scholarly journals Myocardial oxygen consumption during histidine-tryptophan-ketoglutarate cardioplegia in young human hearts

2021 ◽  
Author(s):  
Emanuela Angeli ◽  
Sabrina Martens ◽  
Lucio Careddu ◽  
Francesco D Petridis ◽  
Andrea G Quarti ◽  
...  
Keyword(s):  
Cardiac Surgery ◽  
Oxygen Consumption ◽  
Energy Demand ◽  
Myocardial Oxygen Consumption ◽  
Myocardial Protection ◽  
Cardiac Cells ◽  
Fick Principle ◽  
Group I ◽  
Perfusion Time ◽  
The Mean

Abstract OBJECTIVES Energy demand and supply need to be balanced to preserve myocardial function during paediatric cardiac surgery. After a latent aerobic period, cardiac cells try to maintain energy production by anaerobic metabolism and by extracting oxygen from the given cardioplegic solution. Myocardial oxygen consumption (MVO2) changes gradually during the administration of cardioplegia. METHODS MVO2 was measured during cardioplegic perfusion in patients younger than 6 months of age (group N: neonates; group I: infants), with a body weight less than 10 kg. Histidine-tryptophan-ketoglutarate crystalloid solution was used for myocardial protection and was administered during a 5-min interval. To measure pO2 values during cardioplegic arrest, a sample of the cardioplegic fluid was taken from the inflow line before infusion. Three fluid samples were taken from the coronary venous effluent 1, 3 and 5 min after the onset of cardioplegia administration. MVO2 was calculated using the Fick principle. RESULTS The mean age of group N was 0.2 ± 0.09 versus 4.5 ± 1.1 months in group I. The mean weight was 3.1 ± 0.2 versus 5.7 ± 1.6 kg, respectively. MVO2 decreased similarly in both groups (min 1: 0.16 ± 0.07 vs 0.36 ± 0.1 ml/min; min 3: 0.08 ± 0.04 vs 0.17 ± 0.09 ml/min; min 5: 0.05 ± 0.04 vs 0.07 ± 0.05 ml/min). CONCLUSIONS We studied MVO2 alterations after aortic cross-clamping and during delivery of cardioplegia in neonates and infants undergoing cardiac surgery. Extended cardioplegic perfusion significantly reduces energy turnover in hearts because the balance procedures are both volume- and above all time-dependent. A reduction in MVO2 indicates the necessity of a prolonged cardioplegic perfusion time to achieve optimized myocardial protection.

Direct observation of radial intracellular P O 2 gradients in a single cardiomyocyte of the rat

1998 ◽  
Vol 275 (1) ◽  
pp. H225-H233 ◽  
Author(s):  
Eiji Takahashi ◽  
Keiko Sato ◽  
Hiroshi Endoh ◽  
Zhe-Long Xu ◽  
Katsuhiko Doi
Keyword(s):  
Oxygen Consumption ◽  
Cardiac Cells ◽  
Facilitated Diffusion ◽  
Single Individual ◽  
Radial Profiles ◽  
Carbonyl Cyanide ◽  
Increase Oxygen Consumption ◽  
The Mean ◽  
Rat Ventricle

The purpose of the present study was to directly visualize radial gradients of intracellular [Formula: see text] in a single individual cardiomyocyte isolated from the rat ventricle. Microspectrophotometry with the use of cytosolic myoglobin as an oxygen probe was conducted at 410 nm. When the quiescent cell was incubated with 1 μM carbonyl cyanide m-chlorophenylhydrazone to increase oxygen consumption approximately eightfold, gradual decreases in myoglobin oxygen saturation (SMb) were demonstrated toward the core of the cell, whereas these decreases disappeared when the cell was treated with 2 mM NaCN. These results highlighted the importance of diffusional oxygen transport in determining intracellular oxygenation in cardiac cells. From the measured SMb, we assessed the profile of radial changes in intracellular [Formula: see text]at the mean SMb comparable to that in vivo (∼0.5). Quite steep [Formula: see text]gradients were demonstrated in the vicinity of the sarcolemma that were rapidly attenuated toward the cell core. These radial profiles of intracellular [Formula: see text] demonstrate the significance of myoglobin-facilitated diffusion of oxygen. Furthermore, the shallow gradients of [Formula: see text] near the center of the cell might arise from partial depression of oxygen consumption near the cell core.

