Perfusion

Reduced oxygen delivery (DO₂) during cardiopulmonary bypass (CPB) was proposed as a risk factor for the development of postoperative neurological complications (PONCs), including cerebrovascular accidents (CVA), delirium, and postoperative cognitive dysfunction (POCD). We aimed to review the current evidence on the association between intraoperative DO₂ and the incidence of PONCs.

MEDLINE, Embase, the Cochrane Library, and Web of Science were electronically searched to identify comparative studies from inception until July 2023 that reported the association between intraoperative DO₂ levels and the incidence of PONCs (as defined by the scales and diagnostic tools utilized by the studies’ authors) in adults patients undergoing cardiac surgery using CPB.

Of the 2513 papers identified, 10 studies, including 21,875 participants, were included. Of these, three studies reported on delirium, two on POCD, and five on CVA. Eight studies reported reduced intraoperative DO₂ in patients who developed delirium and CVA. There was a lack of consensus on the cut-off of DO₂ levels or the correlation between the period below these threshold values and the development of PONC.

Limited data suggest that maintaining intraoperative DO₂ above the critical threshold levels and ensuring adequate intraoperative cerebral perfusion may play a role in minimizing the incidence of neurological events in adult patients undergoing cardiac surgery on cardiopulmonary bypass.

To investigate the impact of direct aortic cannulation (DAC) versus femoral arterial cannulation (FAC) on clinical outcomes of surgery for acute type A aortic dissection.

PubMed/MEDLINE, Scopus, and Cochrane Central Register of Controlled Trials were searched until August 25, 2023, to conduct a meta-analysis. Primary endpoints of the study were operative mortality and postoperative stroke. Secondary endpoints were cardiopulmonary bypass time, myocardial ischemic time, hypothermic circulatory arrest time, temporary neurological dysfunction (TND), combined stroke and TND, re-exploration for bleeding, and need for renal replacement therapy. A random-effect model was used to estimate the pooled effect size, and a leave-one-out method was used for the primary endpoints for sensitivity analysis.

15 studies met our eligibility criteria, including a total of 7941 samples. Operative mortality was significantly lower in the DAC group with a pooled odds ratio (OR) of 0.72 [95% confidence interval (CI): 0.61–0.85)]. Incidence of postoperative stroke was also lower in the DAC group with a pooled OR of 0.79 (95% CI: 0.66–0.94). However, after excluding one study with the greatest weight, the difference became nonsignificant. DAC was also associated with a lower incidence of postoperative TND, and re-exploration for bleeding with a pooled OR of 0.52 (95% CI: 0.37–0.73), and 0.60 (95% CI: 0.47–0.77), respectively.

This meta-analysis showed that patients who underwent ATAAD repair with DAC had a lower incidence of operative mortality, postoperative stroke, TND, and re-exploration for bleeding compared to those who underwent FAC.

Following weaning of peripheral venoarterial extracorporeal membrane oxygenation (ECMO) support, removal of cannulas and repair of large-bore arterial sites is traditionally by open surgical repair (OSR). The use of a percutaneous vascular closure device (VCD) offers a minimally invasive alternative to OSR with potential for reduced operative complications, reduced hospital length of stay and in-hospital mortality.

A systematic review of Medline and Embase databases was conducted for studies comparing VCD-assisted decannulation with OSR following decannulation of peripheral ECMO. The primary endpoint was rate of post-procedural complications, namely wound infection and limb ischaemia. The secondary endpoint was in-hospital mortality.

Eight studies, with a total of 685 patients, met inclusion criteria. Forty-eight percent (n = 328) of patients underwent VCD-assisted decannulation with the remainder decannulated by OSR. Pooled analysis demonstrated that patients undergoing VCD-assisted decannulation are at significantly lower risk of overall complications than surgical repair (OR 4.34; 95% CI 2.19-8.57; p < .001). Specifically, there was a substantial decrease in groin infections (OR 6.77; 95% CI 3.07-14.97; p < .001) without notable differences in limb ischaemia or pseudoaneurysm occurrence between the VCD and OSR cohorts. There was a lower incidence of intra-operative bleeding and haematoma in the VCD cohort (p < .001 and p = .002, respectively).

