Dose-dependent influence of red blood cell transfusion volume on adverse outcomes in cardiac surgery

INTRODUCTION

Red blood cell (RBC) transfusion is associated with adverse outcomes, but there are few studies on the RBC volume. This study aimed to evaluate the relationship between intraoperative RBC volume and postoperative adverse outcomes for on-pump cardiac surgery.

METHODS

Adult patients undergoing on-pump cardiac surgery from 1 January 2017 to 31 December 2018 were included. Those transfused with more than 6 units of RBC were excluded. The clinical characteristics of four groups with various RBC volume were compared. We analyzed the relationship between RBC volume and adverse outcomes through multivariable logistic regression.

RESULTS

12,143 patients were analyzed, of which 3353 (27.6%) were transfused with 1-6U RBC intraoperatively. The incidence of death, overall morbidity, acute kidney injury and prolonged mechanical ventilation were increased stepwise along with incremental RBC volume. After adjusting for possible confounders, patients transfused with 1-2U were associated with a 1.42-fold risk of death (99% CI, 1.21-2.34, p = 0.01) compared with patients without RBC, patients with 3-4U were associated with a 1.57-fold risk (99% CI, 1.32-2.80, p = 0.005) and patients with 5-6U had a 2.26-fold risk of death (99% CI, 1.65-3.88, p < 0.001). Similarly, the incidence of overall morbidity, acute kidney injury and prolonged mechanical ventilation increased several folds as the RBC numbers increased.

CONCLUSIONS

There was a significant dose-dependent influence of incremental intraoperative RBC volume on increased risk of adverse outcomes for on-pump cardiac surgery patients. Patient blood management practice should aim to reduce not only transfusion rate but also the volume of blood use.

Red Blood Cell Conservation and Use in the Cardiovascular Operating Rooms at Ben Taub General Hospital

OBJECTIVES

A conservative hemoglobin transfusion threshold is noninferior to a liberal threshold in cardiac surgery. However, red blood cell (RBC) transfusion remains common during cardiac surgery. The authors' single-center, retrospective study aimed to decrease RBC transfusions for hemoglobin >7.5 g/dL in nonemergent cardiovascular surgeries utilizing cardiopulmonary bypass (CPB), by educating the anesthesiology and surgical staff on the benefits of a conservative threshold for transfusions, and incorporating the discussion and routine use of blood conservation methods for all nonemergent cardiac surgeries.

DESIGN

This was a single-center, retrospective study that included all nonemergent coronary artery bypass grafting and single-valve cases utilizing CPB from January 2018 to December 2021 before and after the intervention in July 2019.

SETTING

The data involved a single community hospital.

PARTICIPANTS

A total of 417 patients were included in the study.

INTERVENTIONS

The authors adopted a conservative threshold for blood transfusion and implemented a collaborative multidisciplinary approach to blood conservation.

MEASUREMENTS AND MAIN RESULTS

Baseline patient characteristics were summarized, and the incidence of RBC transfusion before and after the intervention on July 26, 2019, were compared by Wilcoxon rank sum and chi-square tests. Multivariate logistic regression was used. The intervention was significantly associated with reduced RBC transfusion rate after adjusting for confounding variables (p < 0.05). The odds of receiving an RBC transfusion among patients after the intervention was 0.615 times the odds among patients before intervention (95% CI: 0.3913-0.9663).

CONCLUSIONS

The authors' goal was to improve patient outcomes and the quality of perioperative care during cardiac surgery. By implementing a protocol and educating anesthesiologists, surgeons, and perfusionists, they successfully decreased the incidence of RBC transfusion above a hemoglobin of 7.5 g/dL.

Dexmedetomidine as a myocardial protector in pediatric heart surgery using cardiopulmonary bypass: a systematic review

Background

In recent years, dexmedetomidine has been studied as a cardioprotective agent. However, studies on its application in pediatric heart surgery using cardiopulmonary bypass (CPB) remain limited. This systematic review aimed to provide information on the cardioprotective effect of dexmedetomidine in children undergoing heart surgery using CPB.

Methods

The authors searched several databases (MEDLINE, Embase, Cochrane Library, etc.) to identify all trials comparing the levels of myocardial injury via biomarkers, including pediatric patients undergoing heart surgery using CPB who received dexmedetomidine versus placebo or other anesthetic agents. Literatures from non-primary studies were excluded. Two reviewers independently screened studies for eligibility and extracted data. The Cochrane Risk-of-Bias tool was implemented to evaluate any potential biases. Information from eligible studies was summarized and correspondingly reviewed based on any quantitative outcomes.

Results

We identified six trials composed of 419 participants, three of which (n=241) showed significantly reduced interleukin-6 (IL-6) levels in the dexmedetomidine group, while one study (n=40) showed no IL-6 difference between groups. Cardiac troponin I (cTnI) and creatinine kinase-myocardial band (CK-MB), as myocardial injury biomarkers, were found to be lower in two trials (n=180). Despite several limitations hindering this review from pooling the data objectively, the majority of published studies indicated that dexmedetomidine is a seemingly efficacious agent protecting against cardiac injury during bypass.

Conclusions

These studies suggest that dexmedetomidine has cardioprotective effects through the lowering of cardiac injury biomarkers while improving its clinical outcomes after heart surgery using bypass.

The effects of nitric oxide on coagulation and inflammation in ex vivo models of extracorporeal membrane oxygenation and cardiopulmonary bypass

BACKGROUND

Extracorporeal life support (ECLS) has extensive applications in managing patients with acute cardiac and pulmonary failure. Two primary modalities of ECLS, cardiopulmonary bypass (CPB) and extracorporeal membrane oxygenation (ECMO), include several similarities in their composition, complications, and patient outcomes. Both CPB and ECMO pose a high risk of thrombus formation and platelet activation due to the large surface area of the devices and bleeding due to system anticoagulation. Therefore, novel methods of anticoagulation are needed to reduce the morbidity and mortality associated with extracorporeal support. Nitric oxide (NO) has potent antiplatelet properties and presents a promising alternative or addition to anticoagulation with heparin during extracorporeal support.

METHODS

We developed two ex vivo models of CPB and ECMO to investigate NO effects on anticoagulation and inflammation in these systems.

RESULTS

Sole addition of NO as an anticoagulant was not successful in preventing thrombus formation in the ex vivo setups, therefore a combination of low-level heparin with NO was used. Antiplatelet effects were observed in the ex vivo ECMO model when NO was delivered at 80 ppm. Platelet count was preserved after 480 min when NO was delivered at 30 ppm.

CONCLUSION

Combined delivery of NO and heparin did not improve haemocompatibility in either ex vivo model of CPB and ECMO. Anti-inflammatory effects of NO in ECMO systems have to be evaluated further.

Cannulation Strategies in Type A Aortic Dissection: Overlooked Details and Novel Approaches

Aortic dissection type A is a life-threatening condition that frequently necessitates surgical intervention. This review focuses on central aortic cannulation, arch branch vessel (ABV) cannulation, and proximal arch cannulation as key techniques during aortic surgery. It discusses innovative solutions for addressing these challenges. The review synthesizes findings from recent studies and emphasizes the significance of meticulous planning and execution of cannulation in aortic dissection repair. This review aims to contribute to the advancement of surgical practices and the enhancement of patient outcomes in the management of type A aortic dissection (AAD) by addressing these frequently overlooked details.

Modifications to therapeutic plasma exchange to achieve rapid exchange on cardiopulmonary bypass prior to pediatric cardiac transplant

BACKGROUND

Cardiac transplants increasingly occur following placement of ventricular assist devices (VADs). A strong association exists between human leukocyte antigen (HLA) sensitization and VAD placement; however, desensitization protocols that utilize therapeutic plasma exchange (TPE) are fraught with technical challenges and are at increased risk of adverse events. In response to increased VAD utilization in our pre-transplant population, we developed a new institutional standard for TPE in the operating room.

METHODS

Through a multidisciplinary effort, we developed an institutional protocol for intraoperative TPE immediately prior to cardiac transplantation after cannulation onto cardiopulmonary bypass (CPB). All procedures used the standard TPE protocol on the Terumo Optia (Terumo BCT, Lakewood, CO, USA), but incorporated multiple modifications to limit patients' bypass times, and to coordinate with the surgical teams. These modifications included deliberate misidentification of replacement fluid and maximization of the citrate infusion rate.

RESULTS

These adjustments allowed the machine to run at maximal inlet speeds, minimizing duration of TPE. To date, 11 patients have been treated with this protocol. All survived their cardiac transplantation operation. Hypocalcemia and hypotension were noted; however, none of these adverse events appeared to have clinical impact. Technical complications included unexpected fibrin deposition in the TPE circuit and air in the inlet line due to surgical manipulation of the CPB cannula. No thromboembolic complications occurred in any patient.

