Termination Of Cardiopulmonary Bypass Research Articles

Effects of Pulsatile and Non-Pulsatile Cardiopulmonary Bypass Techniques in Coronary Artery Bypass Grafting Surgeries on Cerebral Perfusion.

We aimed to evaluate the effects of cardiopulmonary bypass (CPB) machines used in coronary artery bypass grafting surgeries on cerebral perfusion by performing cerebral oximetry monitoring [near-infrared spectroscopy (NIRS)], S100-β protein measurements, and neurocognitive function assessment tests using both pulsatile and non-pulsatile modes. A total of 44 patients, 22 non-pulsatile (Group NP) and 22 pulsatile (Group P), were included in the study. Hemodynamic parameters, arterial blood gas values, NIRS values and blood S100β protein levels were analyzed at five points: pre-induction (T1), initiation of CPB (T2), termination of CPB (T3), end of surgery (T4), and postoperative 24 h (T5). Two different neuropsychological tests were administered to patients in the preoperative and postoperative periods. There were no significant differences between the groups for demographic characteristics such as age, gender, body mass index, aortic cross-clamping, CPB, and operation durations. The mean arterial blood pressure and PaO2 values for the T2 measurements were significantly higher in group NP (P < 0.05). Regional cerebral oxygen saturation (rSO2) (NIRS) values at T3 and T4 were significantly higher in group P (P < 0.05). Serum S100β measurement values at T3 and T5 were significantly higher in group NP than in group P (P < 0.05). Serum S100β protein levels at T3 correlate with rSO2 results. There was no statistically significant difference between the two groups in terms of pH, lactate, glucose, partial pressure of carbon dioxide, and peripheral oxygen saturation values. Despite no difference between the two groups for neurocognitive function tests, we believe that pulsatile perfusion may be more beneficial for cerebral perfusion when S100β protein and NIRS values are considered. Further clinical studies are needed to evaluate the benefits of the pulsatile technique for cerebral perfusion.

Evaluation of Intraoperative Left-Ventricular Diastolic Function by Myocardial Strain in On-Pump Coronary Artery Bypass Surgery

Left ventricular (LV) diastolic function strongly predicts outcomes after cardiac surgery, but there is no consensus about appropriate intraoperative assessment. Recently, intraoperative diastolic strain-based measurements assessed by transesophageal echocardiography (TEE) have shown a strong correlation with LV relaxation, compliance, and filling, but there are no reports about evaluation through the entire perioperative period. Therefore, the authors describe the intraoperative course of this novel assessment technique in patients who underwent coronary artery bypass grafting, and compare it with conventional echocardiographic measures and common grading algorithms of LV diastolic dysfunction (LVDD). Prospectively obtained data. A single university hospital. Thirty adult patients scheduled for isolated on-pump coronary artery bypass grafting surgery with preoperative preserved left and right ventricular systolic function, without significant heart valve disease and pulmonary hypertension, and an uneventful intraoperative course were included. Transesophageal echocardiography was performed after induction of anesthesia (T1), after termination of cardiopulmonary bypass (T2), and after sternal closure (T3). Echocardiographic evaluation was performed in stable hemodynamic conditions, in sinus rhythm or atrial pacing, and vasopressor support with norepinephrine ≤0.1 µg/kg/min. Strain-based measurements of peak longitudinal strain rate during isovolumetric relaxation (SR-IVR) and during early (SR-E) and late (SR-A) LV filling were assessed using EchoPAC v204 software (GE Vingmed Ultrasound AS, Norway). Evaluation of conventional echocardiographic parameters included transmitral Doppler measures of early (E) and late (A) LV filling, as well as lateral-tissue Doppler velocity assessed during early (e´) and late (a´) LV filling, tricuspid regurgitation, and left atrial dilatation. Evaluation and grading of LV diastolic function by myocardial strain was feasible in all included patients at all time points of assessment. Using conventional grading algorithms, however, a substantial number of patients could not be sufficiently graded, falling into an indeterminate zone and not reliably estimating LVDD (T1, 40%; T2, 33%; T3, 36%). There was significant impairment of LV diastolic function after bypass, as measured by SR-IVR (T1 v T2, 0.28 s-1 [IQR 0.23; 0.31) v 0.18 s-1 [IQR 0.14; 0.22]; p < 0.001), SR-E (T1 v T2, 0.95 ± 0.34 s-1v 1.28 ± 0.36 s-1; p < 0.001), and E/SR-IVR (T1 v T2, 2.3 ± 1.0 m v 4.5 ± 2.1 m; p < 0.001]. Conventional echocardiographic measures remained unchanged during the same period (E/A T1 v T2, 1.27 [IQR 0.94; 1.59] v 1.21 [IQR 1.03; 1.47] [p = 1] and E/e´ T1 v T2, 7.0 [IQR 5.3; 9.6] v 6.35 [IQR 5.7; 9.9] [p = 0.9]). There were no significant changes in the values of SR-IVR, SR-E, SR-A, E/SR-IVR, E/A, and E/e´ before and after sternal closure (T2 v T3). Intraoperative assessment of strain-based measurements of LV diastolic function and strain-based LVDD grading was feasible in this group of selected patients, whereas conventional parameters failed to describe LVDD sufficiently in a substantial number of patients. Diastolic strain-based measurements showed impairment of LV relaxation and compliance after bypass, which was not detected by conventional echocardiographic parameters. Therefore, diastolic myocardial strain analysis might be more sensitive in detecting myocardial diastolic dysfunction by TEE in the perioperative setting, with its dynamic changes of loading conditions, and might provide valuable and additional information on the perioperative changes of LV diastolic function.