Vascular closure device-assisted decannulation of peripheral ECMO offers a significantly reduced risk of complications, particularly groin infections and bleeding. Future research should encompass larger cohorts, randomised controlled trials, cost-benefit analyses, and the training of surgeons, cardiologists and intensivists in VCD-assisted decannulation, potentially through the integration of simulation-based training.

Exercise-based cardiac rehabilitation (EBCR) improves functional capacity in heart failure (HF). However, data on the effect of EBCR in patients with advanced HF and left ventricular assist devices (LVADs) are limited. This meta-analysis aimed to evaluate the impact of EBCR on the functional ability of LVAD patients by comparing the corresponding outcome indicators between the EBCR and ST groups.

PubMed, Embase, Clinical Trials, and Cochrane Library databases were searched for studies assessing and comparing the effects of EBCR and standard therapy (ST) in patients following LVAD implantation. Using pre-defined criteria, appropriate studies were identified and selected. Data from selected studies were extracted in a standardized fashion, and a meta-analysis was performed using a fixed-effects model. The protocol was registered on INPLASY (202340073).

In total, 12 trials involving 477 patients were identified. The mean age of the participants was 52.9 years, and 78.6% were male. The initiation of EBCR varied from LVAD implantation during the index hospitalization to 11 months post-LVAD implantation. The median rehabilitation period ranged from 2 weeks to 18 months. EBCR was associated with improved peak oxygen uptake (VO2) in all trials. Quantitative analysis was performed in six randomized studies involving 214 patients (EBCR: n = 130, ST: n = 84). EBCR was associated with a significantly high peak VO2 (weighted mean difference [WMD] = 1.64 mL/kg/min; 95% confidence interval [CI], 0.20-3.08; p = .03). Similarly, 6-min walk distance (6MWD) showed significantly greater improvement in the EBCR group than in the ST group (WMD = 34.54 m; 95% CI, 12.47-56.42; p = .002) in 266 patients (EBCR, n = 140; ST, n = 126). Heterogeneity was low among the included trials. None of the included studies reported serious adverse events related to EBCR, indicating the safety of EBCR after LVAD implantation.

This study demonstrated that EBCR following LVAD implantation is associated with greater improvement in functional capacity compared with ST as reflected by the improved peak VO2 and 6MWD values. Considering the small number of patients in this analysis, further research on the clinical impact of EBCR in LVAD patients is warranted.

Most cardiac surgery clinical prediction models (CPMs) are developed using pre-operative variables to predict post-operative outcomes. Some CPMs are developed with intra-operative variables, but none are widely used. The objective of this systematic review was to identify CPMs with intra-operative variables that predict short-term outcomes following adult cardiac surgery.

Ovid MEDLINE and EMBASE databases were searched from inception to December 2022, for studies developing a CPM with at least one intra-operative variable. Data were extracted using a critical appraisal framework and bias assessment tool. Model performance was analysed using discrimination and calibration measures.

A total of 24 models were identified. Frequent predicted outcomes were acute kidney injury (9/24 studies) and peri-operative mortality (6/24 studies). Frequent pre-operative variables were age (18/24 studies) and creatinine/eGFR (18/24 studies). Common intra-operative variables were cardiopulmonary bypass time (16/24 studies) and transfusion (13/24 studies). Model discrimination was acceptable for all internally validated models (AUC 0.69-0.91). Calibration was poor (15/24 studies) or unreported (8/24 studies). Most CPMs were at a high or indeterminate risk of bias (23/24 models). The added value of intra-operative variables was assessed in six studies with statistically significantly improved discrimination demonstrated in two.

Weak reporting and methodological limitations may restrict wider applicability and adoption of existing CPMs that include intra-operative variables. There is some evidence that CPM discrimination is improved with the addition of intra-operative variables. Further work is required to understand the role of intra-operative CPMs in the management of cardiac surgery patients.

Retrograde Autologous Priming (RAP) of cardiopulmonary bypass (CPB) circuits is an effective way to reduce prime volume, commonly through the transfer of prime into separate reservoirs or circuit manipulation. We describe a simple and safe technique for RAP without the need for any circuit modifications or manipulations.