CONCLUSION

We feel that this procedure can be rapidly and safely performed in HLA sensitized pediatric patients on CPB to limit the risk of antibody mediated rejection of their heart transplant.

Epidemiology of severe bleeding in children following cardiac surgery involving cardiopulmonary bypass: use of Bleeding Assessment Scale for critically Ill Children (BASIC)

OBJECTIVES

To describe the epidemiology of severe bleeding in the immediate post-operative period in children who undergo cardiopulmonary bypass surgery using the Bleeding Assessment Scale for critically Ill Children (BASIC).

STUDY DESIGN

Retrospective cohort study in a paediatric ICU from 2015 to 2020.

RESULTS

356 children were enrolled; 59% were male with median (IQR) age 2.1 (0.5-8) years. Fifty-seven patients (16%) had severe bleeding in the first 24 hours post-operatively. Severe bleeding was observed more frequently in younger and smaller children with longer bypass and cross-clamp times (p-values <0.001), in addition to higher surgical complexity (p = 0.048). Those with severe bleeding received significantly more red blood cells, platelets, plasma, and cryoprecipitate in the paediatric ICU following surgery (all p-values <0.001). No laboratory values obtained on paediatric ICU admission were able to predict severe post-operative bleeding. Those with severe bleeding had significantly less paediatric ICU-free days (p = 0.010) and mechanical ventilation-free days (p = 0.013) as compared to those without severe bleeding.

CONCLUSIONS

Applying the BASIC definition to our cohort, severe bleeding occurred in 16% of children in the first day following cardiopulmonary bypass. Severe bleeding was associated with worse clinical outcomes. Standard laboratory assays do not predict bleeding warranting further study of available laboratory tests.

Utilizing retrograde autologous priming for blood conservation in cardiac surgery

BACKGROUND

The use of crystalloid priming for extracorporeal circuit in adult cardiac surgery causes inevitable haemodilution. The haemodilution can be reduced by using methods such as retrograde autologous priming (RAP) with the patient's blood. This study compares the RAP technique with standard priming with regards to safety and the impact on haemodilution.

METHODS

This was a retrospective cohort study between a control group (n = 100) consisting of consecutive patients undergoing first time isolated coronary artery bypass surgery (CABG) with crystalloid priming solution in the circuit, and the RAP group (n = 100) consisting of patients undergoing isolated first time CABG with the RAP method. All demographics, procedure and perfusion data were gathered from the local surgical and perfusion database.

RESULTS

Despite starting with comparable mean pre-operative haemoglobin (Hb) levels (control 127 mg/dL versus RAP 129 mg/dL), the RAP group had significantly higher mean post-op Hb level (109 mg/dL versus 92 mg/dL, P < 0.01). Crystalloid use was also significantly lower in RAP group (3.15 L versus 4.17 L P < 0.02). Freedom from red blood cell transfusion (86% versus 76% P = 0.038) and freedom from blood products (78% versus 66%, P = 0.032) was also significantly better in the RAP group.

CONCLUSIONS

This study demonstrates that retrograde autologous priming is a safe and effective method for priming the cardiopulmonary bypass circuit in adult cardiac surgery, with significantly beneficial effects on transfusion rates and intra operative fluid requirements. Given these results the RAP method should be considered as a routine step in priming an extracorporeal circuit for adult cardiac operations.

Inflammatory Biomarkers and Blood Physical Property Transformations Following On-Pump Coronary Artery Bypass Graft Surgery

OBJECTIVE

This study aimed to compare the hemorheological and inflammatory changes before and after coronary artery bypass graft (CABG) surgery, as factors such as hypothermia, hemodilution, transfusion, and other variables affect blood viscosity and inflammation during the procedure.

METHODS

A total of 25 patients who underwent CABG surgery were enrolled in this study. Whole blood was collected just before the CABG (D0), 2 days after surgery (D2), and 5 days after surgery (D5). The plasma viscosity (PV) and whole blood viscosity (WBV) were measured at shear rates ranging from 0.1 to 1000 s-1 using a rheometer, and the mean values were compared. Inflammatory markers were also assessed and analyzed in relation to the hemorheological changes.

RESULTS

Compared with the baseline values, the PV significantly increased after 5 days. WBV showed a significant increase on day 2 and after 5 days. The WBV and fibrinogen were significantly correlated on day 2 and day 5 but not before surgery. Inflammatory markers such as CRP, WBC, platelets, and fibrinogen also demonstrated notable changes in relation to the hemorheological alterations.

CONCLUSIONS

This study highlights the crucial finding that hyperviscosity, characterized by elevated PV and WBV, persists for almost one week after on-pump CABG surgery. Understanding the interplay between inflammation and hemorheological properties during the postoperative period is crucial for optimizing patient care. Future research should focus on exploring the underlying mechanisms and potential therapeutic interventions to mitigate the impact of inflammation on blood viscosity and improve patient outcomes following CABG surgery.

Does heparin rebound lead to postoperative blood loss in patients undergoing cardiac surgery with cardiopulmonary bypass?

BACKGROUND

Heparin rebound is a common observed phenomenon after cardiac surgery with CPB and is associated with increased postoperative blood loss. However, the administration of extra protamine may lead to increased blood loss as well. Therefore, we want to investigate the relation between heparin rebound and postoperative blood loss and the necessity to provide extra protamine to reverse heparin rebound.

METHODS

We searched PubMed, Cochrane, EMBASE, Google Scholar and Web of Science to review the question: "Does heparin rebound lead to postoperative blood loss in patients undergoing cardiac surgery with cardiopulmonary bypass." Combination of search words were framed within four major categories: heparin rebound, blood loss, cardiac surgery and cardiopulmonary bypass. All studies that met our question were included. Quality assessment was performed using the Cochrane risk of bias (RoB2) tool for randomized controlled trials and the risk of bias in non-randomized studies of intervention (ROBINS-I) for non-randomised trials.

RESULTS

4 randomized and 17 non-randomized studies were included. The mean incidence of heparin rebound was 40%. The postoperative heparin levels, due to heparin rebound, were often below or equal to 0.2 IU/mL. We could not demonstrate an association between heparin rebound and postoperative blood loss or transfusion requirements. However the quality of evidence was poor due to a broad variety of definitions of heparin rebound, measured by various coagulation tests and studies with small sample sizes.

CONCLUSION

The influence of heparin rebound on postoperative bleeding seems to be negligible, but might get significant in conjunction with incomplete heparin reversal or other coagulopathies. For that reason, it might be useful to get a picture of the entire coagulation spectrum after cardiac surgery, as can be done by the use of a viscoelastic test in conjunction with an aggregometry test.

Risk factors of gastrointestinal bleeding after cardiopulmonary bypass in children: a retrospective study

Background

During cardiac surgery that involved cardiopulmonary bypass (CPB) procedure, gastrointestinal (GI) system was known to be vulnerable to complications such as GI bleeding. Our study aimed to determine the incidence and risk factors associated with GI bleeding in children who received CPB as part of cardiac surgery.

Methods

This retrospective study enrolled patients aged <18 years who underwent cardiac surgery with CPB from 2013 to 2019 at Shanghai Children's Medical Center. The primary outcome was the incidence of postoperative GI bleeding in children, and the associated risk factors with postoperative GI bleeding episodes were evaluated.

Results

A total of 21,893 children who underwent cardiac surgery with CPB from 2013 to 2019 were included in this study. For age distribution, 636 (2.9%) were neonates, 10,984 (50.2%) were infants, and 10,273 (46.9%) were children. Among the 410 (1.9%) patients with GI bleeding, 345 (84.2%) survived to hospital discharge. Incidence of GI bleeding in neonates, infants and children were 22.6% (144/636), 2.0% (217/10,984) and 0.5% (49/10,273), respectively. The neonates (22.6%) group was associated with highest risk of GI bleeding. Patients with GI bleeding showed longer length of hospital stays (25.8 ± 15.9 vs. 12.5 ± 8.9, P < 0.001) and higher mortality (15.9% vs. 1.8%, P < 0.001). Multivariate logistic regression analysis showed that age, weight, complicated surgery, operation time, use of extracorporeal membrane oxygenation (ECMO), low cardiac output syndrome (LCOS), hepatic injury, artery lactate level, and postoperative platelet counts were significantly associated with increased risk of GI bleeding in children with congenital heart disease (CHD) pediatric patients that underwent CPB procedure during cardiac surgery.

Conclusion

The study results suggest that young age, low weight, long operation time, complicated surgery, use of ECMO, LCOS, hepatic injury, high arterial lactate level, and low postoperative platelet counts are independently associated with GI bleeding after CPB in children.

