Venovenous Extracorporeal Oxygenation Research Articles

Anticoagulation Can Be Held in Traumatically Injured Patients on Veno-Venous Extracorporeal Membrane Oxygenation Support.

Traumatic injury is associated with several pulmonary complications, including pulmonary contusion, transfusion-related acute lung injury (TRALI), and the development of acute respiratory distress syndrome (ARDS). There is a lack of literature on these patients supported with veno-venous extracorporeal oxygenation (VV ECMO). Understanding the safety of using VV ECMO to support trauma patients and the ability to hold anticoagulation is important to broaden utilization. This is a single-center retrospective cohort study of adult trauma patients cannulated for VV ECMO during their initial admission over an 8 year period (2014-2021). We hypothesize that anticoagulation can be held in trauma patients on VV ECMO without increasing mortality or prothrombotic complications. We also describe the coagulopathy of traumatically injured patients on VV ECMO. Withholding anticoagulation was not associated with mortality in our study population, and there were no significant differences in bleeding or clotting complications between patients who did and did not receive systemic anticoagulation. Patients in the nonsurvivor group had increased coagulopathy both pre- and post-cannulation. Our study suggests anticoagulation can be safely withheld in traumatically injured VV ECMO patients without increasing mortality, complication rates, or transfusion requirements. Future, multicenter prospective studies with larger sample sizes are required to confirm our results.

Coronavirus 2019 (COVID-19) venovenous extracorporeal oxygenation: Single community hospital results and insights.

BackgroundThe role of extracorporeal membrane oxygenation (ECMO) for patients with refractory respiratory failure due to coronavirus 2019 (COVID‐19) is still unclear even now over a year into the pandemic. ECMO is becoming more commonplace even at smaller community hospitals. While the advantages of venovenous (VV) ECMO in acute respiratory distress syndrome (ARDS) from COVID‐19 have not been fully determined, we believe the benefits outweighed the risks in our patient population. Here we describe all patients who underwent VV ECMO at our center.MethodsAll patients placed on ECMO at our center since the beginning of the pandemic, May 5, 2020, until February 20, 2021 were included in our study. All patients placed on ECMO during the time period described above were followed until discharge or death. The primary endpoint was in‐hospital death. Secondary outcomes included discharge disposition, that is, whether patients were sent to a long‐term acute care center (LTAC), inpatient rehabilitation, or went directly home.ResultsA total of 41 patients were placed on VV ECMO for refractory acute respiratory failure. Survival to discharge, the primary end point, was 63.4% (26/41). Inpatient mortality was 36.6% (15/41).ConclusionsWe show here that a successful high‐volume VV ECMO program for ARDS is achievable at even a medium‐size community hospital. We think our success can be replicated by most small‐ and medium‐size community hospitals with cardiothoracic surgery programs and intensivist teams.

Veno-venous extracorporeal membrane oxygenation in the management of refractory bilateral bronchial dehiscence after lung transplant: a case report

BackgroundBronchial dehiscence is a life-threatening complication after lung transplant. If it is not treated by placement of stent or reanastomosis, the chance of survival will depend on the availability of a new graft. However, retransplant is not a practical management option in Japan, where waiting time for lung transplant is extensive. We described a case of refractory bilateral bronchial dehiscence managed by veno-venous extracorporeal oxygenation membrane (VV ECMO) while allowing the dehiscence to heal.Case presentationA 25-year-old man with idiopathic pulmonary arterial hypertension underwent a bilateral lung transplant. The patient developed bilateral bronchial dehiscence. Open reanastomosis was not successful, and air leakage recurred under low positive pressure ventilation. VV ECMO was established to maintain oxygenation with spontaneous breathing until both dehiscence were closed by adhesions.ConclusionIn a patient with refractory bilateral bronchial dehiscence, VV ECMO may provide bronchial rest and serve as a bridge therapy to recovery.

Observational study of thrombosis and bleeding in COVID-19 VV ECMO patients.

