Initiation Of Cardiopulmonary Bypass Research Articles

Pre-bypass critical closing pressure predicts acute kidney injury after cardiopulmonary bypass

ObjectivesOptimal blood pressure goals during cardiopulmonary bypass (CPB) remain uncertain and new metrics to individualize perfusion targets are needed. Critical closing pressure (Pcrit) is a fundamental property of the arterial circulation related to vascular tone and represents the outflow pressure impacting flow across the systemic circulation. We examined Pcrit as a prognostic marker of acute kidney injury (AKI). DesignRetrospective cohort study. SettingSingle tertiary care hospital Participants1038 adult cardiac surgery patients that underwent CPB. InterventionsPcrit was calculated using arterial waveform data before initiation of CPB. Pcrit was examined in relation to incidence of stage 2 or higher postoperative AKI according to standard KDIGO definitions. Measurements and Main ResultsOf the 1038 patients included in the study, 50 (5%) experienced AKI. Patients that suffered AKI had significantly higher preoperative risk factors, including higher incidence of severe chronic kidney disease and higher STS risk score (p<0.01). They also had longer operative times and longer cross clamp times (p<0.01). All patients were maintained at similar mean MAP while on CPB. Patients that suffered AKI had a significantly higher pre-bypass Pcrit than those who did not (49.0 vs 44.1 mmHg, p=0.018). In a multivariate regression, Pcrit remained a significant predictor, representing a 16% increased risk of AKI for each 5 mmHg increase in pre-bypass Pcrit (p=0.011). ConclusionsA higher pre-bypass Pcrit is associated with a significantly higher incidence of postoperative AKI. Future study is warranted to investigate using intra-operative Pcrit to determine a personalized blood pressure goal during CPB.

Sanguineous cardiopulmonary bypass prime accelerates the inflammatory response during pediatric cardiac surgery.

The inflammatory response to cardiopulmonary bypass (CPB) in pediatric patients remains an unresolved challenge. Sanguineous CPB prime, composed of allogenic blood products, is one potentially important stimulus. This study aims to identify specific inflammatory mediators active in sanguineous CPB prime and their impact on the inflammatory response at CPB initiation. In a post-hoc analysis of a prospective observational cohort study (NCT05154864), where pediatric patients undergoing cardiac surgery with CPB were enrolled after informed consent, patients were grouped by CPB prime type (sanguineous vs crystalloid). Arterial samples were collected post-sternotomy as a baseline and again at CPB initiation from all patients. In the sanguineous group, CPB prime samples were also collected after buffered ultrafiltration but before CPB initiation. Luminex® measured concentrations of 24 inflammatory mediators for comparison between groups. Statistical analyses were by Mann-Whitney test and Wilcoxon signed-rank test. Data are presented as median [IQR]. Forty consecutive pediatric patients participated. The sanguineous group (n = 26) was younger (4.0 [0.2 - 6.0] vs 48.5 [39.0 - 69.5] months; p = 2.6 × 10-7) and smaller (4.9 [34 - 6.6] vs 17.2 [14.9 - 19.6] kg; p = 2.6 × 10-7) than the crystalloid group (n = 14). Despite this, baseline concentrations of 20 complement and cytokine concentrations were comparable between groups (p > 0.05) while four showed differences between groups (p < 0.05). The sanguineous prime contained supraphysiologic concentrations of complement mediators: C2, C3, C3a, C3b, and C5a. Correspondingly, upon CPB initiation, patients receiving sanguineous prime exhibited a significantly larger burden of C2, C3, C3b, C5, and C5a (p < 0.001) relative to the crystalloid group. Cytokine and chemokine mediators were present at trace levels in the sanguineous prime. Sanguineous prime contains activated complement that accelerates the inflammatory response at CPB initiation in neonates and infants. Immunomodulatory interventions targeting complement during CPB prime preparation could offer substantial benefits for these vulnerable patients.

Kinetics of Renin Concentrations in Infants Undergoing Congenital Cardiac Surgery.