Prevalence of burnout among perfusionists in China: A nationwide survey

BACKGROUND

Burnout has gained increasing attention worldwide as a phenomenon that affects health care professionals. However, there is a lack of relevant research about its impact on practitioners in the field of cardiovascular perfusion in China. This study investigated the prevalence of and the factors associated with the burnout affecting perfusionists in mainland China.

METHODS

This national cross-sectional study included perfusionists from 31 provinces in mainland China. Participants were asked to complete a self-administered questionnaire, which included three parts: (1) demographic information, (2) work-related information, and (3) dissatisfaction with work and sources of pressure. The levels of burnout were calculated, and logistic regression was used to analyze the factors associated with burnout.

RESULTS

The questionnaire, created by the survey program "Questionnaire Star", was sent to 2211 perfusionists in mainland China. A final sample of 1813 perfusionists participated in the survey, with a participation rate of 82.0% (1813/2211). The prevalence of burnout and severe burnout was 86.0% (1559/1813, 95%CI: 84.3%-87.5%) and 13.3% (241/1813, 95%CI: 11.8%-15.0%), respectively. The logistic regression analysis revealed that age [20-29 years, odds ratio (OR) = 1; 30-39 years, OR = 2.009; 40-49 years, OR = 2.220], educational background (bachelor and below, OR = 1; postgraduate, OR = 1.472), and professional background (others, OR = 1; surgery, OR = 1.283; anesthesiology, OR = 2.004) were associated with burnout. We also found that age (20-29 years, OR = 1; 30-39 years, OR = 1.928), professional background (others, OR = 1; surgery, OR = 1.734; anesthesiology, OR = 2.257), annual cardiopulmonary bypass (CPB) case load in the most recent 3 years (< 50, OR = 1; 50-100, OR = 1.613; 100-300, OR = 1.702; ≥300, OR = 2.637), and income level [< 5000 (RMB/month), OR = 1; 5000-10,000, OR = 0.587; 10,000-20,000, OR = 0.366] were associated with severe burnout among perfusionists.

CONCLUSIONS

Cardiovascular perfusionists in mainland China experience high rates of burnout. Age, the professional background, annual CPB caseload in the most recent 3 years, and income level are independently associated with the burnout rates experienced by these health care professionals.

Effect of Cardiopulmonary Bypass on SARS-CoV-2 Vaccination Antibody Levels

Background Adults undergoing heart surgery are particularly vulnerable to respiratory complications, including COVID-19. Immunization can significantly reduce this risk; however, the effect of cardiopulmonary bypass (CPB) on immunization status is unknown. We sought to evaluate the effect of CPB on COVID-19 vaccination antibody concentration after cardiac surgery. Methods and Results This prospective observational clinical trial evaluated adult participants undergoing cardiac surgery requiring CPB at a single institution. All participants received a full primary COVID-19 vaccination series before CPB. SARS-CoV-2 spike protein-specific antibody concentrations were measured before CPB (pre-CPB measurement), 24 hours following CPB (postoperative day 1 measurement), and approximately 1 month following their procedure. Relationships between demographic or surgical variables and change in antibody concentration were assessed via linear regression. A total of 77 participants were enrolled in the study and underwent surgery. Among all participants, mean antibody concentration was significantly decreased on postoperative day 1, relative to pre-CPB levels (-2091 AU/mL, P<0.001). Antibody concentration increased between postoperative day 1and 1 month post CPB measurement (2465 AU/mL, P=0.015). Importantly, no significant difference was observed between pre-CPB and 1 month post CPB concentrations (P=0.983). Two participants (2.63%) developed symptomatic COVID-19 pneumonia postoperatively; 1 case of postoperative COVID-19 pneumonia resulted in mortality (1.3%). Conclusions COVID-19 vaccine antibody concentrations were significantly reduced in the short-term following CPB but returned to pre-CPB levels within 1 month. One case of postoperative COVID 19 pneumonia-specific mortality was observed. These findings suggest the need for heightened precautions in the perioperative period for cardiac surgery patients.

Effect of red blood cell storage time in pediatric cardiac surgery patients: A subgroup analysis of a randomized controlled trial

Objective

This study aimed to determine whether or not transfusion of fresh red blood cells (RBCs) reduced the incidence of new or progressive multiple organ dysfunction syndrome compared with standard-issue RBCs in pediatric patients undergoing cardiac surgery.

Methods

Preplanned secondary analysis of the Age of Blood in Children in Pediatric Intensive Care Unit study, an international randomized controlled trial. This study included children enrolled in the Age of Blood in Children in Pediatric Intensive Care Unit trial and admitted to a pediatric intensive care unit after cardiac surgery with cardiopulmonary bypass. Patients were randomized to receive either fresh (stored ≤7 days) or standard-issue RBCs. The primary outcome measure was new or progressive multiple organ dysfunction syndrome, measured up to 28 days postrandomization or at pediatric intensive care unit discharge, or death.

Results

One hundred seventy-eight patients (median age, 0.6 years; interquartile range, 0.3-2.6 years) were included with 89 patients randomized to the fresh RBCs group (median length of storage, 5 days; interquartile range, 4-6 days) and 89 to the standard-issue RBCs group (median length of storage, 18 days; interquartile range, 13-22 days). There were no statistically significant differences in new or progressive multiple organ dysfunction syndrome between fresh (43 out of 89 [48.3%]) and standard-issue RBCs groups (38 out of 88 [43.2%]), with a relative risk of 1.12 (95% CI, 0.81 to 1.54; P = .49) and an unadjusted absolute risk difference of 5.1% (95% CI, -9.5% to 19.8%; P = .49).

Conclusions

In neonates and children undergoing cardiac surgery with cardiopulmonary bypass, the use of fresh RBCs did not reduce the incidence of new or progressive multiple organ dysfunction syndrome compared with the standard-issue RBCs. A larger trial is needed to confirm these results.

Symptomatic subdural hemorrhage following heart valve surgery: a retrospective cohort study

OBJECTIVE

Subdural hemorrhage (SDH) has been reported to be the most frequent intracranial hemorrhagic complication following open heart surgery; however, its clinical features and pathophysiology remain unclear. The aim of this retrospective study was to elucidate the incidence, clinical course, and factors associated with the development of symptomatic SDH following heart valve surgery.

METHODS

A retrospective review of medical records on the development of symptomatic SDH after heart valve surgery involving cardiopulmonary bypass (CPB) from April 2011 to March 2016 was performed. Patients who had undergone preoperative cranial computed tomography (CT) or brain magnetic resonance imaging (MRI) were included in this study, and factors associated with SDH following heart valve surgery were analyzed. When neurological symptoms developed after heart valve surgery, cranial CT or brain MRI was performed.

RESULTS

A total of 556 patients who had undergone heart valve surgery were analyzed. Among these patients, symptomatic SDH occurred in 11 (2.0%). The mean duration of symptomatic onset was 10.1 days (range 2-37 days). Ten of 11 patients (90.9%) developed SDH in the posterior fossa or occipital convexity. Logistic regression analysis revealed longer aortic clamp time (95% CI 1.00-1.10, p = 0.04), higher dose of heparin after surgery (95% CI 1.00-1.02, p = 0.001), and higher pulmonary artery pressure (PAP) just before disconnection of the CPB (95% CI 1.01-1.37, p = 0.04) as significantly associated with the development of SDH.

CONCLUSIONS

The incidence of symptomatic SDH following heart valve surgery was 2.0%. Symptoms due to SDH usually developed a few days to 1 month after surgery. Surprisingly, most SDHs developed in the posterior fossa or occipital convexity following heart valve surgery. A longer aortic clamp time, higher dose of heparin after surgery, and higher PAP just before disconnection of the CPB were related to the development of symptomatic SDH following heart valve surgery.

Recommendations for Centers Performing Pediatric Heart Surgery in the United States

Care and outcomes for the more than 40,000 patients undergoing pediatric and congenital heart surgery in the United States annually are known to vary widely. While consensus recommendations have been published across numerous fields as one mechanism to promote a high level of care delivery across centers, it has been more than two decades since the last pediatric heart surgery recommendations were published in the United States. More recent guidance is lacking, and collaborative efforts involving the many disciplines engaged in caring for these children have not been undertaken to date. The present initiative brings together professional societies spanning numerous care domains and congenital cardiac surgeons, pediatric cardiologists, nursing, and other healthcare professionals from diverse programs around the country to develop consensus recommendations for United States centers. The focus of this initial work is on pediatric heart surgery, and it is recommended that future efforts focus in detail on the adult congenital population. We describe the background, rationale, and methodology related to this collaborative effort, and recommendations put forth for Essential Care Centers (essential services necessary for any program), and Comprehensive Care Centers (services to optimize comprehensive and high-complexity care), encompassing structure, process, and outcome metrics across 14 domains.

