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1.
Phys Chem Chem Phys ; 17(37): 23795-804, 2015 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-26305344

RESUMO

High temperature/pressure in situ Attenuated Total Reflection Infrared (ATR-IR) spectroscopy was used to investigate the phase transformation of support γ-Al2O3 into boehmite (AlO(OH)) under the hydrothermal conditions of aqueous phase reforming (APR). Activation energy barriers of boehmite formation in hot compressed water at temperatures between 150 and 180 °C were calculated to be 15.9 ± 4.8 kJ mol(-1) for γ-Al2O3 and 43.2 ± 4.3 kJ mol(-1) for Pt/γ-Al2O3. The influence of Pt particles is suggested to slow down the phase transformation by selective blockage of the surface nucleation sites. The presence of ethylene glycol has also an inhibiting effect on the transformation due to the carbon deposits formed on the oxide surface. Post-mortem analysis using Raman spectroscopy, (1)H and (27)Al MAS NMR confirms the formation of boehmite.

2.
Indian J Chest Dis Allied Sci ; 57 Spec No: 5-52, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26987256

RESUMO

Bronchial asthma is an important public health problem in India with significant morbidity. Several international guidelines for diagnosis and management of asthma are available, however there is a need for country-specific guidelines due to vast differences in availability and affordability of health-care facilities across the globe. The Indian Chest Society (ICS) and the National College of Chest Physicians (NCCP) of India have collaborated to develop evidence-based guidelines with an aim to assist physicians at all levels of health-care in diagnosis and management of asthma in a scientific manner. Besides a systematic review of the literature, Indian studies were specifically analysed to arrive at simple and practical recommendations. The evidence is presented under these five headings: (1) definitions, epidemiology and impact, (2) diagnosis, (3) pharmacologic management of stable disease, (4) management of acute exacerbations, and (5) non-pharmacologic management and special situations. The modified grade system was used for classifying the quality of evidence as 1, 2, 3, or usual practice point (UPP). The strength of recommendation was graded as A or B depending upon the level of evidence.


Assuntos
Asma/diagnóstico , Asma/terapia , Humanos , Índia , Sociedades Médicas
3.
Lung India ; 41(3): 230-248, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38704658

RESUMO

Pleural effusion is a common problem in our country, and most of these patients need invasive tests as they can't be evaluated by blood tests alone. The simplest of them is diagnostic pleural aspiration, and diagnostic techniques such as medical thoracoscopy are being performed more frequently than ever before. However, most physicians in India treat pleural effusion empirically, leading to delays in diagnosis, misdiagnosis and complications from wrong treatments. This situation must change, and the adoption of evidence-based protocols is urgently needed. Furthermore, the spectrum of pleural disease in India is different from that in the West, and yet Western guidelines and algorithms are used by Indian physicians. Therefore, India-specific consensus guidelines are needed. To fulfil this need, the Indian Chest Society and the National College of Chest Physicians; the premier societies for pulmonary physicians came together to create this National guideline. This document aims to provide evidence based recommendations on basic principles, initial assessment, diagnostic modalities and management of pleural effusions.

4.
Lung India ; 41(2): 151-167, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38700413

RESUMO

ABSTRACT: Medical Thoracoscopy (MT) is commonly performed by respiratory physicians for diagnostic as well as therapeutic purposes. The aim of the study was to provide evidence-based information regarding all aspects of MT, both as a diagnostic tool and therapeutic aid for pulmonologists across India. The consensus-based guidelines were formulated based on a multistep process using a set of 31 questions. A systematic search of published randomized controlled clinical trials, open labelled studies, case reports and guidelines from electronic databases, like PubMed, EmBase and Cochrane, was performed. The modified grade system was used (1, 2, 3 or usual practice point) to classify the quality of available evidence. Then, a multitude of factors were taken into account, such as volume of evidence, applicability and practicality for implementation to the target population and then strength of recommendation was finalized. MT helps to improve diagnosis and patient management, with reduced risk of post procedure complications. Trainees should perform at least 20 medical thoracoscopy procedures. The diagnostic yield of both rigid and semirigid techniques is comparable. Sterile-graded talc is the ideal agent for chemical pleurodesis. The consensus statement will help pulmonologists to adopt best evidence-based practices during MT for diagnostic and therapeutic purposes.

