Alternative venous access sites for dual-lumen extracorporeal membrane oxygenation cannulation.

OBJECTIVES: Dual-lumen cannulas for veno-venous (VV) extracorporeal membrane oxygenation (ECMO) support are typically inserted in the right internal jugular vein (RIJV); however, some scenarios can make this venous route inaccessible. This multicentre case series aims to evaluate if single-site cannulation using an alternative venous access is safe and feasible in patients with an inaccessible RIJV. METHODS: We performed a multi-institutional retrospective analysis including high-volume ECMO centres with substantial experience in dual-lumen cannulation (DLC) (defined as >10 DLC per year). Three centres [Freiburg (Germany), Toronto (Canada) and Vienna (Austria)] agreed to share their data, including baseline characteristics, technical ECMO and cannulation data as well as complications related to ECMO cannulation and outcome. RESULTS: A total of 20 patients received alternative DLC for respiratory failure. Cannula insertion sites included the left internal jugular vein (n = 5), the right (n = 7) or left (n = 3) subclavian vein and the right (n = 4) or left (n = 1) femoral vein. The median cannula size was 26 (19-28) French. The median initial target ECMO flow was 2.9 (1.8-3.1) l/min and corresponded with used cannula size and estimated cardiac output. No procedural complications were reported during cannulation and median ECMO runtime was 15 (9-22) days. Ten patients were successfully bridged to lung transplantation (n = 5) or lung recovery (n = 5). Ten patients died during or after ECMO support. CONCLUSIONS: Alternative venous access sites for single-site dual-lumen catheters are a safe and feasible option to provide veno-venous ECMO support to patients with inaccessible RIJV.

Case Report: Recurrence of Acute Respiratory Distress Syndrome After Bilateral Lung Transplantation.

BACKGROUND: The main causes of early respiratory failure after lung transplantation include primary graft dysfunction (PGD), acute rejection, and infection. This report describes a case of unclear early respiratory failure after bilateral lung transplantation for extensive COVID-19-induced acute respiratory distress syndrome (ARDS). METHODS: We reviewed the patient file to investigate the course of the functional decline and evaluate reasons for early graft failure. Analyzed data included crossmatching results, biopsy results, HLA antibodies testing, bronchoalveolar lavages, respiratory parameters, and medications. RESULTS: After an initial excellent early postoperative course, the patient developed progressive respiratory failure, making re-implantation of extracorporeal membrane oxygenation (ECMO) support necessary. An extensive diagnostic workup revealed no signs of infection or rejection. Because the patient showed no signs of improvement with any treatment, lung-protective ventilation with the intermittent prone position was initiated. The patient's respiratory situation and bilateral opacities slowly improved over the next few weeks, and ECMO support was eventually discontinued. CONCLUSION: With no evidence of PGD, rejection, or infection, recurrent ARDS caused by a systemic immunologic process was seen as the only plausible cause for the patient's respiratory failure after lung transplantation. The fact that ARDS can develop extrapulmonarily, without direct viral or bacterial damage, makes us conclude that the preceding systemic activation and recruitment of immune cells by the primarily injured lung could potentially lead to the recurrence of ARDS even if the injured organ is removed.

Absolute Lymphocyte Count as a Marker for Cytomegalovirus Infection After Heart Transplantation.

BACKGROUND: Previous studies indicate an association between reduced absolute lymphocyte count (ALC) and cytomegalovirus (CMV) infection after solid organ transplantation and have therefore highlighted the potential of ALC as a simple tool to predict CMV infection in transplant patients. This study aimed to examine the utility of ALC as a valuable marker for CMV infection in heart transplant patients. METHODS: Clinical information and ALC data of all adult patients who received orthotopic heart transplantation at the Medical University of Vienna between January 2004 and May 2019 were collected. We performed a multivariable Cox regression model that incorporates repeated measurements of ALC as a time-varying continuous factor in 2 ways, first as continuous logarithmic factor considering a 50% decrease of ALC levels and second as binary factor using a threshold of 610 cells/µL. RESULTS: One hundred fifty-eight (39%) patients developed CMV infection over the course of 2 y. Patients with lymphopenia were shown to be at higher risk of developing CMV infection both in the continuous approach (HR [per 50% reduction] 1.29; confidence interval [CI], 1.09-1.53; P = 0.003) and the binary approach with a cutoff of 610 cells/µL (HR 1.74; CI, 1.20-2.51; P = 0.003). CONCLUSIONS: This study demonstrated a strong association between reduced ALC and the development of CMV infection after heart transplantation. ALC value monitoring could provide an additional tool to assess individualized CMV risk after solid organ transplantation.