Daniele Camboni

Hand-held minimised extracorporeal membrane oxygenation: a new bridge to recovery in patients with out-of-centre cardiogenic shock

OBJECTIVE Cardiogenic shock is associated with mortality rates up to 70%, even if patients are treated with intensive care support or thrombolytic therapy. Early coronary revascularisation can be life-saving but it is oftentimes not available at the hospital to which the patient was initially taken. Up to now, transferring patients in a state of severe cardiogenic shock and/or cardiopulmonary resuscitation is mostly decided to be impossible. We report on the use of two newly developed minimised systems for hand-held-extracorporeal membrane oxygenation (ECMO) (ELS-System™ and CARDIOHELP™, both from MAQUET Cardiopulmonary AG, Germany), which we have used for rapid extracorporeal life support and interhospital transfer on Mini-ECMO. We characterise the emergency use, safety instructions and bridging function of these novel Mini-ECMO devices. METHODS Between June 2007 and August 2010, we administered percutaneous Mini-ECMO support to 21 adult cardiogenic shock patients. The main components of each Mini-ECMO system are a centrifugal pump and a membrane oxygenator. The systems can act independently from wall connection points, and are they are small enough to be attached nearby a patients side during transport. RESULTS On ECMO, gas exchange improved significantly, vasopressor support could be significantly marked down and signs of shock disappeared in all patients. Emergency medical service was carried out in re-established blood-flow and oxygen delivery. The patients were bridged to coronary artery bypass grafting (CABG) (n = 6), ventricular assist device (n = 1) or pulmonary embolectomy (n=1) or specialised intensive care (n=13). Thirteen patients (62%) had completely recovered. CONCLUSIONS The use of hand-held Mini-ECMO systems enables for the first time the rapid onset of extracorporeal life support independent from the patients current location. However, success is extremely time- and team dependent. Highly skilled interdisciplinary patient management is essential to let minimised-ECMO become a new and highly effective bridge to recovery in out-of-centre cardiogenic shock patients.

Extracorporeal circulatory systems in the interhospital transfer of critically ill patients: experience of a single institution.

Background and Objectives: Critically ill patients with acute circulatory failure cannot be moved to other institutions unless stabilized by mechanical support systems. Extracorporeal heart and lung assist systems are increasingly used as a bridge to end-organ recovery or transplantation, and as an ultimate rescue tool in cardiopulmonary resuscitation. Patients and Methods: From July 2001 to April 2008, we had 38 requests for extracorporeal support for interhospital transfer carried out by the air medical service. Respiratory failure was present in 29 patients, who were provided with pumpless extracorporeal lung assist (PECLA) or veno-venous extracorporeal membrane oxygenation (ECMO). Cardiac failure dominated in 9 patients, who underwent implantation of extracorporeal life support (ECLS). Underlying diseases were acute respiratory distress syndrome in 15 patients, pneumonia in 7, prior lung transplant status in 4, cardiogenic shock in 7, and septic shock in 4. Results: All assist systems were connected via peripheral vessels by the Seldinger technique. Transport was uneventful in all cases with no technical failures. On arrival at the specialized care hospital, two patients had leg ischemia and underwent relocation of the arterial cannula. After a mean (SD) support of 5.1 (3.0) days for PECLA, 3.5 (2.9) days for ECLS, and 7.3 (5.8) days for ECMO, 60%, 66%, and 66% of patients, respectively,could be successfully weaned from the systems. Discharge rates were 45% for PECLA, 44% for ECLS, and 56% for ECMO. Conclusion: Our experience proves that minimized extracorporeal assist devices allow safe assistance of patients with isolated or combined heart and lung failure in need of interhospital transfer. Critically ill patients get a chance to reach a center of maximum medical care.

First experience with the new portable extracorporeal membrane oxygenation system Cardiohelp for severe respiratory failure in adults.