5.
Indian J Med Res ; 137(2): 283-94, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23563371

RESUMO

Medical college faculty, who are academicians are seldom directly involved in the implementation of national public health programmes. More than a decade ago for the first time in the global history of tuberculosis (TB) control, medical colleges of India were involved in the Revised National TB Control Programme (RNTCP) of Government of India (GOI). This report documents the unique and extraordinary course of events that led to the involvement of medical colleges in the RNTCP of GOI. It also reports the contributions made by the medical colleges to TB control in India. For more than a decade, medical colleges have been providing diagnostic services (Designated Microscopy Centres), treatment [Directly Observed Treatment (DOT) Centres] referral for treatment, recording and reporting data, carrying out advocacy for RNTCP and conducting operational research relevant to RNTCP. Medical colleges are contributing to diagnosis and treatment of human immunodeficiency virus (HIV)-TB co-infection and development of laboratory infrastructure for early diagnosis of multidrug-resistant and/or extensively drug-resistant TB (M/XDR-TB) and DOTS-Plus sites for treatment of MDR-TB cases. Overall, at a national level, medical colleges have contributed to 25 per cent of TB suspects referred for diagnosis; 23 per cent of 'new smear-positives' diagnosed; 7 per cent of DOT provision within medical college; and 86 per cent treatment success rate among new smear-positive patients. As the Programme widens its scope, future challenges include sustenance of this contribution and facilitating universal access to quality TB care; greater involvement in operational research relevant to the Programme needs; and better co-ordination mechanisms between district, state, zonal and national level to encourage their involvement.


Assuntos
Antituberculosos/uso terapêutico , Tuberculose Extensivamente Resistente a Medicamentos/tratamento farmacológico , Tuberculose Extensivamente Resistente a Medicamentos/epidemiologia , Mycobacterium tuberculosis/patogenicidade , Coinfecção , Educação Médica , Tuberculose Extensivamente Resistente a Medicamentos/complicações , Tuberculose Extensivamente Resistente a Medicamentos/microbiologia , Tuberculose Extensivamente Resistente a Medicamentos/fisiopatologia , Infecções por HIV/complicações , Infecções por HIV/epidemiologia , Humanos , Índia
6.
Indian J Chest Dis Allied Sci ; 55(3): 171-3, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24380227

RESUMO

Fibrous tumours arising entirely within the substance of the lung are rare. We report one such rare case in whom the diagnosis was established after surgical removal.


Assuntos
Broncografia/métodos , Neoplasias Pulmonares/diagnóstico , Tumores Fibrosos Solitários/diagnóstico , Tomografia Computadorizada por Raios X/métodos , Adulto , Biópsia por Agulha Fina , Diagnóstico Diferencial , Feminino , Humanos
7.
Indian J Tuberc ; 69 Suppl 1: S1-S191, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36372542

