Cardiopulmonary Bypass In Patients Research Articles

Increased vascular permeability after cardiopulmonary bypass in patients with diabetes is associated with increased expression of vascular endothelial growth factor and hepatocyte growth factor

Several inflammatory mediators such as vascular endothelial growth factor and hepatocyte growth factor are known to play a critical role in the regulation of vascular permeability and angiogenesis. We studied the serum levels of growth factors and gene expression profiles of genes involved in growth factor signaling in the peripheral blood of patients with and patients without diabetes following cardiopulmonary bypass and cardioplegic arrest. Serum and total RNA were obtained from the blood samples collected from patients with diabetes and matched patients without diabetes (n = 7 patients each) who had coronary artery bypass graft before and 6 hours and 4 days after cardiopulmonary bypass/cardioplegic arrest. The cytokine panel, consisting of growth factors such as vascular endothelial growth factor, hepatocyte growth factor, fibroblast growth factor, and epidermal growth factor, was quantified in patients with diabetes and patients without diabetes before and 6 hours and 4 days post-cardiopulmonary bypass/cardioplegic arrest using multiplex cytokine quantification system. cDNA microarray analysis was performed and fold-change was calculated. Length of hospitalization (10 vs 6 days; P = .04) and weight gain (5 vs 2.5 kg; P = .001) were significantly greater for patients with diabetes compared with patients without diabetes. The serum levels of vascular endothelial growth factor and hepatocyte growth factor were significantly elevated in patients with diabetes when compared with patients without diabetes before versus 6 hours post-cardiopulmonary bypass/cardioplegic arrest. In addition, significantly elevated mRNA expression of hypoxia-inducible factor-1alpha, cyclic adenosine monophosphate response element binding protein, and E1A binding protein p300 (more than twofold) was observed 4 days post-cardiopulmonary bypass/cardioplegic arrest exclusively in patients with diabetes. The differential profile of gene and protein expression of growth factors and their related genes in patients with diabetes and patients without diabetes could be associated with increased edema and weight gain in patients with diabetes after cardiopulmonary bypass/cardioplegic arrest.

Axillary Artery Cannulation for Cardiopulmonary Bypass during Surgery on the Ascending Aorta and Arch

Performing axillary artery cannulation, during cardiopulmonary bypass in patients with an atherosclerotic ascending aorta or acute dissection of the ascending aorta and arch, is of growing interest. Our aim is to present our experience, to describe the surgical technique, and to demonstrate the sufficient cerebral and total body perfusion through axillary artery cannulation. Twenty-two patients (17 male, five female) underwent surgical treatment with the axillary technique. The log euro SCORE ranged from 6.77% to 70% (mean 28.28). Nine of these patients underwent elective procedure. Eight underwent aortic surgery for pathologies of the aorta and in one patient we performed combined aortic valve replacement and coronary artery bypass grafting. Thirteen patients underwent emergency operation because of acute dissection of the aorta. Twelve of these patients had a type A dissection (according to Stanford classification) and one patient had a type B aortic dissection. The majority of complications were associated with ruptured dissection of the thoracoabdominal aorta and acute dissection of ascending aorta. Despite preoperative disease states that placed our patients at high risk of stroke and visceral end-organ injury, no clinically demonstrable permanent postoperative deficits were observed. Our patients had no neurological dysfunction, stroke, or other complications. Antegrade cerebral perfusion is of paramount importance in cases of aortic atherosclerosis or aortic dissection. The axillary artery provides an excellent site for safe antegrade perfusion, which may play a role in preventing stroke.