COVID-19 has been associated with increased risk of thrombosis, heparin resistance and coagulopathy in critically ill patients admitted to intensive care. We report the incidence of thrombotic and bleeding events in a single center cohort of 30 consecutive patients with COVID-19 supported by veno-venous extracorporeal oxygenation (ECMO) and who had a whole body Computed Tomography Scanner (CT) on admission. All patients were initially admitted to other hospitals and later assessed and retrieved by our ECMO team. ECMO was initiated in the referral center and all patients admitted through our CT scan before settling in our intensive care unit. Clinical management was guided by our institutional ECMO guidelines, established since 2011 and applied to at least 40 patients every year. We diagnosed a thrombotic event in 13 patients on the initial CT scan. Two of these 13 patients subsequently developed further thrombotic complications. Five of those 13 patients had a subsequent clinically significant major bleeding. In addition, two patients presented with isolated intracranial bleeds. Of the 11 patients who did not have baseline thrombotic events, one had a subsequent oropharyngeal hemorrhage. When analyzed by ROC analysis, the area under the curve for % time in intended anticoagulation range did not predict thrombosis or bleeding during the ECMO run (0.36 (95% CI 0.10-0.62); and 0.51 (95% CI 0.25-0.78); respectively). We observed a high prevalence of VTE and a significant number of hemorrhages in these severely ill patients with COVID-19 requiring veno-venous ECMO support.

Prone Positioning during Venovenous Extracorporeal Membrane Oxygenation in Acute Respiratory Distress Syndrome. A Multicenter Cohort Study and Propensity-matched Analysis

Rationale: Prone positioning reduces mortality in patients with severe acute respiratory distress syndrome (ARDS). To date, no evidence supports the use of prone positioning (PP) during venovenous extracorporeal oxygenation (ECMO).Objectives: The aim of the study was to assess the feasibility, safety, and effect on oxygenation and lung mechanics of PP during ECMO. As a secondary exploratory aim, we assessed the association between PP and hospital mortality.Methods: We performed a multicenter retrospective cohort study in six Italian ECMO centers, including patients managed with PP during ECMO support (prone group; four centers) and patients managed in the supine position (control group; two centers). Physiological variables were analyzed at four time points (supine before PP, start of PP, end of PP, and supine after PP). The association between PP and hospital mortality was assessed by multivariate analysis and propensity score-matching.Results: A total of 240 patients were included, with 107 in the prone group and 133 in the supine group. The median duration of the 326 pronation cycles was 15 (12-18) hours. Minor reversible complications were reported in 6% of PP maneuvers. PP improved oxygenation and reduced intrapulmonary shunt. Unadjusted hospital mortality was lower in the prone group (34 vs. 50%; P = 0.017). After adjusting for covariates, PP remained significantly associated with a reduction of hospital mortality (odds ratio, 0.50; 95% confidence interval, 0.29-0.87). Sixty-six propensity score-matched patients were identified in each group. In this matched sample, patients who underwent pronation had higher ECMO duration (16 vs. 10 d; P = 0.0344) but lower hospital mortality (30% vs. 53%; P = 0.0241).Conclusions: PP during ECMO improved oxygenation and was associated with a reduction of hospital mortality.

Semiquantification of Systemic Venous Admixture During Venovenous Extracorporeal Oxygenation Via Bicaval Double-Lumen Cannula in Critically Ill Patients.