Elevated renin has been shown to predict poor response to standard vasoactive therapies and is associated with poor outcomes in adults. Similarly, elevated renin was associated with mortality in children with septic shock. Renin concentration profiles after pediatric cardiac surgery are unknown. The purpose of this study was to characterize renin kinetics after pediatric cardiac surgery. Single-center retrospective study of infants who underwent cardiac surgery with cardiopulmonary bypass (CPB) utilizing serum samples obtained in the perioperative period to measure plasma renin concentrations (pg/mL). Time points included pre-bypass and 1, 4, and 24 h after initiation of CPB. Fifty patients (65% male) with a median age 5 months (interquartile range (IQR) 3.5, 6.5) were included. Renin concentrations peaked 4 h after CPB. There was a significant difference in preoperative and 4 h post-CPB renin concentration (4 h post-CPB vs preoperative: mean difference 100.6, 95% confidence interval (CI) 48.9-152.4, P < .001). Median renin concentration at 24 h after CPB was lower than the preoperative baseline. We describe renin kinetics in infants after CPB. Future studies based on these data can now be performed to evaluate the associations of elevated renin concentrations with adverse outcomes.

Instantaneous Right Ventricular to Pulmonary Artery Systolic Pressure Difference in Cardiac Surgery: A Retrospective and Prospective Cohort Study

BackgroundDuring cardiac surgery, right ventricular outflow tract obstruction (RVOTO) is defined as an instantaneous pressure difference ≥ 6 mm Hg between right ventricular systolic pressure (RVSP) and pulmonary artery systolic pressure (PASP), for ≥ 5 minutes. Risk factors for RVOTO remain poorly understood. This cohort study was designed to evaluate the incidence, characteristics, and outcomes of the patients who experienced RVOTO. MethodsInstantaneous pressure difference between RVSP and PASP was measured by means of a pulmonary artery catheter with a right ventricular port during cardiac surgery from a retrospective (n = 295) and a prospective (n = 105) cohort. ResultsFrom the retrospective and prospective cohorts, respectively, incidence of RVOTO was 30.2% and 36.2% before cardiopulmonary bypass (CPB) initiation and 43.7% and 47.6% after CPB separation. Before CPB initiation, patients with RVOTO had higher cardiac output (4.2 ± 1.5 vs 3.8 ± 1.1 L/min; P = 0.033) and received more inhaled epoprostenol (79% vs 61%; P = 0.005) and inotropes (66% vs 51%; P = 0.016) compared with those without RVOTO. After CPB separation, patients with RVOTO had higher heart rate (62 ± 15 vs 58 ± 13 beats/min; P = 0.011), cardiac output (4.1 ± 1.4 vs 3.7 ± 1.1 L/min; P = 0.003), and CPB duration (90 ± 45 vs 77 ± 30 min, P = 0.014), had lower fluid balance (758 ± 1123 vs 1063 ± 1089 mL; P = 0.021), and were more exposed to intratracheal milrinone (12% vs 4%; P = 0.015) compared with those without RVOTO. The time with persistent organ dysfunction (TPOD) at 28 days after surgery was similar among patients who had an RVOTO event, before CPB initiation or after CPB separation, compared with those who did not. ConclusionsRVOTO is common in cardiac surgery. However, it is not associated with longer TPOD.

Population pharmacokinetic modeling of sufentanil in adult Korean patients undergoing cardiopulmonary bypass surgery.

Sufentanil is frequently used as an anesthetic agent in cardiac surgery owing to its cardiovascular safety and favorable pharmacokinetics. However, the pharmacokinetics profiles of sufentanil in patients undergoing cardiopulmonary bypass (CPB) surgery remain less understood, which is crucial for achieving the desired level of anesthesia and mitigating surgical complications. Therefore, this study aimed to develop a population pharmacokinetic model of sufentanil in patients undergoing CPB surgery and elucidate the clinical factors affecting its pharmacokinetic profile. Adult patients who underwent cardiac surgery with CPB and were administered sufentanil for anesthesia were enrolled. Arterial blood samples were collected to quantify plasma concentrations of sufentanil and clinical laboratory parameters, including inflammatory cytokines. A population pharmacokinetic model was established using nonlinear mixed-effects modeling. Simulations were performed using the pharmacokinetic parameters of the final model. Overall, 20 patients were included in the final analysis. Sufentanil pharmacokinetics were modeled using a two-compartment model, accounting for CPB effects. Sufentanil clearance increased 2.80-fold during CPB and warming phases, while the central compartment volume increased 2.74-fold during CPB. CPB was a significant covariate affecting drug clearance and distribution volume. No other significant covariates were identified despite increased levels of the inflammatory cytokines, including IL-6, IL-8, and TNF-α during CPB. The simulation indicated a 30 μg loading dose and 40 μg/h maintenance infusion for target-controlled infusion. Additionally, a bolus dose of 60 μg was added at CPB initiation to adjust for exposure changes during this phase. Considering the target sufentanil concentrations, a uniform dosing regimen was acceptable for effective analgesia.