Oxygen transport and oxygen consumption vs. cardiac output at different haematocrits

Perfusion ◽  
1987 ◽  
Vol 2 (1) ◽  
pp. 39-50 ◽  
Author(s):  
Esther P Hill ◽  
David C Willford ◽  
William Y Moores ◽  
Ronald Bellamy ◽  
William H Heydorn
Keyword(s):  
Cardiac Output ◽  
Oxygen Consumption ◽  
Flow Rate ◽  
Oxygen Transport ◽  
Blood Flow Rate ◽  
Fick Principle ◽  
Pump Flow ◽  
Arterial Blood ◽  
Group I ◽  
Pump Flow Rate

Oxygen consumption was measured in 10 anaesthetized, surgically instrumented domestic pigs on cardiopulmonary bypass while cardiac output (pump flow rate) was decreased. Oxygen consumption data (calculated by the Fick principle from blood flow rate and arterial and mixed venous content measurements) were plotted against total oxygen transport (TOT=QCaO2, where Q is pump flow rate and CaO2 is arterial blood oxygen content). Oxygen consumption (VO2) measurements were made in each animal at two haematocrits (approximately 30%, which is normal for pigs, and approximately 15%). In five of the animals (Group I) the measurements were made with normal haematocrit first, the blood was then haemodiluted with plasma or Dextran, and the measurements were repeated. In the remaining five animals (Group II), the haematocrit orderwas reversed. The plots showed two regions: above a certain value of TOT which we call critical TOT, VO2 was relatively independent of TOT, while at lower values of TOT, VO2 decreased approximately linearly with TOT. At the low haematocrit, the critical TOT (±S.E.M) was significantly lower ( P <0.05) than at normal haematocrit (6.9 ± 0.9 vs. 10.7 ± 1.2 ml/min/kg). Below the critical TOT, the curves for the two haematocrit levels were not significantly different. Above the critical TOT, the average VO2 was lower at the low haematocrit than at the normal haematocrit (6.0 ± 0.6 vs. 8.8 ± 1.1 ml/min/kg).

Heterogeneity of local myocardial flow and oxidative metabolism

2000 ◽  
Vol 279 (3) ◽  
pp. H1029-H1035 ◽  
Author(s):  
Uwe Schwanke ◽  
Andreas Deussen ◽  
Gerd Heusch ◽  
Jochen D. Schipke
Keyword(s):  
Mathematical Modeling ◽  
Oxygen Consumption ◽  
Oxidative Metabolism ◽  
Myocardial Oxygen Consumption ◽  
Capillary Permeability ◽  
Similar Degree ◽  
Permeability Surface ◽  
The Mean ◽  
Myocardial Flow ◽  
Degree Of Heterogeneity

In mammalian hearts, local myocardial flow (LMF) varies between 20 and 200% of the mean. It is not clear whether oxidative metabolism has a similar degree of heterogeneity. Therefore, we investigated the relation between LMF and local oxidative metabolism in isolated rabbit hearts. Buffer oxygenation with 18O2 resulted in labeled myocardial oxidation water (H2 18O). In four hearts, myocardial oxygen consumption (MV˙o 2) was calculated from the H2 18O production and compared with that calculated according to Fick. In eight additional hearts, LMF was measured using microspheres. Coronary venous H2 18O kinetics and local H2 18O residues were determined and analyzed by mathematical modeling. MV˙o 2 recovery from H2 18O was >93% compared with that according to Fick. LMF ranged from 1.91 to 11.24 ml · min−1 · g−1, and local H2 18O residue ranged from 0.41 to 1.04 μmol/g. Both variables correlated ( r = 0.62, n = 64, P < 0.001). Measurements in nine hearts were fitted by modeling using capillary permeability-surface area products ( PS c) from 2 to 10 ml · min−1 · g−1. With flow-proportional PS c, a 3.33-fold difference in LMF was associated with a 6.45-fold difference in local MV˙o 2. Both LMF and local oxidative metabolism are spatially heterogeneous, and they correlate to one another.

scholarly journals Derived Oxygen Saturations are not Clinically Useful for the Calculation of Oxygen Consumption