Levosimendan Facilitates Weaning From Cardiopulmonary Bypass in Patients Undergoing Coronary Artery Bypass Grafting With Impaired Left Ventricular Function

Levosimendan is a compound with vasodilatory and inotropic properties. Experimental data suggest effective reversal of stunning and cardioprotective properties. This prospective, randomized, placebo-controlled, double-blind study included 60 patients with 3-vessel coronary disease and left ventricular ejection fraction (LVEF) of less than 0.50. Levosimendan administration (12 microg/kg bolus, followed by an infusion of 0.2 microg/kg/min) was started immediately after induction anesthesia. Predefined strict hemodynamic criteria were used to assess the success of weaning. If weaning was not successful, CPB was reinstituted and an epinephrine infusion was started. If the second weaning attempt failed, intraaortic balloon pumping (IABP) was instituted. The groups had comparable demographics. The mean (standard deviation) preoperative LVEF was 0.36 (0.8) in both groups. The baseline cardiac index was 1.8 (0.3) L/min/m(2) in the levosimendan group and 1.9 (0.4) L/min/m(2) in the placebo group. The mean duration of CPB to primary weaning attempt was 104 (25) minutes in the levosimendan and 109 (22) minutes in the placebo group. Primary weaning was successful in 22 patients (73%) in the levosimendan group and in 10 (33%) in the placebo group (p = 0.002). The odds ratio for failure in primary weaning was 0.182 (95% confidence interval, 0.060 to 0.552). Four patients in the placebo group failed the second weaning and underwent IABP compared with none in the levosimendan group (p = 0.112). Levosimendan significantly enhanced primary weaning from CPB compared with placebo in patients undergoing 3-vessel on-pump coronary artery bypass grafting. The need for additional inotropic or mechanical therapy was decreased.

Plasma Exchange During Cardiopulmonary Bypass in Patients With Severe Hemolysis in Cardiac Surgery

Severe mechanical hemolysis after cardiac surgery is a rare occurrence but one of the most common complications leading to reoperation. The aim of this study was to assess the efficiency and safety of plasma exchange (PE) during cardiopulmonary bypass (CPB). Five patients required PE because of severe hemolysis after cardiac surgery in Fuwai Hospital from January 2002 to December 2007: two with periprosthetic leakage and infective endocarditis, one with periprosthetic leakage, one with unsatisfied right ventricular outflow tract patching, and one with thromboses during extracorporeal membrane oxygenation (ECMO). They all needed blood purification to avoid acute renal insufficiency. The amount of transfused crystalloid solution, nonprotein colloid, plasma, and blood were 1,620+/-906.6 mL, 1,960+/-939.7 mL, 2,240+/-844.4 mL, and 680+/-228.1 mL. The volume of PE was 3,800+/-1,701.5 mL, and the volume of ultrafiltrate was 2,470+/-1,327.4 mL. The concentration of free hemoglobin (FHb) before PE, after PE, and before discharge were 3,840+/-538 mg/L, 325+/-27 mg/L, and 60.4+/-27 mg/L, respectively. Five patients were successfully treated with PE during CPB without major complications. All patients recovered well. Plasma exchange during CPB for severe hemolysis is a safe technique. Acute renal failure induced by severe hemolysis can be prevented by PE.

The effect of mannitol on renal function after cardiopulmonary bypass in patients with established renal dysfunction

The effect of mannitol on renal function after cardiopulmonary bypass in patients with established renal dysfunction

Effects of levosimendan started 24 hours before cardiopulmonary bypass in patients admitted to the ICU with an ejection fraction lower than 30%

Patients with poor left ventricular function require inotropic drug support after cardiopulmonary bypass (CPB). The use of levosimendan in these patients is associated with a better postoperative function [1]. A recent study has attributed this phenomenon to preconditioning effects of levosimendan [2]. However, a recent study showed no benefit in starting levosimendan before CPB [3]. We hypothesized that admitting the patient to intensive care 24 hours before CPB and starting levosimendan preoperatively could reduce postoperative cardiac damage.

The effect of mannitol on renal function after cardiopulmonary bypass in patients with established renal dysfunction

The effect of mannitol on renal function after cardiopulmonary bypass in patients with established renal dysfunction

Relative adrenal insufficiency in cardiopulmonary bypass surgery patients: impact on the postoperative hemodynamic status

The objective of this study was to determine the incidence and risk factors for relative adrenal insufficiency (RAI) in cardiopulmonary bypass (CPB) patients and the impact on postoperative hemodynamic status.