For this technique, a separate roller pump for ultrafiltration (UF) is used. After adequate heparinization and arterial cannulation, the UF pump is initiated slowly, removing prime through the effluent of the UF, replacing with the patient’s blood from the aortic cannula. Once the arterial line and UF circuit are autologous primed, the arterial head displaces reservoir crystalloid toward the UF circuit at a flow rate equal to the UF pump, displacing the crystalloid prime with blood from the UF circuit, autologous priming the boot and oxygenator with blood, crystalloid again being removed by the effluent. After venous cannulation, the venous line prime is replaced with autologous blood, the crystalloid removed by the effluent of the UF circuit via the arterial head. During RAP, if the patient becomes hypovolemic, either autologous volume is transfused back to the patient, or CPB is initiated, without the need for circuitry modifications.

The patient population in this sample consisted of 63 patients ranging between 6.1 kg and 115.6 kg. The smaller the patient, the less blood volume available for RAP and therefore the less prime volume able to be removed. Overall percent removal increases as our patients size increases compared to total circuit volume.

This RAP technique is a safe and effective way to achieve a standardized asanguinous prime for many regardless of patient or circuit size in the absence of contraindications such as low starting hematocrit, emergency surgery or physiologic instability. Most importantly, this potentially reduces the amount of hemodilution patients see from CPB initiation and therefore the lowest nadir hematocrit and consequently the amount of required homologous blood products needed during surgery.

Awake Extracorporeal Life Support (aECLS) with active mobilization has gained consensus over time, also within the pediatric community. This individual patient data (IPD) meta-analysis summarizes available evidence on pediatric aECLS, its feasibility, and safety regarding sedation weaning, extubation, and physiotherapy.

PubMed/Medline and Cochrane Database were screened until February 2022. Articles reporting on children (≤18 years) undergoing aECLS were selected. IPD were requested, pooled in a single database, and analyzed using descriptive statistics. Primary outcome was survival to hospital discharge. Secondary outcomes included extubation during ECLS, physiotherapy performed, tracheostomy, and complications.

Nineteen articles and 65 patients (males:n = 30/59,50.8%) were included. Age ranged from 2 days to 17 years. ECLS configurations included veno-venous (n = 42/65, 64.6%), veno-arterial (n = 18/65, 27.7%) and other ECLS settings (n = 5/65, 7.7%). Exclusive neck cannulation was performed in 51/65 (78.5%) patients. Extubation or tracheostomy during ECLS was reported in 66.2% (n = 43/65) and 27.7% (n = 18/65) of patients, respectively. Physiotherapy was reported as unspecified physical activity (n = 34/63, 54%), mobilization in bed (n = 15/63, 23.8%), ambulation (n = 14/63, 22.2%). Complications were reported in 60.3% (n = 35/58) of patients, including hemorrhagic (36.2%), mechanical (17.2%), or pulmonary (17.2%) issues, and need for reintubation (15.5%). Survival at discharge was 81.5% (n = 53/65).

Awake ECLS strategy with active physiotherapy can be applied in children from neonatal age. Ambulation is also possible in selected cases. Complications related to such management were limited. Further studies on aECLS are needed to evaluate safety and efficacy of early physiotherapy and define patient selection.

Evidence supports the role of oxygen delivery (DO₂) in ameliorating acute kidney injury (AKI). While instrumentation for continuous DO₂ measurement exists, a simplified method has been reported for targeting a specific DO₂ index (DO₂i), commonly referred to as a goal-directed perfusion (GDP) strategy, by using a reference table and available data such as body surface area and continuous haematocrit values. This simplified approach can also be used for quality auditing via archived data.

This retrospective sequential audit was conducted to assess the impact of employing a GDP strategy within our institution by examining perfusion practices, DO₂ levels and renal outcomes before and after implementation. A total of 246 patients undergoing elective primary coronary revascularisation were included: 125 patients in the pre-change group and 121 patients in the post-change group. A DO₂i threshold above 280 mL/min/m² was targeted in the post-GDP group.