The Impact of Intraoperative Hyperlactatemia on Weaning from Cardiopulmonary Bypass in Patients Undergoing on-Pump Coronary Artery Bypass Grafting Surgery: An Observational Study

Abstract Background: Hyperlactatemia after cardiac surgery is common. However, the association and the implications of hyperlactatemia on the prognosis after cardiopulmonary bypass (CPB) remains controversial. This study investigated the associations between early-onset hyperlactatemia and the need for doses of inotropes and vasopressors during weaning from CPB, hemodynamic stability after weaning from CPB, and the duration of postoperative mechanical ventilation. Patients and Methods: This prospective cohort study included 300 patients who underwent elective on-pump coronary artery bypass grafting (CABG) surgery and had normal systolic function &gt;55%. Serum lactate levels were measured 1 h before induction, upon initiation of CPB, after removal of aortic cannula and on admission to the intensive care unit (ICU). Patients were divided into two groups: patients with lactate levels &lt;4 mmol/L (Group N) and those with lactate levels ≥4 mmol/L (Group H). Results: Patients with hyperlactatemia constituted 20.7% of the study population. The number of patients who required adrenaline and noradrenaline administration upon weaning from CPB, as well as the doses of these drugs, were significantly higher in Group H (P &lt; 0.001). Arterial blood pressure levels after weaning from CPB and upon admission to the ICU were significantly lower in Group H patients (P &lt; 0.001). The duration of post-operative mechanical ventilation was longer in Group H patients (P &lt; 0.001). Conclusion: Early-onset hyperlactatemia was associated with worse outcomes after CABG surgery. There was difficult weaning from CPB with increased inotrope and vasopressor drug support, early post-operative hemodynamic instability, and a prolonged duration of post-operative mechanical ventilation.

Continuous monitoring of left ventricular function in postoperative intensive care patients using artificial intelligence and transesophageal echocardiography

BackgroundContinuous monitoring of mitral annular plane systolic excursion (MAPSE) using transesophageal echocardiography (TEE) may improve the evaluation of left ventricular (LV) function in postoperative intensive care patients. We aimed to assess the utility of continuous monitoring of LV function using TEE and artificial intelligence (autoMAPSE) in postoperative intensive care patients.MethodsIn this prospective observational study, we monitored 50 postoperative intensive care patients for 120 min immediately after cardiac surgery. We recorded a set of two-chamber and four-chamber TEE images every five minutes. We defined monitoring feasibility as how often the same wall from the same patient could be reassessed, and categorized monitoring feasibility as excellent if the same LV wall could be reassessed in ≥ 90% of the total recordings. To compare autoMAPSE with manual measurements, we rapidly recorded three sets of repeated images to assess precision (least significant change), bias, and limits of agreement (LOA). To assess the ability to identify changes (trending ability), we compared changes in autoMAPSE with the changes in manual measurements in images obtained during the initiation of cardiopulmonary bypass as well as before and after surgery.ResultsMonitoring feasibility was excellent in most patients (88%). Compared with manual measurements, autoMAPSE was more precise (least significant change 2.2 vs 3.1 mm, P < 0.001), had low bias (0.4 mm), and acceptable agreement (LOA − 2.7 to 3.5 mm). AutoMAPSE had excellent trending ability, as its measurements changed in the same direction as manual measurements (concordance rate 96%).ConclusionContinuous monitoring of LV function was feasible using autoMAPSE. Compared with manual measurements, autoMAPSE had excellent trending ability, low bias, acceptable agreement, and was more precise.Graphical

