5 Clinical Trials for Various Conditions
The purpose of this study is to evaluate opioid dose effects on the ability of the diaphragm muscle to generate higher force behaviors.
The purpose of this study is to evaluate the relationship between transdiaphragmatic pressure (Pdi) and diaphragm shear-wave elastography (SWE) during state-of-the-art respiratory muscle testing including volitional efforts (e.g., maximal inspiratory pressure, maximal expiratory pressure, Valsalva maneuver), as well as maximal phrenic nerve stimulation.
The investigators propose to compare two different treatments, continuous positive airway pressure (CPAP) versus breathing of atmospheric pressure, in subjects with obstructive sleep apnea (OSA)recovering from weight loss surgery in the post anesthesia care unit (PACU). WE hypothesize that subjects with OSA will have a higher Apnea-Hypopnea Index (AHI) with desaturation and the investigators expect that post-operative CPAP treatment in the PACU will significantly improve the AHI and therefore improve patient safety in the PACU. The investigators also hypothesize that subjects with OSA have a greater decrease in oxygen saturation in response to opioid administration by patient-controlled opioid analgesia (PCA).
Obesity is a medical problem of epidemic proportions and is associated with high mortality. Obesity has significant effects on the cardiovascular system, producing structural cardiovascular changes including myocardial hypertrophy, fatty infiltration, and fibrosis; diastolic and systolic dysfunction; changes in pulmonary artery compliance; and increased aortic stiffness - all of which can lead to heart failure. Indeed, evidence suggests that obesity increases the risk for heart disease independent of other known risk factors such as coronary artery disease, hypertension, diabetes mellitus, and obstructive sleep apnea. Obesity also causes significant changes in pulmonary function, including a decrease in expiratory reserve volume and functional residual capacity and closure of peripheral airways. The exact mechanisms for the development of cardiopulmonary disease are not well understood - the pathophysiology is complex and likely multifactorial, related to altered hemodynamic load, altered metabolic activity, underlying inflammation, and increased cardiac output. Newer diagnostic modalities available at our institution such as cardiac MRI and pulmonary function tests with impulse oscillometry allow us to better evaluate cardiopulmonary dysfunction in patients with severe obesity. Cardiac MRI is especially promising as a non-invasive imaging modality in obese individuals, providing more reproducible measurements of cardiac and vascular anatomy and function relative to echocardiography. Similarly, pulmonary function testing with impulse oscillometry is more sensitive for detection of abnormalities in the distal airways especially when spirometry is normal, as frequently occurs in the severely obese symptomatic patients. The main objective of the proposed study is to evaluate the effect of obesity on quality of life and health care utilization and its relationship to cardiopulmonary disease in an ethnically diverse, underserved obese population by using state-of-the-art diagnostic modalities before and after significant (20%) weight loss. The investigators propose to perform stress cardiac MRI and pulmonary function testing with oscillometry before and after significant surgical weight loss in 150 severely obese patients with cardiopulmonary symptoms. Patients evaluated in the comprehensive Obesity Center at Bellevue Hospital who meet NIH Consensus Guidelines for Bariatric Surgery, who have cardiopulmonary symptoms, and who meet clinical criteria for cardiac stress testing and pulmonary function testing will be approached by the study personnel and offered enrollment. Informed consent will be obtained. Enrolled patients will undergo clinical evaluation with a detailed medical history including the Borg dyspnea scale, physical examination, laboratory testing including cardiopulmonary biomarkers (brain natriuretic peptide, C-reactive protein, atrial natriuretic peptide), and non-invasive cardiovascular stress MRI and pulmonary physiologic evaluation including spirometry, plethysmography and impulse oscillometry (IOS). Patients with active smoking history and/or asthma will be identified clinically. Cardiovascular MRI will be performed using a 1.5T (Avanto or Espree, Siemens Healthcare) system. Standard cardiovascular techniques will be used for the assessment of myocardial and vascular structure and function, including T1-weighted, T2-weighted, late gadolinium enhancement, cine, tagged and phase contrast imaging in selected planes. Adenosine stress MRI will be performed for evaluation of underlying coronary artery or microvascular disease.
This research study is being performed to begin to determine the effectiveness of two dominant bariatric surgery procedures versus an intensive lifestyle intervention to induce weight loss in patients and promote improvements in Type 2 diabetes mellitus (T2DM) in moderately obese patients. T2DM is currently the 6th leading cause of mortality in the United States and is a major cause of kidney failure, blindness, amputations, heart attack, and other vascular and gastro-intestinal dysfunctions. Traditionally, treatments include intensive lifestyle modifications with or without glucose lowering agents. Neither treatment alone, or in combination, results in complete resolution of diabetes and its potential long-term complications. Bariatric surgery has been proven as an effective treatment to accomplish sustained and significant weight loss for those with severe obesity and has been shown to induce long-term remission of T2DM. However, despite enthusiasm for these potential treatment options, it is not clear whether diabetes is influenced by the type of surgery or by the amount of weight lost or if bariatric surgery is more effective than non-surgical weight loss induced by diet and physical activity in T2DM patients with moderate BMIs (30-40kg/m2; Class I and Class II obesity, or approximately 65-95 pounds overweight depending on your height). More well-controlled studies are needed to more completely inform health care decision making and clinical practice in this area. This research study aims to obtain preliminary information regarding the effectiveness of two major types of bariatric surgery, Laparoscopic Roux-en-Y Gastric Bypass and Laparoscopic Adjustable Gastric Banding versus an intensive lifestyle intervention to induce weight loss with diet and increased physical activity.