John Kirklin's Impact on the Origins of Open Heart Surgery and the Congenital Heart Surgeons' Society

John Kirklin stands out as one of the surgeons most identifiably responsible for bringing the field of open heart surgery to clinical reality and initiating scientific pursuits in the Congenital Heart Surgeons' Society. His accomplishments are perhaps best viewed in the context of other major contributions made by researchers and fellow surgeons, which collectively positioned Kirklin and other cardiac surgery pioneers to usher in the dawn of open heart surgery and later the Congenital Heart Surgeons' Society.

Successful surgical management of cardiac tamponade following direct intrahepatic portosystemic shunt in a child with Budd-Chiari syndrome: A potentially life-threatening situation

Direct intrahepatic portosystemic shunt is a technique of portocaval shunting performed through the percutaneous route in patients with Budd-Chiari syndrome. Stent migration into right-sided heart chambers or perforations causing hemopericardium and cardiac tamponade is rare and underreported. In a child with a coexisting decompensated liver disease, surgical intervention and cardiopulmonary bypass can be challenging. However, surgical management in these life-threatening situations is better than redo interventions.

What can ex vivo experiments contribute to clinical haemostasis management?

A recent ex vivo study found that post-cardiopulmonary bypass platelet defects can be restored with supplemental fibrinogen, but the clinical significance of this finding will require further study. We propose that the best management strategy for achieving haemostasis in bleeding surgical patients is to identify individualised coagulation defects and then use a targeted therapeutic approach that addresses each identified defect systematically.

Improving Trendelenburg position effectiveness by varying cardiopulmonary bypass flow

INTRODUCTION

Trendelenburg position (TP) is used to transport gaseous emboli away from the cerebral region during cardiac surgery. However, TP effectiveness has not been fully considered when combined with varying the cardiopulmonary bypass (CPB) flow. This study simulated the supine and TP at different pump flows and assessed the trapped emboli and embolic load entering the aortic arch branch arteries (AABA).

METHODS

A computational fluid dynamics (CFD) approach used a centrally cannulated adult patient-specific aorta model replicating a CPB circuit. Air emboli of 0.1 mm, 0.5 mm, and 1.0 mm (n = 700 each) were injected into the aorta placed in the supine position (0°) and the TP (-20°) at 2 L/min and 5 L/min. The number of emboli entering the AABA were compared. An aortic phantom flow experiment was performed to validate air bubble behaviour.

RESULTS

TP at 5 L/min had the lowest 0.1 mm mean (±SD) embolic load compared to the supine 2 L/min (55.3 ± 30.8 vs 64.3 ± 35.4). For both the supine and TP, the lower flow of 2 L/min had the highest number of simulated trapped emboli in higher elevated regions than at 5 L/min (541 ± 185 and 548 ± 191 vs 520 ± 159 and 512 ± 174), respectively. The flow experiment demonstrated that 2 L/min promoted bubble coalescence and high amounts of trapped emboli and 5 L/min transported air emboli away from the AABA.

CONCLUSIONS

TP effectiveness was improved by using CPB flow to manage air emboli. These results provide insights for predicting emboli behaviour and improving emboli de-airing procedures.

Early plasma proteomic biomarkers and prediction model of acute respiratory distress syndrome after cardiopulmonary bypass: a prospective nested cohort study

BACKGROUND

Early recognition of the risk of acute respiratory distress syndrome (ARDS) after cardiopulmonary bypass (CPB) may improve clinical outcomes. The main objective of this study was to identify proteomic biomarkers and develop an early prediction model for CPB-ARDS.

METHODS

The authors conducted three prospective nested cohort studies of all consecutive patients undergoing cardiac surgery with CPB at Union Hospital of Tongji Medical College Hospital. Plasma proteomic profiling was performed in ARDS patients and matched controls (Cohort 1, April 2021-July 2021) at multiple timepoints: before CPB (T1), at the end of CPB (T2), and 24 h after CPB (T3). Then, for Cohort 2 (August 2021-July 2022), biomarker expression was measured and verified in the plasma. Furthermore, lung ischemia/reperfusion injury (LIRI) models and sham-operation were established in 50 rats to explore the tissue-level expression of biomarkers identified in the aforementioned clinical cohort. Subsequently, a machine learning-based prediction model incorporating protein and clinical predictors from Cohort 2 for CPB-ARDS was developed and internally validated. Model performance was externally validated on Cohort 3 (January 2023-March 2023).

RESULTS

A total of 709 proteins were identified, with 9, 29, and 35 altered proteins between ARDS cases and controls at T1, T2, and T3, respectively, in Cohort 1. Following quantitative verification of several predictive proteins in Cohort 2, higher levels of thioredoxin domain containing 5 (TXNDC5), cathepsin L (CTSL), and NPC intracellular cholesterol transporter 2 (NPC2) at T2 were observed in CPB-ARDS patients. A dynamic online predictive nomogram was developed based on three proteins (TXNDC5, CTSL, and NPC2) and two clinical risk factors (CPB time and massive blood transfusion), with excellent performance (precision: 83.33%, sensitivity: 93.33%, specificity: 61.16%, and F1 score: 85.05%). The mean area under the receiver operating characteristics curve (AUC) of the model after 10-fold cross-validation was 0.839 (95% CI: 0.824-0.855). Model discrimination and calibration were maintained during external validation dataset testing, with an AUC of 0.820 (95% CI: 0.685-0.955) and a Brier Score of 0.177 (95% CI: 0.147-0.206). Moreover, the considerably overexpressed TXNDC5 and CTSL proteins identified in the plasma of patients with CPB-ARDS, exhibited a significant upregulation in the lung tissue of LIRI rats.

CONCLUSIONS

This study identified several novel predictive biomarkers, developed and validated a practical prediction tool using biomarker and clinical factor combinations for individual prediction of CPB-ARDS risk. Assessing the plasma TXNDC5, CTSL, and NPC2 levels might identify patients who warrant closer follow-up and intensified therapy for ARDS prevention following major surgery.

Supplemental fibrinogen restores thrombus formation in cardiopulmonary bypass-induced platelet dysfunction ex vivo

BACKGROUND

Major cardiac surgery related blood loss is associated with increased postoperative morbidity and mortality. Platelet dysfunction is believed to contribute to post-cardiopulmonary bypass (CPB)-induced microvascular bleeding. We hypothesised that moderately hypothermic CPB induces platelet dysfunction and that supplemental fibrinogen can restore in vitro thrombus formation.

METHODS

Blood from 18 patients, undergoing first-time elective isolated aortic valve surgery was drawn before CPB, 30 min after initiation of CPB, and after CPB and protamine administration, respectively. Platelet aggregation was quantified by optical aggregometry, platelet activation by flow-cytometric detection of platelet surface expression of P-selectin, annexin V, and activated glycoprotein IIb/IIIa, thrombus formation under flow and effect of supplemental fibrinogen (4 mg ml-1) on in vitro thrombogenesis.

RESULTS

Post-CPB adenosine-diphosphate and TRAP-6-induced aggregation decreased by 40% and 10% of pre-CPB levels, respectively (P<0.0001). Although CPB did not change glycoprotein IIb/IIIa receptor expression, it increased the percentage of unstimulated P-selectin (1.2% vs 7%, P<0.01) positive cells and annexin V mean fluorescence intensity (15.5 vs 17.2, P<0.05), but decreased percentage of stimulated P-selectin (52% vs 26%, P<0.01) positive cells and annexin V mean fluorescence intensity (508 vs 325, P<0.05). Thrombus area decreased from 6820 before CPB to 5230 after CPB (P<0.05, arbitrary units [a.u.]). Supplemental fibrinogen increased thrombus formation to 20 324 and 11 367 a.u. before CPB and after CPB, respectively (P<0.001), thereby restoring post-CPB thrombus area to levels comparable with or higher than pre-CPB baseline.

CONCLUSIONS

Single valve surgery using moderately hypothermic CPB induces partial platelet dysfunction. Thrombus formation was restored in an experimental study design by ex vivo supplementation of fibrinogen.

Analysis of P(v-a)CO2/C(a-v)O2 Ratio and Other Perfusion Markers in a Population of 98 Pediatric Patients Undergoing Cardiac Surgery

BACKGROUND

The so-called Low Cardiac Output Syndrome (LCOS) is one of the most common complications in pediatric patients with congenital heart disease undergoing corrective surgery. LCOS requires high concentrations of inotropes to support cardiac contractility and improve cardiac output, allowing for better systemic perfusion. To date, serum lactate concentrations and central venous oxygen saturation (ScVO2) are the most commonly used perfusion markers, but they are not completely reliable in identifying a state of global tissue hypoxia. The study aims to evaluate whether the venoarterial carbon dioxide difference/arterial-venous oxygen difference ratio [P(v-a)CO2/C(a-v)O2] can be a good index to predict the development of LCOS in the aforementioned patients, so as to treat it promptly.

