[Clinical value of the implication of extracorporeal carbon dioxide removal in patients with acute respiratory distress syndrome].

Extracorporeal carbon dioxide removal (ECCO2R) is a respiratory support technique based on extra-pulmonary gas exchange, which can effectively remove carbon dioxide generated in-vivo, reducing the requirements of respiratory support from mechanical ventilation. With improvements in extracorporeal life support technologies and increasing clinical experience, ECCO2R has potential value in clinical application with acute respiratory distress syndrome (ARDS). This review article discusses the principles of ECCO2R, its relevant indications for ARDS, clinical evidence, existing issues, and future directions, aiming to provide more references for the application in ARDS.

The Influence of High-Dose Parenteral Vitamin C on the Incidence and Severity of Postoperative Pulmonary Complications in Cardiac Surgery with Extracorporeal Circulation: A Randomized Controlled Trial.

Cardiac surgery (CS) with extracorporeal circulation (ECC), induces intense oxidative stress (OS) and systemic inflammatory response (SIR), which may seriously affect postoperative lung function. We aimed to test if high parenteral (200 mg/kg/24 h) daily doses of Vitamin C (VitC), given within 48 h after the beginning of the operation, may reduce the incidence and severity of postoperative pulmonary complications (PPCs) in CS patients. This single-center, prospective, randomized, single-blinded, interventional trial included 150 patients, assigned to control Group A (n = 75) and interventional Group B (n = 75). Group B intraoperatively received one-fourth (i.e., 50 mg/kg) of the planned daily Vit C dose, divided into three equal parts and diluted in 10 mL of normal saline, while Group A received an equal volume of normal saline at the same time frames (i.e., the induction of anesthesia, aortic cross-clamp release, and sternal closure). After 6 h from the first intraoperative dose, the following regimen was applied: Group B: 50 mg/kg, 30 min i.v. infusion of VitC in 50 mL of normal saline, every 6 h, for the next 48 h, and Group A: 30 min i.v. infusion of an equal volume of normal saline every 6 h, for the next 48 h. Modified Kroenke's score was used to determine the incidence and severity of PPCs. The overall incidence of PPCs was 36.7% and was significantly lower in Group B (13.3% vs. 60.0%, p < 0.001). The PPCs severity score was also significantly lower in Group B (1 vs. 3, p < 0.001). In addition, patients from Group B had significantly less damaged lungs, better postoperative renal function, shorter ICU stays, fewer ICU re-admissions, and lower hospital mortality. No VitC-related adverse effects were recorded. High parenteral daily VitC doses given within 48 h after the beginning of CS are safe and effective in reducing the incidence and severity of PPCs. A multicenter RCT is needed to confirm these results.

Outcomes of Extracorporeal Life Support (ECLS) in Acute Severe Asthma: A Narrative Review.

BACKGROUND: In this narrative review we aimed to explore outcomes of extracorporeal life support (extracorporeal membrane oxygenation (ECMO) and extracorporeal carbon dioxide removal (ECCO2R)) as rescue therapy in patients with status asthmaticus requiring mechanical ventilation. METHODS: Multiple databases were searched for studies fulfilling inclusion criteria. Articles reporting mortality and complications of ECMO and ECCO2R in mechanically ventilated patients with acute severe asthma (ASA) were included. Pooled estimates of mortality and complications were obtained by fitting Poisson's normal modeling. RESULTS: Six retrospective studies fulfilled inclusion criteria thus yielding a pooled mortality rate of 17% (13-20%), pooled risk of bleeding of 22% (7-37%), mechanical complications in 26% (21-31%), infection in 8% (0-21%) and pneumothorax rate 4% (2-6%). CONCLUSION: Our review identified a variation between institutions in the initiation of ECMO and ECCO2R in patients with status asthmaticus and discrepancy in the severity of illness at the time of cannulation. Despite that, mortality in these studies was relatively low with some studies reporting no mortality which could be attributed to selection bias. While ECMO and ECCO2R use in severe asthma patients is associated with complication risks, further studies exploring the use of ECMO and ECCO2R with mechanical ventilation are required to identify patients with favorable risk benefit ratio.

