The evolving role of the modern perfusionist: Insights from processed electro-encephalography.

Introduction: Since its origin in the 1920s, electroencephalography (EEG) has become a viable option for anesthesia and perfusion teams to monitor anesthetic delivery, optimizing drug dosage and enhancing patient safety. Patients undergoing cardiopulmonary bypass (CPB) are at particular high risk for excessive or inadequate anesthetic doses. During CPB, traditional physiological indicators such as heart rate and blood pressure can be significantly altered. These abnormalities are compounded by rapid changes in anesthetic concentration from hemodilution, circuit absorption, and altered pharmacokinetics. Method: This narrative highlights the use of processed EEG with spectral analysis for anesthetic management during CPB. Conclusion: We emphasize that neuromonitoring using processed EEG during CPB can assess adequacy of anesthesia delivery and monitor for pathologic conditions that can compromise brain function such as inadequate cerebral blood flow, emboli, and seizures. This information is highly valuable for the clinical team including the perfusionist, who regularly diagnose and manage these pathological conditions.

Intracardiac ultrasound-guided transseptal puncture in horses: Outcome, follow-up, and perioperative anticoagulant treatment.

BACKGROUND: Cardiac catheterizations in horses are mainly performed in the right heart, as access to the left heart traditionally requires an arterial approach. Transseptal puncture (TSP) has been adapted for horses but data on follow-up and closure of the iatrogenic atrial septal defect (iASD) are lacking. HYPOTHESIS/OBJECTIVES: To perform TSP and assess postoperative complications and iASD closure over a minimum of 4 weeks. ANIMALS: Eleven healthy adult horses. METHODS: Transseptal puncture was performed under general anesthesia. Serum cardiac troponin I concentrations were measured before and after puncture. Weekly, iASD closure was monitored using transthoracic and intracardiac echocardiography. Relationship between activated clotting time and anti-factor Xa activity during postoperative enoxaparin treatment was assessed in vitro and in vivo. RESULTS: Transseptal puncture was successfully achieved in all horses within a median duration of 22 (range, 10-104) minutes. Balloon dilatation of the puncture site for sheath advancement was needed in 4 horses. Atrial arrhythmias occurred in 9/11 horses, including atrial premature depolarizations (N = 1), atrial tachycardia (N = 5), and fibrillation (N = 3). Serum cardiac troponin I concentrations increased after TSP, but remained under the reference value in 10/11 horses. Median time to iASD closure was 14 (1-35) days. Activated clotting time correlated with anti-factor Xa activity in vitro but not in vivo. CONCLUSIONS AND CLINICAL IMPORTANCE: Transseptal puncture was successfully performed in all horses. The technique was safe and spontaneous iASD closure occurred in all horses. Clinical application of TSP will allow characterization and treatment of left-sided arrhythmias in horses.

Evaluation of university and training standards in clinical perfusion, an European-wide survey.

OBJECTIVES: Adequate theoretical and practical training of prospective clinical perfusionists is essential for maintaining clinical standards and ensuring patient safety during cardiac surgery procedures. Perfusion schools play a crucial role in establishing and maintaining higher education and training standards in clinical perfusion. The aim of this study is to obtain a comprehensive overview of European training standards in clinical perfusion in 2023. METHODS: For this study, 53 perfusion schools in Europe were found and contacted, of which 30 (56.6%) responded, giving a sample size of n = 30, which were then included in the data analysis. The quantitative data of the survey are analysed using descriptive methods. RESULTS: The university and training standards in clinical perfusion in Europe vary in many respects. Starting with the entry criterion for studies (most frequently a required bachelor's degree 36.7% or 2nd most common an university entrance qualification 30%), the duration [from <12 months (13.3%) up to 36 months (13.3%)] and regarding the content of the teaching in clinical perfusion [<30 European Credit Transfer System (ECTS) (33.3%) and more than 180 ECTS (6.7%)]. The mean value for teaching in clinical perfusion content is 62.63 ECTS credits. CONCLUSIONS: The obtained results show important differences between countries and schools. As such, they form a valuable database for future discussions establishing a common European curriculum and training standards for perfusionists. For the generalizability of the results, further evaluations and larger samples are needed.

Adverse renal effects associated with cardiopulmonary bypass.

