Gut Microbiome in Children with Congenital Heart Disease After Cardiopulmonary Bypass Surgery (GuMiBear Study).

The gut microbiome of infants with congenital heart disease (CHD) undergoing cardiopulmonary bypass surgery (CPB) is at risk of profound alteration. The aim of this study was to examine the gut microbiome pre- and post-bypass surgery to explore potential implications of altered gut biodiversity. A prospective cohort study involving infants with CHD who underwent CPB was performed. Faecal samples were collected from infants alongside the collection of demographic and clinical data in order to examine gut microbiome changes before and after surgery. 16S rRNA sequencing analysis was performed on DNA isolated from stool samples to determine changes in gut microbiome composition. Thirty-three patients were recruited, with samples from thirteen of these available for final analysis. Compared with healthy, matched controls, at a genus level, pre-operative samples for infants with CHD demonstrated a higher relative abundance of Escherichia-Shigella (31% vs 2-6%) and a lower relative abundance of Bifidobacterium (13% vs 40-60%). In post-operative samples, the relative abundance of Escherichia-Shigella (35%), Enterococcus (11%), Akkermansia (6%), and Staphylococcus (5%) were higher than pre-op samples. One infant developed post-operative necrotising-enterocolitis (NEC). They displayed a marked abundance of the Enterococcus (93%) genus pre-operatively. This study demonstrates that infants with CHD have an altered gut microbiome when compared with healthy controls and there might be a possible link between an abundance of virulent species and NEC.

Increased numbers of pre-operative circulating monocytes predict risk of developing cardiac surgery-associated acute kidney injury in conditions requiring cardio pulmonary bypass.

BACKGROUND: Evaluating patients' risk for acute kidney injury (AKI) is crucial for positive outcomes following cardiac surgery. Our aims were first to select candidate risk factors from pre- or intra-operative real-world parameters collected from routine medical care and then evaluate potential associations between those parameters and risk of onset of post-operative cardiac surgery-associated AKI (CSA-AKI). METHOD: We conducted two cohort studies in Japan. The first was a single-center prospective cohort study (n = 145) to assess potential association between 115 clinical parameters collected from routine medical care and CSA-AKI (≥ Stage1) risk in the population of patients undergoing cardiac surgery involving cardiopulmonary bypass (CPB). To select candidate risk factors, we employed random forest analysis and applied survival analyses to evaluate association strength. In a second retrospective cohort study, we targeted patients undergoing cardiac surgery with CPB (n = 619) and evaluated potential positive associations between CSA-AKI incidence and risk factors suggested by the first cohort study. RESULTS: Variable selection analysis revealed that parameters in clinical categories such as circulating inflammatory cells, CPB-related parameters, ventilation, or aging were potential CSA-AKI risk factors. Survival analyses revealed that increased counts of pre-operative circulating monocytes and neutrophils were associated with CSA-AKI incidence. Finally, in the second cohort study, we found that increased pre-operative circulating monocyte counts were associated with increased CSA-AKI incidence. CONCLUSIONS: Circulating monocyte counts in the pre-operative state are associated with increased risk of CSA-AKI development. This finding may be useful in stratifying patients for risk of developing CSA-AKI in routine clinical practice.

Fifth-time redo mitral valve replacement via right thoracotomy under systemic hyperkalemia cardiopulmonary bypass without aortic cross-clamp.

The surgical management of prosthetic valvular endocarditis (PVE) can be challenging. We report a case of a 46-year-old female patient who had a history of four cardiac operations. We chose a mitral valve replacement via right thoracotomy to enable optimal exposure of the mitral valve (MV). Because of multi-reoperations, we employed systemic hyperkalemia for cardiac arrest to protect the heart during cardiopulmonary bypass (CPB) without aortic cross-clamping. Here, we present a complex operation that performed management of CPB under hyperkalemia and the patient had a good postoperative recovery.