Develop of endocavitary suction device for MiECC on minimally invasive mitral valve surgery.

The minimally invasive extracorporeal circulation (MiECC) system was developed to minimize the contact of blood with air and foreign surfaces during conventional cardiopulmonary bypass (CPB). It is also aimed to reduce the inflammatory response by further increasing the biocompatibility of the components that make up the MiECC circuits. The Minithoracotomy (MTH) approach for mitral valve disease remains associated with prolonged operative times, but it is beneficial in terms of reduced postoperative complications (renal failure, atrial fibrillation, blood transfusion, wound infection), length of stay in intensive care unit (ICU) and in hospitalization, with finally a reduction in global cost. Combining the use of the MiECC technique with minimally invasive mitral valve surgery (MIMVS) could open up new research scenarios. Although considerable progress has been made in the standardization of the surgical technique, limitations remain to be filled in the setting of Endo-cavitary aspiration for the association of MiECC with MIMVS. In this paper we introduce invention refers to a device and an air-closed endocavitary aspiration system for cardiac chamber surgery, as well as a method aimed at eliminating gaseous micro-embolic activity, hemolysis and CO2 aspiration and alteration of carbon dioxide production (VCO2) the parameters for goal directed perfusion. The system allows the surgery of the cardiac chambers to be associated with a minimally invasive extra-corporeal circulation circuit.

A Split-Lung Ex Vivo Perfusion Model for Time- and Cost-Effective Evaluation of Therapeutic Interventions to the Human Donor Lung.

With the ongoing shortage of donor lungs, ex vivo lung perfusion (EVLP) offers the opportunity for objective assessment and potential therapeutic repair of marginal organs. There is a need for robust research on EVLP interventions to increase the number of transplantable organs. The use of human lungs, which have been declined for transplant, for these studies is preferable to animal organs and is indeed essential if clinical translation is to be achieved. However, experimental human EVLP is time-consuming and expensive, limiting the rate at which promising interventions can be assessed. A split-lung EVLP model, which allows stable perfusion and ventilation of two single lungs from the same donor, offers advantages scientifically, financially and in time to yield results. Identical parallel circuits allow one to receive an intervention and the other to act as a control, removing inter-donor variation between study groups. Continuous hemodynamic and airway parameters are recorded and blood gas, perfusate, and tissue sampling are facilitated. Pulmonary edema is assessed directly using ultrasound, and indirectly using the lung tissue wet:dry ratio. Evans blue dye leaks into the tissue and can quantify vascular endothelial permeability. The split-lung ex vivo perfusion model offers a cost-effective, reliable platform for testing therapeutic interventions with relatively small sample sizes.

Contralateral Thoracotomy With Extracorporeal Circulation for Reoperative Resection of a Kommerell Diverticulum.

Reoperative vascular ring surgery is uncommon. Standard redo ipsilateral thoracotomy may present technical challenges and risks. We describe a patient with right aortic arch, aberrant left subclavian artery, and a Kommerell diverticulum in whom previous vascular ring division via left thoracotomy did not relieve dysphagia. Three years after the unsuccessful operation, left subclavian-carotid transposition via supraclavicular incision followed by resection of the Kommerell diverticulum via right thoracotomy with extracorporeal circulation relieved symptoms. Contralateral thoracotomy with extracorporeal circulation provides a safe, alternative approach to redo ipsilateral thoracotomy for resection of a symptomatic Kommerell diverticulum. We review the literature on the incidence, surgical indications, and operative approaches to manage symptoms from a Kommerell diverticulum.

Extracorporeal Carbon Dioxide Removal to Avoid Invasive Ventilation During Exacerbations of Chronic Obstructive Pulmonary Disease: VENT-AVOID Trial - A Randomized Clinical Trial.

