Perfusion

In the field of extracorporeal life support (ECLS), the rapid influx of novel technologies and innovative techniques presents an ongoing challenge for professionals to stay informed about these advancements. To address this issue and ensure the ECLS community remains up-to-date, we have compiled a concise overview of recent technological innovations in ECLS.

This overview focuses primarily on academically investigated and reported advancements in the ECLS domain. It underscores the importance of transparent communication regarding technological limitations in healthcare and advocates for collaboration between medical professionals and engineers to elevate patient care.

This manuscript presents a compilation of recent technological advancements in ECLS, with an emphasis on innovations that have been academically explored and documented. The research approach involves gathering information from scholarly sources, reports, and studies to provide a comprehensive overview.

The study sample comprises a diverse range of recent technological innovations in the field of extracorporeal life support (ECLS). These innovations span various aspects of ECLS technology and have been investigated and reported on within the academic literature.

Data collection involved systematically reviewing academic literature, reports, and studies related to recent technological advancements in ECLS. The collected information was then analyzed to identify common trends, notable developments, and the impact of these innovations on patient care.

The compilation highlights several significant technological innovations within the ECLS domain. Notable advancements include the development of new dual lumen cannulae, innovative devices for left ventricular (LV) unloading, lightweight ECMO transport systems, streamlined driving consoles to facilitate patient mobility, intricate systems for extracorporeal cardiopulmonary resuscitation (ECPR), standardized driving consoles for networking, and non-invasive circuit pressure monitoring. Some of these innovations have obtained regulatory approvals for distribution in the United States and/or authorization for the European market.

The manuscript underscores the critical role of collaboration between clinicians, researchers, and industry in driving recent technological innovations within the ECLS field. It emphasizes the necessity of open communication about technological limitations and the potential for repurposing established technologies in novel ways. However, the resourcefulness of physicians in repurposing devices requires validation through comprehensive scientific and technical investigation. Thus, fostering broader collaboration among stakeholders is recommended to ensure the rigorous evaluation and validation of new applications for established ECLS devices.

Mitochondrial permeability transition pore (mPTP) opening plays a crucial role in cell death during ischemia-reperfusion injury (IRI). Cyclosporine A (CsA) inhibits mPTP opening. This study aimed to investigate the effects of CsA treatment during cardioplegia on the mitochondrial function and cardiac IRI.

Landrace pigs (52.9 ± 3.7 kg) were subjected to midline sternotomy, cardiopulmonary bypass at 34°C and 90 minutes of cardiac arrest. They received either a single shot of standard 4°C cold histidine-tryptophan-α-ketoglutarate (HTK)-Bretschneider solution (n = 11) or HTK-Bretschneider plus 1.2 mg/L CsA (histidine-tryptophan-α-ketoglutarate plus cyclosporine A (HTK/CsA); n = 11). During reperfusion global left-ventricular function was assessed and myocardial biopsies were harvested at baseline, during ischemia and 45 minutes following reperfusion. High-resolution respirometry and hydrogen peroxide production were measured. Immunohistochemical stainings for apoptosis-inducing factor and hypoxia-inducible factor-1α as well as a flow cytometry-based JC-1 mitochondrial membrane potential assay were performed.

Hemodynamic parameters were comparable between both groups. The cytochrome C release (HTK: 930.3 ± 804.4 pg/mg, HTK/CsA: 699.7 ± 394.0 pg/mg, p = 0.457) as well as PGC1α content (HTK: 66.7%, HTK/CsA: 33.3%, p = 0.284) was lower in the HTK/CsA group. Respiratory measurements revealed that the oxygen flux under basal respiration was higher in the HTK/CsA group (8.2 ± 1.3 pmol·O₂·s⁻¹·mg⁻¹·ww) than in the HTK group (3.8 ± 1.4 pmol·O₂·s⁻¹·mg⁻¹·ww, p = 0.045). There were no significant differences regarding histological surrogates of apoptosis and necrosis.

Supplementing cardioplegic solutions with CsA enhances the basal mitochondrial respiration thereby exerting a cardioprotective effect and diminishing IRI-induced damage. CsA seems to preserve mitochondrial function via non-ROS related pathways.

Mortality rates in patients with acute myocardial infarction and cardiogenic shock (AMI-CS) remain persistently high despite advances over the past decade in percutaneous mechanical circulatory support. This systematic review aims to analyse the existing literature to compare mortality outcomes in patients mechanically supported by intra-aortic balloon pump or percutaneous Impella 2.5/CP^© for AMI-CS undergoing emergency revascularisation.