Advancing cardiotomy suction practices for coronary surgery via multidisciplinary collaborative learning

ObjectiveProfessional standards recommend stopping cardiotomy suction at the termination of cardiopulmonary bypass before protamine administration based on perceived safety concerns. This study evaluated a multidisciplinary collaborative quality-improvement intervention promoting this agreed-upon cardiotomy suction practice during coronary artery bypass grafting (CABG). MethodsA statewide intervention (eg, unblinded surgeon and perfusionist feedback, evidence-based lectures, evaluating barriers to change) involved 32 centers participating in the PERForm (ie, Perfusion Measures and Outcomes) Registry to standardize cardiotomy suction practices at cardiopulmonary bypass termination during CABG. Four non-Michigan registry participating centers were not exposed to collaborative learning. Cardiotomy suction practice was defined as the absence of or stopping cardiotomy suction before protamine administration. The practice changes attributed to the intervention, including Michigan and non-Michigan comparisons, were evaluated with the change of time effect modeled using splines. Multivariable regression was used to evaluate the intervention's associated impact (eg, mortality, reoperation, transfusion). ResultsAmong 10,394 patients undergoing CABG at Michigan centers, 80.7% achieved agreed-upon cardiotomy suction practices. The Michigan centers had nonsignificant changes in agreed-upon cardiotomy suction practices during the preintervention period (P = .24), with significant increased monthly change in practice thereafter, absent adjusted morbidity and mortality increases. The Michigan centers achieved a significantly greater adjusted monthly improvement in agreed-upon practices relative to non-Michigan centers within 7 months after the intervention (adjusted odds ratio for change of trends: 2.53, P < .001). ConclusionsThis initiative demonstrates the effectiveness of multidisciplinary collaborative quality improvement in advancing agreed-upon cardiotomy suction practices without negatively impacting clinical outcomes.

Effect of cardiopulmonary bypass on plasma and erythrocytes oxylipins

BackgroundOxylipins, the oxidative metabolites of polyunsaturated fatty acids (PUFAs), serve as key mediators of oxidative stress, inflammatory responses, and vasoactive reactions in vivo. Our previous work has established that hemodialysis affects both long chain fatty acids (LCFAs) and oxylipins in plasma and erythrocytes to varying degrees, which may be responsible for excess cardiovascular complications in end-stage renal disease. In this study, we aimed to determine changes in blood oxylipins during cardiopulmonary bypass (CPB) in patients undergoing cardiac surgery to identify novel biomarkers and potential metabolites of CPB-related complications. We tested the hypothesis that CPB would differentially affect plasma oxylipins and erythrocytes oxylipins.MethodsWe conducted a prospective observational study of 12 patients undergoing elective cardiac surgery with expected CPB procedure. We collected venous and arterial blood samples before CPB, 15 and 45 min after the start of CPB, and 60 min after the end of CPB, respectively. Oxylipins profiling in plasma and erythrocytes was achieved using targeted HPLC‐MS mass spectrometry.ResultsOur results revealed that most venous plasma diols and hydroxy- oxylipins decreased after CPB initiation, with a continuous decline until the termination of CPB. Nevertheless, no statistically significant alterations were detected in erythrocytes oxylipins at all time points.ConclusionsCPB decreases numerous diols and hydroxy oxylipins in blood plasma, whereas no changes in erythrocytes oxylipins are observed during this procedure in patients undergoing cardiac surgery. As lipid mediators primarily responsive to CPB, plasma diols and hydroxy oxylipins may serve as potential key biomarkers for CPB-related complications.

Intraoperative Augmented Rotation and Circumferential Strain Compensate for Reduction of Left Ventricular Longitudinal Function After On-Pump CABG Surgery