Cardiac surgery on cardiopulmonary bypass (CPB) is associated with postoperative renal dysfunction, one of the most common complications of this surgical cohort. Acute kidney injury (AKI) is associated with increased short-term morbidity and mortality and has been the focus of much research. There is increasing recognition of the role of AKI as the key pathophysiological state leading to the disease entities acute and chronic kidney disease (AKD and CKD). In this narrative review, we will consider the epidemiology of renal dysfunction after cardiac surgery on CPB and the clinical manifestations across the spectrum of disease. We will discuss the transition between different states of injury and dysfunction, and, importantly, the relevance to clinicians. The specific facets of kidney injury on extracorporeal circulation will be described and the current evidence evaluated for the use of perfusion-based techniques to reduce the incidence and mitigate the complications of renal dysfunction after cardiac surgery.

The optimized anticoagulation strategy in prolonged hemodialysis.

Background: During extended (nocturnal) hemodialysis (ENHD), the dose of low-molecular-weight heparin (LMWH) can be administered as a single injection or as a divided dose over different time points. Our hypothesis was that a single injection might be sufficient to maintain dialyzer fiber patency. In addition, we investigated whether the biochemical clotting parameter anti-Xa accurately predicts fiber blocking. Methods: Our hypothesis was tested in 20 stable patients on ENHD in a random cross-over setting during two consecutive midweek sessions. The regular total dose of LMWH (i.e. enoxaparin, Clexane® 40-100  mg, Sanofi, Belgium) was either given (i) in a single injection at the dialysis start or (ii) divided over two injections, at the start and halfway the dialysis session. Blood samples were taken from the arterial blood line at different time points to determine plasma anti-Xa activity levels. Post-dialysis, the rinsed and dried hemodialyzers were scanned with a reference micro-computed tomography (µCT) scanning technique, and non-blocked fibers were counted in a central cross-section of the dialyzer outlet potting (ImageJ, NIH, USA). Results: The percentage of open fibers in the dialyzers after a single injection of LMWH [91 (61-96)%] versus divided administration [94 (79-98)%] was not different. Time averaged anti-Xa activity levels were clinically not significantly different between both sessions. Anti-Xa activity levels correlated with the administered anticoagulation doses normalized for body weight, but not with the percentages open fibers in the dialyzers. Conclusion: Our results indicate that there is no need to administer enoxaparin over two injections for ENHD up to 8 h. The usefulness of monitoring anti-Xa levels to predict fiber patency, assessed by µCT, can be questioned, but further clinical trials are needed.

Cardiac surgery-Associated acute kidney injury - A narrative review.

Cardiac Surgery-Associated Acute Kidney Injury (CSA-AKI) is a serious complication seen in approximately 20-30% of cardiac surgery patients. The underlying pathophysiology is complex, often involving both patient- and procedure related risk factors. In contrast to AKI occurring after other types of major surgery, the use of cardiopulmonary bypass comprises both additional advantages and challenges, including non-pulsatile flow, targeted blood flow and pressure as well as the ability to manipulate central venous pressure (congestion). With an increasing focus on the impact of CSA-AKI on both short and long-term mortality, early identification and management of high-risk patients for CSA-AKI has evolved. The present narrative review gives an up-to-date summary on definition, diagnosis, underlying pathophysiology, monitoring and implications of CSA-AKI, including potential preventive interventions. The review will provide the reader with an in-depth understanding of how to identify, support and provide a more personalized and tailored perioperative management to avoid development of CSA-AKI.

Reference interval, longitudinal variability and reliability of activated clotting time in healthy dogs using a point-of-care analyser.

BACKGROUND: Activated clotting times (ACTs) are used to screen for coagulopathies and monitor heparin therapy. OBJECTIVES: To determine a reference interval (RI) for ACT in dogs using a point-of-care analyser, to quantify intra-subject within- and between-day variability, to quantify analyser reliability and inter-analyser agreement and to study the influence of a delay in measurement. METHODS: Forty-two healthy dogs were included. Measurements were performed on fresh venous blood using the i-STAT 1 analyser. The RI was determined using the Robust method. Intra-subject within-day variability and between-day variability were quantified between baseline and 2 h (n = 8) or 48 h (n = 10) later. Analyser reliability and inter-analyser agreement were studied by duplicate measurements (n = 8) on identical analysers. The influence of measurement delay was studied before and after a delay of one analytical run (n = 6). RESULTS: Mean, lower and upper reference limits for ACT were 92.9 ± 9.1, 74.4 and 111.2 s, respectively. Coefficients of variation of intra-subject within- and between-day variability were 8.1% and 10.4%, respectively, resulting in a significant between-day measurement difference. Analyser reliability assessed by the intraclass correlation coefficient and coefficient of variation were 0.87% and 3.3%, respectively. Significantly lower ACT values were observed after a measurement delay compared to direct analysis. CONCLUSIONS: Our study provides an RI for ACT in healthy dogs using the i-STAT 1 and suggests low intra-subject within- and between-day variability. Analyser reliability and inter-analyser agreement were good; however, analysis delay and between-day differences could significantly influence ACT results.