Venovenous extracorporeal membrane oxygenation (VV-ECMO) is increasingly utilized in acute reversible cases of severe respiratory failure and as a bridge to lung transplantation. Venovenous extracorporeal membrane oxygenation using a bicaval double-lumen cannula (BCDLC) has several advantages over the traditional ECMO configuration; however, it also presents with several unique challenges. The assessment and quantification of venous admixture is difficult due to the specific position of BCDLC within the circulatory system. We describe the nature of the double-lumen bicaval venovenous ECMO cannula and relevant specific issues associated with monitoring complex details of oxygenation within different parts of circulation, including existing barriers for quantification of recirculation and venous admix. New conceptual approach to the quantification of venous admix is described. Right side echocardiographic contrast, when sequentially injected in separate superior vena cava (SVC) and inferior vena cava (IVC) venous basins, bypasses drainage ports of the catheter in double-lumen bicaval VV-ECMO configuration together with deoxygenated returning from the periphery venous blood. It was easily detectable entering right heart chambers by two- and three-dimensional echocardiography. Amount of bubbles from the agitated fluid contrast within right atrium indicates relative amount of venous admixture in relation to the returning from the oxygenator blood which is bubble free.

Procalcitonin dynamics, lactates, and haemoglobin serum levels might be a useful predictive tool of mortality in patients undergoing veno-venous extracorporeal oxygenation membrane support. Single centre experience.

Veno-venous extracorporeal membrane oxygenation (VV-ECMO) is a well-established therapeutic option in respiratory failure refractory to mechanical ventilation. Due to the growing popularity of VV-ECMO, new methods to improve patient outcome are desired. This study aimed to evaluate the impact of patient age, sequential organ failure assessment score, respiratory ECMO survival prediction score, and early laboratory results on mortality of patients undergoing VV-ECMO. The study population included 39 patients who underwent VV-ECMO between 2016 and 2019. The study compared the laboratory results during the first three days of therapy. The parameters included procalcitonin, C-reactive protein, haemoglobin, lactates, arterial blood partial pressure of carbon dioxide and oxygen. The decrease of procalcitonin by 10% between the 1st and the 3rd day was more often observed in the positive outcome group (71.4% vs. 38.9%, P = 0.041). Serum lactate concentrations at the 1st day corresponded with the negative outcome (AUC = 0.70, P = 0.026). The negative outcome group had a higher occurrence of serum lactates of 2 mmol L-1 at the 1st day (P = 0.039). The haemoglobin levels at the 1st and 3rd day corresponded with patients' outcome (AUC = 0.69, P = 0.023 and AUC = 0.074, P = 0.006, respectively). The study showed significant differences in early laboratory results between patients with a positive and negative outcome. In our opinion, serum lactate, haemoglobin and procalcitonin concentrations should be monitored daily to ensure an optimal therapeutic strategy and improve patient outcome. Our study provides valuable observations on predictive tools in VV-ECMO and possible directions for future research.

Injection of agitated saline to detect recirculation with transthoracic echocardiography during venovenous extracorporeal oxygenation: A pilot study

PurposeWe assessed the security and efficiency of intravenously injected agitated saline in conjunction with transthoracic echocardiography to identify recirculation in patients supported with a venovenous extracorporeal membrane oxygenation (VV ECMO) device. Materials and MethodsWe injected agitated saline 4 consecutive times separated by an interval of 5 minutes in 2 patients supported by VV ECMO. In both patients, the drainage cannula was placed in the left femoral vein, and the return cannula was placed in the right internal jugular vein. Echocardiography was performed during the injection and until the bubbles disappeared. The security of the method was assessed by evaluating the mechanical function of the ECMO and the efficiency of the oxygenator. The value of this method was assessed by visualizing the increase of inferior vena cava's echogenicity as well as by measuring the time required for this change to occur after the injection of agitated saline at different ECMO output levels. ResultsWe did not observe any change in ECMO, oxygenation function, or the hemodynamic status of patients after the 4 injections of agitated saline. The echogenicity of the inferior vena cava increased more rapidly as the ECMO's output increased. The recirculation phenomenon was noted even with low levels of ECMO output (<2 L/min). ConclusionsTransthoracic echocardiography in conjunction with agitated saline administration may be a safe and easily applicable method to evaluate a recirculation phenomenon in patients supported with VV ECMO.