Rationale: It is unclear whether extracorporeal CO2 removal (ECCO2R) can reduce the rate of intubation or the total time on invasive mechanical ventilation (IMV) in adults experiencing an exacerbation of chronic obstructive pulmonary disease (COPD). Objectives: To determine whether ECCO2R increases the number of ventilator-free days within the first 5 days postrandomization (VFD-5) in exacerbation of COPD in patients who are either failing noninvasive ventilation (NIV) or who are failing to wean from IMV. Methods: This randomized clinical trial was conducted in 41 U.S. institutions (2018-2022) (ClinicalTrials.gov ID: NCT03255057). Subjects were randomized to receive either standard care with venovenous ECCO2R (NIV stratum: n = 26; IMV stratum: n = 32) or standard care alone (NIV stratum: n = 22; IMV stratum: n = 33). Measurements and Main Results: The trial was stopped early because of slow enrollment and enrolled 113 subjects of the planned sample size of 180. There was no significant difference in the median VFD-5 between the arms controlled by strata (P = 0.36). In the NIV stratum, the median VFD-5 for both arms was 5 days (median shift = 0.0; 95% confidence interval [CI]: 0.0-0.0). In the IMV stratum, the median VFD-5 in the standard care and ECCO2R arms were 0.25 and 2 days, respectively; median shift = 0.00 (95% confidence interval: 0.00-1.25). In the NIV stratum, all-cause in-hospital mortality was significantly higher in the ECCO2R arm (22% vs. 0%, P = 0.02) with no difference in the IMV stratum (17% vs. 15%, P = 0.73). Conclusions: In subjects with exacerbation of COPD, the use of ECCO2R compared with standard care did not improve VFD-5. Clinical trial registered with www.clinicaltrials.gov (NCT03255057).

Beating Heart Transplants-Overview and Implications for Anesthesiologists.

As the demand for heart allografts for transplantation continues to rise, ex vivo organ perfusion strategies are playing an increasingly important role in the preservation of organs from donation after circulatory death and extended-criteria donors. One such method uses the Organ Care System (TransMedics, Andover, MA). Traditionally, this technique of preservation requires 2 periods of warm ischemia and subsequent cardioplegic arrest. In a novel surgical technique pioneered at the authors' institution, heart allograft implantation no longer requires a second cardioplegic arrest. This article discusses the surgical approach for this procedure, the advantages and disadvantages of this approach, and analogs to current clinical practice to theorize what impact this may have on cardiac transplantation volumes in the future.

High-molecular-weight linear polymers improve microvascular perfusion after extracorporeal circulation.

High-molecular-weight linear polymers (HMWLPs) have earned the name "drag-reducing polymers" because of their ability to reduce drag in turbulent flows. Recently, these polymers have become popular in bioengineering applications. This study investigated whether the addition of HMWLP in a venoarterial extracorporeal circulation (ECC) model could improve microvascular perfusion and oxygenation. Golden Syrian hamsters were instrumented with a dorsal skinfold window chamber and subjected to ECC using a circuit comprised of a peristaltic pump and a bubble trap. The circuit was primed with lactated Ringer solution (LR) containing either 5 ppm of polyethylene glycol (PEG) with a low molecular weight of 500 kDa (PEG500k) or 5 ppm of PEG with a high molecular weight of 3,500 kDa (PEG3500k). After 90 min of ECC at 15% of the animal's cardiac output, the results showed that the addition of PEG3500k to LR improved microvascular blood flow in arterioles and venules acutely (2 h after ECC), whereas functional capillary density showed improvement up to 24 h after ECC. Similarly, PEG3500k improved venular hemoglobin O2 saturation on the following day after ECC. The serum and various excised organs all displayed reduced inflammation with the addition of PEG3500k, and several of these organs also had a reduction in markers of damage with the HMWLPs compared to LR alone. These promising results suggest that the addition of small amounts of PEG3500k can help mitigate the loss of microcirculatory function and reduce the inflammatory response from ECC procedures.NEW & NOTEWORTHY High-molecular-weight linear polymers have gained traction in bioengineering applications. The addition of PEG3500k to lactated Ringer solution (LR) improved microvascular blood flow in arterioles and venules acutely after extracorporeal circulation (ECC) in a hamster model and improved functional capillary density up to 24 h after ECC. PEG3500k improved venular hemoglobin O2 saturation and oxygen delivery acutely after ECC and reduced inflammation in various organs compared to LR alone.