Acute Changes in Myocardial Expression of Heat Shock Proteins and Apoptotic Response Following Blood, delNido, or Custodiol Cardioplegia in Infants Undergoing Open-Heart Surgery.

Stress caused by cardioplegic ischemic arrest was shown to alter the expression levels of heat shock proteins (Hsp), but little is known about their effects, particularly on pediatric hearts. This study aimed to investigate whether myocardial cellular stress and apoptotic response changes due to different cardioplegia (CP) solutions during cardiopulmonary bypass (CPB) in infants and to determine their influence on surgical/clinical outcomes. Therefore, twenty-seven infants for surgical closure of ventricular septal defect were randomly assigned to a CP solution: normothermic blood (BCP), delNido (dNCP), and Custodiol (CCP). Hsp levels and apoptosis were determined by immunoblotting in cardiac tissue from the right atrium before and after CP, and their correlations with cardiac parameters were evaluated. No significant change was observed in Hsp27 levels. Hsp60, Hsp70, and Hsp90 levels decreased significantly in the BCP-group but increased markedly in the CCP-group. Decreased Hsp60 and increased Hsp70 expression were detected in dNCP-group. Importantly, apoptosis was not observed in dNCP- and CCP-groups, whereas marked increases in cleaved caspase-3 and -8 were determined after BCP. Serum cardiac troponin-I (cTn-I), myocardial injury marker, was markedly lower in the BCP- and dNCP-groups than CCP. Additionally, Hsp60, Hsp70, and Hsp90 levels were positively correlated with aortic cross-clamp time, total perfusion time, and cTn-I release. Our findings show that dNCP provides the most effective myocardial preservation in pediatric open-heart surgery and indicate that an increase in Hsp70 expression may be associated with a cardioprotective effect, while an increase in Hsp60 and Hsp90 levels may be an indicator of myocardial damage during CPB.

A prospective observational study of emboli exposure in open versus closed chamber cardiac surgery.

OBJECTIVE: Exposure to cerebral emboli is ubiquitous and may be harmful in cardiac surgery utilizing cardiopulmonary bypass. This was a prospective observational study aiming to compare emboli exposure in closed-chamber with open-chamber cardiac surgery, distinguish particulate from gaseous emboli and examine cerebral laterality in distribution. METHODS: Forty patients underwent either closed-chamber procedures (n = 20) or open-chamber procedures (n = 20). Emboli (gaseous and solid) were detected using transcranial Doppler in both middle cerebral arteries in two monitoring phases: 1, initiation of bypass to the removal of the aortic cross-clamp; and 2, removal of aortic cross-clamp to 20 minutes after venous decannulation. RESULTS: Total (median (interquartile range)) emboli counts (both phases) were 898 (499-1366) and 2617 (1007-5847) in closed-chamber and open-chamber surgeries, respectively. The vast majority were gaseous; median 794 (closed-chamber surgery) and 2240 (open-chamber surgery). When normalized for duration, there was no difference between emboli exposures in closed-chamber and open-chamber surgery in phase 1: 6.8 (3.6-15.2) versus 6.4 (2.0-18.1) emboli per minute, respectively. In phase 2, closed-chamber surgery cases were exposed to markedly fewer emboli than open-chamber surgery cases: 9.6 (5.1-14.9) versus 43.3 (19.7-60.3) emboli per minute, respectively. More emboli (total) passed into the right cerebral circulation: 985 (397-2422) right versus 376 (198-769) left. CONCLUSIONS: Patients undergoing open-chamber surgery are exposed to considerably higher numbers of cerebral arterial emboli after removal of the aortic cross-clamp than those undergoing closed-chamber surgery, and more emboli enter the right middle cerebral artery than the left. These results may help inform the evaluation of the pathophysiological impact of emboli exposure.

Higher total ultrafiltration volume during cardiopulmonary bypass-assisted infant cardiac surgery is associated with acute kidney injury and fluid overload.