The following MeSH terms were applied to the databases Ovid Medline, Ovid Embase, Cochrane and Web of Science: ‘Intra-aortic balloon pump’, ‘Impella’, ‘Cardiogenic shock’, ‘Myocardial Infarction’ and ‘Mortality’. This yielded 2643 studies. Using predefined inclusion and exclusion criteria, the studies were initially screened by title and abstract before full text analysis.

Fourteen studies met eligibility criteria: two randomised controlled trials (RCTs) and 12 observational studies. Data from a total of 21,006 patients were included across the studies. Notably, one study claimed reduced mortality with IABP versus control, and one study concluded that Impella^© improved survival rates over the IABP. The average 30-day all-cause mortality in patients supported by IABP was 38.1%, 54.3% in Impella^© groups and 39.4% in control groups.

AMI-CS presents an important cohort of patients in whom conducting RCTs is difficult. As a result, the literature is limited. Analysis of the available literature suggests that there is insufficient evidence to support superior survival in those supported by IABP or Impella^© when compared to control despite suggestions that the Impella^© offers superior haemodynamic support. Limitations of the studies have been discussed to outline suggestions for future research.

Peripheral veno-arterial extracorporeal membrane oxygenation (VA ECMO) creates a retrograde flow along the aorta competing with the left ventricle (LV) in the so-called ‘mixing zone’ (MZ). Detecting it is essential to understand which of the LV or the ECMO flow perfuses the upper body – particularly the brain and the coronary arteries – in case of differential hypoxemia (DH).

We described a mock circulation loop (MCL) that enabled experimental research on DH. We recreated the three clinical situations relevant to clinicians: where the brain is either totally perfused by the ECMO or the LV or both. In a second step, we used this model to investigate two scenarios to diagnose DH: (i) pulse pressure and (ii) thermodilution via injection of cold saline in the ECMO circuit.

The presented MCL was able to reproduce the three relevant mixing zones within the aortic arch, thus allowing to study DH. Pulse pressure was unable to detect location of the MZ. However, the thermodilution method was able to detect whether the brain was totally perfused by the ECMO or not.

We validated an in-vitro differential hypoxemia model of cardiogenic shock supported by VA ECMO. This MCL could be used as an alternative to animal studies for research scenarios.

Clot formation, infection, and biofouling are unfortunate but frequent complications associated with the use of blood-contacting medical devices. The challenge of blood-foreign surface interactions is exacerbated during medical device applications involving substantial blood contact area and extended duration of use, such as extracorporeal life support (ECLS). We investigated a novel surface modification, a liquid-impregnated surface (LIS), designed to minimize protein adsorption and thrombus development on medical plastics.

The hemocompatibility and efficacy of LIS was investigated first in a low-shear model with LIS applied to the lumen of blood incubation vials and exposed to human whole blood. Additionally, LIS was evaluated in a 6 h ex vivo circulation model with swine blood using full-scale ECLS circuit tubing and centrifugal pumps with clinically relevant flow rate (1.5 L/min) and shear conditions for extracorporeal carbon dioxide removal.

Under low-shear, LIS preserved fibrinogen concentration in blood relative to control polymers (+40 ± 6 mg/dL vs polyvinyl chloride, p < .0001), suggesting protein adsorption was minimized. A fibrinogen adhesion assay demonstrated a dramatic reduction in protein adsorption under low shear (87% decrease vs polyvinyl chloride, p = .01). Thrombus deposition and platelet adhesion visualized by scanning electron microscopy were drastically reduced. During the 6 h ex vivo circulation, platelets in blood exposed to LIS tubing did not become significantly activated or procoagulant, as occurred with control tubing; and again, thrombus deposition was visually reduced.

A LIS coating demonstrated potential to reduce thrombus formation on medical devices. Further testing is needed specialized to clinical setting and duration of use for specific medical target applications.

To evaluate a restrictive transfusion policy of red blood cells (RBC) and platelets in pediatric patients submitted to extracorporeal membrane oxygenation (ECMO).

Retrospective descriptive study of pediatric patients supported with ECMO, from January 2010 to December 2019. Hemoglobin, platelet, lactate and mixed venous oxygen saturation (SvO2) values of each patient while on ECMO, were collected. Transfusion efficiency and tissue oxygenation were statistically evaluated comparing pre-transfusion hemoglobin, lactate and SvO2 with post-transfusion values. Ranges of hemoglobin and platelets were established, and the number of transfusions registered. The bleeding complications and outcome were documented.