Treatment of Staphylococcus aureus infection with sphingosine in ex vivo perfused and ventilated lungs.

BACKGROUND: Ex vivo lung perfusion (EVLP) has expanded the donor pool for lung transplantation. Pulmonary Staphylococcus aureus infection, especially that caused by multidrug-resistant strains, is a severe threat to posttransplantation outcomes. Sphingosine is a lipid compound that exhibits broad-spectrum antibacterial activity. Therefore, we aimed to evaluate the effects of S aureus infection on EVLP and whether sphingosine administration during EVLP prevents infection with S aureus. METHODS: Eighteen pigs were randomly assigned to 3 groups: uninfected, infected with S aureus with NaCl treatment, or infected with sphingosine treatment. Bacterial numbers were determined before and after treatment. Sphingosine concentrations in the lung tissues were determined using biochemical assays. Lung histology, lung physiological parameters, perfusate content, lung weight, and cell death were measured to analyze the effects of infection and sphingosine administration on EVLP. RESULTS: Sphingosine administration significantly reduced the bacterial load. The concentration of sphingosine in the bronchial epithelium was elevated after sphingosine administration. S aureus infection increased pulmonary artery pressure and pulmonary vascular resistance. Lung edema, histology scores, lactate and lactate dehydrogenase levels in the perfusate, ΔPO2 in the perfusate, static lung compliance, and lung peak airway pressure did not differ among the groups. CONCLUSIONS: Infection of S aureus did not affect the lung function during EVLP but induced higher pulmonary artery pressure and pulmonary vascular resistance. Administration of sphingosine effectively eliminated S aureus without side effects in isolated, perfused, and ventilated pig lungs.

Use of Subclavian Extracorporeal Carbon Dioxide Removal for COVID-19 Acute Respiratory Distress Syndrome as a Bridge to Lung Transplantation.

Severe acute hypercapnia is independently associated with increased adverse effects and intensive care unit mortality in mechanically ventilated patients. During the severe acute respiratory syndrome coronavirus 2 (COVID-19) pandemic, some patients were placed on extracorporeal carbon dioxide removal support when extracorporeal membrane oxygenation (ECMO) support was at capacity or not offered. We present a patient with severe acute respiratory distress syndrome caused by COVID-19 pneumonia, who was supported with Hemolung Respiratory Assist System (ALung Technologies, Inc., LivaNova, Pittsburgh, PA) via the right subclavian vein as a bridge to lung transplantation after venovenous ECMO support. The patient survived and was discharged home.

Genetic Modulation: Future Trends Toward Graft Optimization During Machine Perfusion.

Dynamic preservation methods such as normothermic, subnormothermic, and hypothermic machine perfusion circuits have emerged as viable alternatives to conventional static cold storage. These organ perfusion technologies serve as preservation methods and enable organ assessment, reconditioning, and repair before transplantation. Gene therapy is a novel strategy with the potential to transform the field of graft optimization and treatment. Thereby specific pathways involved in the transplantation process can be targeted and modified. This review aims to provide an overview of gene delivery methods during ex vivo machine perfusion of kidney and liver grafts. Recent literature on state-of-the-art gene therapy approaches during ex situ organ preservation, especially with respect to ischemia-reperfusion injury, as well as acute and chronic graft rejection have been analyzed. Additionally, potential challenges that could affect further refinement of this therapeutic modality are outlined.

Limited cumulative experience with ex vivo lung perfusion is associated with inferior outcomes after lung transplantation.