Left ventricular (LV) longitudinal function is reduced after on-pump coronary artery bypass grafting (CABG), while global LV function often is preserved. There are only limited data on the underlying compensatory mechanism. Therefore, the authors aimed to describe intraoperative changes of LV contractile pattern by myocardial strain analysis. A prospective observational study. At a single university hospital. A total of 30 patients scheduled for isolated on-pump CABG with an uneventful intraoperative course and preoperative preserved LV and RV function, sinus rhythm, without more-than-mild heart valve disease, or elevated pulmonary pressure. Transesophageal echocardiography was performed after induction of anesthesia (T1), after termination of cardiopulmonary bypass (T2), and after sternal closure (T3). Echocardiographic evaluation was performed under stable hemodynamics, in sinus rhythm or atrial pacing, and vasopressor support with norepinephrine ≤0.1 µg/kg/min. EchoPAC v204 software (GE Vingmed Ultrasound AS, Norway) was used for analysis of 2-dimensional (2D) and 3-dimensional (3D) LV ejection fraction (EF), LV global longitudinal strain (GLS), LV global circumferential strain (GCS), LV global radial strain (GRS), LV apical rotation (aRot), LV basal rotation (bRot), and LV twist. Strain analysis was feasible in all included patients after termination of cardiopulmonary bypass (T2). Although there were no significant differences in the values of conventional echocardiographic parameters during the intraoperative interval, GLS deteriorated significantly after CABG compared to pre-bypass assessment (T1 v T2, -13.4% ± 2.9 v -11.8% ± 2.9; p=0.007). GCS improved significantly after surgery (T1 v T2, -19.4% (IQR -17.1% to -21.2%) v -22.8% (IQR -21.1% to -24.7%); p < 0.001) as well as aRot (T1 v T2, -9.7° (IQR -7.1° to -14.1°) v -14.5° (IQR -12.1° to -17.1°); p < 0.001), bRot (T1 v T2, 5.1° (IQR 3.8°-6.7°) v 7.2° (IQR 5.6°-8.2°); p=0.02), and twist (T1 v T2, 15.8° (IQR 11.7°-19.4°) v 21.6° (IQR 19.2°-25.1°); p < 0.001), while GRS remained unchanged. There were no significant changes in the values of GLS, GCS, GRS, aRot, bRot, or twist, as well as in the values of 2D and 3D LV EF before and after sternal closure (T2 v T3). Beyond evaluation of longitudinal LV strain, measurements of circumferential and radial strain, as well as LV rotation and twist mechanics, were feasible in the intraoperative course of this study. Reduction of longitudinal function after on-pump CABG was compensated intraoperatively by improvement of GCS and rotation in the authors' group of patients. Perioperative assessment of GCS, GRS, as well as rotation and twist, might provide deeper insight into perioperative changes of cardiac mechanics.

Is del Nido cardioplegia safe in isolated coronary bypass surgery? It may be possible with this method

Objectives: This study aimed to share the early results of the del Nido (DN) solution used with a different method in patients who underwent isolated coronary bypass. Patients and methods: The retrospective study included 150 patients (123 males, 27 females; mean age: 59.8±9.7 years; range, 38 to 84 years) who underwent isolated coronary bypass operation between January 2020 and May 2022. The DN solution was applied differently from the practice in the literature. Seventy-five percent of the dose calculated according to the body weight of the patients was administered at the first moment. The remaining amount was continued to be given through the saphenous veins as distal anastomoses were made. When the cross-clamp was lifted, all grafts were tied to the aorta cannula, and the coronary vascular bed was cleared. Follow-up of patients was done routinely. Results: The mean preoperative ejection fraction was 49.9±5.6, and the mean postoperative ejection fraction value was 50.3±5.0 (p=0.079). A statistically significant difference was found between the preoperative troponin level and the postoperative troponin level at 6 h (p&lt;0.001). However, there was no significant difference between the postoperative 6 h and the postoperative 24 h. Spontaneous rhythm occurred at the termination of cardiopulmonary bypass in most of the patients (97%). No permanent pacing was required in any patient. An intra-aortic balloon pump was used in nine patients, and extracorporeal membrane oxygenation was used in two patients. Two patients died in the early period. Conclusion: The use of DN with this method seems to be a reliable alternative to eliminate hesitations in isolated coronary bypass surgery.

INTRAOPERATIVE NON-INVASIVE LEFT VENTRICULAR MYOCARDIAL WORK INDICES IN PATIENTS UNDERGOING ON-PUMP CORONARY ARTERY BYPASS SURGERY