Continuous Right Ventricular Pressure Monitoring in Cardiac Surgery

Right ventricular (RV) dysfunction in cardiac surgery can lead to RV failure, which is associated with increased morbidity and mortality. Abnormal RV function can be identified using RV pressure monitoring. The primary objective of the study is to determine the proportion of patients with abnormal RV early to end-diastole diastolic pressure gradient (RVDPG) and abnormal RV end-diastolic pressure (RVEDP) before initiation and after cardiopulmonary bypass (CPB) separation. The secondary objective is to evaluate if RVDPG before CPB initiation is associated with difficult and complex separation from CPB, RV dysfunction, and failure at the end of cardiac surgery. Prospective study. Tertiary care cardiac institute. Cardiac surgical patients. Cardiac surgery. Automated electronic quantification of RVDPG and RVEDP were obtained. Hemodynamic measurements were correlated with cardiac and extracardiac parameters from transesophageal echocardiography and postoperative complications. Abnormal RVDPG was present in 80% of the patients (n = 105) at baseline, with a mean RVEDP of 14.2 ± 3.9 mmHg. Patients experienced an RVDPG > 4 mmHg for a median duration of 50.2% of the intraoperative period before CPB initiation and 60.6% after CPB separation. A total of 46 (43.8%) patients had difficult/complex separation from CPB, 18 (38.3%) patients had RV dysfunction, and 8 (17%) had RV failure. Abnormal RVDPG before CPB was not associated with postoperative outcome. Elevated RVDPG and RVEDP are common in cardiac surgery. RVDPG and RVEDP before CPB initiation are not associated with RV dysfunction and failure but can be used to diagnose them.

Perioperative serum syndecan-1 concentrations in patients who underwent cardiovascular surgery with cardiopulmonary bypass and its association with the occurrence of postoperative acute kidney injury: a retrospective observational study

BackgroundVarious factors can cause vascular endothelial damage during cardiovascular surgery (CVS) with cardiopulmonary bypass (CPB), which has been suggested to be associated with postoperative complications. However, few studies have specifically investigated the relationship between the degree of vascular endothelial damage and postoperative acute kidney injury (pAKI).The objectives of this study were to measure perioperative serum syndecan-1 concentrations in patients who underwent CVS with CPB, evaluate their trends, and determine their association with pAKI.MethodsThis was a descriptive and case‒control study conducted at the National University Hospital. Adult patients who underwent CVS with CPB at a national university hospital between March 15, 2016, and August 31, 2020, were included. Patients who were undergoing preoperative dialysis, had preoperative serum creatinine concentrations greater than 2.0 mg dl−1, who were undergoing surgery involving the descending aorta were excluded. The perioperative serum syndecan-1 concentration was measured, and its association with pAKI was investigated.ResultsFifty-two patients were included. pAKI occurred in 18 (34.6%) of those patients. The serum syndecan-1 concentration increased after CPB initiation and exhibited bimodal peak values. The serum syndecan-1 concentration at all time points was significantly elevated compared to that after the induction of anesthesia. The serum syndecan-1 concentration at 30 min after weaning from CPB and on postoperative day 1 was associated with the occurrence of pAKI (OR = 1.10 [1.01 to 1.21], P = 0.03]; OR = 1.16 [1.01 to 1.34], P = 0.04]; and the cutoff values of the serum syndecan-1 concentration that resulted in pAKI were 101.0 ng ml−1 (sensitivity = 0.71, specificity = 0.62, area under the curve (AUC) = 0.67 (0.51 to 0.83)) and 57.1 ng ml−1 (sensitivity = 0.82, specificity = 0.56, AUC = 0.71 (0.57 to 0.86)). Multivariate logistic regression analysis revealed that the serum syndecan-1 concentration on postoperative day 1 was associated with the occurrence of pAKI (OR = 1.02 [1.00 to 1.03]; P = 0.03).ConclusionThe serum syndecan-1 concentration at all time points was significantly greater than that after the induction of anesthesia. The serum syndecan-1 concentration on postoperative day 1 was significantly associated with the occurrence of pAKI.Trial registrationThis study is not a clinical trial and is not registered with the registry.

A novel approach to retrograde autologous priming for infant, pediatric and adult populations undergoing congenital heart surgery.