RESUMO

Inhalational therapy, today, happens to be the mainstay of treatment in obstructive airway diseases (OADs), such as asthma, chronic obstructive pulmonary disease (COPD), and is also in the present, used in a variety of other pulmonary and even non-pulmonary disorders. Hand-held inhalation devices may often be difficult to use, particularly for children, elderly, debilitated or distressed patients. Nebulization therapy emerges as a good option in these cases besides being useful in the home care, emergency room and critical care settings. With so many advancements taking place in nebulizer technology; availability of a plethora of drug formulations for its use, and the widening scope of this therapy; medical practitioners, respiratory therapists, and other health care personnel face the challenge of choosing appropriate inhalation devices and drug formulations, besides their rational application and use in different clinical situations. Adequate maintenance of nebulizer equipment including their disinfection and storage are the other relevant issues requiring guidance. Injudicious and improper use of nebulizers and their poor maintenance can sometimes lead to serious health hazards, nosocomial infections, transmission of infection, and other adverse outcomes. Thus, it is imperative to have a proper national guideline on nebulization practices to bridge the knowledge gaps amongst various health care personnel involved in this practice. It will also serve as an educational and scientific resource for healthcare professionals, as well as promote future research by identifying neglected and ignored areas in this field. Such comprehensive guidelines on this subject have not been available in the country and the only available proper international guidelines were released in 1997 which have not been updated for a noticeably long period of over two decades, though many changes and advancements have taken place in this technology in the recent past. Much of nebulization practices in the present may not be evidence-based and even some of these, the way they are currently used, may be ineffective or even harmful. Recognizing the knowledge deficit and paucity of guidelines on the usage of nebulizers in various settings such as inpatient, out-patient, emergency room, critical care, and domiciliary use in India in a wide variety of indications to standardize nebulization practices and to address many other related issues; National College of Chest Physicians (India), commissioned a National task force consisting of eminent experts in the field of Pulmonary Medicine from different backgrounds and different parts of the country to review the available evidence from the medical literature on the scientific principles and clinical practices of nebulization therapy and to formulate evidence-based guidelines on it. The guideline is based on all possible literature that could be explored with the best available evidence and incorporating expert opinions. To support the guideline with high-quality evidence, a systematic search of the electronic databases was performed to identify the relevant studies, position papers, consensus reports, and recommendations published. Rating of the level of the quality of evidence and the strength of recommendation was done using the GRADE system. Six topics were identified, each given to one group of experts comprising of advisors, chairpersons, convenor and members, and such six groups (A-F) were formed and the consensus recommendations of each group was included as a section in the guidelines (Sections I to VI). The topics included were: A. Introduction, basic principles and technical aspects of nebulization, types of equipment, their choice, use, and maintenance B. Nebulization therapy in obstructive airway diseases C. Nebulization therapy in the intensive care unit D. Use of various drugs (other than bronchodilators and inhaled corticosteroids) by nebulized route and miscellaneous uses of nebulization therapy E. Domiciliary/Home/Maintenance nebulization therapy; public & health care workers education, and F. Nebulization therapy in COVID-19 pandemic and in patients of other contagious viral respiratory infections (included later considering the crisis created due to COVID-19 pandemic). Various issues in different sections have been discussed in the form of questions, followed by point-wise evidence statements based on the existing knowledge, and recommendations have been formulated.


Assuntos
COVID-19 , Doença Pulmonar Obstrutiva Crônica , Criança , Humanos , Idoso , Pandemias , Broncodilatadores/uso terapêutico , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Pessoal de Saúde
8.
Indian J Chest Dis Allied Sci ; 53(2): 113-5, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21545074

RESUMO

Distant metastases in squamous cell carcinoma of head and neck are most often to the lung, liver and bone. They rarely metastasise to chest wall. We report a 60-year-old male patient who initially presented with an abscess over the anterior chest wall that was initially treated for infective pathology. Due to lack of response, cytological examination was performed that turned out to be metastasis from carcinoma larynx.


Assuntos
Carcinoma de Células Escamosas/secundário , Neoplasias Laríngeas/patologia , Neoplasias Torácicas/secundário , Parede Torácica/patologia , Biópsia por Agulha Fina , Carcinoma de Células Escamosas/patologia , Humanos , Neoplasias Laríngeas/tratamento farmacológico , Neoplasias Laríngeas/radioterapia , Masculino , Pessoa de Meia-Idade , Radiografia , Neoplasias Torácicas/patologia , Parede Torácica/diagnóstico por imagem
10.
Lung India ; 36(Supplement): S37-S89, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32445309

RESUMO

Flexible bronchoscopy (FB) is commonly performed by respiratory physicians for diagnostic as well as therapeutic purposes. However, bronchoscopy practices vary widely across India and worldwide. The three major respiratory organizations of the country supported a national-level expert group that formulated a comprehensive guideline document for FB based on a detailed appraisal of available evidence. These guidelines are an attempt to provide the bronchoscopist with the most scientifically sound as well as practical approach of bronchoscopy. It involved framing appropriate questions, review and critical appraisal of the relevant literature and reaching a recommendation by the expert groups. The guidelines cover major areas in basic bronchoscopy including (but not limited to), indications for procedure, patient preparation, various sampling procedures, bronchoscopy in the ICU setting, equipment care, and training issues. The target audience is respiratory physicians working in India and well as other parts of the world. It is hoped that this document would serve as a complete reference guide for all pulmonary physicians performing or desiring to learn the technique of flexible bronchoscopy.