While both groups maintained a mean DO₂ above the threshold, the post-GDP group exhibited a higher average DO₂i (311 vs 291 mL/min/m²). The GDP strategy led to higher nadir DO₂i (255 vs 225, p < .001) and was coupled with a reduction in the time below the 280 mL/min/m² threshold (30 min vs 50 min, p < .001). The average cardiac index in the post-GDP group was higher (1.87 vs 1.65, p < .001) while also demonstrating a smaller creatinine rise of 6.8% compared to 13.5% in the control group (p = .035). There was no difference in AKI or mortality rates between the groups.

The implementation of the GDP strategy demonstrated an enhancement in oxygen delivery during cardiopulmonary bypass, primarily attributable to elevated pump flow rates. A statistically significant decrease in serum creatinine levels was observed. The published reference table emerged as a simple yet effective tool in optimising our GDP strategy.

The purpose of this study was to compare techniques for securing the aortic extracorporeal membrane oxygenation (ECMO) cannula, using in vitro models.

Two models were studied: a tissue model using porcine aortas and a stand model replacing the aorta with a metal stand to study the system independent of the tissue. Interventions in each model were divided into three experimental groups: Group 1 (3-0 Prolene^® + 20-French Medtronic Arterial Cannula EOPA™), Group 2 (4-0 Prolene^® + 16-French Medtronic Arterial Cannula DLP Pediatric), and Group 3 (5-0 Prolene^® + 8-French Medtronic Arterial Cannula DLP Pediatric). In separate experiments, both gradual and rapid forces were applied to the cannulas, starting with 9.8 Newtons and increasing exponentially if the cannula remained secured. Additionally, the method of securing the tourniquet and the number of ties securing the tourniquet to the cannula were evaluated.

In the tissue model, even with a minimum force of 9.8 Newtons, the suture pulled through the aortic tissue, leaving sutures and ties intact. In the stand model, two purse-string sutures secured by two ligaclips held the cannula reliably and withstood higher total force. Dislodgement was prevented at forces close to 60 Newtons with only two hemostatic clips included in cannulation.

The weakest part of the aortic ECMO cannulation system using in vitro experiments was the tissue. Assuming that these experiments translate in vivo, it is therefore critical to prevent any pull on the cannulas by securing ECMO cannulas and ECMO tubing to both the patient and the patient’s bed. Sutures with a larger diameter withstand more force. Two medium hemostatic clips can secure Prolene^® sutures within snares as safely as a mosquito hemostat. Two polypropylene purse-string sutures secured by two hemostatic clips were most reliable at greater forces. The rationale for publishing our experiments in this manuscript is to (1) communicate our quantification of possible contributing factors to this rare and likely catastrophic complication of unintended decannulation, (2) increase awareness about this potential complication, and (3) increase vigilance to assure prevention of this dreaded complication.

During cardiopulmonary bypass (CPB), gaseous microemboli (GME) that originate from the extracorporeal circuit are released into the arterial blood stream of the patient. Gaseous microemboli may contribute to adverse outcome after cardiac surgery with CPB. Possibly, air may be collected in the right atrium during induction of anesthesia and released during CPB start. The aim of this study was to assess if the GME load entering the venous line of the CPB circuit could be reduced by training of anesthesia personal in avoiding air introduction during administration of intravenous medication.

In 94 patients undergoing coronary artery bypass grafting with CPB, GME number and volume were measured intraoperatively with a bubble counter (BCC300). The quantity and the relationship between GME number and volume in the venous and arterial line were determined in 2 periods before and after education of the anesthesiologists and nurses.

In the venous line no significant differences were observed between numbers and volumes of GME between groups. Comparing patients with low versus high GME load, showed significantly more patients from the intervention group in the low GME-load group, namely 29 versus 18. Administration of medication by anesthesia was confirmed as a clear cause of GME/air-introduction into the venous circulation. Scavenging properties of the CPB circuit including the oxygenator showed a 99.9% reduction of GME.

A wide spread of GME generation during perfusion was present with no difference in generation of GME between groups. Lower GME load observed in patients (intervention group) and examples of air introduction during drug administration suggest that air introduced by anesthesia contributes to the GME load during CPB. Scavenging properties of the CPB circuit contribute very much to patient safety regarding reduction of venous air. Awareness and education create the possibilities for further reduction of GME during cardiopulmonary bypass.