BACKGROUND: Ultrafiltration (UF) is used for fluid removal during and after infant cardiopulmonary bypass (CPB) surgery to reduce fluid overload. Excessive UF may have the opposite of its intended effect, resulting in acute kidney injury (AKI), oliganuria, and fluid retention. METHODS: This is a single-center, retrospective review of infants treated with conventional and/or modified UF during CPB surgery. UF volume was indexed to weight. AKI was defined using serum creatinine "Kidney Disease Improving Global Outcome (KDIGO)" criteria. Fluid balance was defined according to: [Formula: see text]. Peak fluid overload was determined on postoperative day 3. Multivariable logistic regression adjusted for multiple covariates was used to explore associations with UF, AKI, and fluid overload. RESULTS: Five hundred thirty subjects < 1 year of age underwent CPB-assisted congenital heart surgery with UF. Sixty-four (12%) developed postoperative AKI. On multivariable regression, higher indexed total UF volume was associated with increased AKI risk (OR 1.11, 95% CI=1.04-1.19, p = 0.003). UF volume > 119.9 mL/kg did not reduce peak fluid overload. Subjects with AKI took longer to reach a negative fluid balance (2 vs. 3 days, p = 0.04). Those with more complex surgery were at highest AKI risk (STAT 3 [25-75 percentile: 3-4] in AKI group versus STAT 3 [25-75 percentile: 2-4] in non-AKI group, p = 0.05). AKI was reduced in subjects undergoing more complex surgery and treated with UF volume < 119.9 mL/kg. CONCLUSIONS: Judicious use of UF in more complex congenital cardiac surgery reduces the risk of AKI.

Protective effect of soluble Klotho in pediatric patients undergoing cardiac surgery with cardiopulmonary bypass support-A pilot study.

OBJECTIVE: The Klotho protein family plays important roles in several metabolic pathways. Soluble Klotho has been recently put forward as an antiaging protein, demonstrating renal and cardiovascular protective traits. Cardiopulmonary bypass (CPB) support during cardiac surgery has been implicated in several adverse outcomes in pediatric and adult patients. Our goal was to assess whether serum Klotho levels can be used to predict outcomes in children undergoing cardiac surgery with CPB due to congenital heart defects (CHDs). METHODS: This prospective study was conducted on pediatric patients admitted to two Pediatric Cardiac Intensive Care Units, between 2012 and 2018. All patients were born with CHD and underwent corrective surgery with CPB. Sequential blood samples were analyzed by enzyme-linked immunosorbent assay for soluble Klotho levels at baseline, 2, 6, and 24 h after surgery. The association between Klotho levels and several demographic, intraoperative, and postoperative clinical and laboratory parameters was studied. RESULTS: Twenty-nine children undergoing cardiac surgery with CPB support were included. Serum Klotho levels were shown to significantly decrease 2 h after surgery and increase to baseline levels after 6 h (p < .001 and p < .05, respectively). Patients with low Klotho levels 2 h after surgery were at a 32-fold higher risk for developing postoperative complications (p = .015, odds ratio < 0.03). Moreover, Klotho levels at each of the four time points were lower in patients who developed postoperative complications. CONCLUSIONS: Cardiac surgery with CPB results in a significant decrease of serum Klotho levels 2 h after surgery in pediatric patients with CHDs, which can be used to predict development of postoperative complications in this patient population.

The Successful Use of an Exchange Transfusion in a Child with Hereditary Spherocytosis Undergoing Congenital Cardiac Surgery.

Little is reported in the literature regarding hereditary spherocytosis (HS) and cardiopulmonary bypass (CPB). We present a case of a 19-month-old girl child who was referred for an atrioventricular septal defect (AVSD) and HS. The patient underwent surgical repair, and an exchange transfusion was performed at the initiation of CPB. No significant hemolysis or events attributed to HS were observed during or after CPB. The surgical repair of an AVSD in a pediatric patient with HS and total volume exchange transfusion is herein reported.