Background: Over the last decade, technical improvements in extracorporeal membrane oxygenation (ECMO) equipment have reduced procedure-related complications and have made ECMO an effective option for patients with acute respiratory distress syndrome (ARDS) if conventional therapy fails. Methods: In this report, we present our early experience with the Cardiohelp, a new portable miniaturized ECMO system, in 22 consecutive patients with ARDS. All patients were placed on venovenous ECMO. Cannulas were inserted percutaneously, employing the Seldinger technique. Data were collected prospectively. Results: The median patient age was 47 years (36 to 61). Fifteen patients from regional hospitals were too unstable for conventional transport and were placed on Cardiohelp at the referring hospital and then transported to our institution. The patients were transported by ambulance (n=2) or helicopter (n=13) over a distance of 50-250 km. Cardiohelp support resulted in immediate improvement of gas exchange and highly protective ventilation. The median duration of support was 13 days (8 to 19). An exchange of the device was necessary in 9 patients. Sixteen patients (72.7%) were successfully weaned from ECMO and fifteen patients (68.2%) survived. Device-related complications were not observed. Conclusions: The compact portable ECMO device Cardiohelp is a highly effective method to secure vital gas exchange and to reduce further ventilator-induced lung injury in patients with acute respiratory failure. Crucial technical innovations and ease of device transport and implantation allow location-independent stabilization with consecutive inter-hospital transfer.

Cardiac decompression on extracorporeal life support: a review and discussion of the literature.

Extracorporeal life support is a worldwide expanding technology for patients in critical cardiogenic shock. The device is usually attached to the femoral vessels using percutaneous techniques. Despite sufficient extracorporeal circulatory support, an unclear number of patients develop high end-diastolic pressures leading to left ventricular distension and pulmonary edema, and ventricular thrombus formation may evolve. This article discusses the strategies to prevent ventricular distension by conservative, interventional, and surgical means, also illustrated by case presentations.

Thoracic surgical procedures supported by a pumpless interventional lung assist.

BACKGROUND For support of pulmonary function during complex thoracic surgical procedures, especially in respiratory compromised patients, a pumpless interventional lung assist (iLA) was applied. Feasibility and effectiveness for this novel indication were evaluated. METHODS Ten patients underwent thoracic surgery with respiratory support by iLA. Indication for iLA application was the need for intraoperative prolonged discontinuation of ventilation (tracheal surgery and lung resections after pneumonectomy [n = 6], and emergency procedures in patients with acute respiratory failure [n = 4]. The pumpless extracorporeal system was inserted percutaneously into the femoral blood vessels before surgery. Blood flow through the iLA, cardiac output, and gas exchange were monitored. RESULTS In all patients, the surgical procedure was successfully performed because of the support by the pumpless iLA. Mean blood flow across the iLA was 1.58 +/- 0.3 L/min (1.2 L/min to 2.2 L/min). Low-dose norepinephrine was required to maintain sufficient systemic blood pressure. There was a moderate improvement in oxygenation (49 mL/min transfer of O(2)) and a very efficient elimination of carbon dioxide (121 mL/min transfer of CO(2)). Thus, extended periods of apneic oxygenation were possible during surgery. The device was removed immediately after surgery in 6 patients. In 4 patients with severe respiratory insufficiency, the iLA was continued for a mean of 6.8 days to allow for protective postoperative ventilation. CONCLUSIONS The application of pumpless iLA was hemodynamically well tolerated, and allowed for safe procedures in respiratory compromised patients, avoiding the application and consequences of cardiopulmonary bypass or pump-driven extracorporeal membrane oxygenation.

Use of venovenous extracorporeal membrane oxygenation and an atrial septostomy for pulmonary and right ventricular failure.

BACKGROUND Right ventricular failure is a major contributor to morbidity and mortality on the lung transplant waiting list. This study was designed to evaluate the effectiveness of an atrial septostomy with venovenous extracorporeal membrane oxygenation (VV-ECMO) as a novel potential bridge to transplantation. METHODS Adult sheep (58±3 kg; n=12) underwent a clamshell thoracotomy and instrumentation to measure all relevant pressures and cardiac output (CO). Sheep with tricuspid insufficiency (TI [n=5]) and without tricuspid insufficiency (ØTI [n=7]) were examined. After creation of a 1-cm atrial septal defect and initiating VV-ECMO, the pulmonary artery (PA) was banded to allow progressive reduction of pulmonary blood flow, and data were collected. RESULTS The CO in both groups remained unchanged from baseline at all pulmonary blood flow conditions. With TI, the CO was 5.1±1.2 L/min at baseline versus 5.1±1.2 L/min with a fully occluded PA (p=0.99). For ØTI, the CO was 4.5±1.4 L/min at baseline versus 4.5±1.2 L/min with no pulmonary blood flow (p=0.99). Furthermore, CO was not affected by the presence of TI (p=0.76). Mean right ventricular pressures were significantly lower in the TI group (TI=20.2±11 mm Hg versus ØTI=29.9±8.9 mm Hg; p<0.00001). Right and left atrial mean arterial pressures were not different between both groups (p>0.5). Lastly, VV-ECMO maintained normal blood gases, with mean O2 saturations of 99% ± 4.1% in both groups. CONCLUSIONS Right to left atrial shunting of oxygenated blood with VV-ECMO is capable of maintaining normal systemic hemodynamics and normal arterial blood gases during high right ventricular afterload dysfunction.