In recent years, major findings on concomitant procedures and anticoagulation management have occurred in Mitral Valve (MV) surgery. Therefore, we sought to evaluate the current practices in MV interventions across Europe.

In October 2021, all national cardio-thoracic societies in the European region were identified following an electronic search and sent an online survey of 14 questions to distribute among their member consultant/attending cardiac surgeons.

The survey was completed by 91 consultant/attending cardiac surgeons across 12 European countries, with 78% indicating MV repair as their specialty area. 57.1% performed >150 operations/year and 71.4% had 10+ years of experience.

Concomitant tricuspid valve repair is performed for moderate tricuspid regurgitation (TR) by 69% of surgeons and for mild TR by 26.3%, both with annular diameter >40 mm. 50.6% indicated ischaemic MV surgery in patients undergoing CABG if moderate mitral regurgitation with ERO >20 mm² and regurgitant volume >30 mL, and 45.1% perform it if severe MR with ERO >40 mm² and regurgitant volume >60 mL. For these patients the preferred management was: MVR if predictors of repair failure identified (47.2%) and downsizing annuloplasty ring only (34.1%).

For atrial fibrillation (AF) in cardiac surgery, 34.1% perform ablation with biatrial lesion and 20% with left sided only. 62.6% perform concomitant Left Atrial Appendage (LAA) Occlusion irrespective of AF ablation with a left atrial clip. A wide variability in anticoagulation strategies for MV repair and bioprosthetic MV valve was reported both for patients in sinus rhythm and AF.

These results demonstrate a variable practice for MV surgery, and a degree of lack of compliance with surgical intervention guidelines and anticoagulation strategy.

Acute type A aortic dissection necessitates rapid and effective arterial cannulation techniques for optimal outcomes. This meta-analysis compares the safety and effectiveness of direct aortic cannulation (AoC) with peripheral cannulation (PC) via the femoral or axillary arteries in aortic surgery for acute type A aortic dissection.

A systematic review following PRISMA guidelines identified 10 retrospective studies encompassing 2518 patients (961 AoC, 1557 PC). Pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated to analyze perioperative characteristics, short-term mortality rates, and postoperative complications including stroke and acute kidney injury.

Short-term mortality did not significantly differ between AoC and PC (OR [95% CI] = 0.78 [0.61-1.01], p = .06). Likewise, postoperative stroke (OR [95% CI] = 0.86 [0.63-1.17], p = .33) nor acute kidney injury (OR [95% CI] = 1.11 [0.89-1.37], p = .35) showed no significant differences. AoC exhibited shorter operation time whereas there were no significant differences in aortic cross clamp time and cardiopulmonary bypass time between both groups. Our meta-regression analysis, considering the distal extent of aortic replacement, indicated that variations in aortic replacement rates did not significantly impact the observed outcomes.

AoC is a viable alternative to PC for acute type A aortic dissection. While both approaches offer comparable outcomes, AoC’s advantage in shorter operation time warrants thoughtful consideration in clinical practice.

Over the past decade, there has been an increase in the use of recombinant Anti-Thrombin III (AT-III) administration during neonatal and pediatric short- and long-term mechanical support for the replacement of acquired deficiencies. Recombinant AT-III (Thrombate) administration is an FDA licensed drug indicated primarily for patients with hereditary deficiency to treat and prevent thromboembolism and secondarily to prevent peri-operative and peri-partum thromboembolism. Herein we propose further use of Thrombate for primary AT-III deficiency of the newborn as well as for acquired dilution and consumption secondary to cardiopulmonary bypass (CPB).

All patients undergoing CPB obtain a preoperative AT-III level. Patients with identified deficiencies are normalized in the OR using recombinant AT-III as a patient load, in the CPB prime, or both. Patient baseline Heparin Dose Response (HDR) is assessed using the Heparin Management System (HMS) before being exposed to AT-III. If a patient load of AT-III is given, a second HDR is obtained and this AT-III Corrected HDR is used as the primary goal during CPB. Once CPB is initiated, an AT-III level is obtained with the first patient blood analysis. A subtherapeutic level results in an additional dose of AT-III. During the rewarm period, a final AT-III level is obtained and AT-III treated once again if subtherapeutic. A retrospective, matched analysis review of practice analyzing two groups, a Study Group (Repeat HDR, May 2022 onward) and Matched Group (Without Repeat HDR, July 2019 to April 2022), for age (D), weight (Kg) and operation was conducted. The focus of the study was to determine any change in heparin sensitivity identified post AT-III patient bolus load in the HDR (U/mL), Slope (U/mL/s), ACT (s), and total amount of heparin on CPB (U) and protamine (mg) used in each group.