METHODS

This study followed a population of 98 children undergoing corrective cardiac surgery from June 2018 to October 2020 at the Department of Cardiac Surgery of University Hospital Integrated Trust and their subsequent admission at the Postoperative Cardiothoracic Surgery Intensive Care Unit. During the study, central arterial and venous blood gas analyses were carried out before and after cardiopulmonary bypass (CPB) (pre-CPB and post-CPB), at admission to the intensive care unit, before and after extubation, and at any time of instability or modification of the patient's clinical and therapeutic conditions.

RESULTS

The data analysis shows that 46.9% of the children developed LCOS (in line with the current literature) but that there is no statistically significant association between the P(v-a)CO2/C(a-v)O2 ratio and LCOS onset. Despite the limits of statistical significance, however, a 31% increase in the ratio emerged from the pre-CPB phase to the post-CPB phase when LCOS is present.

CONCLUSIONS

This study confirms a statistically significant association between the most used markers in adult patients (serum lactate concentration, ScVO2, and oxygen extraction ratio-ERO2) measured in the pre-CPB phase and the incidence of LCOS onset, especially in patients with hemodynamic instability before surgery.

Paraprotein associated heparin resistance during cardiopulmonary bypass

INTRODUCTION

Heparin resistance during cardiopulmonary bypass poses a significant intraoperative dilemma. Antithrombin deficiency related heparin resistance is well described, but less common causes are still poorly understood and inadequately managed.

CASE REPORT

We present a case of heparin resistance during cardiopulmonary bypass in a gentleman with no previous haematological history or thrombotic risk factors. The patient required three times the regular dose of unfractionated heparin to achieve acceptable conditions to initiate and maintain bypass. The patient was found to have elevated serum immunoglobulin M (IgM) kappa paraprotein on post-operative investigation.

DISCUSSION

Paraproteins may exhibit non-specific binding to long polymeric chains of unfractionated heparin and inhibits the interaction between heparin and antithrombin. As a result, excessive doses of heparin are required to overcome this, which increases the risk of perioperative bleeding and other complications.

CONCLUSION

Elevated serum paraprotein levels should be recognised as a cause of heparin resistance during cardiopulmonary bypass.

Establishment of a national quality improvement process on oxygen delivery index during cardiopulmonary bypass

Targeted oxygen delivery during cardiopulmonary bypass (CPB) has received significant attention due to its influence on patient outcomes, especially in mitigating acute kidney injury. While it has gained popularity in select institutions, there remains a gap in establishing it globally across multiple centers. The purpose of this investigation was to describe the development of a quality improvement process of targeted oxygen delivery during CPB across hospitals throughout the United States. A systematic approach to utilize oxygen delivery index (DO2i) as a key performance indicator within hospitals serviced by a national provider of perfusion services. The process included a review of the current literature on DO2i, which yielded a target nadir value (272 mL/min/m2) and an area under the curve (DO2i272AUC) cut off of 632. All data is displayed on a dashboard with results categorized across multiple levels from system-wide to individual clinician performance. From January 2020 through December 2022, DO2i data from 91 hospitals and 11,165 coronary artery bypass graft procedures were collected. During this period the monthly proportion of DO2i measurements above the target nadir DO2i272 ranged from 60.5% to 78.4% with a mean+/-SD of 70.8 +/- 4.2%. Binary logistic regression for the first 7 months following monthly DO2i performance reporting has shown a statistically significant positive linear trend in the probability of achieving the target DO2i272 (p < .001), with a crude increase of approximately 7.8% for DO2i272AUC, and a 73.8% success rate (p < .001). A survey was sent to all individuals measuring oxygen delivery during CPB to assess why a target DO2i272 could not be reached. The two most common responses were an 'inability to improve CPB flow rates' and 'restrictive allogeneic red blood cell transfusion policies'. This study demonstrates that targeting a minimum level of oxygen delivery can serve as a key performance indicator during CPB using a structured quality improvement process.

A novel survival rat model of hyperkalemia and landiolol induced cardioplegic arrest and resuscitation via cardiopulmonary bypass

OBJECTIVE

A small animal model would be an effective tool for research on the pathophysiology of cardiopulmonary bypass (CPB). However, numerous CPB models do not involve myocardial arrest and resuscitation. The aim of this research is to establish an easily achievable myocardial arrest and resuscitation CPB model through hyperkalemia and landiolol, simulating clinical cardiac surgery.

MATERIALS AND METHODS

Ten Sprague-Dawley rats were chosen for CPB. Rats underwent sevoflurane inhalation induction anesthesia and were sustained in an anesthesia state by intubation and intraperitoneal injection's of esketamine and propofol. The entire CPB circuit include a reservoir, a membrane oxygenator and a roller pump, which were connected into a complete loop via silicon tubes and infusion tube.After CPB was established through the tail artery and internal jugular vein, cardioplegic arrest was induced and maintained for 5 min at a rectum temperature of 28.5 ± 0.5°C with hyperkalemia and landiolol. Calcium chloride, epinephrine and insulin were then used for resuscitation.

RESULT

All rats successfully finished cardioplegic arrest, resuscitation procedure and survived 2 h postoperatively. Mean hematocrit during CPB was significantly lower than physiologic values of the baseline. The mean time of arrest-resuscitation and CPB was 5.4 ± 0.8 min and 98.5 ± 5.0 min. The blood gas at each detection point were in range with the normal standard requirement of CPB.

CONCLUSION

The establishment of cardioplegic arrest and resuscitation procedure via hyperkalemia and landiolol during CPB of WD rat could be achieved successfully. This animal model could be an alternative organ injury research on organ injury of patients undergoing cardiac surgery.

Complete Resection of a Cavoatrial Metastatic Liposarcoma under Hypothermic Circulatory Arrest

A patient underwent surgical resection twice for primary and metastatic dedifferentiated liposarcomas. Computed tomography revealed a tumor mass at the cavoatrial junction. Prompt surgical resection of the tumor with thrombectomy was successfully performed using cardiopulmonary bypass with hypothermic circulatory arrest. Despite the poor prognosis of metastatic or recurrent liposarcoma, the patient has survived for 8 years since the first tumor resection.

Subfatin, Asprosin, Alamandine and Maresin-1 Inflammation Molecules in Cardiopulmonary Bypass

Purpose

Cardiopulmonary bypass (CPB) is a nonphysiological procedure in which inflammatory reactions and oxidative stress are induced, hormones and hemodynamic parameters are affected, and circulation is maintained outside the body. This study aimed to examine the effects of CPB on blood subfatin (SUB), asprossin (ASP), alamandine (ALA) and maresin-1 (MaR-1) levels.

Materials and Methods

Controls and patients who underwent open-heart surgery with CPB and whose age and body mass indices were compatible with each other were included in the study. Venous blood samples were collected from CPB patients (n =19) before anesthesia induction (T1), before CPB (T2), 5 min before cross-clamp removal (T3), 5 min after cross-clamp removal (T4), when taken to the intensive care unit (T5), postoperative 24th hour (T6) and 72nd hour (T7) postoperatively. Venous blood was collected from the healthy controls (n =19). The amounts of SUB, ASP, ALA, and MaR-1 in the blood samples were measured using an Enzyme-Linked Immunosorbent Assay (ELISA).

Results

The amounts of SUB and MaR-1 in the control group were significantly higher than those in CPB patients, while these parameters in T1-T3 blood gradually decreased in CPB patients (p<0.01). It was also reported that the amounts of ASP and ALA in the control group were significantly lower than those in CPB patients, whereas those parameters in the T1-T3 blood samples increased gradually in CPB patients, but started to decrease in T4-T7 blood samples.

Conclusion

These hormonal changes in the organism due to CPB demonstrate that "hormonal metabolic adaptation" mechanisms may be activated to eliminate the negative consequences of surgery. According to these data, SUB, MaR-1, anti-alamandine, and anti-asprosin could be used in CPB surgeries may come to the fore in the future to increase the safety of CPB surgeries.