To RAP or Not to RAP: A Retrospective Comparison of the Effects of Retrograde Autologous Priming.

Retrograde autologous priming (RAP) is a process used to reduce hemodilution associated with the initiation of cardiopulmonary bypass (CPB). Previous studies have reported potential benefits to RAP; however, many of these studies do not evaluate the benefits of RAP with limited preoperative fluid administration combined with a condensed CPB circuit. We examined clinical metrics of patients who underwent RAP versus those who did not undergo RAP prior to the initiation of CPB. This was a retrospective data review of 1,303 patients who underwent CPB in the setting of open-heart surgery for a 2-year period. RAP was used on all patients between June 1, 2017 and June 30, 2018 (n = 519) and not used on patients between July 1, 2018 and June 30, 2019 (n = 784). Both groups were subjected to a low-prime CPB circuit volume of 800-900 mL. We compared the clinical metrics for packed red blood cell (PRBC) transfusion, oxygen delivery, postoperative acute kidney injury (AKI), Albumin utilization, ventilator time, Intensive Care Unit length of stay (ICU LOS), and 30-day mortality between the two groups. Our data analysis showed there were no statistically significantly differences between the two groups on the incidence of postoperative AKI, PRBC administration, ventilator time, ICU LOS or 30-day mortality. In the RAP group, there was a statistically significant lower oxygen delivery and a statistically significant increased volume of Albumin administered postoperatively, although those differences were so small, they were potentially not clinically significant. Our analysis revealed no significant benefit to performing RAP with limited preoperative fluid administration and minimized CPB circuit prime volume. We formalized a process that included limiting preoperative fluid administration and minimizing the CPB circuit volume so that we were not required to RAP and did not simultaneously sacrifice patient outcomes in other areas.

Systemic Absorption of Lidocaine from Continuous Erector Spinae Plane Catheters After Congenital Cardiac Surgery: A Retrospective Study.

OBJECTIVES: To examine postoperative serum lidocaine levels in patients with intermittent lidocaine bolus erector spinae plane block (ESPB) catheters after cardiac surgery with or without cardiopulmonary bypass (CPB). DESIGN: A retrospective study. SETTING: Single-center pediatric quaternary teaching hospital. PARTICIPANTS: Patients who received ESPB catheters after congenital cardiac surgery from April 2018 to March 2019. INTERVENTIONS: Postoperative serum lidocaine levels were extracted from the record. MEASUREMENTS AND MAIN RESULTS: Twenty-seven of 40 patients were included in the final analyses (19 with CPB and 8 with no CPB, age 1-47 years, undergoing congenital heart repair). Patients who received ropivacaine or were missing data were excluded. The initial intraoperative bolus of lidocaine ranged from 0- to- 3.72 mg/kg, and the range of postoperative intermittent lidocaine boluses ranged from 0.35- to- 0.83 mg/kg, which were administered every hour. Serum lidocaine levels were measured by the hospital laboratory and ranged from <0.05- to- 3.0 µg/mL in the CPB group and from <0.05- to- 3.2 µg/mL in the no- CPB group. CPB was not associated with differences in lidocaine levels when controlling for time (P = 0.529). Lidocaine concentrations ranged from 0.50- to- 1.68 µg/mL in the CPB group and 0.86- to- 2.07 µg/mL in the no- CPB group. There was a normally distributed overall mean peak level of 1.818 ± standard deviation of 0.624 µg/mL, with 95% confidence interval of 0.57- to- 3.06 µg/mL. No patients had clinical signs of toxicity. CONCLUSION: Postoperative serum lidocaine concentrations did not appreciably differ due to CPB. Serum lidocaine concentrations did not reach near- toxic doses despite the presence of additional lidocaine in the cardioplegia. The results suggested that lidocaine for ESPBs after cardiac surgery is below systemic toxic range at the doses described.