11.
Indian J Chest Dis Allied Sci ; 48(3): 201-3, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-18610678

RESUMO

Occurrence of pneumothorax in silicosis is rare and when it occurs, pneumothorax is usually unilateral. We report here a patient with accelerated silicosis who presented with bilateral spontaneous pneumothoraces occurring simultaneously. The rarity of its clinical presentation in the form of bilateral simultaneous spontaneous pneumothorax combined with the typical clinical and radiological features of accelerated silicosis with tuberculosis make us to report this case.


Assuntos
Pneumotórax/diagnóstico , Pneumotórax/etiologia , Silicose/complicações , Adulto , Humanos , Masculino , Tomografia Computadorizada por Raios X
12.
Indian J Chest Dis Allied Sci ; 48(4): 275-7, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16970295

RESUMO

Isolated pulmonary amoebiasis without involvement of liver and other systems is extremely rare. Its presentation with superior vena cava (SVC) syndrome is not well documented. The case of 38-year-old male who developed SVC syndrome due to a large pulmonary amoebic abscess, which initially mimicked a pulmonary neoplasm with distal lung abscess is presented here. Subsequent bacteriological examination of the aspirated pus and the sputum along with suggestive serology confirmed the diagnosis of pulmonary amoebic abscess.


Assuntos
Amebíase/complicações , Abscesso Pulmonar/complicações , Síndrome da Veia Cava Superior/etiologia , Adulto , Humanos , Masculino
13.
Endocrinology ; 136(2): 431-9, 1995 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-7835273

RESUMO

Insulin-stimulated glucose transport in adipocytes is mediated by the insulin receptor. To ascertain whether a related receptor could also trigger this response, the epidermal growth factor (EGF) receptor (EGFR) was introduced into adipocytes. 3T3-L1 fibroblasts were infected by a retroviral construct encoding either the full-length (WT) or a carboxy-terminal truncated (c'973) human EGFR; truncation of the amino acids distal to 973 removes all autophosphorylation motifs. After selection and conversion to adipocytes, the level of EGFR expression was retained in infectant adipocytes (150,000 and 250,000/cell, respectively), but not in the parental 3T3-L1 adipocytes (< 5000/cell). WT and c'973 EGFR exhibited ligand-dependent tyrosine kinase activity and stimulated mitogen-activated protein kinase activity equivalently; neither phosphorylated insulin receptor substrate-1. WT EGFR, but not c'973 EGFR, underwent ligand-induced autophosphorylation. EGF did not stimulate tyrosine phosphorylation of the insulin receptor or insulin receptor substrate-1. EGF had a minimal effect on glucose transport by parental 3T3-L1 adipocytes. Glucose transport in the WT EGFR adipocytes was stimulated equivalently by insulin and EGF; exposure to insulin and EGF in combination did not result in augmented transport. Glucose transport in the c'973 EGFR adipocytes was stimulated by insulin, but not by EGF. GLUT4 was translocated to the plasma membrane to a similar extent in response to insulin or EGF in the WT EGFR adipocytes; only insulin caused a significant GLUT4 translocation in the parental or c'973 EGFR adipocytes. These data suggest that the insulin and EGF signaling pathways that lead to glucose transport converge in these adipocytes down-stream of the insulin receptor, and that activation of this pathway requires signaling motifs in the carboxy-terminus of the EGFR. This model system represents a novel approach with which to dissect signal transduction pathways in terminally differentiated adipocytes.


Assuntos
Adipócitos/metabolismo , Fator de Crescimento Epidérmico/metabolismo , Receptores ErbB/metabolismo , Glucose/metabolismo , Proteínas Musculares , Células 3T3 , Animais , Transporte Biológico/efeitos dos fármacos , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , DNA Viral/genética , Fator de Crescimento Epidérmico/farmacologia , Receptores ErbB/genética , Transportador de Glucose Tipo 4 , Humanos , Insulina/metabolismo , Insulina/farmacologia , Células L , Camundongos , Proteínas de Transporte de Monossacarídeos/análise , Proteínas de Transporte de Monossacarídeos/efeitos dos fármacos , Proteínas Tirosina Quinases/análise , Proteínas Tirosina Quinases/efeitos dos fármacos , Receptor de Insulina/metabolismo , Transdução de Sinais , Transfecção
14.
J Thorac Cardiovasc Surg ; 104(3): 752-62, 1992 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1513164