Potentials of Acetylcholinesterase and Butyrylcholinesterase Alterations in On-Pump Coronary Artery Bypass Surgery in Postoperative Delirium: An Observational Trial

Cardiac surgery is regularly associated with postoperative delirium (POD), affected by neuro-inflammation and changes in cholinergic activity. Therefore, this prospective observational study aimed to evaluate whether pre- and perioperative changes in blood acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activity were associated with POD development in patients undergoing isolated elective coronary artery bypass graft (CABG) surgery. It included 93 patients. Pre- and postoperative blood AChE and BChE activities were measured with photometric rapid-point-of-care-testing. The Intensive Care Delirium Screening Checklist and the Confusion Assessment Method for the Intensive Care Unit were used to screen patients for POD. POD developed in 20 patients (21.5%), who were older (p = 0.003), had higher EuroSCOREs (p ≤ 0.001), and had longer intensive care unit stays (p < 0.001). On postoperative day one, BChE activity decreased from preoperative values more in patients with (31.9%) than without (23.7%) POD (group difference p = 0.002). Applying a cutoff of ≥32.0% for BChE activity changes, receiver operating characteristic analysis demonstrated a moderate prediction capability for POD (area under the curve = 0.72, p = 0.002). The risk of developing POD was 4.31 times higher with a BChE activity change of ≥32.0% (p = 0.010). Monitoring the pre- to postoperative reduction in BChE activity might be a clinically practicable biomarker for detecting patients at risk of developing POD after CABG surgery.

Perioperative brain injury marker concentrations in neonatal open-heart surgery: a prospective observational study

Neonates with critical congenital heart defects undergoing open-heart surgery on cardiopulmonary bypass circulation are at risk for white matter brain injury. This article reports on pre- and postoperative plasma concentrations of brain injury markers glial fibrillary acidic protein (GFAP), neurofilament light (NfL) and Tau, and their respective associations with white matter lesions detected on postoperatively performed brain MRI. Forty term newborns with isolated critical congenital heart defects were included in a prospective observational study. Brain injury marker plasma concentrations were determined prior to surgery and at postoperative days 1, 2 and 3. Brain magnetic resonance imaging was performed pre- and postoperatively. Concentrations of brain injury markers were analysed using ultrasensitive single molecule array technology. Absolute pre- and postoperative plasma biomarker concentrations, and postoperative concentrations adjusted for preoperative concentrations were used for subsequent analysis. Plasma concentrations of GFAP, NfL and Tau displayed a well-defined temporal trajectory after neonatal cardiopulmonary bypass circulation. GFAP and Tau reached peak concentrations at postoperative day 2 (median concentrations 170.5 and 67.2 pg/ml, respectively), whereas NfL continued to increase throughout the study period (median concentration at postoperative day 3 191.5 pg/ml). Adjusted Tau at postoperative day 2 was significantly higher in infants presenting with white matter lesions on postoperative MRI compared to infants without white matter injury.

Changes in colloid oncotic pressure during cardiac surgery with different prime fluid strategies

OBJECTIVE

In cardiac surgery, colloid oncotic pressure (COP) is affected by haemodilution that results from composition and volume of prime fluid of cardiopulmonary bypass (CPB). However, the extent to which different priming strategies alter COP is largely unknown. Therefore, we investigated the effect of different priming strategies on COP in on-pump cardiac surgery.

METHODS

Patients (n = 60) were divided into 3 groups (n = 20 each), based on the center in which they were operated and the specific prime fluid strategy used in that center during the inclusion period. CPB prime fluids were either gelofusine-, albumin-, or crystalloid based, the latter two with or without retrograde autologous priming.

RESULTS

In all groups, COP was lowest after weaning from CPB and one hour after CPB. Between groups, COP was lowest with gelofusine prime fluid (16.4, 16.8 mmHg, respectively) compared with crystalloids (MD: -1.9; 95% CI:-3.6, -0.2; p = .02 and MD: -2.4, 95% CI: -4.2, -0.7; p = .002) and albumin (MD: -1.8, 95% CI: -3.5, -0.50; p = .041 and MD: -2.4, 95% CI: -4.1, -0.7; p = .002). In all groups, the decrease in COP one hour after bypass compared to baseline correlated positively with fluid balance at the end of surgery (p < .001).

CONCLUSIONS

COP significantly decrease during CPB surgery with the largest decrease in COP at the end of surgery, while at the same time fluid balance increases. We suggest that prime fluid strategy should be carefully selected when maintenance of COP during cardiac surgery is desirable.

A Multimodal Cardioprotection Strategy During Cardiac Surgery: The ProCCard Study

OBJECTIVE

The ProCCard study tested whether combining several cardioprotective interventions would reduce the myocardial and other biological and clinical damage in patients undergoing cardiac surgery.

DESIGN

Prospective, randomized, controlled trial.

SETTING

Multicenter tertiary care hospitals.

PARTICIPANTS

210 patients scheduled to undergo aortic valve surgery.

INTERVENTIONS

A control group (standard of care) was compared to a treated group combining five perioperative cardioprotective techniques: anesthesia with sevoflurane, remote ischemic preconditioning, close intraoperative blood glucose control, moderate respiratory acidosis (pH 7.30) just before aortic unclamping (concept of the "pH paradox"), and gentle reperfusion just after aortic unclamping.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was the postoperative 72-h area under the curve (AUC) for high-sensitivity cardiac troponin I (hsTnI). Secondary endpoints were biological markers and clinical events occurring during the 30 postoperative days and the prespecified subgroup analyses. The linear relationship between the 72-h AUC for hsTnI and aortic clamping time, significant in both groups (p < 0.0001), was not modified by the treatment (p = 0.57). The rate of adverse events at 30 days was identical. A non-significant reduction of the 72-h AUC for hsTnI (-24%, p = 0.15) was observed when sevoflurane was administered during cardiopulmonary bypass (46% of patients in the treated group). The incidence of postoperative renal failure was not reduced (p = 0.104).

CONCLUSION

This multimodal cardioprotection has not demonstrated any biological or clinical benefit during cardiac surgery. The cardio- and reno-protective effects of sevoflurane and remote ischemic preconditioning therefore remain to be demonstrated in this context.

Immediate Postoperative Management of Cardiac Surgery Patients

Cardiac surgery is quite common in the United States. Outcomes after cardiac surgery are not only dependent on how the surgery went and how the anesthesia care was provided intraoperatively but also on the optimal management in the postoperative critical care setting. It is of paramount importance that the cardiac intensivist has a comprehensive understanding of cardiopulmonary physiology and the sequelae of cardiopulmonary bypass. Most preventable deaths after cardiac surgery have been linked to postoperative problems in the intensive care unit (ICU).1,2 Failure to recognize and rescue a patient from potentially reversible complications is a cause of perioperative morbidity and mortality. Patients who undergo cardiac surgery often present with multiple rapidly changing clinical problems; they are initially unstable with extremely fluid and dynamic clinical status. Postoperative care of these patients requires knowledge of general fundamental concepts of patient care as well as concepts unique to this set of patients. The initial management of these patients as they return from the operating room is critical, because clinical errors at this time can have far-reaching implications. The initial management should begin even before the patient arrives in the cardiovascular intensive care unit (CVICU). It is vital that the cardiac intensivist reviews the chart and notes the type of surgery, indications, preoperative hemodynamic data, comorbid conditions, medications, and allergies. Upon the patient's arrival in the CVICU, a careful systematic assessment of the patient begins with obtaining a comprehensive handoff from the surgical and anesthesia team. The cardiac intensivist should ascertain what procedure was done in the operating room and inquire as to any intraoperative events that might impact the patient's postoperative course. Then, they should physically examine the patient as part of this initial evaluation. During the initial assessment, the intensivist should avoid focusing on any one issue and attempt to get a global picture of the patient's clinical status. A thorough knowledge of the specific monitoring and drug delivery lines is imperative, as is knowledge of where the drains are placed. Once the initial assessment is complete, specific issues can be identified, prioritized, and addressed.3,4.

A transfusion risk stratification score to facilitate quality management in cardiopulmonary bypass

BACKGROUND

Our previous showed that a blood management program in the cardiopulmonary bypass (CPB) department, reduced red blood cell (RBC) transfusion and complications, but assessing transfusion practice solely based on transfusion rates was insufficient. This study aimed to design a risk stratification score to predict perioperative RBC transfusion to guide targeted measures for on-pump cardiac surgery patients.

STUDY DESIGN AND METHODS

We analyzed data from 42,435 adult cardiac patients. Eight predictors were entered into the final model including age, sex, anemia, New York Heart Association classification, body surface area, cardiac surgery history, emergency surgery, and surgery type. We then simplified the score to an integer-based system. The area under the receiver operating characteristic curve (AUC), Hosmer-Lemeshow goodness-of-fit test, and a calibration curve were used for its performance test. The score was compared to existing scores.

RESULTS

The final score included eight predictors. The AUC for the model was 0.77 (95% CI, 0.76-0.77) and 0.77 (95% CI, 0.76-0.78) in the training and test set, respectively. The calibration curves showed a good fit. The risk score was finally grouped into low-risk (score of 0-13 points), medium-risk (14-19 points), and high-risk (more than 19 points). The score had better predictive power compared to the other two existing risk scores.

