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Hemodynamic Monitoring (hemodynamic + monitoring)
Selected AbstractsBench to Bedside: Electrophysiologic and Clinical Principles of Noninvasive Hemodynamic Monitoring Using Impedance CardiographyACADEMIC EMERGENCY MEDICINE, Issue 6 2003Richard L. Summers MD Abstract The evaluation of the hemodynamic state of the severely ill patient is a common problem in emergency medicine. While conventional vital signs offer some insight into delineating the circulatory pathophysiology, it is often impossible to determine the true clinical state from an analysis of blood pressure and heart rate alone. Cardiac output measurements by thermodilution have been the criterion standard for the evaluation of hemodynamics. However, this technology is invasive, expensive, time-consuming, and impractical for most emergency department environments. Impedance cardiography (ICG) is a noninvasive method of obtaining continuous measurements of hemodynamic data such as cardiac output that requires little technical expertise. ICG technology was first developed by NASA in the 1960s and is based on the idea that the human thorax is electrically a nonhomogeneous, bulk conductor. Variation in the impedance to flow of a high-frequency, low-magnitude alternating current across the thorax results in the generation of a measured waveform from which stroke volume can be calculated by a modification of the pulse contour method. To adequately judge the possible role of this technology in the practice of emergency medicine, it is important to have a sufficient understanding of the basic scientific principles involved as well as the clinical validity and limitations of the technique. [source] Hemodynamic Monitoring During Syncope: Utility and LimitationsJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 1 2009MOHAMED H. HAMDAN M.D. [source] Percutaneous transtracheal emergency ventilation with a self-made device in an animal modelPEDIATRIC ANESTHESIA, Issue 10 2007RAIK SCHAEFER Summary Background:, Special equipment for emergency percutaneous transtracheal ventilation is often not immediately available. We used a self-made device consisting of a three-way stopcock connected between a G-15 transtracheal airway catheter and an oxygen supply in a simulated 'cannot intubate, cannot ventilate' scenario and tested the hypothesis that the effectiveness of the device depends on the body weight of the experimental animals. Methods:, With approval of the local animal protection committee, two groups of six pigs each with a body weight of 21 ± 2 and 36 ± 6 kg, respectively, were tracheally intubated and mechanically ventilated after induction of anesthesia. Hemodynamic monitoring included cardiac output and arterial, central venous and pulmonary artery pressures. An emergency transtracheal airway catheter was inserted into the trachea and a situation of partial expiratory airway obstruction was created. Each animal was ventilated for 15 min via the transtracheal airway catheter with the self-made device (FiO2 1.0 at an oxygen flow of 15 l·min,1; respiratory rate of 60 min,1; I/E ratio approximately 1 : 1). Results:, Whereas satisfactory oxygenation was achieved in all animals, sufficient ventilation was obtained only in the lightweight animals. Conclusions:, Adequate oxygenation could be provided by jet-like transtracheal ventilation with a simple self-made device using easily available materials. Sufficient ventilation depends on the body weight of the animals. [source] The Use of Impedance Cardiography in Predicting Mortality in Emergency Department Patients With Severe Sepsis and Septic ShockACADEMIC EMERGENCY MEDICINE, Issue 4 2010Anthony M. Napoli MD Abstract Objectives:, Pulmonary artery catheterization poses significant risks and requires specialized training. Technological advances allow for more readily available, noninvasive clinical measurements of hemodynamics. Few studies exist that assess the efficacy of noninvasive hemodynamic monitoring in sepsis patients. The authors hypothesized that cardiac index, as measured noninvasively by impedance cardiography (ICG) in emergency department (ED) patients undergoing early goal-directed therapy (EGDT) for sepsis, would be associated with in-hospital mortality. Methods:, This was a prospective observational cohort study of patients age over 18 years meeting criteria for EGDT (lactate > 4 or systolic blood pressure < 90 after 2 L of normal saline). Initial measurements of cardiac index were obtained by ICG. Patients were followed throughout their hospital course until discharge or in-hospital death. Cardiac index measures in survivors and nonsurvivors are presented as means and 95% confidence intervals (CI). Diagnostic performance of ICG in predicting mortality was tested by receiver operating characteristic (ROC) curve and areas under the ROC curves (AUC) were compared using Wilcoxon test. Results:, Fifty-six patients were enrolled; one was excluded due to an inability to complete data acquisition. The mean cardiac index in nonsurvivors (2.3 L/min·m2, 95% CI = 1.6 to 3.0) was less than that for survivors (3.2, 95% CI = 2.9 to 3.5) with mean