<h3>Objective</h3> Non-invasive echocardiographic analysis of left ventricular (LV) myocardial work (MW) enables insights into cardiac mechanics, contractility, and efficacy beyond ejection fraction and global longitudinal strain. MW incorporates myocardial deformation and loading conditions into its analysis and correlates well with invasively measured myocardial work outside the operative setting. However, there are no reports on the use of this method by transesophageal echocardiography (TEE) in patients undergoing coronary artery bypass graft (CABG) surgery. Therefore, we aim to describe the intraoperative course of this novel assessment tool of ventricular function in these patients and compare it to conventional two- and three-dimensional echocardiographic parameters and strain analysis. <h3>Design and Method</h3> Twenty-five patients scheduled for isolated on-pump CABG surgery with preoperative preserved left and right ventricular function and a complication-free intraoperative course, were included into this prospective observational trial. TEE was performed intraoperatively after induction of anesthesia (T1), after termination of cardiopulmonary bypass (T2), and after sternal closure (T3) using General Electric Vivid E95 echocardiography machines and 6VT-D TEE probes. All measurements were performed under stable hemodynamic conditions, in sinus rhythm or atrial pacing and vasopressor support with Norepinephrine ≤ 0.1 µg/kg/min. EchoPAC v204 software (GE Vingmed Ultrasound AS, Norway) was used for analysis of 2D- and 3D LV ejection fraction (EF), LV global longitudinal strain (GLS), LV global work index (GWI), LV global constructive work (GCW), LV global wasted work (GWW) and LV global work efficiency (GWE). <h3>Results</h3> Myocardial work analysis was feasible in all patients. Although there was no significant difference in the values of 2D- and 3D-EF during the intraoperative interval, GLS deteriorated significantly after CABG compared to assessment after induction of anesthesia (T1 v T2, -13.3±3.0% v -11.6±3.1%; p=0.012). GWI declined significantly after surgery (T1 v T2, 1224±312mmHg% v 940±267mmHg%; p<0.001) as well as GCW (T1 v T2, 1460±312mmHg% v 1244±336 mmHg%; p=0.005). GWW increased after CABG (T1 v T2, 143mmHg% (IQR 99-183) v 251mmHg% (IQR 179-361); p<0.001) and GWE decreased (T1 v T2, 89% (IQR 85-92) v 80% (IQR 75-87); p<0.001). There was no significant change in the values of 2D- and 3D-EF, GLS, GWI, GCW, GWW and GWE before and after sternal closure (T2 v T3). <h3>Conclusions</h3> Intraoperative non-invasive echocardiographic assessed left ventricular myocardial work analysis appears feasible in this study. In our small sample with 25 CABG patients, strain and myocardial work analysis showed a deterioration of left ventricular function. In the short-term period after uncomplicated on-pump CABG, global and constructive myocardial work was decreased, while wasted work was increased, resulting in a less efficient left ventricle. None of these aspects was detected by two- and three-dimensional ejection fraction. Therefore, myocardial work analysis might be a more sensitive parameter in detecting myocardial dysfunction by TEE in the perioperative setting.

Intraoperative Noninvasive Left Ventricular Myocardial Work Indices in Patients Undergoing On-Pump Coronary Artery Bypass Surgery

Noninvasive echocardiographic analysis of left ventricular (LV) myocardial work (MW) enables insights into cardiac mechanics, contractility, and efficacy beyond ejection fraction (EF) and global longitudinal strain (GLS). However, there are limited perioperative data on patients undergoing coronary artery bypass graft (CABG) surgery. The authors aimed to describe the feasibility and the intraoperative course of this novel assessment tool of ventricular function in these patients, and compare it to conventional 2-dimensional (2D) and 3-dimensional (3D) echocardiographic parameters and strain analysis. A prospective observational study. At a single university hospital. Twenty-five patients with preoperative preserved LV and right ventricular function, sinus rhythm, without significant heart valve disease or pulmonary hypertension, and an uncomplicated intraoperative course scheduled for isolated on-pump CABG surgery. Transesophageal echocardiography (TEE) was performed intraoperatively after the induction of anesthesia (T1), after termination of cardiopulmonary bypass (T2), and after sternal closure (T3). All measurements were performed under stable hemodynamic conditions, in sinus rhythm or atrial pacing, and vasopressor support with norepinephrine ≤ 0.1 µg/kg/min. The EchoPAC v204 software (GE Vingmed Ultrasound AS, Norway) was used for analysis of 2D and 3D LVEF, LV GLS, LV global work index (GWI), LV global constructive work (GCW), LV global wasted work (GWW), and LV global work efficiency (GWE). The MW analysis was feasible in all patients. Although there was no significant difference in the values of 2D and 3D EF during the intraoperative interval, GLS deteriorated significantly after CABG compared to assessment after induction of anesthesia (T1 v T2, -13.3 ± 3.0% v -11.6 ± 3.1%; p=0.012). The GWI declined significantly after surgery (T1 v T2, 1,224 ± 312 mmHg% v 940 ± 267 mmHg%; p < 0.001), as well as GCW (T1 v T2, 1,460 ± 312 mmHg% v 1,244 ± 336 mmHg%; p=0.005). The GWW increased after CABG (T1 v T2, 143 mmHg% (IQR 99-183) v 251 mmHg% (IQR 179-361); p < 0.001), and GWE decreased (T1 v T2, 89% (IQR 85-92) v 80% (IQR 75-87); p < 0.001). There were no significant changes in the values of 2D and 3D EF, GLS, GWI, GCW, GWW, and GWE before and after sternal closure (T2 v T3). The intraoperative analysis of noninvasive echocardiographically-assessed LV MW indices is feasible. In the short-term period after uncomplicated on-pump CABG, GLS, as well as global and constructive MW, decreased, whereas wasted work increased, resulting in a less efficient left ventricle. None of these aspects was detected by conventional echocardiographic parameters. Therefore, strain and MW analysis might be more sensitive parameters in detecting myocardial dysfunction by TEE in the perioperative setting, adding information on perioperative cardiac energetics.