DISCUSSION

We developed an effective risk stratification score with eight variables to predict perioperative RBC transfusion for on-pump cardiac surgery. It assists perfusionists in proactively preparing blood conservation measures for high-risk patients before surgery.

Successful Nafamostat Mesilate Administration for Andexanet Alfa-Induced Heparin Resistance

Andexanet alfa is an analog of activated factor X and is used as an antagonist of anti-activated factor X agents. Andexanet alfa is useful for hemostasis in emergent bleeding during direct oral anticoagulant administration, which contributes to safety. In patients undergoing surgery with cardiopulmonary bypass because of heparin resistance, anesthesiologists are faced with a choice of anticoagulants. Herein, we experienced anesthesia for vascular prostheses with cardiopulmonary bypass for acute aortic dissection in a patient who had received andexanet alfa preoperatively. Heparin was initially used as the anticoagulant during cardiopulmonary bypass; however, despite the administration of large doses and antithrombin III preparations, anticoagulation was insufficient. Therefore, nafamostat mesilate was administered and sufficient anticoagulation was attained. The patient completed surgery under cardiopulmonary bypass, coagulation function was recovered shortly after withdrawal, and no obvious adverse effects were observed.

Blood Pressure Goals in Critically Ill Patients

Blood pressure goals in the intensive care unit (ICU) have been extensively investigated in large datasets and have been associated with various harm thresholds at or greater than a mean pressure of 65 mm Hg. While it is difficult to perform interventional randomized trials of blood pressure in the ICU, important evidence does not support defense of a higher pressure, except in retrospective database analyses. Perfusion pressure may be a more important target than mean pressure, even more so in the vulnerable patient population. In the cardiac ICU, blood pressure targets are tailored to specific cardiac pathophysiology and patient characteristics. Generally, the goal is to maintain adequate blood pressure within a certain range to support cardiac function and to ensure end organ perfusion. Individualized targets demand the use of both invasive and noninvasive monitoring modalities and frequent titration of medications and/or mechanical circulatory support where necessary. In this review, we aim to identify appropriate blood pressure targets in the ICU, recognizing special patient populations and outlining the risk factors and predictors of end organ failure.

Study on the Characteristics of Early Cytokine Storm Response to Cardiac Surgery

Cardiac surgery can provoke an acute cytokine storm that may contribute to the development of postoperative multiple organ dysfunction syndrome. We prospectively observed patients undergoing cardiac surgery and divided them into two groups: the severe group and the mild group. Healthy individuals were enrolled acting as the control group for comparison. Plasma samples and clinical data were recorded at the initiation of cardiac-pulmonary bypass (CPB) and 3, 6, 12, 24, and 48 h after initiation of CPB. Cytokine levels were detected using the Luminex® technique. Thirty-nine adults were enrolled in this study (14 in the severe group, 15 in the mild group, and 10 in the control group). Cytokine concentrations were significantly higher in the severe group. Principal component analysis was used to establish a cytokine storm intensity curve, which represented the overall trend of 10 cytokines. The peak concentrations of interleukin (IL)-6, IL-10, and IL-16 were 425.1, 198.5, and 623.0 pg/mL, which were more than 1,200, 1,800, and 240 times the normal level, respectively. The maximum cytokine storm intensity predated the maximum Vasoactive-Inotropic Score (VIS) and Sequential Organ Failure Assessment (SOFA) score in the severe group. Cytokine storm response to cardiac surgery occurred early and was associated with disease severity. Interventions to cytokine storm should be initiated early as guided by cytokine storm biomarkers such as IL-6, IL-10, and IL-16 in severe patients undergoing cardiac surgery. Clinical Trial Registration: ChiCTR1900021351.

Outcomes of Vascular Surgery Performed Jointly With Other Departments

OBJECTIVE

The purpose of this study is to evaluate the results of vascular surgery performed at our hospital, a tertiary emergency general hospital, in patients undergoing surgery in other departments. The results of the study were reviewed.

METHODS

The study included cases in which cardiovascular surgery was performed at the request of other departments over a 15-year period from January 2006 to October 2022. Patient backgrounds, departments that requested surgery, surgical procedures, use of extracorporeal circulation, and surgical techniques were reviewed. Patients with femoral artery exposure or ECMO removal during transcatheter aortic valve implantation (TAVI) requested by cardiology were excluded.

RESULTS

There were 58 vascular surgery cases requested by other departments during the study period. The age was 63±14 years, 43 (74%) were male and 15 (26%) were female. The departments of the patients were urology in 29 (50%), gastroenterology in 18 (31%), orthopedics in seven (12%), emergency department in three (5%), and obstetrics and gynecology in one (2%). The following surgical procedures were performed: tumor resection and reconstruction due to tumor invasion of the inferior vena cava in 27 cases (47%), bypass to secure intraperitoneal arterial blood flow in 15 cases (26%), bypass during resection of the femoral tumor in four cases (7%), hemostasis due to trauma in three cases (5%), intraperitoneal hemostasis in three cases (5%), thrombectomy in two cases (3%), and others in four cases (7%). Extracorporeal circulation was used in six (10%) of the patients.

CONCLUSION

A 15-year case study of vascular surgery supports operations requested by other departments at our hospital. All reconstructed sites were open at the time of discharge.

Temporary venovenous extracorporeal membrane oxygenation after cardiopulmonary bypass in minimally invasive cardiac surgery via right minithoracotomy

OBJECTIVES

In minimally invasive cardiac surgery, it can be difficult at times to maintain adequate oxygenation with single-lung ventilation after weaning from cardiopulmonary bypass (CPB), and intermittent double-lung ventilation is required during hemostasis. Venovenous extracorporeal membrane oxygenation (VV-ECMO) after weaning from CPB eliminates the necessity of overinflation of the left lung and intermittent double-lung ventilation and enables secure and fast hemostasis. We investigated the effectiveness and safety of temporary VV-ECMO in MICS.

METHODS

Between May 2018 and March 2021, 149 patients underwent temporary VV-ECMO during minimally invasive cardiac surgery in our institutions. After weaning from CPB, the arterial circuit was reconnected to the right internal jugular venous cannula, the femoral venous cannula was pulled down by 20 cm, and VV-ECMO was established using the CPB machine and cannulas. After starting VV-ECMO, we administered protamine and performed hemostasis. Operative data and outcomes were retrospectively reviewed.

RESULTS

The mean VV-ECMO time and flow were 26 ± 13 minutes and 2.38 ± 0.40 L/m2, respectively. There was no thrombus in the CPB circuit, including the oxygenator. The trans-oxygenator pressure gradient index at the end of VV-ECMO significantly correlated with that at the start of VV-ECMO (r = 0.88; 95% CI, 0.79-0.94; P = .01). The 30-day mortality rate was 2.0%. The incidences of unilateral pulmonary edema, prolonged ventilation, and re-exploration for bleeding were 2.7%, 5.4%, and 2.0%, respectively.

CONCLUSIONS

Temporary VV-ECMO is safe and useful to maintain single-lung ventilation without overinflation after weaning from CPB for secure and fast hemostasis in minimally invasive cardiac surgery. No thrombotic event was found during temporary VV-ECMO without heparinization.

Accurate protamine:heparin matching (not just smaller protamine doses) decreases postoperative bleeding in cardiac surgery; results from a high-volume academic medical center

BACKGROUND

A multidisciplinary Quality Assurance/Performance Improvement study to identify the incidence of "heparin rebound" in our adult cardiac surgical population instead detected a thromboelastometry pattern suggestive of initial protamine overdose in 34% despite Hepcon-guided anticoagulation management. Analysis of our practice led to an intervention that made an additional lower-range Hepcon cartridge available to the perfusionists.

METHODS

One year later, an IRB-approved retrospective study was conducted in >500 patients to analyze the effects of the intervention, specifically focusing on the impact of the initial protamine dose accuracy and 18-h mediastinal chest tube drainage (MCTd).

RESULTS

No differences were observed between group demographics, surgical procedures, duration of CPB or perioperative blood product transfusion. Both groups were managed using the same perfusion and anesthesia equipment, strategies, and protocols. The median initial protamine dose decreased by 19% (p < .001) in the intervention group (170 [IQR 140-220] mg; n = 295) versus the control group (210 [180-250] mg; n = 257). Mean 18-h MCTd decreased by 13% (p < .001) in the intervention group (405.15 ± 231.54 mL; n = 295) versus the control group (466.13 ± 286.73 mL; n = 257). Covariate-adjusted mixed effects model showed a significant reduction of MCTd in the intervention group, starting from hour 11 after surgery (group by time interaction p = .002).

