Oxygen consumption cardiopulmonary bypass

BACKGROUND: Cardiac valve replacement (CVR) is currently the main surgical treatment for patients with valvular heart diseases (VHD). Postoperative cognitive dysfunction (POCD) is one of the most serious complications of cardiac surgery. Permissive hypercapnia (PHC), an important lung-protective ventilation strategy, has protective effects on vital organs, including the heart, lungs, and central nervous system (CNS). The main objective of this study is to assess the effect of the PHC ventilation strategy on rSO2 and postoperative cognitive function in patients undergoing CVR...

OBJECTIVE: Adenosine triphosphate potassium sensitive channels provide endogenous myocardial protection via coupling of cell membrane potential to myocardial metabolism. Adenosine triphosphate potassium sensitive channel openers, such as diazoxide, mimic ischemic preconditioning, prevent cardiomyocyte swelling, preserve myocyte contractility after stress, and provide diastolic protection. We hypothesize that diazoxide combined with hyperkalemic cardioplegia provides superior myocardial protection compared with cardioplegia alone during prolonged global ischemia in a large animal model...

Extracorporeal life support (ECLS) is a treatment modality that provides prolonged blood circulation, gas exchange and can partially support or fully substitute functions of heart and lungs in patients with severe but potentially reversible cardiopulmonary failure refractory to conventional therapy. Due to high-volume bypass, the extracorporeal flow is interacting with native cardiac output. The pathophysiology of circulation and ECLS support reveals significant effects on arterial pressure waveforms, cardiac hemodynamics, and myocardial perfusion...

Background: Myocardial protection in cardiac surgeries is a must and requires multimodal approaches in perioperative period to decrease and prevent the increase of myocardial oxygen demand and consumption that lead to postoperative cardiac complications including myocardial ischemia, dysfunction, and heart failure. Study Design: Prospective, controlled, randomized, double-blinded study. Aims: This study aims to study the effect of propofol-dexmedetomidine continuous infusion cardioprotection during open-heart surgery in adult patients...

BACKGROUND: The objective of cardiopulmonary bypass (CPB) is to maintain an adequate balance between oxygen delivery (Ḋo2 ) and consumption. The critical Ḋo2 is that at which consumption becomes supply dependent. This study aimed to identify the critical Ḋo2 in neonates, who have higher metabolic rates than adults. METHODS: In a retrospective cohort of neonates, Ḋo2 was calculated from CPB parameters recorded during aortic cross-clamping. High lactate concentration measured after aortic unclamping (lactOFF) was used to identify anaerobic metabolism...

BACKGROUND: Patients undergoing heart surgery involving cardiopulmonary bypass (CPB) experience global myocardial ischemia with subsequent reperfusion which, despite cardioplegic protection, may result in different degrees of transient ventricular dysfunction. Levosimendan is a "calcium sensitisers", it improves myocardial contractility by sensitising troponin C to calcium without increasing myocardial oxygen consumption and without impairing relaxation and diastolic function. AIM: To evaluate the adding effect of a calcium sensitiser (levosimendan) compared to the conventional inotropic and vasoactive agent used in the patient with poor left ventricular function undergoing cardiac surgery on different measured hemodynamic variables and the effect on the outcome...

PURPOSE: Early postoperative heart failure is common after cardiac surgery, and inotrope treatment may impact renal perfusion and oxygenation. We aimed to study the renal effects of the inodilator milrinone when used for the treatment of heart failure after weaning from cardiopulmonary bypass (CPB). MATERIAL AND METHODS: In 26 patients undergoing cardiac surgery with CPB, we used renal vein catheterization to prospectively measure renal blood flow (RBF), glomerular filtration rate (GFR), and renal oxygenation...

INTRODUCTION: Low oxygen delivery during cardiopulmonary bypass is related to a range of adverse outcomes. Previous research specified certain critical oxygen delivery levels associated with acute kidney injury. However, a single universal critical oxygen delivery value is not sensible, as oxygen consumption has to be considered when determining critical delivery values. This study examined the associations between oxygen delivery and oxygen consumption and between oxygen delivery and kidney function in patients undergoing cardiopulmonary bypass...

<AbstractText Label="OBJECTIVES" NlmCategory="OBJECTIVE">Acute kidney injury is a well-known complication after cardiac surgery and cardiopulmonary bypass (CPB). In this experimental animal study, we evaluated the effects of atrial natriuretic peptide (ANP) on renal function, perfusion, oxygenation and tubular injury during CPB. METHODS: Twenty pigs were blindly randomized to continuous infusion of either ANP (50 ng/kg/min) or placebo before, during and after CPB. Renal blood flow as well as cortical and medullary perfusion was measured...

BACKGROUND: Levosimendan, a calcium sensitizer and potassium channel opener, has been demonstrated to improve myocardial function without increasing oxygen consumption and to show protective effects in other organs. Recently, a prospective, randomized controlled trial (RCT) revealed an association between levosimendan use and a possible increased risk of bleeding postoperatively. Levosimendan's anti-platelet effects have been shown in in vitro studies. Current studies do not provide sufficient data to support a relation between perioperative levosimendan administration and increased bleeding risk...

We have previously developed a three-dimensional computational model of oxygen transport in the renal medulla. In the present study, we used this model to quantify the sensitivity of renal medullary oxygenation to four of its major known determinants: medullary blood flow (MBF), medullary oxygen consumption rate (V̇o2,M ), hemoglobin (Hb) concentration in the blood, and renal perfusion pressure. We also examined medullary oxygenation under special conditions of hydropenia, extracellular fluid volume expansion by infusion of isotonic saline, and hemodilution during cardiopulmonary bypass...