Implementation of a Prescriptive Extracorporeal Circuit and Its Effect on Hemodilution and Blood Product Usage during Cardiac Surgery.

The use of cardiopulmonary bypass (CPB) contributes significantly to intraoperative anemia. The use of a prescriptive circuit that is tailored to the patient size could significantly reduce priming volumes, resulting in less hemodilution. The purpose of this study was to determine whether a prescriptive circuit resulted in decreased hemodilution, reduced blood product usage, and improved outcomes. In total, 204 patients prospectively received the prescriptive protocol between March 2019 and November 2019. This protocol was composed of three circuit sizes: small [body surface area (BSA) ≤ 1.85 m2], medium (BSA 1.86-2.30 m2), and large (BSA ≥ 2.31 m2). Data for CPB and post-bypass transfusions were collected, along with postoperative outcomes. These patients were then 1:2 propensity score matched to 401 patients who were retrospectively reviewed who had undergone cardiac surgery using a one-sized CPB circuit. The prescriptive protocol cohort had more patients with renal disease, whereas the conventional cohort had more history of hypertension. Intraoperative results show the prescriptive circuit had lower mean prime volume and total prime volume after reverse autologous prime (1,084 mL vs. 1,798 mL, p < .0001; 725 mL vs. 1,181 mL, p < .0001). Ultrafiltration was higher in the prescriptive group (872 vs. 645 mL, p < .0001), which likely balanced the increased use of del Nido cardioplegia in the prescriptive group (1,295 vs. 377 mL, p < .0001). The drop in hematocrit (HCT) from baseline was less in the prescriptive group (15.1 ± 4.91 vs. 16.2 ± 4.88, p = .0149), whereas the postoperative HCT was higher (32.79 ± 4.88 vs. 31.68 ± 4.99, p = .0069). Transfusion of packed red cells did not change between the two groups. Implementation of a prescriptive circuit did not reduce on-bypass or intraoperative blood product usage. However, there was a significant reduction in on-bypass hemodilution and increased postoperative HCT.

Cardiopulmonary Bypass Mean Global Oxygen Delivery May Be Associated with Neurocognitive Preservation during Hypothermic Aortic Surgery.

The purpose of this retrospective research was to investigate the relationship between mean global oxygen delivery (DO2) and neurocognitive function in adult patients who presented for aortic surgery with deep hypothermic circulatory arrest using cardiopulmonary bypass (CPB). From a pool of 132 patients, data from 100 CPB patients from 2012 to 2014 aged 50 years or older were randomly selected and analyzed, and global DO2 on CPB was used to categorize patients into those for whom the mean indexed cerebral oxygen delivery (DO2i) was either ≥272 mL O2/min/m2 (critical DO2 [DO2crit]) or less than DO2crit. Ten patients experienced either stroke or expired in the perioperative course. The proportion of patients with evidence of neurocognitive preservation was 98.3% in the group in which the DO2crit was met, compared with 80.6% in the group where DO2crit was not met (X 2 [1, 100] = 3.27, p = .07). Potentially, because of causes other than DO2, the subset of patients with stroke and/or death were removed, and data from 90 cases were analyzed, and a global mean DO2i value of 239.9 mL O2/min/m2 was identified. A larger sample size with controls may yield deeper insights into the hypothesis that a mean global CPB DO2i of 239.9 mL O2/min/m2 may play a role in predicting neurocognitive preservation in this patient population.

Correlation between acute degradation of the endothelial glycocalyx and microcirculation dysfunction during cardiopulmonary bypass in cardiac surgery.