Retrograde Autologous Priming (RAP) of cardiopulmonary bypass (CPB) circuits is an effective way to reduce prime volume, commonly through the transfer of prime into separate reservoirs or circuit manipulation. We describe a simple and safe technique for RAP without the need for any circuit modifications or manipulations. For this technique, a separate roller pump for ultrafiltration (UF) is used. After adequate heparinization and arterial cannulation, the UF pump is initiated slowly, removing prime through the effluent of the UF, replacing with the patient's blood from the aortic cannula. Once the arterial line and UF circuit are autologous primed, the arterial head displaces reservoir crystalloid toward the UF circuit at a flow rate equal to the UF pump, displacing the crystalloid prime with blood from the UF circuit, autologous priming the boot and oxygenator with blood, crystalloid again being removed by the effluent. After venous cannulation, the venous line prime is replaced with autologous blood, the crystalloid removed by the effluent of the UF circuit via the arterial head. During RAP, if the patient becomes hypovolemic, either autologous volume is transfused back to the patient, or CPB is initiated, without the need for circuitry modifications. The patient population in this sample consisted of 63 patients ranging between 6.1kg and 115.6kg. The smaller the patient, the less blood volume available for RAP and therefore the less prime volume able to be removed. Overall percent removal increases as our patients size increases compared to total circuit volume. This RAP technique is a safe and effective way to achieve a standardized asanguinous prime for many regardless of patient or circuit size in the absence of contraindications such as low starting hematocrit, emergency surgery or physiologic instability. Most importantly, this potentially reduces the amount of hemodilution patients see from CPB initiation and therefore the lowest nadir hematocrit and consequently the amount of required homologous blood products needed during surgery.

THE INFLUENCE OF BIOCOMPATIBILITY OF THE EXTRACORPOREAL OXYGENATOR CIRCUIT ON THE DEGREE OF HEMOLYSIS AND OPTIMIZATION OF OXYGEN STATUS IN MINIMALLY INVASIVE CORONARY ARTERY BYPASS GRAFTING

Introduction. A distinctive feature of cardiopulmonary bypass in minimally invasive coronary artery bypass grafting (CABG) is the significantly longer perfusion time, involving active blood drainage from the vein to the cardiotomy reservoir, which carries the risk of hemolysis development. In this context, mechanical hemolysis disrupts the gas transport function of the blood.&#x0D; The aim of the research. Reducing hemolysis and optimizing oxygen status of patients during minimally invasive coronary artery bypass grafting surgeries.&#x0D; Materials and methods. The study included 60 patients, who underwent minimally invasive coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB) under moderate hypothermia. The patients were divided into two groups of 30 individuals each. To improve the biocompatibility of the oxygenator, the circuit in Group 1 (Gr1) was treated with an adaptive composition, while in Group 2 (Gr2), the oxygenator circuit remained untreated. The following parameters were examined: hemoglobin (Hb), hematocrit (Ht), red blood cell count (RBC), oxygen delivery index (DO2I), oxygen consumption index (VO2I), oxygen extraction ratio (O2ER%), oxygen extraction index (O2EI%), venous (SpvO2), and arterial (SpaO2) oxygen saturation, oxygen tension in arterial (PaO2) and venous blood (PvO2), acid-base status of the blood (pH, pCO2,HCO3ˉ, BE), and the degree of hemolysis.&#x0D; Results. Before initiation of cardiopulmonary bypass (CPB), an insignificant increase in O2IE% was observed in Gr1 (26.07±1.57) and Gr2 (27.11±0.81); p=0.875, indicating an increase in tissue oxygen consumption. At the hypothermic stage CPB, both Gr1 and Gr2 demonstrated a statistically significant decrease in Hb, Ht, and RBC levels (p&lt;0.05) due to hemodilution, accompanied by a decrease in IDO2, IVO2, O2IE%, and O2ER% in both groups due to hypothermia. After rewarming, O2ER% in Gr1 (22.91±2.68) and Gr2 (24.59±2.02); p=0.191, and O2EI% in Gr1 (22.92±2.44) and Gr2 (24.61±2.01); p=0.215, were in the normal range. After weaning off cardiopulmonary bypassin Gr2, O2EI% was 27.34±1.97, indicating an increase in oxygen consumption and oxygen extraction. Upon separation from CPB, Gr2 showed a tendency to mild compensated metabolic acidosis, mainly due to HCO3ˉ 21.9±0.3. During the rewarming stage, the hemolysis value was 0.36±0.09in Gr1 and 0.45±0.17 in Gr2 (p&lt;0.001). After CPB, hemolysis was 0.41±0.15 in Gr1 and 0.61±0.22 in Gr2 (p&lt;0.001).&#x0D; Conclusions. Improving the biocompatibility of the extracorporeal oxygenatorcircuit makes it possible to reduce hemolysis and optimise the patient's oxygen status after cardiopulmonary bypass in minimally invasive coronary artery bypass grafting.