1992 ◽  
Vol 20 (4) ◽  
pp. 460-463 ◽  
Author(s):  
J. A. Myburgh
Keyword(s):  
Oxygen Consumption ◽  
Critically Ill ◽  
Indirect Calorimetry ◽  
Critically Ill Patients ◽  
Severity Of Illness ◽  
Gas Monitoring ◽  
Limits Of Agreement ◽  
Fick Principle ◽  
The Mean ◽  
A Prospective Study

In critically ill patients, oxygen consumption (VO2) and delivery (Do2) are used to determine optimal haemodynamic management and to grade severity of illness. Vo2 may be measured by indirect calorimetry with metabolic gas monitoring systems or derived using the reverse Fick principle. Oxygen saturation (Sao2) may be measured directly by co-oximetry or derived by equations for incorporation into reverse Fick equations. A prospective study comparing Vo2 measured by these methods was performed in 20 critically ill patients. The mean Vo2 measured by the metabolic gas monitoring system (308 ± 63.9 ml/min) was significantly greater than that measured by reverse Fick using measured Sao2 (284 ± 72.0 ml/min) (P < 0.01). This difference may be due to intrapulmonary Vo2. When SaO2 was, calculated from three logarithmic equations and incorporated into the reverse Fick equations, calculated Vo2‘s were significantly greater (P < 0.001) than those measured by indirect calorimetry. Correlation was poor and wide limits of agreement (-118 to + 350 ml/min) were demonstrated. Vo2 should ideally be measured by indirect calorimetry in the critically ill, or if reverse Fick is used, SaO2 should be measured by co-oximetry as the use of equations for clinical measurement of SaO2 is clinically suspect.

scholarly journals Myocardial Oxygen Consumption and Lactate Release by the Hypoxic Hagfish Heart

1991 ◽  
Vol 156 (1) ◽  
pp. 583-590 ◽  
Author(s):  
M. E. FORSTER
Keyword(s):  
Oxygen Consumption ◽  
Energy Demand ◽  
Myocardial Oxygen Consumption ◽  
Isolated Heart ◽  
Regression Line ◽  
Maximal Power Output ◽  
Wide Range ◽  
Consumption Rates ◽  
Rate Of Oxygen Consumption

Myocardial oxygen consumption (MOO2)and lactic acid release were measured in the isolated heart of a hagfish (Eptatretus cirrhatus Forster) perfused in vitro. Two different ranges of partial pressures of oxygen were employed (PIOO2 3.87-5.87 and 1.60-2.67 kPa). All hearts released lactate into the perfusate, but the rate of release was greater and MOO2 was depressed at the lower PIOO2. When energy production through the glycolytic pathway to lactate is converted to oxygen equivalents and added to measured oxygen consumption rates, over a wide range of power outputs and different values of POO2, the data can be fitted to a single linear regression line. The rate of oxygen consumption of the hagfish myocardium, so obtained, is similar to values reported for teleost fish. The unusual ability of the hagfish myocardium to support perhaps up to 50 + of its maximal power output through anaerobic metabolism is related to its extremely low cardiac energy demand.

Clinical and Experimental Analysis of 201Thallium Uptake of the Heart

1978 ◽  
Vol 17 (04) ◽  
pp. 142-148
Author(s):  
U. Büll ◽  
S. Bürger ◽  
B. E. Strauer
Keyword(s):  
Oxygen Consumption ◽  
Left Ventricle ◽  
Muscle Mass ◽  
Myocardial Oxygen Consumption ◽  
Animal Experiments ◽  
Left Ventricular ◽  
Left Ventricular Wall ◽  
Ventricular Wall ◽  
Flow Measurements ◽  
Myocardial Flow