OBJECTIVE: The association between the shedding of the endothelial glycocalyx (EG) and the pathogenesis of microcirculatory perfusion disturbances has been discussed in experimental studies. This discussion, however, has limited relevance in a clinical setting. We investigated EG shedding in patients undergoing cardiopulmonary bypass (CPB) and its association with alterations in microvascular perfusion. METHODS: The plasma levels of syndecan-1, heparan sulfate, and hyaluronan were used as markers of glycocalyx degradation. Microcirculatory parameters included perfused vessel density (PVD) and De Backer Scores. Sidestream dark field imaging (SDF) was applied to visualize sublingual microcirculation during the preoperative resting state (T0), after sternum splitting, after aortic clamping, 5 min before aortal declamping, 1 h after CPB (T4), 4 h after CPB, 24 h after CPB (T6), and 48 h after CPB. RESULTS: Thirty patients undergoing cardiac surgery were recruited. The plasma levels of glycocalyx degradation markers increased after CPB. This increase indicated severe glycocalyx shedding at T4 relative to that at T0. By T6, the plasma levels of glycocalyx degradation markers had decreased to baseline levels in a stepwise manner. PVD and the De Backer Scores decreased at T4 and recovered at T6. Glycocalyx marker concentrations were correlated with microvascular alterations during cardiac surgery. CONCLUSIONS: Glycocalyx components are closely related to microcirculation perfusion disorders. Damage to the glycocalyx during surgery with CPB may play a key role in microcirculation perfusion dysfunction.

Rolipram plus Sivelestat inhibits bone marrow-derived leukocytic lung recruitment after cardiopulmonary bypass in a primate model.

Cardiopulmonary bypass (CPB) recovery is complicated by lung inflammation from bone marrow (BM)-derived polymorphonuclear leukocytes (PMNs) and monocytes (MO). Although Sivelestat reduces inflammatory mediators and Rolipram inhibits PMN and MO activation, any kinetic effects to improve CPB recovery in vivo are unknown. We hypothesized that intraoperative co-administration of these compounds would reduce CPB-induced lung inflammation through downregulation of PMN and MO recruitment. A 2-h CPB was surgically established in cynomolgus monkeys (n = 13), and BM leukocyte release and lung recruitment were monitored postoperatively by flow cytometry with 5'-bromo-2'-deoxyuridine (BrdU) and cytokine ELISA. Either Sivelestat, Sivelestat plus Rolipram, or saline (control) was administered intraoperatively and both peripheral and perfusion sampling courses revealed BrdU-labeled cells representative of activated leukocyte infiltration. Levels of cytokines CD11b and CD18 were leukocytic activation markers. Sivelestat plus Rolipram attenuated increases in CPB-associated circulating band cells, prolonged BM-transit time (PMN: 121.0 ± 3.7 to 96.2 ± 4.3 h [control], p = 0.012; MO: 84.4 ± 4.1 to 61.4 ± 3.0 h [control], p = 0.003), and reduced their alveolar appearance. CD11b-mediated PMN and MO changes during CPB and the post-surgical increases of Interleukin (IL)-6 and IL-8 in the bronchoalveolar lavage fluid were suppressed. Sivelestat alone increased PMN transit time to 115.8 ± 6.6 h, but monocytes were unaffected. Therefore, Rolipram has additive inhibitory effects with Sivelestat on the CPB-induced activation and release of BM-derived PMNs and MO and their recruitment to the lungs. Co-administration of these compounds could, therefore, hold value for preventing CPB-induced lung injury.

The role of surgical transcatheter valve implantation for the treatment of severe mitral annular calcification.

With a rise in the aging population, mitral annular calcification is increasingly encountered with an incidence of 10% in over 70 years old. This with increasing patient comorbidities presents a technical challenge due to the risk of atrioventricular disruption which is associated with high operative mortality of up to 75%. We describe two cases of severe mitral disease with marked annular calcification successfully treated with a balloon expandable transcatheter valve which was deployed on cardiopulmonary bypass via a trans-atrial approach.

Use of Augmented Reality to Assist Teaching for Future Perfusionists in Extracorporeal Technology.