Intraoperative Thrombus Embolization During Nephrectomy and Tumor Thrombectomy: Critical Analysis of the University of California-Los Angeles Experience

Vascular invasion commonly occurs in renal cell carcinoma and intraoperative thrombus embolization is a known complication of tumor thrombectomy. We reviewed our experience with this complication to determine frequency, mortality, common factors and management strategies. We retrospectively reviewed a prospective database of cases of open nephrectomy/tumor thrombectomy performed from 1989 to 2008. All cases were reviewed to identify clinicopathological variables, the thrombus extent and intraoperative complications. All cases with events were reviewed to identify preoperative pulmonary embolism, preoperative imaging, thrombus extent, presentation, management and outcome. A total of 282 cases of venous tumor thrombus were identified. Tumor thrombus level was 0 in 133 cases (47.2%), I to II in 85 (30.1%), III in 27 (9.6%) and IV in 29 (10.3%). Thrombus embolization was identified in 5 patients (1.8%). The incidence in level 0 vs I to IV was 0 of 133 cases (0%) vs 5 of 149 (3.4%), which was statistically significant (p = 0.04). Three patients (60%) died of the event. A review of recent series demonstrated a 1.49% incidence with 75% mortality. Intraoperative thrombus embolization is rare but when it occurs, mortality is extremely high. Strict attention to surgical principles is necessary to decrease risk. Extension into the vena cava, preoperative pulmonary embolism and a bland thrombus component may indicate increased risk. Adjunct procedures, such as preoperative filters and endoluminal occlusive balloons, may be justified in patients at high risk. Even with prompt recognition and embolectomy survival is rare.

Glycogen Phosphoprylase (EC 2.4.1.1) Activity During Cardiopulmonary Bypass in Patients Undergoing Cardiac Surgery

Glycogen Phosphoprylase (EC 2.4.1.1) Activity During Cardiopulmonary Bypass in Patients Undergoing Cardiac Surgery

Aggressive Zero Balance Ultrafiltration on CPB in Patients with Renal Failure May Cause Cerebral Edema: A Theoretical Analysis

The objective of this study was to determine the brain volume changes that occur secondary to hemofiltration during cardiopulmonary bypass in patients with renal failure. We hypothesized that in patients with elevated urea levels, quick aggressive hemofiltration could be associated with cerebral edema. We constructed a simple two-compartment model similar to the urea kinetic model developed by Depner. Intracellular urea exit was assumed to be minimal based on known urea redistribution times. Calculations were based on a 70-kg patient, with an intracellular volume of 25 L, extracellular volume of 15 L, and a preoperative urea of 40 mmol/L filtered to a post-procedure urea of 6 mmol/L. Analysis showed that a standard size 1500-mL human brain filtered from a preoperative urea of 40 to 6 mmol/L over a short period will expand by 59 mL secondary to the osmotic disequilibrium secondary to hemofiltration (p < .05). The higher the preoperative urea, the larger the fluid shift. This figure does not include the cerebral edema component that is known to arise secondary to cardiopulmonary bypass. Significant cerebral edema theoretically occurs secondary to hemofiltration during cardiopulmonary bypass. More detailed mathematical urea kinetic analysis and clinical correlation are needed.