Staged Norwood operation for patients with hypoplastic left heart syndrome and cor triatriatum: a report of two cases

Two patients with hypoplastic left heart syndrome (HLHS) concomitant with cor triatriatum underwent the staged Norwood procedure following hybrid palliation. Cor triatriatum was diagnosed after birth in both cases. Case 1 with aortic stenosis and mitral atresia underwent bilateral pulmonary artery banding at 2 days of age. Subsequently, balloon atrial septostomy was conducted at 21 days of age due to hypoxia and increased intra-atrial pressure gradient. At 2 months of age, concomitant Norwood operation, cor triatriatum repair, and tricuspid valve repair were successfully performed. She has suffered from branch pulmonary artery hypoplasia since then; thus, Fontan operation was out of indication. Case 2 with aortic stenosis and mitral stenosis underwent bilateral pulmonary artery banding at 6 days of age. After that, the patient’s hemodynamic condition remained stable. The Norwood operation concomitant with cor triatriatum repair was performed at 2 months of age. However, during the procedure, massive pulmonary edema and hemorrhage occurred right after the initiation of cardiopulmonary bypass. She could not be weaned from cardiopulmonary bypass.

Assessing venous congestion in cardiac surgery with extracorporeal circulation using point‐of‐care transesophageal ultrasonography

AbstractPurposeIndividualizing fluid resuscitation utilizing indicators that assess fluid tolerance could positively impact optimizing volemia while avoiding venous congestion in cardiac surgery. Our study aims to describe hemodynamic changes based on the assessment of venous congestion using transesophageal ultrasonography (TEUS), both before and after cardiopulmonary bypass (CPB) in patients with preserved right ventricle (RV) function.MethodsA retrospective study was conducted at the Hospital Privado Universitario de Córdoba, involving patients who underwent cardiac surgery with CPB. The study assessed ultrasonographic venous congestion parameters before and after CPB using TEUS. The measured parameters included the diameter of the inferior vena cava (IVC), the pattern of hepatic vein flow (HVF), and the pulsatility index of portal vein flow (PVF).ResultsA total of 43 patients who underwent cardiac surgery between January 2021 and January 2022 were enrolled. A significant difference in the IVC diameter was observed before and after initiation of CPB (p = .0001). Comparative measurements of the HVF pattern before and after CPB revealed a significant difference, indicating modifications in congestion patterns related to CPB initiation (p = .0001). Pre‐CPB, portal flow was normal in all patients, while more than 50% of patient showed altered post‐CPB PVF. A significant difference in the PVF pulsatility index related to CPB initiation was observed, suggesting increased portal venous congestion (p = .0001).ConclusionOur study demonstrates that extracorporeal circulation can induce signs of venous congestion, which are detectable by TEUS, in patients with preserved RV function preoperatively.

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.

Complications from peripheral cardiopulmonary bypass in minimally invasive mitral valve surgery

Background: To determine the incidence of peripheral complications associated with peripheral cardiopulmonary bypass (CPB) and to detail cases of severe complications necessitating surgical intervention during peripheral CPB at the HCMC University of Medicine and Pharmacy Hospital. Material and Methods: A cross-sectional, retrospective study on patients who underwent minimally invasive mitral valve surgery with the establishment of peripheral CPB between January 2017 and January 2022. Results: Of the 199 patients who underwent the surgery, 24 cases (12%) experienced peripheral complications. The incidence rates were as follows: femoral artery stenosis from thrombosis at 1.5%, femoral vein occlusion from thrombosis at 0.5%, lower limb compartment compression at 0.5%, and inguinal incision bleeding at 1%. There were no recorded cases of incisional infections in the groin area. Five patients had serious peripheral vascular complications that necessitated urgent surgical intervention. However, no life-threatening complications or deaths during hospitalization were reported. Conclusion: The occurrence of peripheral complications from the initiation of peripheral CPB is relatively low. These complications are manageable and do not diminish the efficacy of peripheral CPB in minimally invasive mitral valve procedures. Key words: peripheral cardiopulmonary bypass, vascular complications, cardiac surgery, minimally invasive surgery, mitral valve surgery.

Cardiopulmonary Bypass Settings for the Prevention of Early Hypotension During CABG.