RESUMO

Anteroapical left ventricular aneurysms were produced in 23 sheep by coronary arterial ligation. Plication of the aneurysm does not change stroke volume or cardiac output and does not significantly change left ventricular oxygen consumption from the preoperative value of 5.1 +/- 2.6 ml/100 gm per minute. Plication, however, does increase left ventricular end-systolic elastance from 3.2 +/- 0.9 to 4.4 +/- 1.5 mm Hg/mm (p = 0.005). In nine of these sheep the midsagittal plane of the left ventricle was imaged by means of an array of sonomicrometry crystals before and after plication of the aneurysm. Regional wall stresses at end-systole and end-diastole and changes in diastolic function were calculated for anterior and posterior ventricular walls in the border zone adjacent to the aneurysm and in more basilar myocardium remote from the infarct. Plication significantly reduced end-systolic wall stresses and systolic stress integrals in the posterior border zone and remote myocardium, but it did not significantly change anterior wall systolic stresses or stress integrals. Plication also decreased diastolic stretching of border zone myocardium. Plication of anteroapical left ventricular aneurysm produced a shorter, more spherical ventricle and removed the dyskinetic segments but altered deformation (strain) in both circumferential and longitudinal directions. The changes in ventricular wall geometry and deformation provide an explanation for the increased ventricular end-systolic elastance and unchanged stroke volume observed after aneurysm plication.


Assuntos
Aneurisma Cardíaco/cirurgia , Função Ventricular , Animais , Fenômenos Biomecânicos , Débito Cardíaco , Circulação Coronária , Diástole , Ventrículos do Coração/metabolismo , Hemodinâmica , Consumo de Oxigênio , Ovinos , Volume Sistólico , Sístole
15.
J Thorac Cardiovasc Surg ; 112(3): 712-26, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8800160

RESUMO

OBJECTIVES: The first objective was to develop a quantitative method for tracking the three-dimensional geometry of the mitral valve. The second was to determine the complex interrelationships of various components of the mitral valve in vivo. METHODS AND RESULTS: Sixteen sonomicrometry transducers were placed around the mitral vale anulus, at the tips and bases of both papillary muscles, at the ventricular apex, across the ventricular epicardial short axis, and on the anterior chest wall before and during cardiopulmonary bypass in eight anesthetized sheep. Animals were studied later on 17 occasions. Reproducibility of derived chord lengths and three-dimensional coordinates from sonomicrometry array localization, longevity of transducer signals, and the dynamics of the mitral valve and left ventricle were studied. Reproducibility of distance measurements averages 1.6%; Procrustes analysis of three-dimensional arrays of coordinate locations predicts an average error of 2.2 mm. Duration of serial sonomicrometry array localization signals ranges between 60 and 151 days (mean 114 days). Sonomicrometry array localization demonstrates the saddle-shaped mitral anulus, its minimal orifice area immediately before end-diastole, and uneven, apical descent during systole. Papillary muscles shorten only 3.0 to 3.5 mm. Sonomicrometry array localization demonstrates nonuniform torsion of papillary muscle transducers around a longitudinal axis and shows rotation of papillary muscular bases toward each other during systole. CONCLUSION: Tagging of ventricular structures in experimental animals by sonomicrometry array localization images is highly reproducible and suitable for serial observations. In sheep the method provides unique, quantitative information regarding the interrelationship of mitral valvular and left ventricular structures throughout the cardiac cycle.