Of a total of 1016 hemoglobin values, the mean value before transfusion was 8.6 g/dl. Hemoglobin and SvO2 increased significantly post-transfusion. Red blood cell transfusion varied with hemoglobin values: when hemoglobin value was less than 7 g/dl, 89% (41/46) were transfused but just 23% (181/794) when greater or equal to 7 g/dl. In the presence of active bleeding, the frequency of RBC transfusion increased from 32% to 62%, with hemoglobin between 7 g/dl and 8 g/dl.

The mean value for platelet transfusion was 32 x 10⁹/L. Thirty-eight (43%) platelet values between 20 x 10⁹/L and 30x10⁹/L, and 31 (40%) between 30 x 10⁹/L and 40 x 10⁹/L led to platelet transfusion; between 40 x 10⁹/L and 50 x 10⁹/L, only 7 (9%) prompted platelet transfusion.

Comparing the 2010–2015 to 2016–2019 periods there was a decrease in RBC and platelet transfusion threshold with similar survival (p = .528). Survival to discharge was 68%.

Using a restrictive RBC and platelet transfusion policy was safe and allowed a good outcome in this case series. The presence of active bleeding was an important decision factor when hemoglobin was above 7 g/dl and platelets were above 30 x 10⁹/L.

After cardiac surgery, patients on venoarterial extracorporeal membrane oxygenation (VA-ECMO) have a higher risk of nosocomial infection in the intensive care unit (ICU). We aimed to establish an intuitive nomogram to predict the probability of nosocomial infection in patients on VA-ECMO after cardiac surgery.

We included patients on VA-ECMO after cardiac surgery between January 2011 and December 2020 at a single center. We developed a nomogram based on independent predictors identified using univariate and multivariate logistic regression analyses. We selected the optimal model and assessed its performance through internal validation and decision-curve analyses.

Overall, 503 patients were included; 363 and 140 patients were randomly divided into development and validation sets, respectively. Independent predictors derived from the development set to predict nosocomial infection included older age, white blood cell (WBC) count abnormality, ECMO environment in the ICU, and mechanical ventilation (MV) duration, which were entered into the model to create the nomogram. The model showed good discrimination, with areas under the curve (95% confidence interval) of 0.743 (0.692–0.794) in the development set and 0.732 (0.643–0.820) in the validation set. The optimal cutoff probability of the model was 0.457 in the development set (sensitivity, 0.683; specificity, 0.719). The model showed qualified calibration in both the development and validation sets (Hosmer–Lemeshow test, p > .05). The threshold probabilities ranged from 0.20 to 0.70.

For adult patients receiving VA-ECMO treatment after cardiac surgery, a nomogram-monitoring tool could be used in clinical practice to identify patients with high-risk nosocomial infections and provide an early warning.

Lactate levels have been recognized as a reliable tool for monitoring critically ill patients requiring venoarterial extracorporeal membrane oxygenation (VA ECMO) or venovenous extracorporeal membrane oxygenation (VV ECMO) but the reasons behind the overproduction of lactate are different and the influance for survival remains controversial. We analyzed the lactate values and lactate clearance in adult patients in these two forms of extracorporeal support.

Patient demographics, ECMO duration, 30-day mortality, lactate values and lactate clearance at 24, 48 and 72 h from ECMO initiation of patients supported with VV and VA ECMO at Silesian Centre for Heart Deasese, between January 2011 and April 2020 were retrospectively analyzed. The changes in lactate levels were analyzed using the non-parametric U Mann-Whitney tests and Chi-square test. The ROC curves were draw and the area under the curve was calculated.

The study comprised 91 adult patients, Mortality in the first 30 days from initiation of VV and VA ECMO was 39% and 66%, respectively. Lactate levels were significantly higher in non-survivors that received VV and VA ECMO (p < .001), while lactate clearance was similar (p = .256 and p = 1.000, respectively). Survival curves for patients with elevated (>2.0 mmol/L) vs normal (≤2.0 mmol/L) lactate levels at 72 h were significantly different for VV ECMO (p = .007) and VA ECMO (p = .037) but in both groups of ECMO, lactate levels above 2.0 mmol/L at 72 h from ECMO initiation predicted 30 day-mortality.