difference of 0.9 (95% CI = 0.12 to 1.71). The AUC for ICG in predicting mortality was 0.71 (95% CI = 0.58 to 0.88; p = 0.004). A cardiac index of < 2 L/min·m2 had a sensitivity of 43% (95% CI = 18% to 71%), specificity of 93% (95% CI = 80% to 95%), positive likelihood ratio of 5.9, and negative likelihood ratio of 0.6 for predicting in-hospital mortality. Conclusions:, Early, noninvasive measurement of the cardiac index in critically ill severe sepsis and septic shock patients can be performed in the ED for those who meet criteria for EGDT. There appears to be an association between an initial lower cardiac index as measured noninvasively and in-hospital mortality. ACADEMIC EMERGENCY MEDICINE 2010; 17:452,455 © 2010 by the Society for Academic Emergency Medicine [source] Reliability of a new ultrasonic cardiac output monitor in recipients of living donor liver transplantation,,§¶LIVER TRANSPLANTATION, Issue 7 2008Bai-Chuan Su The ultrasonic cardiac output monitor (USCOM) is a new Doppler device for noninvasive hemodynamic monitoring. The aim of this prospective nonrandomized study was to test the feasibility, perioperative reliability, and clinical applicability of using USCOM as an alternative to pulmonary artery catheterization in recipients of living donor liver transplantation. Thirteen patients scheduled to receive living donor liver transplants were initially recruited. Three were subsequently excluded prior to the commencement of surgery because of technical difficulties in obtaining diagnostic-quality images with USCOM. Ten patients proceeded to be studied. Cardiac output measurements by thermodilution and USCOM were compared at 30-minute intervals throughout the procedure and at 10 specific procedural reference points during the surgery when hemodynamic changes were most likely to be observed. The data were analyzed with Lin's concordance coefficient and Bland-Altman analysis. Two hundred ninety paired cardiac output values were obtained from the 10 patients. The concordance between both methods was excellent in 8 patients and satisfactory in 2. Bland-Altman analysis of all data produced a mean bias of , 0.02 L/minute for USCOM, and the 95% limits of agreement were ,1.06 to +1.10 L/minute. Further analysis of the 10 reference time points showed minimal bias and high levels of agreement between the methods. We conclude that USCOM provides an accurate and noninvasive method for cardiac output measurement during liver transplantation. It may therefore represent an alternative to pulmonary artery catheter placement with consequent reduction in patient's risk and morbidity associated with catheterization. Liver Transpl 14:1029,1037, 2008. © 2008 AASLD. [source] Critical management in patients with severe enterovirus 71 infectionPEDIATRICS INTERNATIONAL, Issue 3 2006JIEH-NENG WANG Abstract Objective: The aim of this study was to analyze clinical details occurring in children with severe enterovirus 71 (EV71) infection and synthesize the critical care experience for patients with severe EV71 infection. Methods: A retrospective clinical, laboratory, and hemodynamic study was performed in a pediatric intensive care unit in a university hospital. From March 1998 to April 2000, seven consecutive pediatric patients with severe EV71 infection were retrospectively analyzed as the comparison group. From May 2000 to March 2003, eight consecutive patients with severe EV71 infection who had received the protocol therapy were enrolled as the study group. Detailed information about clinical treatment and pharmacological therapy was collected for comparison. Results: The clinical presentations and laboratory findings between the comparison and the study groups were not significantly different. The amount of intravenous fluid in the first 24 h was significantly higher in the comparison group (9.2 ± 5.0 vs 4.9 ± 1.3 mL/kg per h). More patients in the study group received low doses of dopamine infusion, patients in the comparison group received more epinephrine, and none of them received milrinone. The acute-stage and long-term survival rates were higher in the study group (100% vs 43%, 87% vs 29%). Conclusion: Early cardiopulmonary support may prevent the vicious cycle of cardiopulmonary failure and improve the clinical outcome of severe EV71 infection. Milrinone may be the ideal inotropic agent for these patients. Echocardiography, a central line, and an arterial line could be an alternate method to replace direct intracardiac hemodynamic monitoring for guiding critical management. [source] Cocaine and Ethanol: Combined Effects on Coronary Artery Blood Flow and Myocardial Function in DogsACADEMIC EMERGENCY MEDICINE, Issue 7 2009Lance D. Wilson MD Abstract Objectives:, In combination, cocaine and ethanol are more cardiotoxic than is either substance alone. These substances together constitute a drug abuse combination that commonly results in fatality. Previously the authors have demonstrated that cardiotoxicity of cocaine and ethanol is in part due to synergistic myocardial-depressant effects. However, it remains unclear whether this myocardial depression is associated with concomitant adverse effects on coronary blood