Studies were carried out in order to determine the factors influencing myocardial 201T1 uptake. A total of 158 patients was examined with regard to both 201T1 uptake and the assessment of left ventricular and coronary function (e. g. quantitative ventriculography, coronary arteriography, coronary blood flow measurements). Moreover, 42 animal experiments (closed chest cat) were performed. The results demonstrate that:1) 201T1 uptake in the normal and hypertrophied human heart is linearly correlated with the muscle mass of the left ventricle (LVMM);2) 201T1 uptake is enhanced in the inner (subendocardial) layer and is decreased in the outer (subepicardial) layer of the left ventricular wall. The 201T1 uptake of the right ventricle is 40% lower in comparison to the left ventricle;3) the basic correlation between 201T1 uptake and LVMM is influenced by alterations of both myocardial flow and myocardial oxygen consumption; and4) inotropic interventions (isoproterenol, calcium, norepinephrine) as well as coronary dilatation (dipyridamole) may considerably augment 201T1 uptake in accordance with changes in myocardial oxygen consumption and/or myocardial flow.It is concluded that myocardial 201T1 uptake is determined by multiple factors. The major determinants have been shown to include (i) muscle mass, (ii) myocardial flow and (iii) myocardial oxygen consumption. The clinical data obtained from patient groups with normal ventricular function, with coronary artery disease, with left ventricular wall motion abnormalities and with different degree of left ventricular hypertrophy are correlated with quantitated myocardial 201T1 uptake.

The Effect of Desmopressin on Reducing Blood Loss in Cardiac Surgery – A Meta-Analysis of Double-Blind, Placebo-Controlled Trials

1995 ◽  
Vol 74 (04) ◽  
pp. 1064-1070 ◽  
Author(s):  
Marco Cattaneo ◽  
Alan S Harris ◽  
Ulf Strömberg ◽  
Pier Mannuccio Mannucci
Keyword(s):  
Cardiac Surgery ◽  
Blood Loss ◽  
Meta Analysis ◽  
Postoperative Blood Loss ◽  
Controlled Trials ◽  
Double Blind ◽  
Double Blind Placebo ◽  
Transfusion Requirements ◽  
The Mean ◽  
Excessive Blood Loss

SummaryThe effect of desmopressin (DDAVP) on reducing postoperative blood loss after cardiac surgery has been studied in several randomized clinical trials, with conflicting outcomes. Since most trials had insufficient statistical power to detect true differences in blood loss, we performed a meta-analysis of data from relevant studies. Seventeen randomized, double-blind, placebo-controlled trials were analyzed, which included 1171 patients undergoing cardiac surgery for various indications; 579 of them were treated with desmopressin and 592 with placebo. Efficacy parameters were blood loss volumes and transfusion requirements. Desmopressin significantly reduced postoperative blood loss by 9%, but had no statistically significant effect on transfusion requirements. A subanalysis revealed that desmopressin had no protective effects in trials in which the mean blood loss in placebo-treated patients fell in the lower and middle thirds of distribution of blood losses (687-1108 ml/24 h). In contrast, in trials in which the mean blood loss in placebo-treated patients fell in the upper third of distribution (>1109 ml/24 h), desmopressin significantly decreased postoperative blood loss by 34%. Insufficient data were available to perform a sub-analysis on transfusion requirements. Therefore, desmopressin significantly reduces blood loss only in cardiac operations which induce excessive blood loss. Further studies are called to validate the results of this meta-analysis and to identify predictors of excessive blood loss after cardiac surgery.

Assessment of Acute Kidney Injury in Patients Undergoing Elective Coronary Angiography and Percutaneous Coronary Intervention

2012 ◽  
Vol 5 (1) ◽  
pp. 37-43
Author(s):  
ABMM Alam ◽  
M Moniruzzaman ◽  
MB Alam ◽  
N Islam ◽  
F Khatoon ◽  
...  
Keyword(s):  
Serum Creatinine ◽  
Contrast Media ◽  
Creatinine Level ◽  
Ace Inhibitor ◽  
Kidney Injury ◽  
Coronary Intervention ◽  
Group I ◽  
Percutaneous Coronary ◽  
The Mean ◽  
Group Ii