CONCLUSION

Though previous investigators have associated lower protamine doses with less MCTd, this study demonstrates that more accurately matching the initial protamine dose to the remaining circulating heparin concentration reduces postoperative bleeding.

Children with single ventricle heart disease have a greater increase in sRAGE after cardiopulmonary bypass

INTRODUCTION

Reducing cardiopulmonary bypass (CPB) induced inflammatory injury is a potentially important strategy for children undergoing multiple operations for single ventricle palliation. We sought to characterize the soluble receptor for advanced glycation end products (sRAGE), a protein involved in acute lung injury and inflammation, in pediatric patients with congenital heart disease and hypothesized that patients undergoing single ventricle palliation would have higher levels of sRAGE following bypass than those with biventricular physiologies.

METHODS

This was a prospective, observational study of children undergoing CPB. Plasma samples were obtained before and after bypass. sRAGE levels were measured and compared between those with biventricular and single ventricle heart disease using descriptive statistics and multivariate analysis for risk factors for lung injury.

RESULTS

sRAGE levels were measured in 40 patients: 19 with biventricular and 21 with single ventricle heart disease. Children undergoing single ventricle palliation had a higher factor and percent increase in sRAGE levels when compared to patients with biventricular circulations (4.6 vs. 2.4, p = 0.002) and (364% vs. 181%, p = 0.014). The factor increase in sRAGE inversely correlated with the patient's preoperative oxygen saturation (Pearson correlation (r) = -0.43, p = 0.005) and was positively associated with red blood cell transfusion (coefficient = 0.011; 95% CI: 0.004, 0.017; p = 0.001).

CONCLUSIONS

Children with single ventricle physiology have greater increase in sRAGE following CPB as compared to children undergoing biventricular repair. Larger studies delineating the role of sRAGE in children undergoing single ventricle palliation may be beneficial in understanding how to prevent complications in this high-risk population.

Soluble TREM-1 plasma levels are associated with acute kidney injury, acute atrial fibrillation and prolonged ICU stay after cardiac surgery- a proof-concept study

Background

Cardiopulmonary bypass (CPB) during cardiac surgery leads to deleterious systemic inflammation. We hypothesized that TREM-1, a myeloid receptor shed after activation, drives systemic inflammation during CPB.

Methods

Prospective observational bi-centric study. Blood analysis (flow cytometry and ELISA) before and at H2 and H24 after CPB. Inclusion of adult patients who underwent elective cardiac surgery with CPB.

Results

TREM-1 expression on neutrophils decreased between H0 and H2 while soluble (s)TREM-1 plasma levels increased. sTREM-1 levels increased at H2 and at H24 (p < 0.001). IL-6, IL-8, G-CSF and TNF-α, but not IL-1β, significantly increased at H2 compared to H0 (p < 0.001), but dropped at H24. Principal component analysis showed a close relationship between sTREM-1 and IL-8. Three patterns of patients were identified: Profile 1 with high baseline sTREM-1 levels and high increase and profile 2/3 with low/moderate baseline sTREM-1 levels and no/moderate increase overtime. Profile 1 patients developed more severe organ failure after CPB, with higher norepinephrine dose, higher SOFA score and more frequently acute kidney injury at both H24 and H48. Acute atrial fibrillation was also more frequent in profile 1 patients at H24 (80% vs. 19.4%, p = 0.001). After adjustment on age and duration of CPB, H0, H2 and H24 sTREM-1 levels remained associated with prolonged ICU and hospital length of stay.

Conclusions

Baseline sTREM-1 levels as well as early kinetics after cardiac surgery identified patients at high risk of post-operative complications and prolonged length of stay.

Mastering the Best Practices: A Comprehensive Look at the European Guidelines for Cardiopulmonary Bypass in Adult Cardiac Surgery

The successful outcome of a cardiac surgery procedure is significantly dependent on the management of cardiopulmonary bypass (CPB). Even if a cardiac operation is technically well-conducted, a patient may suffer CPB-related complications that could result in severe comorbidities, reduced quality of life, or even death. However, the role of clinical perfusionists in perioperative patient care, which is critical, is often overlooked. Therefore, the European Association for Cardio-Thoracic Surgery (EACTS), the European Association of Cardiothoracic Anaesthesiology (EACTA), and the European Board of Cardiovascular Perfusion (EBCP) have agreed to develop joint clinical practice guidelines (CPGs) for CPB due to its significant impact on patient care and significant variations in practice patterns between countries. The European guidelines, based on the EACTS standardized framework for the development of CPGs, cover the entire spectrum of CPB management in adult cardiac surgery. This includes training and education of clinical perfusionists, machine hardware, disposables, preparation for initiation of CPB, a complete set of procedures during CPB to help maintain end-organ function and anticoagulation, weaning from CPB, and the gaps in evidence and future research directions. This comprehensive coverage ensures that all aspects of CPB management are addressed, providing clinicians with a standardized approach to CPB management based on the latest evidence and best practices. To ensure better integration of these evidence-based recommendations into daily practice, this review aims to provide a general understanding of guideline development and an overview of essential treatment recommendations for CPB management.

Reduced Invasiveness of Cardiopulmonary Bypass: The Mini-Circuit and the Micro-Cardioplegia

The aim of cardiopulmonary bypass is the maintenance of a sufficient whole body perfusion and gas exchange during open or closed heart surgery procedure (coronary artery bypass grafting, valve repair and replacement, surgical intervention on the ascending aorta and/or aortic arch, repair of congenital malformations, and finally implantation of ventricular assist devices or cardiac transplantation). The main components of cardiopulmonary bypass are the pump that supplies the circulation and the oxygenator that regulates gas exchange. However, even though this technology has been extensively developed and improved over the last decades, one of the major drawbacks-which is the fact that blood has to flow through tubing systems with foreign surfaces-persists so far. Nevertheless, interesting innovations have been made more recently in order to better control the side-effects that culminate into a major activation of the coagulation and inflammatory systems: among them, miniaturization of the circuits, together with reduction of the priming volume and a simplified cardioplegia concept. All of these lead to a significant decrease of hemodilution and thereby a significant reduction of volume overload during surgery. In this brief review we will present some of these most interesting topics around minimized circuits and the simplified low-volume cardioplegia and discuss their potential benefits on the clinical outcome.

Changes in SedLine-derived processed electroencephalographic parameters during hypothermia in patients undergoing cardiac surgery with cardiopulmonary bypass

Objective

Processed electroencephalography (pEEG) is used to monitor depth-of-anesthesia during cardiopulmonary bypass (CPB). The SedLine device has been recently introduced for pEEG monitoring. However, the effect of hypothermia on its parameters during CPB is unknown. Accordingly, we aimed to investigate temperature-induced changes in SedLine-derived pEEG parameters during CPB.

Design

Prospective observational study.

Setting

Cardiac surgery operating theatre.

Participants

28 patients undergoing elective cardiac surgery with CPB.

Interventions

We continuously measured patient state index (PSI), suppression ratio (SR), bilateral spectral edge frequency (SEF) and temperature. We used linear mixed modelling with fixed and random effects to study the interactions between pEEG parameters and core temperature.

Measurements and main results

During CPB maintenance, the median temperature was 32.1°C [interquartile range (IQR): 29.8-33.6] at the end of cooling and 32.8°C (IQR: 30.1-34.0) at rewarming initiation. For each degree Celsius change in temperature during cooling and rewarming the PSI either decreased by 0.8 points [95% confidence interval (CI): 0.7-1.0; p < 0.001] or increased by 0.7 points (95% CI: 0.6-0.8; p < 0.001). The SR increased by 2.9 (95% CI: 2.3-3.4); p < 0.001) during cooling and decreased by 2.2 (95% CI: 1.7-2.7; p < 0.001) during rewarming. Changes in the SEF were not related to changes in temperature.

Conclusions

During hypothermic CPB, temperature changes led to concordant changes in the PSI. The SR increased during cooling and decreased during rewarming. Clinicians using SedLine for depth-of-anesthesia monitoring should be aware of these effects when interpreting the PSI and SR values.

Central Aortic Cannula Disruption Following Left Atrial Myxoma Excision

Central aortic cannulation is used to give oxygenated blood to the patient through a heart-lung machine. Central aortic cannula disruption during cardiopulmonary bypass (CPB) is a rare complication. This could result in aortic dissection, extensive tears, bleeding, posterior aortic wall injury, oesophageal trauma, and cardiac arrest. We are reporting a central aortic cannula disruption during a left atrium (LA) myxoma excision in which the metal tip part of the cannula detached from its body, resulting in massive blood loss. The intraoperative blood salvage technique was used to maintain hemodynamics during surgery. Pre-procedural visual inspection of all cardiac consumables, including cannula, should be performed to eliminate this complication. All surgical team members should be observant to avoid such complications.