Enzymatic Deglycation of Damaged Skin by Means of Combined Treatment of Fructosamine-3-Kinase and Fructosyl-Amino Acid Oxidase.

The consensus in aging is that inflammation, cellular senescence, free radicals, and epigenetics are contributing factors. Skin glycation through advanced glycation end products (AGEs) has a crucial role in aging. Additionally, it has been suggested that their presence in scars leads to elasticity loss. This manuscript reports fructosamine-3-kinase (FN3K) and fructosyl-amino acid oxidase (FAOD) in counteracting skin glycation by AGEs. Skin specimens were obtained (n = 19) and incubated with glycolaldehyde (GA) for AGE induction. FN3K and FAOD were used as monotherapy or combination therapy. Negative and positive controls were treated with phosphate-buffered saline and aminoguanidine, respectively. Autofluorescence (AF) was used to measure deglycation. An excised hypertrophic scar tissue (HTS) (n = 1) was treated. Changes in chemical bonds and elasticity were evaluated using mid-infrared spectroscopy (MIR) and skin elongation, respectively. Specimens treated with FN3K and FAOD in monotherapy achieved an average decrease of 31% and 33% in AF values, respectively. When treatments were combined, a decrease of 43% was achieved. The positive control decreased by 28%, whilst the negative control showed no difference. Elongation testing of HTS showed a significant elasticity improvement after FN3K treatment. ATR-IR spectra demonstrated differences in chemical bounds pre- versus post-treatment. FN3K and FAOD can achieve deglycation and the effects are most optimal when combined in one treatment.

Neurologic complications after cardiopulmonary bypass - A narrative review.

Neurologic complications, associated with cardiac surgery and cardiopulmonary bypass (CPB) in adults, are common and can be devastating in some cases. This comprehensive review will not only consider the broad categories of stroke and neurocognitive dysfunction, but it also summarises other neurological complications associated with CPB, and it provides an update about risks, prevention and treatment. Where appropriate, we consider the impact of off-pump techniques upon our understanding of the contribution of CPB to adverse outcomes.

2021 MiECTiS focused update on the 2016 position paper for the use of minimal invasive extracorporeal circulation in cardiac surgery.

The landmark 2016 Minimal Invasive Extracorporeal Technologies International Society (MiECTiS) position paper promoted the creation of a common language between cardiac surgeons, anesthesiologists and perfusionists which led to the development of a stable framework that paved the way for the advancement of minimal invasive perfusion and related technologies. The current expert consensus document offers an update in areas for which new evidence has emerged. In the light of published literature, modular minimal invasive extracorporeal circulation (MiECC) has been established as a safe and effective perfusion technique that increases biocompatibility and ultimately ensures perfusion safety in all adult cardiac surgical procedures, including re-operations, aortic arch and emergency surgery. Moreover, it was recognized that incorporation of MiECC strategies advances minimal invasive cardiac surgery (MICS) by combining reduced surgical trauma with minimal physiologic derangements. Minimal Invasive Extracorporeal Technologies International Society considers MiECC as a physiologically-based multidisciplinary strategy for performing cardiac surgery that is associated with significant evidence-based clinical benefit that has accrued over the years. Widespread adoption of this technology is thus strongly advocated to obtain additional healthcare benefit while advancing patient care.

Adult essential extracorporeal membrane oxygenation (ECMO) skills for use in an e-learning program for ICU physicians, nurses and perfusionists: a consensus by a modified Delphi questionnaire.