The aim of this study was to foster the better perfusion education when providing extracorporeal circulation (ECC) technology for future perfusionists. For this purpose, we have developed an augmented reality (AR) program for ECC students. Currently, the cost of equipment and its simulator is high. Furthermore, it is desirable for ECC students to practice at any time. AR describes user experiences that add 2D (plane detection) or 3D elements to the live view from a device's camera in a way that makes those elements appear to inhabit the real world. We can use these technologies to create AR experiences using the back camera of a smartphone or tablet. We can also build our own instrument with custom visualization and data analysis. Although AR technology may not be new, its potential in ECC student education is just beginning to be explored. Unlike other computing technologies, AR interfaces offer seamless interaction between the real and virtual worlds, a tangible interface metaphor, and a means for transitioning between real and virtual worlds. Here, we have shown our experiences of cost-effective AR technology for future perfusionists.

Improving Decreased Heater-Cooler Efficiency as a Result of Heater-Cooler Infection Control Strategy.

Heater-cooler units (HCUs) play a vital role in temperature management during cardiopulmonary bypass. In recent years, HCUs have been shown to play a significant role in the propagation of bacteria causing patient infection and significant harm. As a result, various institutions across the world have begun moving the HCU either far away or outside of the operative theater entirely. The purpose of this study was to examine the effect that the increased length of HCU water lines have on the ability of the device to heat and cool. We hypothesized that the increase in water line distance leads to a decrease in HCU efficiency and that insulating the water lines would blunt the effect of this increase in distance. Five water line conditions were compared under two cooling and two warming ranges. Short water lines, long water lines, and long water lines with foam, rubber, or tape insulation were compared. Cooling from an arterial line temperature of 26.7-19.7°C showed no difference between conditions with the exception that every long line condition takes significantly longer to cool than short water lines. Cooling from 35.6 to 28.6°C revealed that all insulations reduce the cooling time compared with long water lines without insulation, but only foam insulation reduces to the level of the short water lines. During warming conditions, all insulations reduced the warming time compared with long uninsulated water lines, but none were comparable with short water lines. Increased water line length leads to a decrease in HCU efficiency. Insulation is effective at increasing efficiency of long water lines, but only at warmer temperatures and not to the level of short water lines. Only foam-insulated long water lines were able to match the efficiency of short water lines, but only across a single temperature range.

Net Prime Volume Is Associated with Increased Odds of Blood Transfusion.

Hemodilutional anemia has been cited as a contributing factor to red blood cell (RBC) transfusions in cardiac surgery patients. Accordingly, efforts have been made to minimize hemodilution by reducing cardiopulmonary bypass (CPB) prime volume. We sought to assess the impact of these efforts on intraoperative RBC transfusions. We evaluated 21,360 patients undergoing coronary artery bypass with or without aortic valve surgery between July 2011 through December 2016 at any of 42 centers participating in the Perfusion Measures and Outcomes registry. The primary exposure was net CPB prime volume (total prime volume minus retrograde autologous prime volume) indexed to body surface area (mL/m2), which was further divided into quartiles (Q1: <262 mL/m2, Q2: 262-377 mL/m2, Q3: 377-516 mL/m2, and Q4: >516 mL/m2). The primary outcome was intraoperative RBC transfusion. We modeled the effect of index net prime volume on transfusion, adjusting for patient (age, gender, race, diabetes, vascular disease, previous myocardial infarction, ejection fraction, creatinine, preoperative hematocrit (HCT), total albumin, status, aspirin, and antiplatelet agents), procedural (procedure types) characteristics, surgical year, and hospital. The median net prime volume was 378 mL/m2 (25th percentile: 262 mL/m2, 75th percentile: 516 mL/m2). Relative to patients in Q1, patients in Q4 were more likely to be older, female, nondiabetic, have higher ejection fraction, have more ultrafiltration volume removed, and undergo more elective and aortic valve procedures (all p < .05). Patients in Q4 relative to Q1 were exposed to lower nadir HCTs on bypass, p < .05. The net prime volume was associated with an increased risk of transfusion (8.9% in Q1 vs. 22.6% in Q4, p < .001). After adjustment, patients in Q4 (relative to Q1) had a 2.9-fold increased odds (ORadj = 2.9, 95% CI [2.4, 3.4]) of intraoperative RBC transfusion. In this large, multicenter experience, patients exposed to larger net prime volumes were associated with greater adjusted odds of receiving intraoperative transfusions. Our findings reinforce the importance of efforts to reduce the net CPB prime volume. Based on these findings and other supporting evidence, the net prime volume should be adopted as a national quality measure.