flow in relation to these substances. The aim of this study was to investigate combined effects of cocaine and ethanol on myocardial blood flow, in relation to indices of myocardial function. Methods:, Anesthetized dogs were instrumented for hemodynamic monitoring with Doppler flow probes placed on the circumflex and left anterior descending (LAD) coronary arteries. Dogs were randomized to three groups (each n = 6): ethanol (E, 1.5 g/kg followed by placebo), cocaine (C, placebo followed by cocaine, 7.5 mg/kg IV), or cocaine plus ethanol (C + E). All measurements were made at control, after placebo or ethanol, and then at fixed time intervals after cocaine or placebo bolus over 3 hours. Results:, In both the C + E and the C groups, circumflex blood flow (CBF) decreased by 71% (95% confidence interval [CI] = 56% to 85%) and 57% (95% CI = 43% to 72%, both p < 0.04 vs. baseline) immediately after cocaine bolus. This was associated with transient depression of cardiac output, myocardial contractile function, and rate-pressure product (RPP), all indices of myocardial oxygen demand. A subsequent rebound increase of coronary sinus blood flow (CSBF) of 56% (95% CI = 26% to 137%, p < 0.03) compared to baseline occurred only in the C group and was associated with increases of myocardial contractile function and RPP. In the C + E group, 2 hours after drug administration, there was a decrease in CSBF of 49% (95% CI = 32% to 67%; p < 0.01) compared to baseline, which was associated with concomitant numerical decreases of the indices of myocardial oxygen demand and accumulation of cocaethylene. Conclusions:, Acute decreases in myocardial flow secondary to cocaine, and cocaine and ethanol in combination, were similar and temporally associated with cocaine's direct myocardial-depressant effects. Rebound increases in myocardial function and blood flow due to cocaine were attenuated by ethanol. Delayed myocardial depression and decreases in myocardial blood flow were observed only with coadministration of cocaine and ethanol. [source] Hemodynamic Changes in a Model of Chronic Heart Failure Induced by Multiple Sequential Coronary Microembolization in SheepARTIFICIAL ORGANS, Issue 11 2009Jan Dieter Schmitto Abstract Although a large variety of animal models for acute ischemia and acute heart failure exist, valuable models for studies on the effect of ventricular assist devices in chronic heart failure are scarce. We established a stable and reproducible animal model of chronic heart failure in sheep and aimed to investigate the hemodynamic changes of this animal model of chronic heart failure in sheep. In five sheep (n = 5, 77 ± 2 kg), chronic heart failure was induced under flouroscopic guidance by multiple sequential microembolization through bolus injection of polysterol microspheres (90 µm, n = 25.000) into the left main coronary artery. Coronary microembolization (CME) was repeated up to three times in 2 to 3-week intervals until animals started to develop stable signs of heart failure. During each operation, hemodynamic monitoring was performed through implantation of central venous catheter (central venous pressure [CVP]), arterial pressure line (mean arterial pressure [MAP]), implantation of a right heart catheter {Swan-Ganz catheter (mean pulmonary arterial pressure [PAPmean])}, pulmonary capillary wedge pressure (PCWP), and cardiac output [CO]) as well as pre- and postoperative clinical investigations. All animals were followed for 3 months after first microembolization and then sacrificed for histological examination. All animals developed clinical signs of heart failure as indicated by increased heart rate (HR) at rest (68 ± 4 bpm [base] to 93 ± 5 bpm [3 mo][P < 0.05]), increased respiratory rate (RR) at rest (28 ± 5 [base] to 38 ± 7 [3 mo][P < 0.05]), and increased body weight 77 ± 2 kg to 81 ± 2 kg (P < 0.05) due to pleural effusion, peripheral edema, and ascites. Hemodynamic signs of heart failure were revealed as indicated by increase of HR, RR, CVP, PAP, and PCWP as well as a decrease of CO, stroke volume, and MAP 3 months after the first CME. Multiple sequential intracoronary microembolization can effectively induce myocardial dysfunction with clinical and hemodynamic signs of chronic ischemic cardiomyopathy. The present model may be suitable in experimental work on heart failure and left ventricular assist devices, for example, for studying the impact of mechanical unloading, mechanisms of recovery, and reverse remodeling. [source] Rapid clinical assessment of hemodynamic profiles and targeted treatment of patient with acutely decompensated heart failureCLINICAL CARDIOLOGY, Issue S5 2004Greegg C. Fonarow M.D. Abstract Acutely decompensated heart failure (ADHF) is characterized by hemodynamic abnormalities and neurohormonal activation that contribute to heart failure (HF) symptoms, end-organ dysfunction, arrhythmias, and progressive cardiac failure. The management of ADHF in the emergency department (ED) can be simplified and improved by a 2-min bedside assessment that identifies any of four possible hemodynamic profiles on the basis of clinical signs and symptoms. The profiles are based on whether