Vasoplegic syndrome is a form of vasodilatory shock that can occur before, during or after cardiopulmonary bypass (CPB). We introduce a strategy to reduce the incidence of early hypotension phenomena during Coronary Artery Bypass Graft (CABG) procedures. In this prospective cohort study, 100 patients underwent elective CABG with two perioperative CPB settings. The study group (50 patients) was managed with retrograde autologous priming (RAP), 3-minute stepwise for the institution of CPB, and pulsatile flow (PP). The control group (50 patients) was managed without RAP, with the rapid initiation of CPB, and non-pulsatile (NP) flow. The primary endpoints were MAP (mmHg), number of hypotensive phenomena (MAP < 50 mmHg for > 30 sec), the venous return volume on CPB (ml), the cardiac index (L/min/m2), hemoglobin (g/dL), indexed oxygen delivery (DO2i, ml/min/m2), the systemic vascular resistance index (SVRI, dynes s m2/cm5), number of 1-ml boluses of a vasoactive substance (norepinephrine), the positive fluid balance (ml), and the number of red blood cell units for transfusion. During CPB, the mean values in the study and control groups were as follows: MAP, 68± 7 vs 56 ± 7 (p-value, 0.0019); hypotensive phenomena, 3 ± 1 vs 8 ±2 (p-value, 0.019); venous return volume, 840±79 vs 1129 ±123 (p-value, 0.0017); cardiac index, 2.4 ± 0.4 vs 2.7 ±0.2 (p-value, 0.0023); hemoglobin, 9.13 ± 0.29 vs 7.8± 0.23 (p-value, 0.0001); DO2i, 301± 12 vs 276±23 (p-value, 0.0011); SVRI, 1879 ±280 vs 2210 ±140 (p-value, 0.0017); norepinephrine, 1±2 vs 8 ±3 (p-value, 0.0023); positive fluid balance, 750 ±212 vs 1450 ±220 (p-value, 0.005); and total number of red blood cell units for transfusion, 16 ±4.2 vs 27 ± 5.3 (p-value, 0.008). In this prospective cohort study, during CPB, the study group showed a better preservation of MAP, SVRI, and DO2i, and a reduction of vasoconstrictor use in a CPB setting with the RAP technique, 3-minute stepwise for the initiation of CPB and pulsatile pump flow, compared to the control group. Further studies are needed to validate this perioperative approach to CPB.

Hemolysis Precedes Urine Color Change in Patients Undergoing Open-Heart Surgery on Cardiopulmonary Bypass.

Red-colored urine often occurs in patients in the perioperative period who undergo cardiac surgery using cardiopulmonary bypass (CPB). This urine color change has been utilized for approximating hemolysis during CPB without a proven relationship for ongoing hemolysis. This case series study aimed to examine the relationship between plasma free hemoglobin (Hb) levels and quantified measures of urine color. Ten patients were enrolled in this study. Blood and urine were collected for analyses for the following time points: before surgery, two hours after the initiation of CPB, every 30 min during CPB thereafter, and 0, 2, 4, 12, and 24 hours after the completion of CPB. We measured free Hb in plasma and urine using the azide-methemoglobin method. Photographs of urine were obtained, and the luminance of the three basic colors (red/green/blue) was analyzed by quantitative luminance contrast analysis to find a correlation for hemolysis. Median levels of plasma free Hb were 0.015 (0.010-0.080, n = 10) g/dL at baseline. During the CPB, increases in plasma free Hb levels were measured: median plasma free Hb levels were increased to0.100 g/dL(0.020-0.240, p = 0.039, vs. baseline, n = 9) at two hours into CPB, median and range, respectively.In contrast, increases in urinary free Hb levels and/or urine color changes were measured only after cessation of CPB in nine patients. Urine color change or elevation of urinary free Hb levels followed the elevation of plasma free Hb levels with considerable delay.