This results emphasized the importance of lactate levels below 2.0 mmol/L at 72 h from both VV and VA ECMO initiation.

Patients with kidney failure are at risk for lethal complications from hyperkalemia. Resuscitation, medications, and hemodialysis are used to mitigate increased potassium (K⁺) levels in circulating blood; however, these approaches may not always be readily available or effective, especially in a resource limited environment. We tested a sorbent cartridge (KC, K⁺ontrol CytoSorbents Medical Inc., Monmouth Junction, New Jersey) which contains a resin adsorber for K⁺. The objective of this study was to test the utility of KC in an ex vivo circulation system. We hypothesized that KC reduces K⁺ levels in extracorporeal circulation of donor swine whole blood infused with KCl.

A six-hour circulation study was carried out using KC, a NxStage (NxStage Medical, Inc., Lawrence, MA) membrane, blood bag containing heparinized whole blood with KCl infusion, 3/16-inch ID tubing, a peristaltic pump, and flow sensors. The NxStage permeate line was connected back to the main circuit in the Control group (n = 6), creating a recirculation loop. For KC group (n = 6), KC was added to the recirculation loop, and a continuous infusion of KCl at 10 mEq/hour was administered for two hours. Blood samples were acquired at baseline and every hour for 6 h.

In the control group, K⁺ levels remained at ∼9 mmol/L; 9.1 ± 0.4 mmol/L at 6 h. In the KC group, significant decreases in K⁺ at hour 1 (4.3 ± 0.3 mmol/L) and were sustained for the experiment duration equilibrating at 4.6 ± 0.4 mmol/L after 6 h (p = 0.042). Main loop blood flow was maintained under 400 mL/min; recirculation loop flow varied between 60 and 70 mL/min in the control group and 45–55 mL/min in the KC group. Decreases in recirculation loop flow in KC group required 7% increase of pump RPM.

During ex-vivo extracorporeal circulation using donor swine blood, KC removed approximately 50% of K⁺, normalizing circulating levels.

Although venovenous extracorporeal membrane oxygenation (VV ECMO) is a reasonable salvage treatment for acute respiratory distress syndrome (ARDS), it requires sedating the patient. Sevoflurane and propofol have pulmonary protective and immunomodulatory properties. This study aimed to compare the effectiveness of sevoflurane and propofol on rats with induced ARDS undergoing VV ECMO.

Fifteen sprague-dawley (SD) rats were randomly divided into three groups: Con group, sevoflurane (Sevo) group and propofol (Pro) group. Arterial blood gas tests were performed at time pointsT0 (baseline), T1 (the time to ARDS), and T2 (weaning from ECMO). Oxygenation index (PaO₂/FiO₂) was calculated, and lung edema assessed by determining the lung wet:dry ratio. The protein concentration in bronchial alveolar lavage fluid (BALF) was determined by using bicinchoninic acid assay. Haematoxylin and eosin staining was used to evaluate the lung pathological scores in each group. IL-1β and TNF-α were also measured in the BALF, serum and lung.

Oxygenation index showed improvement in the Sevo group versus Pro group. The wet:dry ratio was reduced in the Sevo group compared with propofol-treated rats. Lung pathological scores were substantially lower in the Sevo group versus the Pro group. Protein concentrations in the BALF and levels of IL-1β and TNF-α in the Sevo group were substantially lower versus Pro group.

This study demonstrates that compared with propofol, sevoflurane was more efficacious in improving oxygenation and decreasing inflammatory response in rat models with ARDS subject to VV ECMO treatment.

We aimed to identify risk factors associated with ICU mortality in critically ill patients with COVID-19 pneumonia treated with Extracorporeal membrane oxygenation (ECMO). We also aimed to assess protocol violations of the local eligibility criteria of ECMO initiation.

All 31 consecutive adult patients with confirmed COVID-19 pneumonia admitted to ICU and treated with ECMO from March 13th 2020 to 8 December 2021 were enrolled. Eligibility criteria for ECMO initiation were: P/F-ratio<50 mmHg >3 hours, P/F-ratio<80 mmHg >6 hours or pH<7.25 + PaCO2>60 mmHg >6 hours, despite maximal protective invasive ventilation. Primary outcome was ICU mortality. Univariate logistic regression analyses were performed to identify predictors of ICU mortality.