congestion is present or absent (wet or dry) and perfusion is adequate or limited (warm or cold). A wet-warm profile is seen more frequently in the ED than any of the other three profiles (wet-cold, dry-warm, and dry-cold). The four clinically determined profiles have been shown to predict clinical outcomes and may be used to guide initial HF therapy. The goals of treating ADHF are to stabilize the patient, reverse acute hemodynamic abnormalities, rapidly reverse dyspnea and/or hypoxemia caused by pulmonary congestion, and initiate treatments that will decrease disease progression and improve survival. An ideal agent for the wet-warm profile would rapidly reduce pulmonary congestion, produce balanced arterial and venous dilation, promote natriuresis, lack direct positive inotropic effects, and not cause reflex neuroendocrine activation. Intravenous nesiritide in conjunction with loop diuretics has been found safe and effective as initial treatment for patients with the wet-warm profile. For the wet-cold profile, more intensive therapy and invasive hemodynamic monitoring may prove useful. This review will discuss the rapid clinical determination of hemodynamic profiles in patients presenting to the ED with ADHF and the options for their initial medical management. Case studies representing the wet-warm, wet-cold, dry-warm, and dry-cold profiles will be presented and discussed. [source] Hemodynamic significance of heart rate in neurally mediated syncopeCLINICAL CARDIOLOGY, Issue 11 2004Wan Leong Chan M.D. Abstract Background: Vasovagal and vasodepressor syncope are used interchangeably in the literature to describe the common faint syndrome, now collectively named neurally mediated syncope. The significance of heart rate (HR) in these reflex-induced reactions remains unclear. Hypothesis: The study was undertaken to investigate the hemodynamic significance of HR in tilt-induced neurally mediated syncope. Methods: In all, 113 patients with syncope of unknown etiology were studied by head-up tilt test with invasive hemodynamic monitoring. Thirty-five patients (15 women, 20 men, age range 21 to 72 years) developed syncope and were enrolled for analysis. The hemodynamic data were compared between patients who developed bradycardia (vasovagal group, n = 15) and those without bradycardia (vasodepressor group, n = 20). Results: The baseline hemodynamic data (mean ± standard deviation) and the hemodynamic responses after 10-min head-up tilt were similar between patients in the vasovagal and vasodepressor groups. During syncope, patients with vasovagal reaction developed hypotension and paradoxical bradycardia (HR = 52.4 ± 5.9 beats/min), while patients with vasodepressor reaction developed a precipitous drop in arterial blood pressure with inappropriate HR (105 ± 21 beats/min) compensation. Patients with vasovagal syncope manifested a significantly lower cardiac index and a significantly higher systemic vascular resistance index than patients with vasodepressor syncope (1.47 ±0.29 vs. 1.97 ±0.41 l/min/m2, p< 0.001 and 2098 ± 615 vs. 1573 ± 353 dynes·s·cm,5·m2, p<0.003, respectively). A positive correlation existed between HR and cardiac index (r = 0.44, p = 0.008) during syncope in the patients studied. Conclusions: These findings suggest that the hemodynamic characteristics of vasovagal and vasodepressor reactions are different, and that HR plays a significant role in neurally mediated syncope. [source] Maximizing management of patients with decompensated heart failureCLINICAL CARDIOLOGY, Issue S3 2000E. Loh M.D. Abstract Patients with decompensated congestive heart failure can be categorized into those with either acute or chronic presentations. Patients with acute decompensated heart failure most often have an acute injury that affects either myocardial performance (i.e., myocardial infarction) or valvular/chamber integrity (mitral regurgitation, ventricular septal rupture), which leads to an acute rise in left ventricular (LV) filling pressures resulting in pulmonary edema and dyspnea. Therapy for these patients is aimed at treating the underlying cause of the myocardial injury as well as pharmacologic strategies to reduce LV filling pressures and to improve cardiac performance. In contrast, the therapy of patients presenting with decompensated heart failure in the setting of chronic LV systolic dysfunction, treated with angiotensin-converting enzyme inhibitors, digoxin, diuretics, and maybe beta blockers, represent a poorly defined clinical entity that lacks clear guidelines for treatment. These patients can present with symptoms of volume overload and/or low cardiac output without evidence for a volume overloaded state. Potential diagnostic and therapeutic approaches include (1) a pulmonary artery catheter for invasive hemodynamic monitoring, (2) intravenous inotropic therapy, (3) LV mechanical assist device therapy, and (4) cardiac transplantation. This review presents some of the advantages and disadvantages of each of these interventions for patients with chronic systolic dysfunction who present with decompensated symptoms and require specialized management in the hospital setting. [source] | ||||||||||