Reduction in Postoperative Right Ventricular Echocardiographic Indices Predicts Longer Duration of Vasoactive Support After Cardiac Surgery.

Objectives: To assess perioperative right ventricular (RV) echocardiographic indices and their relationship to vasopressor and inotropic support in cardiac surgical patients. The authors hypothesized that a reduction in echocardiographic parameters of RV function would be associated with a longer duration of vasopressor and inotropic support in the intensive care unit (ICU).

Design: A prospective observational study.

The use of Guyton's approach to the control of cardiac output for clinical fluid management.

Infusion of fluids is one of the most common medical acts when resuscitating critically ill patients. However, fluids most often are given without consideration of how fluid infusion can actually improve tissue perfusion. Arthur Guyton's analysis of the circulation was based on how cardiac output is determined by the interaction of the factors determining the return of blood to the heart, i.

Long-term survival and functional outcomes of critically ill patients with hematologic malignancies: a Canadian multicenter prospective study.

Purpose: Patients with hematologic malignancy (HM) commonly develop critical illness. Their long-term survival and functional outcomes have not been well described.

Methods: We conducted a prospective, observational study of HM patients admitted to seven Canadian intensive care units (ICUs) (2018-2020).

The Ins and Outs of IV Fluids in Hemodynamic Resuscitation.

Objectives: Concise definitive review of the physiology of IV fluid (IVF) use in critically ill patients.

Data Sources: Available literature on PubMed and MEDLINE databases.

Study Selection: Basic physiology studies, observational studies, clinical trials, and reviews addressing the physiology of IVF and their use in the critically ill were included.

Fontan Heart: Insight Into the Physiological Role of the Right Heart.

Background: Cardiac output (CO) is almost normal in children born without a functional right ventricle (RV), and a Fontan repair, so why is RV dysfunction such a clinical problem? We tested the hypotheses that increased pulmonary vascular resistance (PVR) is the dominant factor and volume expansion by any means is of limited benefit.

Methods: We removed the RV from a previously used MATLAB model and altered vascular volume, venous compliance (Cv), PVR, and measures of left ventricular (LV) systolic and diastolic function. CO and regional vascular pressures were the primary outcome measures.

Interchangeability of transthoracic and transesophageal echocardiographic right heart measurements in the perioperative setting and correlation with hemodynamic parameters.

Reduction of right ventricular (RV) function after cardiac surgery has been shown to impact outcomes. Conventional indices for right ventricular dysfunction are validated using transthoracic echocardiogram (TTE) which has limited use compared to transesophageal echocardiogram (TEE) in the perioperative settings. The aim of this study was to assess the agreement of RV systolic function assessment with TEE compared to TTE and assess the association of echocardiographic parameter with hemodynamic indices of RV dysfunction.

Right Ventricular Limitation: A Tale of Two Elastances.

Right ventricular (RV) dysfunction is a commonly considered cause of low cardiac output in critically ill patients. Its management can be difficult and requires an understanding of how the RV limits cardiac output. We explain that RV stroke output is caught between the passive elastance of the RV walls during diastolic filling and the active elastance produced by the RV in systole.

Right Ventricular Loading by Lung Inflation during Controlled Mechanical Ventilation.

The inspiratory rise in transpulmonary pressure during mechanical ventilation increases right ventricular (RV) afterload. One mechanism is that when Palv exceeds left atrial pressure, West zone 1 or 2 (non-zone 3) conditions develop, and Palv becomes the downstream pressure opposing RV ejection. The Vt at which this impact on the right ventricle becomes hemodynamically evident is not well established.

Intracellular pH regulation and the acid delusion.

The hydrogen ion concentration ([H]) in intracellular cytoplasmic fluid (ICF) must be maintained in a narrow range in all species for normal protein functions. Thus, mechanisms regulating ICF are of fundamental biological importance. Studies on the regulation of ICF [H] have been hampered by use of pH notation, failure to consider the roles played by differences in the concentration of strong ions (strong ion difference, SID), the conservation of mass, the principle of electrical neutrality, and that [H] and bicarbonate ions [HCO] are dependent variables.

Periodicity, time constants of drainage, and the mechanical determinants of peak cardiac output during exercise.