A Randomized Pilot Trial Assessing the Role of Human Fibrinogen Concentrate in Decreasing Cryoprecipitate Use and Blood Loss in Infants Undergoing Cardiopulmonary Bypass

The objective of this study was to determine whether treatment with human fibrinogen concentrate decreases the need for component blood therapy and blood loss in neonate and infant patients undergoing cardiopulmonary bypass. Pediatric patients (N = 30) undergoing elective cardiac surgery were randomized to receive human fibrinogen concentrate or placebo following cardiopulmonary bypass termination. The primary endpoint was the amount of cryoprecipitate administered. Secondary endpoints included estimated blood loss during the 24 h post-surgery; perioperative blood product transfusion; effects of fibrinogen infusion on global hemostasis, measured by laboratory testing and rotational thromboelastometry; and adverse events. No clinically significant differences were identified in baseline characteristics between groups. A significantly lower volume of cryoprecipitate was administered to the treatment group during the perioperative period [median (interquartile range) 0.0 (0.0–0.0) cc/kg vs 12.0 (8.2–14.3) cc/kg; P < 0.0001] versus placebo. No difference was observed between treatment groups in blood loss, laboratory coagulation tests, use of other blood components, or incidence of adverse events. FIBTEM amplitude of maximum clot firmness values was significantly higher among patients treated with human fibrinogen concentrate versus placebo (P ≤ 0.0001). No significant differences were observed in post-drug HEPTEM, INTEM, and EXTEM results. Human fibrinogen concentrate (70 mg/kg) administered after the termination of cardiopulmonary bypass reduced the need for transfusion with cryoprecipitate in a neonate and infant patient population.ClinicalTrials.gov identifier: NCT02822599.

Neuroprotective effect of memantine on serum S100-B levels after on-pump coronary artery bypass graft surgery: A randomized clinical trial.

Background:Brain injury is one of the complications of open heart surgery. Glutamate plays a key role in this process. In this study, we evaluated the neuroprotective effect of memantine as NMDAR inhibitor in patients undergoing on-pump coronary artery bypass graft surgery (CABG).Methods:From July 2019 to May 2020, thirty-four consecutive patients selected for elective isolated on-pump coronary artery bypass graft surgery (CABG) enrolled in the trial. Patients were randomly assigned into two groups; memantine and the control group. For the memantine group, 10 mg of memantine twice daily was administered at least 72 h before surgery. Venous blood samples were collected before surgery (T1), at the end of cardiopulmonary bypass (CPB) (T2), 6h and 24h after CPB (T3 and T4). Serum concentration of S100-B was measured by enzyme-linked immunosorbent assay (ELISA) technique.Results:Serum S100-B increased during CPB with a peak plasma concentration at the termination of CPB. Then it gradually decreased during the first 24 hours in both groups (P=0.001). The mean S100-B levels were significantly lower in the memantine group compared to the control group at the termination of CPB (0.863±0.203 μg/l vs 1.117±0.304 μg/l), at 6 hours post-CPB (0.731±0.168 μg/l vs 0.938±0.206 μg/l), and 24 hours post-CPB (0.595±0.189 μg/l vs 0.852±0.227 μg/l), respectively (P=0.023). The mean level of serum S100-B in memantine group was about 0.19 μg/l less than the control group during the study (CI, 0.07 to 0.30; P=0.001). One (6.2%) patient in the control group had post-operative left arm paresthesiaConclusion:Administration of memantine before on-pump CABG can attenuate the post-operative concentrations of serum S100-B, which may reduce cerebral damage during surgery.

Abstract 13580: DNA Methylation of Skeletal Muscle Tissue in Patients With Hypertension and Diabetes Undergoing Cardiopulmonary Bypass

Introduction: Epigenomic changes may affect the condition of patients before and after surgery. The epigenome-wide DNA methylation profiling of human skeletal muscle (SKM) specimens obtained from patients undergoing cardiac surgery utilizing cardiopulmonary bypass (CPB) was examined. Hypothesis: We hypothesized that regulatory changes in SKM that develop in patients with HTN and DM include epigenetic regulation and aimed to characterize the epigenome-wide signature of these changes, both at baseline and after cardiac surgery. Methods: SKM was obtained from the internal mammary artery bed before and after termination of cardiopulmonary bypass. Specimens of patients without hypertension or diabetes (control), those with hypertension alone (BP ≥ 130), those with hypertension combined with either controlled (HbA1C &lt;=7) or poorly controlled (HbA1C &gt; 7) diabetes were examined. SKM DNA methylation was profiled via Illumina MethylationEpic arrays and analyzed by principal component analysis, cluster analysis and analysis of variance followed by network and pathway analysis. Results: DNA methylation in samples from patients with hypertension and diabetes was significantly different in 5822 loci for controlled diabetes and in 7177 loci for uncontrolled diabetes; hypertension alone produced minimal effect. These loci produced a tightly interacting network with 560 hubs and 7055 edges. These loci were associated with genes involved in pathways of IL-1, IL-12, IL-18, TNFα; IFNγ and VEGF signaling, in NF-κB and Wnt pathways, apoptosis and DNA damage response. SKM at the end of CPB revealed 282 highly significant loci or 193,567 loci with lower significance and the magnitude of the effect not exceeding 10-20%. Conclusions: Preoperatively, patients with diabetes show substantial change in SKM DNA methylation epigenome wide. Compared to diabetes, hypertension did not as substantially influence the methylome in the SKM. During surgery multiple low-grade methylation changes occur that may mask the effects of the disease; moreover in a few loci more prominent changes occur that may be part of a compensatory/regulatory response to surgery utilizing CPB.