Assuntos
Ecocardiografia/métodos , Ventrículos do Coração/diagnóstico por imagem , Valva Mitral/diagnóstico por imagem , Animais , Ponte Cardiopulmonar , Cordas Tendinosas/anatomia & histologia , Cordas Tendinosas/diagnóstico por imagem , Cordas Tendinosas/fisiologia , Diástole , Ecocardiografia/instrumentação , Previsões , Ventrículos do Coração/anatomia & histologia , Aumento da Imagem/instrumentação , Aumento da Imagem/métodos , Valva Mitral/anatomia & histologia , Valva Mitral/fisiologia , Músculos Papilares/anatomia & histologia , Músculos Papilares/diagnóstico por imagem , Músculos Papilares/fisiologia , Pericárdio/diagnóstico por imagem , Reprodutibilidade dos Testes , Rotação , Ovinos , Sístole , Transdutores , Função Ventricular Esquerda
16.
J Thorac Cardiovasc Surg ; 109(4): 684-93, 1995 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7715215

RESUMO

Changes in the geometric and intravalvular relationships between subunits of the ovine mitral valve were measured before and after acute posterior wall myocardial infarction in three dimensions by means of sonomicrometry array localization. In 13 sheep, nine sonomicrometer transducers were attached around the mitral anulus and to the tip and base of each papillary muscle. Five additional transducers were placed on the epicardium. Snares were placed around three branches of the circumflex coronary artery. One to 2 weeks later, echocardiograms, dimension measurements, and left ventricular pressures were obtained before and after the coronary arteries were occluded. Data were obtained from seven sheep. Coronary occlusion infarcted 32% of the posterior left ventricle and produced 2 to 3+ mitral regurgitation by Doppler color flow mapping. Multidimensional scaling of dimension measurements obtained from sonomicrometry transducers produced three-dimensional spatial coordinates of each transducer location throughout the cardiac cycle before and after infarction and onset of mitral regurgitation. After posterior infarction, the mitral anulus enlarges asymmetrically along the posterior anulus, and the tip of the posterior papillary muscle moves 1.5 +/- 0.3 mm closer to the posterior commissure at end-systole. The posterior papillary muscle also elongates 1.9 +/- 0.3 mm at end-systole. The left ventricle enlarges asymmetrically and ventricular torsion along the long axis changes. The development of postinfarction mitral regurgitation appears to be the consequence of multiple small changes in ventricular shape and contractile deformation and in the spatial relationship of mitral valvular subunits.


Assuntos
Insuficiência da Valva Mitral/patologia , Infarto do Miocárdio/patologia , Animais , Insuficiência da Valva Mitral/diagnóstico por imagem , Insuficiência da Valva Mitral/etiologia , Infarto do Miocárdio/complicações , Infarto do Miocárdio/diagnóstico por imagem , Ovinos , Ultrassonografia
17.
Ann Thorac Surg ; 49(1): 123-8, 1990 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-2297259

RESUMO

We studied the effects of mechanical circulatory assist devices on left ventricular oxygen consumption, the integrals of systolic left ventricular wall stress (SSI), and end-systolic elastance (Ees) in 8 sheep after 25 minutes of global ischemia. Extracorporeal membrane oxygenation at 35 mL/kg/min, intraaortic balloon counterpulsation, and an intraaortic double-balloon pump were studied alone or in combination. Left ventricular oxygen consumption, SSI, and Ees were measured before and during mechanical circulatory assistance. Left ventricular oxygen consumption was calculated from transit-time measurements of left main coronary artery blood flow and fiberoptic measurements of coronary sinus blood oxygen saturation. Three pairs of sonomicrometry crystals placed across three orthogonal ventricular axes were used to calculate instantaneous ventricular volumes and pressure-volume loops from which the SSI data were derived. The Ees was measured using a new single-beat aortic occlusive method. Extracorporeal membrane oxygenation alone increased SSI and did not change Ees in postischemic poorly contracting hearts. Intraaortic balloon counterpulsation alone significantly reduced SSI and increased Ees. The combination of extracorporeal membrane oxygenation and either the intraaortic balloon pump or the intraaortic double-balloon pump reduced SSI, increased Ees, and reduced left ventricular oxygen consumption. In postischemic dilated, poorly contracting hearts, the combination of extracorporeal membrane oxygenation and intraaortic balloon counterpulsation has important advantages over extracorporeal membrane oxygenation alone.