BACKGROUND: Education in ECMO starts with basic theory and physiology. For this type of training, self-assessment e-learning modules may be beneficial. The aim of this study was to generate consensus on essential ECMO skills involving various professional groups involved in caring for ECMO patients. These skills can be used for educational purposes: development of an e-learning program and fine-tuning of ECMO-simulation programs. METHODS: Experts worldwide received an e-mail inviting them to participate in the modified Delphi questionnaire. A mixture of ECMO experts was contacted. The expert list was formed based on their scientific track record mainly in adult ECMO (research, publications, and invited presentations). This survey consisted of carefully designed questionnaires, organized into three categories, namely knowledge skills, technical skills, and attitudes. Each statement considered a skill and was rated on a 5-point Likert-scale and qualitative comments were made if needed. Based on the summarized information and feedback, the next round Delphi questionnaire was developed. A statement was considered as a key competency when at least 80% of the experts agreed or strongly agreed (rating 4/5 and 5/5) with the statement. Cronbach's Alpha score tested internal consistency. Intraclass correlation coefficient was used as reliability index for interrater consistency and agreement. RESULTS: Consensus was achieved in two rounds. Response rate in the first round was 45.3% (48/106) and 60.4% (29/48) completed the second round. Experts had respectively for the first and second round: a mean age of 43.7 years (8.2) and 43.4 (8.8), a median level of experience of 11.0 years [7.0-15.0] and 12.0 years [8.3-14.8]. Consensus was achieved with 29 experts from Australia (2), Belgium (16), France (1), Germany (1), Italy (1), Russia (2), Spain (1), Sweden, (1), The Netherlands (4). The consensus achieved in the first round was 90.9% for the statements about knowledge, 54.5% about technical skills and 75.0% about attitudes. Consensus increased in the second round: 94.6% about knowledge skills, 90.9% about technical skills and 75.0% about attitudes. CONCLUSION: An expert consensus was accomplished about the content of "adult essential ECMO skills". This consensus was mainly created with participation of physicians, as the response rate for nurses and perfusion decreased in the second round.

Impact of mean perfusion pressure and vasoactive drugs on occurrence and reversal of cardiac surgery-associate acute kidney injury: A cohort study.

PURPOSE: Low cardiac output and kidney congestion are associated with acute kidney injury after cardiac surgery (CSA-AKI). This study investigates hemodynamics on CSA-AKI development and reversal. MATERIALS AND METHODS: Adult patients undergoing cardiac surgery were retrospectively included. Hemodynamic support was quantified using a new time-weighted vaso-inotropic score (VISAUC), and hemodynamic variables expressed by mean perfusion pressure and its components. The primary outcome was AKI stage ≥2 (CSA-AKI ≥2) and secondary outcome full AKI reversal before ICU discharge. RESULTS: 3415 patients were included. CSA-AKI ≥2 occurred in 37.4%. Mean perfusion pressure (MPP) (OR 0.95,95%CI 0.94-0.96, p < 0.001); and central venous pressure (CVP) (OR 1.17, 95%CI 1.13-1.22, p < 0.001) are associated with CSA-AKI ≥2 development, while VISAUC/h was not (p = 0.104). Out of 1085 CSA-AKI ≥2 patients not requiring kidney replacement therapy, 76.3% fully recovered of AKI. Full CSA-AKI reversal was associated with MPP (OR 1.02 per mmHg (95%CI 1.01-1.03, p = 0.003), and MAP (OR = 1.01 per mmHg (95%CI 1.00-1.02), p = 0.047), but not with VISAUC/h (p = 0.461). CONCLUSION: Development and full recovery of CSA-AKI ≥2 are affected by mean perfusion pressure, independent of vaso-inotropic use. CVP had a significant effect on AKI development, while MAP on full AKI reversal.

Comparison of coagulation monitoring using ROTEM and Sonoclot devices in cardiac surgery: a single-center prospective observational study.

BACKGROUND: Viscoelastic tests (VETs) are recommended during cardiac surgery to monitor coagulation status and guide transfusion. We compared the results of two VETs, the Sonoclot Analyzer and the ROTEM Sigma. Agreement between viscoelastic tests' subdiagnoses and overall diagnosis severity was assessed. Correlations with conventional coagulation tests (CCT) and the discriminatory potential of numerical VET outputs for transfusion thresholds was determined. METHODS: Single-center, prospective observational study in a tertiary academic center. In fifty adult patients undergoing elective cardiac surgery, parallel Sonoclot, ROTEM and CCT analysis was performed before heparin, or after protamine or coagulation product administration. All patients completed the study, resulting in 139 data points. RESULTS: Agreement on the severity of coagulation disorders was acceptable (83%), but poor (27%) on the differentiation of the underlying causes. Correlations between ROTEM parameters and CCT were good (postprotamine: FIBTEM A5 (r2=0.90 vs. fibrinogen) and EXTEM-FIBTEM A5 difference (r2=0.81 vs. platelet count). Sonoclot correlated less (Clot Rate (r2=0.25 vs. fibrinogen) and Platelet Function (r2=0.43 vs. platelet count). This was reflected in the discriminatory potential of these parameters as found by linear mixed modelling. We suggest clinically useful grey zones for VET cutoff interpretation. CONCLUSIONS: ROTEM and Sonoclot accord well on the detection of severity of coagulation dysfunction, but not on the diagnosis of the underlying cause. ROTEM correlated more closely with CCT then Sonoclot. We propose a testing strategy that could lead to a cost-effective approach to the bleeding cardiac surgery patient.