Safety and utility of modified ultrafiltration in pediatric cardiac surgery.

Modified ultrafiltration (MUF) is employed at the termination of cardiopulmonary bypass (CPB) in pediatric and neonatal patients undergoing congenital heart surgery to reduce the accumulation of total body water thus increasing the concentration of red blood cells and the other formed elements in the circulation. Modified ultrafiltration has been reported to remove circulating pro-inflammatory mediators that result in systemic inflammatory response syndrome (SIRS) postoperatively. Four hundred patients undergoing cardiac surgery requiring cardiopulmonary bypass and weighing less than or equal to 12 kg were retrospectively evaluated for the effectiveness of MUF. After the termination of CPB, blood was withdrawn through the aortic cannula and passed through a hemoconcentrator attached to the blood cardioplegia set and returned to the patient through the venous cannula. The entire CPB circuit volume in addition to the patient's circulating blood volume were concentrated until the hematocrit value displayed on the CDI cuvette within the MUF circuit reached 45% or there was no more volume to safely remove. At the same time a full unit of FFP can be infused as water is being removed, thus maintaining euvolemia. MUF was performed in all 400 patients with no MUF-related complications. Following the conclusion of MUF, anecdotal observations included improved surgical hemostasis, improved hemodynamic parameters, decreased transfusion requirements, and decreased ventilator times. Complete MUF enables the clinician to safely raise the post-CPB hematocrit to at least 40% while potentially removing mediators that could result in SIRS. In addition a full unit of FFP can be administered while maintaining euvolemia.

Calcium administration In patients undergoing CardiAc suRgery under cardiopulmonary bypasS (ICARUS trial): Rationale and design of a randomized controlled trial

IntroductionWeaning from cardiopulmonary bypass (CPB) is a critical step of any cardiac surgical procedure and often requires pharmacologic intervention. Calcium ions are pivotal elements for the excitation-contraction coupling process of cardiac myocytes. Thus, calcium administration might be helpful during weaning from CPB. MethodsWe describe a multicenter, placebo-controlled, double blind randomized clinical trial to assess the effect of calcium chloride on the need for inotropic support among adult patients during weaning from CPB. The experimental group (409 patients) will receive 15 mg/kg of calcium chloride. The control group (409 patients) will receive an equivalent volume of 0.9% sodium chloride. Both drugs will be administered intravenously as a bolus at the beginning of weaning from CPB. ResultsThe primary outcome will be the need for inotropic support between termination of CPB and completion of surgery. Secondary outcomes will be: duration of inotropic support, vasoactive-inotropic score 30 min after transfer to intensive care unit and on postoperative day 1, plasma alpha-amylase on postoperative day 1, plasma Ca2+ concentration immediately before and 10–15 min after calcium chloride administration, non-fatal myocardial infarction, blood loss on postoperative day 1, need for transfusion of red blood cells, signs of myocardial ischemia on electrocardiogram after arrival to intensive care unit, all-cause mortality at 30 days or during hospital stay if this is longer than 30 days. DiscussionThis trial is designed to assess whether intravenous calcium chloride administration could reduce the need for inotropic support after cardiopulmonary bypass weaning among adults undergoing cardiac surgery.

Coagulation Profile of Neonates Undergoing Arterial Switch Surgery With Crystalloid Priming of the Cardiopulmonary Bypass Circuit

ObjectivesThe aim was to evaluate changes in the coagulation profile of cyanotic neonates, to analyze the effects of cardiopulmonary bypass (CPB) with crystalloid priming on their coagulation status, and to determine factors predicting a requirement for hemostasis-derived transfusion. DesignRetrospective cohort. SettingSingle-center, tertiary academic hospital. ParticipantsIn total, 100 consecutive neonates who underwent arterial switch surgery between December 2014 and June 2020. InterventionsRotational thromboelastometry (ROTEM) and coagulation parameters before surgery and before termination of CPB were evaluated. Transfusion of platelets, fresh frozen plasma, and fibrinogen, defined as hemostasis-derived transfusion (HD transfusion), were determined. Patients with and without HD transfusion were compared to identify predictors. Measurements and Main ResultsAfter CPB, fibrinogen was reduced by 24.5% (interquartile range [IQR] 8.9-32.1) to 201 mg/dL (IQR 172-249), resulting in a reduction of FIBTEM A10 by 20% (1.8-33.3) to 8 mm (6-11). The platelet count decreased by a median of 47.2% (25.6-61.3) to 162 × 103/µL (119-215). However, the median fibrinogen concentration and platelet count remained within normal range. Neonates with abnormal ROTEM results were more likely to receive HD transfusions. The HD transfusions were more likely with lower preoperative FIBTEM maximum clot firmness values (p = 0.031), lower hemoglobin concentrations at termination of CPB (p = 0.02), and longer CPB duration (p = 0.017). Perioperative hemostasis without any HD transfusion was achieved in 64 neonates. ConclusionsGuidance from ROTEM analyses facilitates hemostasis management after neonatal CPB. Circuit miniaturization with transfusion-free CPB is associated with acceptable changes in ROTEM in most patients, and allows sufficient hemostasis without any HD transfusions in most patients.