Acid-Base Effects of a Bicarbonate-Balanced Priming Fluid during Cardiopulmonary Bypass: Comparison with Plasma-Lyte 148. A Randomised Single-Blinded Study

Fluid-induced metabolic acidosis can be harmful and can complicate cardiopulmonary bypass. In an attempt to prevent this disturbance, we designed a bicarbonate-based crystalloid circuit prime balanced on physico-chemical principles with a strong ion difference of 24 mEq/l and compared its acid-base effects with those of Plasma-Lyte 148, a multiple electrolyte replacement solution containing acetate plus gluconate totalling 50 mEq/l. Twenty patients with normal acid-base status undergoing elective cardiac surgery were randomised 1:1 to a 2 litre prime of either bicarbonate-balanced fluid or Plasma-Lyte 148. With the trial fluid, metabolic acid-base status was normal following bypass initiation (standard base excess 0.1 (1.3) mEq/l, mean, SD), whereas Plasma-Lyte 148 produced a slight metabolic acidosis (standard base excess -2.2 (2.1) mEq/l). Estimated group difference after baseline adjustment was 3.6 mEq/l (95% confidence interval 2.1 to 5.1 mEq/l, P=0.0001). By late bypass, mean standard base excess in both groups was normal (0.8 (2.2) mEq/l vs. -0.8 (1.3) mEq/l, P=0.5). Strong ion gap values were unaltered with the trial fluid, but with Plasma-Lyte 148 increased significantly on bypass initiation (15.2 (2.5) mEq/l vs. 2.5 (1.5) mEq/l, P < 0.0001), remaining elevated in late bypass (8.4 (3.4) mEq/l vs. 5.8 (2.4) mEq/l, P < 0.05). We conclude that a bicarbonate-based crystalloid with a strong ion difference of 24 mEq/l is balanced for cardiopulmonary bypass in patients with normal acid-base status, whereas Plasma-Lyte 148 triggers a surge of unmeasured anions, persisting throughout bypass. These are likely to be gluconate and/or acetate. Whether surges of exogenous anions during bypass can be harmful requires further study.

Economic Evaluation of Coronary Artery Bypass Grafting Surgery With and Without Cardiopulmonary Bypass: Cost‐Effectiveness and Quality‐Adjusted Life Years in a Randomized Controlled Trial

The objective of this study is to evaluate the costs and health benefits of coronary artery bypass grafting (CABG) surgery with and without cardiopulmonary bypass (CPB). Randomized controlled clinical trial is used as the design. The setting is in a single tertiary cardiothoracic center in Middlesex, UK. Participants were 168 patients (27 females) requiring primary isolated CABG surgery. Patients were randomized to have the procedure performed by a single surgeon either with CPB (n = 84) or by an off-pump coronary artery bypass (OPCAB) surgery (n = 84). Health-related quality of life was assessed at baseline, 6 weeks, and 6 months using the World Health Organization Quality-of-Life (WHOQOL-100) questionnaire. Mean total costs of patient management by either technique were calculated using different available key sources. A utility measure, derived from WHOQOL-100, was used to calculate quality-adjusted life year (QALY) gained in each group, on basis of which a cost-effectiveness analysis was performed. The mean total costs of an OPCAB patient was 5859 pounds , whereas for a CPB patient it was 7431 pounds with a mean difference of 1572 pounds (standard error [SE] 674 pounds ; P = 0.02). Three patients died in the CPB group and two in the OPCAB group during the 6-month follow-up period. Mean QALYs over 6 months was 0.379 in the OPCAB group and 0.362 in the CPB group, but the difference was not significant (mean difference 0.017; SE 0.016; P = 0.305). OPCAB surgery offered patients in this randomized trial similar health benefits to CPB over a 6-month period, but at a significantly less cost.

A randomized comparative study of patients undergoing myocardial revascularization with or without cardiopulmonary bypass surgery: The MASS III Trial.