Assuntos
Doença das Coronárias/fisiopatologia , Coração Auxiliar , Contração Miocárdica , Miocárdio/metabolismo , Consumo de Oxigênio , Animais , Pressão Sanguínea , Volume Cardíaco , Cateterismo , Circulação Coronária , Doença das Coronárias/metabolismo , Contrapulsação , Circulação Extracorpórea , Balão Intra-Aórtico , Oxigenadores de Membrana , Ovinos
18.
Ann Thorac Surg ; 45(5): 526-32, 1988 May.
Artigo em Inglês | MEDLINE | ID: mdl-3365043

RESUMO

Extracorporeal membrane oxygenation (ECMO) reduces the systolic stress integral (SSI) in the normal left ventricle. We tested the hypothesis that the SSI does not decrease in poorly contracting, dilated, ejecting hearts during ECMO. In 14 sheep, four pairs of ultrasonic crystals measured changes in left ventricular (LV) wall thickness and three LV diameters. Volume calculations were validated by balloon distention of the ventricles after death (slope = 0.85; r = 0.85). SSI was measured during ECMO flows of 20 to 100 ml/kg/min in both normal and dilated, poorly contracting hearts produced by 30 minutes of warm ischemia. After warm ischemia, end-systolic elastance, an index of contractility, decreased from 8.3 +/- 0.6 mm Hg/ml to 2.9 +/- 0.4 mm Hg/ml (p = 0.001) and peak systolic pressure decreased from 47.4 +/- 0.7 mm Hg to 37.5 +/- 0.08 mm Hg (p = 0.01). In normal hearts, as ECMO flow increased, SSI decreased from 10.5 +/- 2.2 mm Hg.sec to 7.7 +/- 0.8 mm Hg.sec at 60 ml/kg/min (p = 0.001). However, in postischemic hearts, SSI progressively increased from 6.6 +/- 0.3 mm Hg.sec before ECMO to 12.4 +/- 1.8 mm Hg.sec at ECMO = 100 ml/kg/min. These studies indicate that the initial effect of ECMO on the poorly contracting, dilated heart increases LV wall stress and that the increase in stress is proportional to ECMO flow. The increase in stress is primarily due to an increase in afterload, which more than offsets decreases in systolic and diastolic volumes.


Assuntos
Doença das Coronárias/fisiopatologia , Circulação Extracorpórea , Contração Miocárdica , Oxigenadores de Membrana , Animais , Pressão Sanguínea , Volume Sanguíneo , Ventrículos do Coração/fisiopatologia , Ovinos , Estresse Mecânico
19.
IEEE Trans Biomed Eng ; 42(6): 587-98, 1995 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7790015

RESUMO

We describe a new method which uses sonomicrometry and the statistical technique of multidimensional scaling (MDS) to measure the three-dimensional (3-D) coordinates of multiple cardiac locations. We refer to this new method as sonomicrometry array localization (SAL). The new method differs from standard sonomicrometry in that each piezoelectric transducer element is used as both transmitter and receiver and the set of intertransducer element distances is measured. MDS calculates the 3-D coordinates of each sonomicrometry transducer element from the set of intertransducer element distances. The feasibility of this new method was tested with mathematical simulations which demonstrated the ability of MDS to compensate for signal error and missing intertransducer element distances. We describe the design elements of a modified digitally controlled sonomicrometer in which a single transducer element can sequentially broadcast to as many as eight receiver elements. That design is used to validate SAL in a water bath and in ex vivo and living hearts. Correlation with caliper measurement in the water bath (y int. = 3.91 +/- 3.36 mm, slope = 1.04 +/- 0.05, r2 = 0.969 +/- 0.027) and with radiography in ex vivo (y int. = -0.87 +/- 0.92 mm, slope = 0.97 +/- 0.02, r2 = 0.960 +/- 0.023) and in vivo hearts (y int. = 2.98 +/- 2.59 mm, slope = 1.01 +/- 0.06, r2 = 0.953 +/- 0.031) was excellent. Sonomicrometry array localization is able to accurately measure the 3-D coordinates of multiple cardiac locations. It can potentially measure myocardial deformation and remodeling after ischemic or valvular injury.


Assuntos
Ecocardiografia/métodos , Algoritmos , Animais , Artefatos , Ecocardiografia/instrumentação , Ecocardiografia/estatística & dados numéricos , Estudos de Viabilidade , Técnicas In Vitro , Microcomputadores , Modelos Estruturais , Distribuição Normal , Reprodutibilidade dos Testes , Ovinos , Transdutores
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