Comparing Conscious Sedation With Regional Anesthesia Versus General Anesthesia in Minimally Invasive Mitral Valve Surgery With Right-Sided Minithoracotomy: A Retrospective Study

The aims of the present study were to evaluate and compare the safety and feasibility, including hospitalization, intensive care unit (ICU) stay, frequency of conversion to general anesthesia (GA), pH, PaCO2, and PaO2, of selected patients who underwent minimally invasive mitral valve surgery (MIMVS) via a right minithoracotomy under conscious sedation (CS) to avoid GA. The authors also aimed to evaluate the perioperative management of spontaneous breathing. A retrospective, observational study. Single-center. This study enrolled 101 patients who underwent MIMVS under CS or GA. The patients who underwent MIMVS were managed under CS or GA according to indication criteria. ICU stay (p=0.010), postoperative time until first fluid intake (p < 0.0001), and duration of mechanical ventilation (p=0.004) were shorter in the CS group than in the GA group. No patients converted to GA from CS. PaCO2 during cardiopulmonary bypass (CPB) in the CS group was significantly lower than that in the GA group. However, PaCO2 at the termination of CPB in the CS group was significantly higher than that in the GA group. In the CS group, advanced-age patients with comorbidities underwent mitral surgery without postoperative complications. The authors' findings suggested that MIMVS under CS could be a potentially less-invasive method, providing a quicker recovery than MIMVS under GA.

Rotational thromboelastometry and conventional coagulation tests in patients undergoing major cardiac or aortic surgery: a retrospective single-center cohort study

Algorithms for treatment of diffuse bleeding in cardiac surgery are based on intervention thresholds of coagulation tests, such as rotational thromboelastometry (ROTEM) or conventional laboratory tests. The relationship between these two approaches is unclear in patients with increased risk of coagulation abnormalities. We retrospectively analyzed the data of 248 patients undergoing major cardiac and/or aortic surgery. ROTEM and conventional laboratory tests were performed simultaneously after termination of cardiopulmonary bypass and protamine administration to investigate the extrinsic and intrinsic system, and to determine deficiencies in platelets and fibrinogen. We evaluated the association between ROTEM and conventional tests by linear regression analysis and compared the frequency of exceeding established thresholds for clinical intervention. Significant linear associations between ROTEM 10 min after the start of coagulation, and plasma fibrinogen concentration or platelet count (FIBTEM A10, R2 = 0.67, p < 0.001; EXTEM A10, R2 = 0.47, p < 0.001) were obtained. However, the 95% prediction intervals exceeded clinically useful ranges (92–233 mg/dL fibrinogen at the intervention threshold of FIBTEM A10 = 10 mm; 14 × 103–122 × 103/µL platelets at the intervention threshold of EXTEM A10 = 40 mm). The association between EXTEM and INR (R2 = 0.23), and INTEM and aPTT (R2 = 0.095) was poor. The frequency of exceeding intervention thresholds and, consequently, of triggering treatment, varied markedly between ROTEM and conventional tests (p < 0.001 for all comparisons). The predictability of conventional coagulation test results by ROTEM is limited, thus hampering the interchangeability of methods in clinical practice.

Nuclear factor erythroid 2-related factor 2 (Nrf2), tumor necrosis factor alpha protein (TNF-α), heme oxygenase-1 (HO-1) gene expressions during cardiopulmonary bypass

During extracorporeal circulation, blood is in contact with nonendothelial surfaces. The increase in the amount of blood touching the non-endothelial surface increases the damage to the blood elements. This initiates and increases oxidative stress. Increased oxidative stress leads to the activation of antioxidant systems. These two systems work gradually in the process of Cardiopulmonary Bypass. This study aims to investigate the changes of TNF-α, Nrf2 and HO-1 gene expression in extracorporeal circulation. Fifteen patients who underwent open heart surgery were included in the study. Blood samples were taken preoperatively, during cardiopulmonary bypass (CPB) and 24 hours postoperatively. TNF-α, Nrf2 and HO-1 gene expressions in plasma samples were studied by using appropriate kits. Changes in gene expressions were compared. TNF-α gene expression increased during CPB compared to preoperative levels (p <0.05). Similarly, Nrf-2 gene expression increased significantly during CPB (p <0.001) and decreased postoperatively (p <0.001). There was a significant increase in HO-1 gene expression during CPB (p <0.01). Postoperatively, this increase was found to decrease similar to Nrf2 (p <0.05). According to the results, TNF-α, Nrf2, HO-1 gene expressions increase during CPB and these values decrease after the operation. This shows that oxidative stress and inflammatory processes start with CPB and antioxidant processes start similarly. With the termination of CPB, both processes are terminated. This has been demonstrated by gene expressions. Future studies will make it easier to understand these processes.