BACKGROUND: The benefits of fenestration for patients undergoing Fontan procedure seem controversial at early and late postoperative stages. OBJECTIVE: We aimed to compare the outcomes between the fenestrated and non-fenestrated Fontan procedures. METHODS: Studies comparing the fenestrated and non-fenestrated Fontan procedures were identified by searching the PubMed, EMBASE, and Cochrane Library databases until July 2018. The assessed variables included postoperative oxygen saturation (SaO2), pulmonary artery pressure, mortality, cardiopulmonary bypass (CPB) time, ventilation time, intensive care unit stay, hospital stay, chest tube duration, protein-losing enteropathy, arrhythmia, and other follow-up outcomes including reintervention, stroke/thrombosis, and peak oxygen consumption...

A primary goal of improving neonatal cardiopulmonary bypass has been making the circuit smaller and reduce the blood contacting surfaces. As bypass circuit size has decreased, bloodless surgery has become possible even in neonates. Since transfusion guidelines are difficult to construct based on existing literature, these technical advances should be taken advantage of in conjunction with an individualized transfusion scheme, based on monitoring of oxygen availability to the tissues. For the majority of neonatal heart operations, several centers have shifted toward normothermic bypass even for complex neonatal surgeries, in order to avoid the adverse effects of hypothermia...

BACKGROUND: Cardiac surgery with cardiopulmonary bypass (CPB) is associated with acute kidney injury, and the risk increases with low oxygen delivery during CPB. We hypothesized that renal oxygenation could be improved at higher than normal CPB flow rates. METHODS: After ethical approval and informed consent, 17 patients with normal serum creatinine undergoing normothermic CPB were included and received pulmonary artery and renal vein catheters after anesthesia induction for measurements of systemic and renal variables...

AIMS: It has been widely accepted that ischemic preconditioning (IPC) exhibits a promising and reproducible cardioprotective effect against ischemia/reperfusion (I/R) injury. However, the actual trigger that amplifies the molecular signaling and protects I/R heart is still unclear. MAIN METHODS: To separate the factors involved in IPC, we established a dog double-circuit cardiopulmonary bypass (CPB) model, which consists of a systemic circuit and a coronary circuit...

OBJECTIVES: Cardiac surgery-associated acute kidney injury is common in children and associates with negative outcomes. Novel interventions to reduce cardiac surgery-associated acute kidney injury require knowledge of its pathophysiology. States of altered perfusion, oxygen delivery, and energy consumption occur during cardiopulmonary bypass and could protect against or contribute to renal cellular injury and recovery. Near-infrared spectroscopy is noninvasive technology for monitoring regional blood flow and tissue oxygenation...

Tetralogy of Fallot (TOF) often carries long-term seqüelae following surgical intervention. We hypothesized that early perioperative factors are associated with long-term adverse right ventricular (RV) remodeling, diminished exercise capacity, and increased morbidity. We conducted a retrospective cohort study of patients operated for TOF that underwent cardiac magnetic resonance imaging study (CMR), exercise stress test (EST), and detailed review of past medical history. Outcome variables included measures of RV size, and function, maximal work rate, and oxygen consumption, and interim hospitalizations, surgeries, and catheterizations...

Aims: Assessments of cardiac rehabilitation (CR) in coronary heart disease (CHD) cohorts usually examine mortality in aggregate. This study examines the prognosis and characteristics of patients who enrolled and completed CR, stratified by their level of improvement in cardiorespiratory fitness (CRF) by examining the characteristics, outcomes and predictors of non-response in CRF (NonRes) compared with low-responders (LowRes) and high-responders (HighRes) after CR. Methods and results: A total of 1171 CHD patients were referred for a phase II CR programme after therapy for an acute coronary syndrome, coronary artery bypass graft procedure or a percutaneous coronary intervention between 1 January 2000 and 30 June 2013 underwent cardiopulmonary exercise testing before and after CR...

Following cardiac surgery, hyperlactatemia due to anaerobic metabolism is associated with an increase in both morbidity and mortality. We previously found that an elevated respiratory quotient (RQ) predicts anaerobic metabolism. In the present study we aimed to demonstrate that it is also associated with poor outcome following cardiac surgery. This single institution, prospective, observational study includes all those patients that were consecutively admitted to the intensive care unit (ICU) after cardiac surgery with cardiopulmonary bypass, that had also been monitored using pulmonary artery catheter...

BACKGROUND: Pulsatile perfusion may offer microcirculatory advantages over conventional nonpulsatile perfusion during cardiopulmonary bypass (CPB). Here, we present direct visual evidence of microvascular perfusion and vasoreactivity between perfusion modalities. METHODS: A prospective, randomized cohort study of 20 high-risk cardiac surgical patients undergoing pulsatile (n = 10) or nonpulsatile (n = 10) flow during CPB was conducted. Changes in sublingual mucosal microcirculation were assessed with orthogonal polarization spectral imaging along with near-infrared spectroscopic indices of thenar muscle tissue oxygen saturation (StO2 ) and its recovery during a vascular occlusion test at the following time points: baseline (T0 ), 30 minutes on CPB (T1 ), 90 minutes on CPB (T2 ), 1 hour after CPB (T3 ), and 24 hours after CPB (T4 )...