Background: CIN has gained increased attention in the clinical setting, particularly during cardiac intervention but also in many other radiological procedures in which iodinated contrast media are used. There is at present good clinical evidence from well-controlled randomized studies that CIN is a common cause of acute renal dysfunction.Methodology: This was a prospective study conducted among the patients who underwent coronary angiography and percutaneous coronary intervention in the Department of Cardiology, Dhaka Medical College Hospital during January 2010 to December 2010. A total of 111 patients age range from 25 to 75 years were included in the study. Serum creatinine level at baseline and at the end of 48 hours was done in all these patients. Study population was divided into two groups according to development of acute kidney injury (AKI). Group-I = AKI, Group II = Not developed AKI. Results: AKI developed 11.7% of the study patient. DM and Preexisting renal insufficiency were significantly higher in group I patients. HTN was (61.5% Vs 44.9%) higher in group I but not significantly. History of ACE inhibitor/ARB, NSAID intake and LVEF <40% were significantly higher in group I patients. The mean±SD volume of CM (Contrast Media) were 156.9±44.8 ml and 115.4±30.0 ml in group I and group II respectively, which was significant. The mean±SD of serum creatinine after 48-72 hours of CAG/PCI was 1.4±0.37 mg/dl and 1.1±0.2 mg/dl in group I and group II respectively. The serum creatinine level increased significantly (p<0.05) after 48-72 hours of CAG/PCI in group I. In group II, S. creatinine level increased but not significant (p>0.05). Impaired renal function was found 76.9% and 2.0% in group I and group II respectively. DM, HTN, preexisting renal insufficiency, ACE inhibitor/ARB, NSAIDs, contrast volume (>150 ml), eGFR (<60 ml/min/ 1.73m2) and LVEF (<40%) are significantly (p0.05) associated for CIN development.Conclusion: CIN is an iatrogenic but preventable disorder results from the administration of contract media. Although rare in the general population, CIN occurs frequently in patients with underlying renal dysfunction and diabetes. In patients with pre angiographic normal renal function, the prevalence is low but in pre-existing renal impairment it may pose a serious threat. Thus risk factors are synergistic in their ability to predispose to the development of CIN. A careful risk-benefit analysis must always be performed prior to the administration of contrast media to patients at risk for CIN. DOI: http://dx.doi.org/10.3329/cardio.v5i1.12227 Cardiovasc. j. 2012; 5(1): 37-43

Preoperative Low Serum Albumin Levels Increase the Requirement of Renal Replacement Therapy after Cardiac Surgery

2016 ◽  
Vol 19 (3) ◽  
pp. 123 ◽  
Author(s):  
Orhan Findik ◽  
Ufuk Aydin ◽  
Ozgur Baris ◽  
Hakan Parlar ◽  
Gokcen Atilboz Alagoz ◽  
...  
Keyword(s):  
Acute Kidney Injury ◽  
Regression Analysis ◽  
Cardiac Surgery ◽  
Renal Replacement Therapy ◽  
Serum Albumin ◽  
Replacement Therapy ◽  
Kidney Injury ◽  
Preoperative Serum ◽  
Group I ◽  
Group Ii

<strong>Background:</strong> Acute kidney injury is a common complication of cardiac surgery that increases morbidity and mortality. The aim of the present study is to analyze the association of preoperative serum albumin levels with acute kidney injury and the requirement of renal replacement therapy after isolated coronary artery bypass graft surgery (CABG).<br /><strong>Methods:</strong> We retrospectively reviewed the prospectively collected data of 530 adult patients who underwent isolated CABG surgery with normal renal function. The perioperative clinical data of the patients included demographic data, laboratory data, length of stay, in-hospital complications and mortality. The patient population was divided into two groups: group I patients with preoperative serum albumin levels &lt;3.5 mg/dL; and group II pateints with preoperative serum albumin levels ≥3.5 mg/dL.<br /><strong>Results:</strong> There were 413 patients in group I and 117 patients in group II. Postoperative acute kidney injury (AKI) occured in 33 patients (28.2%) in group I and in 79 patients (19.1%) in group II. Renal replacement therapy was required in 17 patients (3.2%) (8 patients from group I; 9 patients from group II; P = .018). 30-day mortality occurred in 18 patients (3.4%) (10 patients from group I; 8 patients from group II; P = .037). Fourteen of these patients required renal replacement therapy. Logistic regression analysis revealing the presence of lower serum albumin levels preoperatively was shown to be associated with increased incidence of postoperative AKI (OR: 1.661; 95% CI: 1.037-2.661; <br />P = .035). Logistic regression analysis also revealed that DM (OR: 3.325; 95% CI: 2.162-5.114; P = .000) was another independent risk factor for AKI after isolated CABG. <br /><strong>Conclusion:</strong> Low preoperative serum albumin levels result in severe acute kidney injury and increase the rate of renal replacement therapy and mortality after isolated CABG.

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