12 out of 31 patients (38.7%) did not survive ECMO treatment in ICU. Half of the non-survivors suffered from acute kidney failure compared to 3 out of 19 survivors (15.79%) (p = .04). Half of the non-survivors required CRRT treatment versus 1 patient in the survivor group (5.3%) (p < .01). Higher age (2.45 (0.97–6.18), p = .05), the development of AKI (5.33 (1.00–28.43), p = .05), need of CRRT during ICU stay (18.00 (1.79–181.31), p = .01) and major bleeding during ECMO therapy (0.51 (0.19–0.89), p < .01) were identified to be predictors of ICU mortality.

Almost 60% of patients could be treated successfully with ECMO with sustained results at 3 months. Predictors for ICU mortality were development of AKI and need of CRRT during ICU stay, higher age category and major bleeding. Inadvertent ECMO allocation was noted in almost one in five patients.

Extracorporeal membrane oxygenation (ECMO) continues to play an essential role in organ support in cardiogenic shock or acute respiratory distress syndrome and bridging to transplantation. The main purpose of the present survey was to define which clinical and organizational practices are adopted for the administration of physiotherapy in adult patients undergoing ECMO support worldwide.

This international survey was conceived in November 2021. The survey launch was announced at the 10th EuroELSO (European ELSO chapter) Congress, London, May 2022.

The survey returned 32 questionnaires from 29 centers across 14 countries. 17 centers (53.1%) had more than 30 intensive care unit beds available and most (46.8%) were able to care for five to 10 patients on extracorporeal life support simultaneously. The predominant physiotherapist-to-patient ratio was 1:>5 (37.5%); physiotherapy was available 5/7 days and 7/7 days by 31.2% and 25% respectively. Respiratory physiotherapy was not defined by a specific protocol in most centers (46.8%) while 31.2% declared that the treatment commences less than 12 h after sedation is stopped/reduced. Mostly, early physiotherapy in non-cooperative ventilated patients was provided within the first 48 h (68.6%) and consisted of as passive range of motion, in-bed positioning, and splinting. Postural passages and sitting were provided to patients and walking was included in those advanced motor activities which are part of the treatment.

Physiotherapy in patients on ECLS is feasible, however substantial variability exists between centers with a trend of delivering not protocolized and understaffed rehabilitation practices.

To explore the life experiences of patients who have been discharged after undergoing extracorporeal membrane oxygenation (ECMO) support.

A qualitative descriptive approach was used.

Patients who have undergone ECMO support and have been discharged were recruited. Thirteen participants were involved in this study. The data were collected through a semi-structured interview and analyzed using the Colaizzi method.

Four major themes in life experiences were reported by the participants: changes in physical function, changes in psychological state, active adaptation to daily life, and substantial rehabilitation needs.

Different, continuous, and convenient post-discharge physical and mental interventions, social support, spiritual support, and rehabilitation services should be provided according to the patient’s circumstances. We also call on the government to increase the patient reimbursement rate for ECMO treatment. These measures may help to improve the quality of life of patients.

cardiac surgery associated acute kidney injury (CSA-AKI) has a number of preoperative and intraoperative risk factors. Cardiopulmonary bypass (CPB) factors have not yet been elucidated in a single multivariate model. The aim of this study is to develop a dynamic predictive model for CSA-AKI.

retrospective study on 910 consecutive adult cardiac surgery patients. Baseline data were used to settle a preoperative CSA-AKI risk model (static risk model, SRM); CPB related data were assessed for association with CSA-AKI. CPB duration, nadir oxygen delivery, time of exposure to a low oxygen delivery, nadir mean arterial pressure, peak lactates and red blood cell transfusion were included in a multivariate dynamic perfusion risk (DPR). SRM and DPR were merged into a final logistic regression model (multifactorial dynamic perfusion index, MDPI). The three risk models were assessed for discrimination and calibration.

the SRM model had an AUC of 0.696 (95% CI 0.663–0.727), the DPR model of 0.723 (95% CI 0.691–0.753), and the MDPI model an AUC of 0.769 (95% CI 0.739–0.798). The difference in AUC between SRM and DPR was not significant (p = 0.495) whereas the AUC of MDPI was significantly larger than that of SRM (p = 0.004) and DPR (p = 0.015).

inclusion of dynamic indices of the quality of CPB improves the discrimination and calibration of the preoperative risk scores. The MDPI has better predictive ability than the existing static risk models and is a promising tool to integrate different factors into an advanced concept of goal-directed perfusion.