No significance was seen in Baseline AT-III (%), post heparin load HDR (U/mL), first CPB ACT (s), first CPB HDR (U/mL), or total CPB heparin (u/Kg) between the two groups. Statistical significance was seen in Baseline ACT (s), Baseline HDR (U/mL), Baseline Slope (U/mL/s), Post Heparin Load ACT (s), first CPB AT-III (%), and Protamine (mg/Kg) (p < .05). No statistical significance was seen in the Study Intragroup between pre versus post AT-III patient load baseline sample in ACT (s), however significance was seen in HDR (U/mL) and Slope (U/mL/s) (p < .05).

Implementation of AT-III monitoring and therapy before and during CPB in conjunction with the HMS allows patients to maintain a steady state of anticoagulation with overall less need for excessive heparin replacement and potentially thrombin activation. The result is obtaining a steady state of anticoagulation, a reduced fluctuation in the heparin and ACT levels and a potential for lower co-morbidities associated with prolonged CPB times.

Postoperative delirium (POD) has a major impact on patient recovery after cardiac surgery. Although its pathophysiology remains unclear, there could be a correlation between cerebral blood flow (CBF) variations during cardio-pulmonary bypass (CPB) and POD. Our study aimed to evaluate whether variations in on-pump CBF, compared to pre-anesthesia and pre-CPB values, are associated with POD following coronary artery bypass grafting (CABG) surgery.

This prospective observational cohort study included 95 adult patients undergoing elective on-pump CABG surgery. Right middle cerebral artery blood flow velocity (MCAV) was assessed using Transcranial Doppler before anesthesia induction, before CPB and every fifteen minutes during CPB. Pre-anesthesia and pre-CPB values were chosen as baselines. Individual values, measured during CPB, were converted as percentage changes relative to these baselines and named as %MCAV₀ and %MCAV₁, respectively. POD was assessed using the Confusion Assessment Method for ICU (CAM-ICU) during the first 48 post-operative hours and with the 3-Minute Diagnostic Interview for Confusion Assessment Method (3D-CAM) on the fifth post-surgical day.

Overall POD incidence was 17.9%. At 30 minutes of CPB, %MCAV₀ was higher in POD group than in no-POD group (p = .05). %MCAV₀ at 45 minutes of CPB was significantly higher in POD group (87 (±17) %) than in no-POD group (68 (±24) %), p = .04. %MCAV₁ at 30 and 45 minutes of CPB were higher in POD group than in no-POD group, at the limit of statistical significance. We found %MCAV₁ > 100% in POD group, but not in no-POD group.

Significant differences in %MCAV₀ became evident after 30 minutes of CPB, whereas differences in %MCAV₁ at 45 minutes of CPB were at limit of statistical significance. In POD group %MCAV₁ was higher than 100% at 30 and 45 minutes of CPB, which is supposed to be a sign of cerebral hyperperfusion. Monitoring CBF during CPB could have prognostic value for POD.

Cardiac surgery is fraught with increased consumption of blood and blood products. Various strategies for blood conservation have been described. Our aim was to study the impact of a structured blood conservation protocol (BCP) on the utilization of blood and patient outcome.

Retrospective analysis of prospectively collected data comparing adult patients undergoing open heart surgery with BCP with those undergoing surgery without BCP. The primary objective was to compare the amount of blood utilized and the hematocrit at discharge. The secondary objective was to compare the parameters of patient outcomes. The level of significance was set at 0.05.