Impact of pre-bypass ultrafiltration on prime values and clinical outcomes in neonatal and infant cardiopulmonary bypass

Background: A standard blood prime for cardiopulmonary bypass (CPB) in congenital cardiac surgery may possess non-physiologic values for electrolytes, glucose, and lactate. Pre-bypass Ultrafiltration (PBUF) can make these values more physiologic and standardized prior to bypass initiation. We aimed to determine if using PBUF on blood primes including packed red blood cells and thawed plasma would make prime values more predictable and physiologic. Additionally, we aimed to evaluate whether the addition of PBUF had an impact on outcome measures. Methods: Retrospective review of consecutive patients ≤ 1 year of age undergoing an index cardiac operation on CPB between 8/2017 and 9/2021. As PBUF was performed at the perfusionists’ discretion, a natural grouping of patients that received PBUF vs. those that did not occur. Differences in electrolytes, glucose, and lactate were compared at specific time points using Fisher’s exact test for categorical variables and the Wilcoxon rank sum test for continuous variables. Clinical outcomes were also assessed. Results: In both cohorts, the median age at surgery was 3 months and 47% of patients were female; 308/704 (44%) of the PBUF group and 163/414 (39%) of the standard prime group had at least one preoperative risk factor. The proportion of PBUF circuits which demonstrated more physiologic values for glucose (318 [45%]), sodium (434, [62%]), potassium (688 [98%]), lactate (612 [87%]) and osmolality (595 [92%]) was significantly higher when compared to standard prime circuit levels for glucose (8 [2%]), sodium (13 [3%], potassium (150 [36%]), lactate (56 [13%]) and osmolality (23 [6%]) prior to CPB initiation. There were no differences in clinical outcomes or rates of major adverse events between the two cohorts. Conclusions: PBUF creates standardized and more physiologic values for electrolytes, glucose, and lactate before the initiation of bypass without significant impacts on in-hospital outcomes.

Effect of cardiopulmonary bypass on coagulation factors II, VII and X in a primate model: an exploratory pilot study.

The use of cardiopulmonary bypass (CPB) in cardiac surgery is a major risk factor for postoperative bleeding. We hypothesized that consumptive coagulopathy and haemodilution influence the coagulation factors; therefore, we aimed to estimate the activity profiles of coagulation factors II, VII and X during CPB circulation. A 120-min bypass was surgically established in cynomolgus monkeys (n = 7). Activities of coagulation factors II, VII and X were measured at 6 time points during the experiment (baseline, 0, 30, 60, 120 min of bypass and 60 min after bypass). To assess the influence of consumptive coagulopathy, the values were adjusted for haemodilution using the haematocrit values. Data were expressed as mean (standard deviation). Activities of coagulation factors decreased during the experiment. In particular, the activities for II, VII and X were decreased the most by 44.2% (5.0), 61.4% (4.3) and 49.0% (3.7) at 30 min following CPB initiation (P < 0.001, P < 0.001 and P < 0.001, respectively). Following adjustments for haemodilution, change magnitudes lessened but remained significant for factor VII. The adjusted concentration of factor VII was observed to decrease from the baseline to the initiation of bypass circulation. In conclusion, coagulation factor II, VII and X concentrations decreased during CPB. Following adjustment for haemodilution, a decrease in concentration was observed with factor VII.

Diffuse Optical Monitoring of Cerebral Hemodynamics and Oxygen Metabolism during and after Cardiopulmonary Bypass: Hematocrit Correction and Neurological Vulnerability.

Cardiopulmonary bypass (CPB) provides cerebral oxygenation and blood flow (CBF) during neonatal congenital heart surgery, but the impacts of CPB on brain oxygen supply and metabolic demands are generally unknown. To elucidate this physiology, we used diffuse correlation spectroscopy and frequency-domain diffuse optical spectroscopy to continuously measure CBF, oxygen extraction fraction (OEF), and oxygen metabolism (CMRO2) in 27 neonatal swine before, during, and up to 24 h after CPB. Concurrently, we sampled cerebral microdialysis biomarkers of metabolic distress (lactate-pyruvate ratio) and injury (glycerol). We applied a novel theoretical approach to correct for hematocrit variation during optical quantification of CBF in vivo. Without correction, a mean (95% CI) +53% (42, 63) increase in hematocrit resulted in a physiologically improbable +58% (27, 90) increase in CMRO2 relative to baseline at CPB initiation; following correction, CMRO2 did not differ from baseline at this timepoint. After CPB initiation, OEF increased but CBF and CMRO2 decreased with CPB time; these temporal trends persisted for 0-8 h following CPB and coincided with a 48% (7, 90) elevation of glycerol. The temporal trends and glycerol elevation resolved by 8-24 h. The hematocrit correction improved quantification of cerebral physiologic trends that precede and coincide with neurological injury following CPB.