The MASS III Trial is a large project from a single institution, The Heart Institute of the University of Sao Paulo, Brazil (InCor), enrolling patients with coronary artery disease and preserved ventricular function. The aim of the MASS III Trial is to compare medical effectiveness, cerebral injury, quality of life, and the cost-effectiveness of coronary surgery with and without of cardiopulmonary bypass in patients with multivessel coronary disease referred for both strategies. The primary endpoint should be a composite of cardiovascular mortality, cerebrovascular accident, nonfatal myocardial infarction, and refractory angina requiring revascularization. The secondary end points in this trial include noncardiac mortality, presence and severity of angina, quality of life based on the SF-36 Questionnaire, and cost-effectiveness at discharge and at 5-year follow-up. In this scenario, we will analyze the cost of the initial procedure, hospital length of stay, resource utilization, repeat hospitalization, and repeat revascularization events during the follow-up. Exercise capacity will be assessed at 6-months, 12-months, and the end of follow-up. A neurocognitive evaluation will be assessed in a subset of subjects using the Brain Resource Center computerized neurocognitive battery. Furthermore, magnetic resonance imaging will be made to detect any cerebral injury before and after procedures in patients who undergo coronary artery surgery with and without cardiopulmonary bypass.Clinical Trial registration informationISRCTN59539154 Off-pump vs. on-pump surgery in patients with Stable CAD MASS III

The effect of mannitol on renal function after cardiopulmonary bypass in patients with established renal dysfunction*

The usefulness of mannitol in the priming fluid for cardiopulmonary bypass is uncertain in patients with normal renal function, and has not been studied in patients with established renal dysfunction. We studied 50 patients with serum creatinine between 130 and 250 micromol.l(-1) having cardiac surgery. Patients were randomised to receive mannitol 0.5 g.kg(-1), or an equivalent volume of Hartmann's solution, in the bypass prime. There were no differences between the groups in plasma creatinine or change in creatinine from baseline, urine output, or fluid balance over the first three postoperative days. We conclude that mannitol has no effect on routine measures of renal function during cardiac surgery in patients with established renal dysfunction.

Changes in glomerular filtration rate after cardiac surgery with cardiopulmonary bypass in patients with mild preoperative renal dysfunction

BackgroundCardiac surgery with cardiopulmonary bypass (CPB) is commonly perceived as a risk factor for decline in renal function, especially in patients with preoperative renal dysfunction. There are few data on the effects of CPB on renal function in patients with mild preoperative renal dysfunction. The purpose of this study was to evaluate renal function in patients with pre-existing mild renal dysfunction undergoing cardiac surgery with CPB. MethodsIn a multicentre study cohort we measured prospectively the glomerular filtration rate (GFR) by radioactive markers both before operation and on the 7th postoperative day in cardiac surgical patients with preoperative serum creatinine >120 μmol l−1 (n=56). In a subgroup of patients (n=14) in addition to the GFR, the effective renal plasma flow (ERPF) and the filtration fraction (FF) were measured. ResultsWhile preoperative GFR [77.9 (25.5) ml min−1] increased to 84.4 (23.7) ml min−1 (P=0.005) 1 week after surgery, ERPF did not change [295.8 (75.2) ml min−1 and 295.9 (75.9) ml min−1, respectively; P=0.8]. In accordance, the FF increased from 0.27 (0.05) (before operation) to 0.30 (0.04) (Day 7, P=0.01). ConclusionOur results oppose the view that cardiac surgery with CPB adversely affects renal function in patients with preoperative mild renal dysfunction and an uncomplicated clinical course.

Carbon Monoxide

Carbon Monoxide

Clinical benefit of steroid use in patients undergoing cardiopulmonary bypass: a meta-analysis of randomized trials

We sought to establish the efficacy and safety of prophylactic steroids in adult patients undergoing cardiopulmonary bypass (CPB). We performed a meta-analysis of randomized trials reporting the effects of prophylactic steroids on clinical outcomes after CPB. Outcomes examined were mortality, myocardial infarction, neurological events, new onset atrial fibrillation, transfusion requirements, postoperative bleeding, duration of ventilation, intensive care unit (ICU) stay, hospital stay, wound complications, gastrointestinal complications, and infectious complications. We included 44 trials randomizing 3205 patients. Steroids reduced new onset atrial fibrillation [relative risk (RR) 0.71, 95% confidence interval (CI) 0.59 to 0.87], postoperative bleeding [weighted mean difference (WMD) -99.6 mL, 95% CI -149.8 to -49.3], and duration of ICU stay (WMD -0.23 days, 95% CI -0.40 to -0.07). Length of hospital stay was also reduced (WMD -0.59 days, 95% CI -1.17 to -0.02), but this result was less robust. A trend towards reduction in mortality was observed (RR 0.73, 95% CI 0.45 to 1.18). Randomized trials suggest that perioperative steroids have significant clinical benefit in CPB patients by decreasing the risk of new onset atrial fibrillation, while results are encouraging for reducing bleeding, length of stay, and mortality. These data do not raise major safety concerns, however, a sufficiently powered trial is warranted to confirm or refute these findings.