The proportion of patients requiring transfusion (19.1% [9/47] vs 58.9% [33/56]; p < 0.001) and the quantity of blood transfused (12 units vs 45 units; p 0.003) in the BCP group was significantly lower. Interestingly, the hematocrit level at discharge was comparable between the groups (30.9 (4.8) versus 31.8 (2.4), p-0.671). The average cost incurred for transfusing blood in the BCP group was ₹ 370.2 as compared to ₹1165.1 in the other (p < 0.001). BCP reduced the odds of overall blood transfusion by 79.8% (OR 0.202 (0.084-0.485); p < 0.001) and intraoperative blood transfusion by 95.3% (OR 0.047 (0.010-0.213); p < 0.001). The morbidity and mortality were comparable between the groups.

Implementing a structured blood conservation protocol in patients undergoing open heart surgery significantly reduces the need for blood transfusion. It also has a promising impact on patient recovery after surgery and significant positive cost implications.

A radical paradigm shift in the treatment of premature infants failing conventional treatment is to recreate fetal physiology using an extracorporeal Artificial Placenta (AP). The aim of this study is to evaluate the effects of changing fetal hemoglobin percent (HbF%) on physiology and circuit function during AP support in an ovine model.

Extremely premature lambs (n = 5) were delivered by cesarean section at 117-121 d estimated gestational age (EGA) (term = 145d), weighing 2.5 ± 0.35 kg. Lambs were cannulated using 10-14Fr cannulae for drainage via the right jugular vein and reinfusion via the umbilical vein. Lambs were intubated and lungs were filled with perfluorodecalin to a meniscus with a pressure of 5–8 cm H₂O. The first option for transfusion was fetal whole blood from twins followed by maternal red blood cells. Arterial blood gases were used to titrate AP support to maintain fetal blood gas values.

The mean survival time on circuit was 119.6 ± 39.5 h. Hemodynamic parameters and lactate were stable throughout. As more adult blood transfusions were given to maintain hemoglobin at 10 mg/dL, the HbF% declined, reaching 40% by post operative day 7. The HbF% was inversely proportional to flow rates as higher flows were required to maintain adequate oxygen saturation and perfusion.

Transfusion of adult blood led to decreased fetal hemoglobin concentration during AP support. The HbF% was inversely proportional to flow rates. Future directions include strategies to decrease the priming volume and establishing a fetal blood bank to have blood rich in HbF.

The study objective was to investigate whether a Ringer’s acetate based priming solution with addition of Mannitol and sodium concentrate increases the risk of cardiac surgery associated kidney injury (CSA-AKI).

This is a double blind, prospective randomized controlled trial from a single tertiary teaching hospital in Sweden including patients aged ≥65 years (n = 195) admitted for routine cardiac surgery with cardiopulmonary bypass. Patients in the study group received Ringer’s acetate 1000 mL + 400 mL Mannitol (60 g) + sodium chloride 40 mL (160 mmol) and heparin 2 mL (10 000 IU) 966 mOsmol (n = 98), while patients in the control group received Ringer’s acetate 1400 mL + heparin 2 mL (10 000 IU), 388 mOsmol (n = 97) as pump prime. Acute kidney injury was analysed based on the Kidney Disease Improving Outcomes (KDIGO 1-3) definition.

The overall incidence of CSA-AKI (KDIGO stage 1) was 2.6% on day 1 in the ICU and 5.6% on day 3, postoperatively. The serum creatinine level did not show any postoperative intergroup differences, when compared to baseline preoperative values. Six patients in the Ringer and five patients in the Mannitol group developed CSA-AKI (KDIGO 1-3), all with glomerular filtration rates <60 mL/min/1.73 m². These patients showed significantly higher plasma osmolality levels compared to preoperative values. Hyperosmolality together with patient age and the duration of the surgery were independent risk factors for postoperative acute kidney injury (KDIGO 1-3).

The use of a hyperosmolar prime solution did not increase the incidence of postoperative CSA-AKI in this study, while high plasma osmolality alone increased the associated risk by 30%. The data suggests further examination of plasma hyperosmolality as a relative risk factor of CSA-AKI.

The lysine analog tranexamic acid (TXA) is used as a blood protective drug in cardiac surgery, but efficacy and safety outcomes in patients treated with extracorporeal membrane oxygenation (ECMO) after surgery remain poorly understood.