To analyze mechanical adaptations that must occur in the cardiovascular system to reach the high cardiac outputs known to occur at peak aerobic performance, we adapted a computational model of the circulation by adding a second parallel venous compartment as proposed by August Krogh in 1912. One venous compartment has a large compliance and slow time constant of emptying; it is representative of the splanchnic circulation. The other has a low compliance and fast time constant of emptying and is representative of muscle beds.

Diastolic pressure should be used to guide management of patients in shock: PRO.

Based primarily on the rational that adequate diastolic pressure is needed to maintain sufficient coronary blood for myocardial needs, diastolic pressure has been proposed as a treatment target for patients in shock. To date, clinical evidence supporting this is limited to observational data. Key points are that what is important for tissues is flow not pressure; the coronary circulation has very large flow reserves and can maintain flow with a low pressure; raising arterial pressure by only increasing vascular resistance does not alter tissue perfusion and could even increase myocardial oxygen demand.

Heart-Lung interaction in spontaneous breathing subjects: the basics.

Heart-lung interactions occur primarily because of two components of lung inflation, changes in pleural pressure and changes in transpulmonary pressure. Of these, changes in pleural pressure dominate during spontaneous breathing. Because the heart is surrounded by pleural pressure, during inspiration the environment of the heart falls relative to the rest of the body.

Physical contact between human vascular endothelial and smooth muscle cells modulates cytosolic and nuclear calcium homeostasis.

The interaction between vascular endothelial cells (VECs) and vascular smooth muscle cells (VSMCs) plays an important role in the modulation of vascular tone. There is, however, no information on whether direct physical communication regulates the intracellular calcium levels of human VECs (hVECs) and (or) human VSMCs (hVSMCs). Thus, the objective of the study is to verify whether co-culture of hVECs and hVSMCs modulates cytosolic ([Ca]) and nuclear calcium ([Ca]) levels via physical contact and (or) factors released by both cell types.

Perioperative fluid management in kidney transplantation: a black box.

The incidence of delayed graft function in patients undergoing kidney transplantation remains significant. Optimal fluid therapy has been shown to decrease delayed graft function after renal transplantation. Traditionally, the perioperative volume infusion regimen in this patient population has been guided by central venous pressure as an estimation of the patient's volume status and mean arterial pressure, but this is based on sparse evidence from mostly retrospective observational studies.

Neuropeptide Y and its receptors in ventricular endocardial endothelial cells.

Endocardial endothelial cells (EECs) constitute an important component of the heart. These cells form a monolayer that covers the cavities of the right (EECRs) and left (EECLs) ventricles. They play an important role in cardiac excitation-contraction coupling via their secretion of cardioactive factors such as neuropeptide Y (NPY).

Cardiovascular outcomes with an inhaled beta2-agonist/corticosteroid in patients with COPD at high cardiovascular risk.

Objectives: Cardiovascular disease (CVD) and chronic obstructive pulmonary disease (COPD) often coexist. We assessed the effect of inhaled COPD treatments on CVD outcomes and safety in patients with COPD and at heightened CVD risk.

Methods: The SUMMIT (Study to Understand Mortality and MorbidITy) was a multicentre, randomised, double-blind, placebo-controlled, event-driven trial in 16 485 patients with moderate COPD who had or were at high risk of CVD.

Long-term general and cardiovascular safety of tiotropium/olodaterol in patients with moderate to very severe chronic obstructive pulmonary disease.

Background: Long-term safety, particularly cardiovascular safety, is of special interest in maintenance treatment of chronic obstructive pulmonary disease (COPD) with long-acting β-agonists and long-acting muscarinic antagonists, given potential cardiovascular effects.

Methods: Two 52-week Phase III trials (TONADO) investigated tiotropium/olodaterol (5/5 and 2.5/5 μg) versus tiotropium 2.

Active Expiration and the Measurement of Central Venous Pressure.

Purpose: To obtain a point prevalence estimate of alterations in central venous pressure (CVP) produced by active expiration in a consecutive series of intensive care patients.

Methods: We evaluated CVP tracings taken by the nurses at their morning shift change in a consecutive series of 60 cardiac surgery and 59 noncardiac surgery patients. We also assessed change in values due to the change in transducer level.