Protamine Test Dose: Impact on Activated Clotting Time and Circuit Integrity

BackgroundRecurrent observation of clot in the cardiopulmonary bypass circuit after the administration of a protamine test dose (PTD) prompted concern over the effects of PTDs on patient activated clotting times (ACTs). MethodsData were prospectively collected on 120 patients who had cardiopulmonary bypass while undergoing a variety of cardiac surgical procedures from July to October 2018 at the Toronto General Hospital, Toronto, Canada. ACTs were documented before cardiopulmonary bypass termination, after PTDs, and after protamine full doses. Statistical analysis was completed using a paired t test. ResultsThe average PTD was calculated to be 36 ± 21 mg or 11% ± 7% of the full protamine dose of 367 ± 153 mg. This “test” dose ranged from 1% to 67% of full dose depending on the anesthetist. Post-PTD ACTs were widely variable. On average, there was a 40% ± 25% drop from the last ACT during cardiopulmonary bypass (650 ± 155 seconds) to the ACT after PTD (376 ± 153 seconds) (P < .0001). In fact, 81% ± 5% of the patients’ post-PTD ACTs were lower than the institutional ACT standard of 480 seconds for safe cardiopulmonary bypass initiation. ConclusionsRegardless of the PTD, there is no reliable way to predict how a patient’s ACT will respond to a PTD. Clot formation is possible and circuit integrity is at risk when pump suction devices are continuously in use during PTD administration. Therefore, the study investigators strongly recommend that the direct recovery of mediastinal shed blood into the pump circuit be discontinued before any amount of protamine is administered to the patient.

Intraoperative Cell Saving: Is the Solution the Actual Problem?

Allogenic blood is a scarce, precious, and expensive resource that is not always available on demand. After termination of cardiopulmonary bypass, a large amount of residual pump blood remains in the extracorporeal circuit. The cell saver washes and concentrates this blood with .9% normal saline (NS), making autologous blood available and reducing the demand for allogenic blood. To quantify the quality of residual pump blood it was washed with either NS or a bicarbonate-buffered solution (Balsol). A qualitative in vitro analysis was conducted. Residual cardiopulmonary bypass blood from forty bypass circuits was processed with a cell saver device, using NS or Balsol solution. Measurements made compared the pH, electrolytes, metabolites, hematocrit, hemoglobin, osmolality, albumin, total protein, and strong ion difference. There were significant differences between the NS and Balsol groups. In the Balsol group, osmolality, electrolytes, and strong ion difference were similar to the constitution of Balsol solution after washing, but not with the normal saline group. Washing residual cardiopulmonary bypass pump blood with Balsol solution results in a resuspended red cell concentrate with a superior electrolyte profile and a strong ion difference similar to that of residual pump blood.

Application of Molecular Hydrogen in Heart Surgery under Cardiopulmonary Bypass.

The aim of this work was to study the effect of molecular hydrogen on oxidative processes in cardiac surgery patients with acquired valve heart disease applied during surgery under cardiopulmonary bypass (CPB).Materials and Methods.The study involved 20 patients (16 men and 4 women) with acquired heart valve disease who were operated on under CPB. Two groups of patients were formed. In group 1 (n=11), anesthesia included inhalations of molecular hydrogen, which was supplied to the breathing circuit of the ventilator at a concentration of 1.5–2.0% immediately after tracheal intubation and throughout the operation. In group 2 (n=9), inhalation of molecular hydrogen was not performed. Blood sampling was taken at 4 stages: immediately after anesthesia induction, before CPB and after its termination, and also one day after the operation. The intensity of the processes of lipid peroxidation was evaluated by the level of diene (DC) and triene (TC) conjugates, Schiff bases (SB).Results.In the patients of group 1, the arterial blood samples showed a decrease in the level of TC and SB, as compared to the first stage of the study, before the initiation of CPB and one day after the operation. An increase in the level of DC and TC was detected after the termination of CPB (p<0.05). In the venous blood samples, an increase in the level of DC was noted before the initiation of CPB, which was restored by the third stage of the study (p<0.05). At the same time, after the termination of CPB, a tendency towards a decrease in TC and SB was observed, which persisted one day after the operation.In the patients of group 2, an increase in the concentration of SB in the arterial blood samples was recorded during the study as compared to the first stage. The level of TC and SB in the venous blood samples increased one day after the operation.Conclusion.Intraoperative inhalation of molecular hydrogen leads to a decrease in the oxidative stress manifestation, it being most pronounced one day after the operation. This suggests that molecular hydrogen can be used in cardiac surgery as an effective and safe antioxidant.