OBJECTIVE: Ex vivo lung perfusion (EVLP) allows for prolonged preservation and evaluation/resuscitation of donor lungs. We evaluated the influence of center experience with EVLP on lung transplant outcomes. METHODS: We identified 9708 isolated, first-time adult lung transplants from the United Network for Organ Sharing database (March 1, 2018-March 1, 2022), 553 (5.7%) involved using donor lungs after EVLP. Using the total volume of EVLP lung transplants per center during the study period, centers were dichotomized into low- (1-15 cases) and high-volume (>15 cases) EVLP centers. RESULTS: Forty-one centers performed EVLP lung transplants, including 26 low-volume and 15 high-volume centers (median volume, 3 vs 23 cases; P < .001). Recipients at low-volume centers (n = 109) had similar baseline comorbidities compared with high-volume centers (n = 444). Low-volume centers used numerically more donation after circulatory death donors (37.6 vs 28.4%; P = .06) and more donors with Pao2/Fio2 ratio <300 (24.8 vs 9.7%; P < .001). After EVLP lung transplants, low-volume centers had worse 1-year survival (77.8% vs 87.5%; P = .007), with an adjusted hazard ratio of 1.63 (95% CI, 1.06-2.50, adjusting for recipient age, sex, diagnosis, lung allocation score, donation after circulatory death donor, donor Pao2/Fio2 ratio, and total annual lung transplant volume per center). When compared to non-EVLP lung transplants, 1-year survival of EVLP lung transplants was significantly worse at low-volume centers (adjusted hazard ratio, 2.09; 95% CI, 1.47-2.97) but similar at high-volume centers (adjusted hazard ratio, 1.14; 95% CI, 0.82-1.58). CONCLUSIONS: The use of EVLP in lung transplantation remains limited. Increasing cumulative EVLP experience is associated with improved outcomes of lung transplantation using EVLP-perfused allografts.

Hemoglobin levels and clinical outcomes after extracorporeal circulation auxiliary to open heart surgery: a retrospective cohort study.

BACKGROUND: Extracorporeal circulation auxiliary to open heart surgery is a common procedure used to treat heart diseases. However, the optimal transfusion strategy for patients undergoing this surgery remains a subject of debate. This study aims to investigate the association between hemoglobin levels and clinical outcomes in patients undergoing extracorporeal circulation auxiliary to open heart surgery, with the ultimate goal of improving surgical success rates and enhancing patients' quality of life. METHODS: A retrospective analysis was conducted on data from the Medical Information Mart for Intensive Care IV 2.2 (MIMIC-IV 2.2) database, including 4144 patients. The patients were categorized into five groups based on their minimum hemoglobin levels during hospitalization. Baseline characteristics, clinical scores, laboratory results, and clinical outcome data were collected. Statistical analyses utilized descriptive statistics, ANOVA or Kruskal-Wallis tests, Kaplan-Meier method, and Log-rank test. RESULTS: The results revealed a significant correlation between hemoglobin levels and in-hospital mortality, as well as mortality rates at 30 days, 60 days, and 180 days (p < 0.001). Patients with lower hemoglobin levels exhibited higher mortality rates. However, once hemoglobin levels exceeded 7g/dL, no significant difference in mortality rates was observed (p = 0.557). Additionally, lower hemoglobin levels were associated with prolonged hospital stay, ICU admission time, and mechanical ventilation time (p < 0.001). Furthermore, hemoglobin levels were significantly correlated with complication risk, norepinephrine dosage, and red blood cell transfusion volume (p < 0.001). However, there was no significant difference among the groups in terms of major complications, specifically sepsis (p > 0.05). CONCLUSION: The study highlights the importance of managing hemoglobin levels in patients undergoing heart surgery with extracorporeal circulation. Hemoglobin levels can serve as valuable indicators for predicting clinical outcomes and guiding treatment decisions. Physicians should carefully consider hemoglobin levels to optimize transfusion strategies and improve postoperative patient outcomes. Further research and intervention studies are warranted to validate and implement these findings in clinical practice.