious. OSA also can be cured with sufficient lifestyle-mediated or surgical weight loss; however, in the absence of long-term weight maintenance, OSA returns with weight gain. Although not curative, nasal CPAP is the initial treatment of choice for most patients because of its noninvasive approach and technical efficacy. It is limited, however, by patient acceptance and long-term compliance. Advances in mask comfort and use of humidified air should increase its acceptance. Future management strategies include newer generations of positive airway devices that automatically titrate pressures (which are not yet recommended by expert organizations) and multidisciplinary approaches to managing the care of patients with OSA.

Blood Coagulation Disorders↗
PubMed2003

Respiratory monitoring tools in the intensive care unit.

PURPOSE OF REVIEW: Respiratory monitoring tools remain important in the overall assessment of a patient in the ICU. A working knowledge of the various tools is helpful in applying their use to patient care. RECENT FINDINGS: The past year has seen tremendous research in this domain of patient care, fueled by rapid advances in modern technology. Still, the ICU clinician continues to rely on tried and true established tools while awaiting proof of clinical efficacy of newer modalities. SUMMARY: This review discusses traditional methods of respiratory system evaluation and their current controversies. Attention is also given to newer modalities, including those that are investigational or currently limited to bench application, that show promise of future application in ICU clinical practice.

Adult↗