Severe hypoxemia during veno-venous extracorporeal membrane oxygenation: exploring the limits of extracorporeal respiratory support

OBJECTIVE:Veno-venous extracorporeal oxygenation for respiratory support has emerged as a rescue alternative for patients with hypoxemia. However, in some patients with more severe lung injury, extracorporeal support fails to restore arterial oxygenation. Based on four clinical vignettes, the aims of this article were to describe the pathophysiology of this concerning problem and to discuss possibilities for hypoxemia resolution.METHODS:Considering the main reasons and rationale for hypoxemia during veno-venous extracorporeal membrane oxygenation, some possible bedside solutions must be considered: 1) optimization of extracorporeal membrane oxygenation blood flow; 2) identification of recirculation and cannula repositioning if necessary; 3) optimization of residual lung function and consideration of blood transfusion; 4) diagnosis of oxygenator dysfunction and consideration of its replacement; and finally 5) optimization of the ratio of extracorporeal membrane oxygenation blood flow to cardiac output, based on the reduction of cardiac output.CONCLUSION:Therefore, based on the pathophysiology of hypoxemia during veno-venous extracorporeal oxygenation support, we propose a stepwise approach to help guide specific interventions.

A new formula for determining arterial oxygen saturation during venovenous extracorporeal oxygenation

Venovenous extracorporeal membrane oxygenation (VV-ECMO) is used to treat severe forms of acute respiratory distress syndrome (ARDS). VV-ECMO management may be confusing due to the lack of information about the interplay between the determinant parameters and their impact on oxygenation. We found a relationship between arterial oxygen saturation (SaO(2)) and its relevant parameters. The aim of this study was to assess the validity of this model. We report our experience in 17 patients under VV-ECMO for severe ARDS. We compared, at two different levels of pump flow, SaO(2) and the oxygen saturation measured in the pulmonary artery (SpaO(2)) with the predicted saturation using the formula: SpaO(2) = (EF/CO)SmO(2) + (1 - EF/CO)SvO(2) + 10(-2)PmO(2), where PF is pump flow, R is recirculation, EF is effective flow [= (1 - R)PF], SmO(2) is saturation of the oxygenator outgoing blood, CO is cardiac output, SvO(2) is saturation of mixed venous blood, and PmO(2) is oxygen partial pressure of the oxygenator outgoing blood. There was no significant difference between predicted and measured SpaO(2): the mean predicted and measured SpaO(2) values were 90.7 ± 2.8 % and 90.4 ± 2.7 % , respectively (p = 0.696, r = 0.966). Bland-Altman analysis showed good agreement between predicted and measured SpaO(2). Predicted SpaO(2) and SaO(2) was well correlated (r = 0.80). We have presented an explicit relationship between SaO(2) and its direct determinants during VV-ECMO. Good agreement was found with the measured values of SaO(2), but the model remains to be fully validated before its use in clinical practice.

Initial Experience With Single Cannulation for Venovenous Extracorporeal Oxygenation in Adults

Historically, venovenous extracorporeal membrane oxygenation has required dual cannulation. A single-venous cannulation strategy may facilitate implantation and patient mobilization. Here we present our early experience with a single cannulation technique. Review of venovenous extracorporeal membrane oxygenation support using internal jugular vein insertion of the Avalon elite bicaval dual lumen catheter (Avalon Laboratories, Rancho Dominguez, CA) in 11 consecutive patients with severe respiratory failure. Adequate oxygenation was obtained in all patients: 115 mm Hg PaO(2) (median), 53 to 401 mm Hg (range). Median time of support was 78 hours (range, 3 to 267 hours). No mortality was directly related to the cannulation strategy. There were three nonfatal cannulation-related events. Two patients had proximal cannula displacement requiring repositioning. One patient suffered an acute thrombosis of the cannula. Our series supports single-venous cannulation in venovenous extracorporeal membrane oxygenation as a promising technique. It may be an excellent alternative to current cannulation strategies in patients requiring prolonged support and specifically for those considered for a bridge-to-lung transplantation.