Nitric Oxide Synthase Inhibitor (MTR-105) during Open-Heart Surgery

Objectives: Hypotension is common immediately following cardiopulmonary bypass. Experimentally, MTR-105 (S-ethylisothiuronium diethylphosphate), a fast-acting synthetic nitric oxide synthase inhibitor, rapidly increases blood pressure. The purpose of the current study was to assess the influence of MTR-105 on hemodynamics early after cardiopulmonary bypass in patients undergoing open-heart surgery. Methods:Thirty-six patients with an ejection fraction >50% undergoing open-heart surgery were randomly assigned to either 50 µg kg^–1 min^–1 MTR-105 (M50, n = 12), 10 µg kg^–1 min^–1 MTR-105 (M10, n = 12) or buffered phosphate solution (placebo control, n = 12). Half suffered from atrial fibrillation and 75% had severe tricuspid regurgitation. Patients received the drug for 6 h after cross-clamp removal. Hemodynamic variables were measured before drug administration until 24 h after operation. Adverse events were recorded from study drug initiation through 30 days after the operation. Results:Compared with control, both MTR-105 doses were associated with an immediate increase in systemic blood pressure (16%) and systemic vascular resistance and a decrease in cardiac index. Half-life time of MTR-105 was calculated to be 4.1 ± 0.8 h (M10) and 4.45 ± 0.92 h (M50). Three patients died during hospitalization, unrelated to the study medication. Conclusions:At the doses employed, MTR-105 appears hemodynamically active in increasing both blood pressures.

Surgical Management, Complications, and Outcome of Radical Nephrectomy with Inferior Vena Cava Tumor Thrombectomy Facilitated by Vascular Bypass

To describe the technique, complications, and outcomes of vascular bypass during radical nephrectomy and tumor thrombectomy for patients with renal cell carcinoma and venous tumor thrombus. The indications and results for venovenous bypass (VVB) versus cardiopulmonary bypass (CPB) were reviewed as well. We identified 41 patients who had undergone radical nephrectomy and thrombectomy requiring VVB (n = 13) or CPB (n = 28) at our institution from 1970 to 2005 for renal cell carcinoma with venous tumor thrombus. The clinicopathologic variables and complication rates were compared between the VVB and CPB patients. The postoperative cancer-specific survival was estimated using the Kaplan-Meier method and compared using the log-rank test. The patients undergoing VVB experienced significantly shorter median bypass times (P = 0.015), operative times (P <0.001), and anesthesia times (P <0.001) compared with those treated with CPB. In addition, VVB was associated with trends toward decreased median intraoperative blood loss (1200 mL versus 2725 mL, P = 0.336), decreased blood/blood products transfused (median 2300 mL versus 4275 mL, P = 0.256), and decreased length of hospitalization (median 7 days versus 9 days, P = 0.078). The 5-year cancer-specific survival rate was not significantly different for patients undergoing VVB (29.8%) versus those treated with CPB (36.4%; P = 0.989). VVB was associated with significantly shorter bypass, operative, and anesthesia times, as well as trends toward decreased blood loss and hospital stay. Although the choice of bypass technique must be individualized according to the assessment of the bulk of thrombus to be resected, our results support the continued use of VVB in the management of renal cell carcinoma with extensive venous tumor thrombus, when appropriate.