From January 1, 2017 to December 31, 2022, we retrospectively analyzed patients assisted by ECMO after cardiac surgery and divided them into TXA and control groups depending on whether TXA was used or not. The primary study outcome was red blood cell (RBC) transfusion during ECMO.

In total, 321 patients treated with ECMO after cardiac surgery were assessed; 185 patients were eligible for inclusion into to the TXA-intervention group and 136 into to the control group. RBC transfusion during ECMO was 8.0 IU (4.0 IU–14.0 IU) in the TXA group versus 10.0 IU (6.0 IU–16.0 IU) in the control group (p = .034). Median total chest drainage volume after surgery was 1460.0 mL (650.0–2910.0 mL) and 1680.0 mL (900.0–3340.0 mL) in TXA and control groups, respectively (p = .021). Postoperative serum D-dimer levels were significantly lower in the TXA group when compared with the control group; 1.125 µg/mL (0.515–2.176 µg/mL) versus 3.000 µg/mL (1.269–5.862 µg/mL), p < .001. Serious adverse events, including vascular occlusive events, did not differ meaningfully between groups.

In patients treated with ECMO after cardiac surgery, TXA infusion modestly but significantly reduced RBC transfusions and chest tube output when compared with the control group.

Oxygenators, as used in cardiopulmonary bypass (CPB) circuits, are components with good air removal properties. However, under some conditions the semipermeable characteristics of hollow fibers allow air to accidentally enter the blood side of the CPB circuit. This may occur when a fluid in motion is stopped suddenly by which the rapid change in momentum may cause a relative negative pressure drop, the so-called hammer effect. The hammer effect is not yet described in literature related to CPB. The aim of this in vitro study was to reproduce the hammer effect.

The in vitro setup consisted of a CPB circuit with a fully occluded roller pump and one of four test oxygenators. The hammer test was performed by a sudden pump stop. The pressure wave was measured and after the test the residual air present in the oxygenator was forced into the arterial line and measured with a bubble detector.

We showed that a sudden pump stop could lead to the hammer effect, represented as a relative negative pressure drop in the arterial line. This hammer effect resulted in air release through the semipermeable fibers as we showed in two of the four tested brands of oxygenators.

We conclude that the hammer effect may occur before connection of the CPB system to the patient, and this may result in air release into the arterial blood side of the oxygenator. The hammer effect can be caused by clamping of the tubing in combination with a centrifugal pump, or by suddenly stopping the roller pump. With this study we would like to raise awareness of the hammer effect.

This case report aims to describe an aortic root enlargement in combination with the replacement of the ascending aorta in a patient presenting with severe aortic valve stenosis.

A 68-year-old woman with severe aortic stenosis due to a type 0 bicuspid aortic valve and an aortic aneurysm underwent surgery for treatment. The annulus was preoperatively measured with 19 mm. Enlargement was performed by using a tissue patch to create a neo-noncoronary sinus and enlarge the root.

Patients with a small aortic root face an increased risk of patient prosthesis mismatch. Enlarging the aortic root can mitigate this, but it extends cross-clamp and overall operative times. This case shows the need for carefully planned surgical interventions to optimize outcomes in complex anatomies.

Each step of the performed surgery is well-established, however the combination and the creation of a neo-noncoronary sinus is not described so far.

Critical poisoning with sodium nitrite (NaNO₂) can present challenges in promptly identifying and managing acute methemoglobinemia.

We report the case of an overt self-intoxication by an initially unknown agent, leading to cardiac arrest. Despite prodromal signs of cyanosis, coma, desaturation, and hypotension, methemoglobinemia went unrecognized during extracorporeal cardiopulmonary resuscitation (ECPR) as the point-of-care test failed to provide methemoglobin levels, leading to untreated methemoglobinemia. The blood flowing through the oxygenator notably maintained the same brown colour. Return of spontaneous circulation was never achieved, and the patient was declared dead after 60 min of unsuccessful resuscitation. Cause of death by means of NaNO₂ voluntary ingestion was later clarified and confirmed by postmortem finding of elevated nitrite and nitrate concentration.

This case highlights the risk of failure of ECPR in the context of cardiac arrest due to methemoglobinemia, emphasizing the critical need for prompt recognition of the causative agent and early administration of antidotes.