Effects of ECMO Simulations and Protocols on Patient Safety.

The use of extracorporeal membrane oxygenation (ECMO) has greatly increased over the years; however, the survival rate is only above 56%. There has been a drastic increase in ECMO centers and cases. ECMO has become a popular therapy route for patients with respiratory and cardiac complications; however, patient safety is a major concern. Perfusion and non-perfusion students from the University of Nebraska Medical Center were recruited to participate in three simulation trials. The trials consisted of five different tasks that are required for managing or preventing catastrophic events on ECMO. Students were evaluated for the time it took to complete each task, number of errors made, and protocol referencing. The data indicated that there was a decrease in time for the 1st vs. 2nd trial (p = .02) for perfusion students and a decrease from the 1st to 3rd trial (p = .001) for the circuit set-up simulation. There was a decrease in priming time from the 1st to 3rd trial (p = .02) and for the pump change (p = .0098) for the perfusion students as well. The non-perfusion students had a significant decrease in time for the circuit set-up in the 1st vs. 2nd (p = .004) and 1st vs. 3rd trial (p = .002). There was a decrease in time for priming (.004), pump change (p = .002), tubing change (p = .0098), and errors during the tubing change (p = .02) in the non-perfusion students. Both groups felt more confident after the simulations and the non-perfusion students specifically felt like they were more familiar with the purpose of ECMO after the simulation. ECMO simulations and protocols may improve patient safety by strengthening the skills needed for rapid management, fewer errors, and higher levels of confidence during the management of ECMO and catastrophic events.

The effect of methylprednisolone prophylaxis on inflammatory monocyte subsets and suppressive regulatory T cells of patients undergoing cardiopulmonary bypass.

BACKGROUND: Cardiopulmonary bypass (CPB) during open-heart surgery triggers an inflammatory response that can cause significant morbidity and mortality. Human monocytes and regulatory T (Treg) cells are phenotypically and functionally heterogeneous and have been shown to play a significant role in the inflammatory dysfunction triggered by CPB. Glucocorticoids (GCs) have been widely administered for decades in patients undergoing CPB to reduce this inflammatory response. However, it has not been clearly established how routine prophylactic administration of glucocorticoids (GCs) affects monocyte and Treg subsets. METHODS: Thirty-six patient who underwent heart surgery with CPB were randomly assigned to a methylprednisolone group (MG, N = 18; 500 mg in the CPB priming) and a non-methylprednisolone group (NMG, N = 18). The circulating monocyte and Treg subsets were analyzed by flow cytometry. RESULTS: The MG and NMG groups had comparable percentages of monocyte subsets and similar expression levels of HLA-DR, CD86, CD64 and toll-like receptor 4 (TLR4). Remarkably, methylprednisolone increased the percentage of CD4+CD25+ Treg cells among CD4+ T cells in patients undergoing CPB, but did not increase the proportion of suppressive Treg cells, either resting or activated, in these patients undergoing CPB. CONCLUSIONS: Our results showed that prophylactic administration of methylprednisolone neither decreased the percentages and counts of inflammatory monocyte subsets nor did it induce the expansion of suppressive Treg cells in patients undergoing CPB. These results clarified the effects of GCs on cell-mediated immune responses and provided additional evidence in practice. TRIAL REGISTRATION: Clinicaltrials.gov : NCT01296074. Registered 14 February 2011.