Support time-dependent outcome analysis for veno-venous extracorporeal membrane oxygenation §,§§

OBJECTIVE The majority of patients suffering from pulmonary failure refractory to mechanical ventilation require extracorporeal membrane oxygenation (ECMO) support between 1 and 2 weeks. This study was designed to evaluate differences in outcome depending on ECMO duration. METHODS A retrospective analysis on n = 127 patients requiring veno-venous (VV) ECMO support at our institution between April 2006 and March 2010 was applied. The patient population was divided into three groups according to the support duration (A: 0-10 days), 75 patients; B: 11-20 days, 32 patients; C: >21 days, (max. 67 days), 19 patients). Statistical comparisons between groups were calculated. RESULTS Mean age of all patients (♀ = 42 patients ♂=85 patients) was 48 ± 16 years (range 15-78 years). Bilateral pneumonia due to bacterial infection (n = 45 patients) or due to aspiration (n = 19 patients) was the main cause for pulmonary failure, other causes were extrapulmonary sepsis (n = 27 patients), major surgery (n = 17 patients), and severe trauma (n = 12 patients). Mean lung injury score (LIS) according to Murray was 3.4 ± 0.4, and mean sequential organ failure assessment (SOFA) score was 12.6 ± 3.7. Statistical comparisons revealed no significant difference in demographic parameters between groups. VV ECMO support immediately improved oxygenation, within 2h the PaO(2)/FiO(2) ratio rose from 80 ± 42 mm Hg to 129 ± 72 mm Hg (p = 0.001). Overall survival to discharge was 51.2%. There was a statistical difference in survival between groups (A = 59%, B = 31%, C = 52%; p = 0.029). Multivariate logistic regression analysis revealed renal failure (odds ratio (OR) 12.1; confidence interval (CI) 3.9-30.0; p < 0.001) and the use of NO (OR=5.8; CI=1.9-24.9; p=0.002) as risk factors for mortality. Complications consisted of cannula-related complications (14%), bleeding issues (13%), partial vein thrombosis of the cannulated vessels (9.5%), and pumphead failure (1.5%). CONCLUSION VV ECMO in patients suffering from severe lung failure is effective in improving gas exchange with an overall survival of higher than 50%. Prolonged need of ECMO support does not have an impact on survival.

Tumor marker carbohydrate antigen 125 predicts adverse outcome after transcatheter aortic valve implantation.

OBJECTIVES This study sought to predict the value of tumor marker carbohydrate antigen 125 (CA125) before and after transcatheter aortic valve implantation (TAVI) for all-cause death and a composite endpoint of death, admission for heart failure, myocardial infarction, and stroke (major adverse cardiac events [MACE]). BACKGROUND Risk stratification after TAVI remains challenging. The use of biomarkers in this setting represents an unmet need. METHODS CA125 was measured in 228 patients before and after TAVI. The association with outcomes was assessed using parametric Cox regression and joint modeling for baseline and longitudinal analyses, respectively. CA125 was evaluated as logarithm transformation and dichotomized by its median value (M1 ≤15.7 U/ml vs. M2 >15.7 U/ml). RESULTS At a median follow-up of 183 days (interquartile range: 63 to 365) and 144 days (interquartile range: 56 to 365), 50 patients (22%) died and 75 patients (33%) experienced MACE. A 3-fold increase in the rates for death and MACE was observed in patients above the median (M2 vs. M1) of CA125 (5.2 vs. 1.6 per 10 person-years and 8.3 vs. 3.3 per 10 person-years, respectively; p for both <0.001). In a multivariable analysis adjusted for logistic EuroSCORE, New York Heart Association functional class III/IV, and device success, baseline values of CA125 (M2 vs. M1) independently predicted death (hazard ratio [HR]: 2.18; 95% confidence interval [CI]: 1.11 to 4.26; p = 0.023) and MACE (HR: 1.77; 95% CI: 1.05 to 2.98; p = 0.031). In the longitudinal analysis, lnCA125 as a time-varying exposure, was highly associated with both endpoints: HR: 1.47; 95% CI: 1.01 to 2.14; p = 0.043 and HR: 2.26; 95% CI: 1.28 to 3.98; p = 0.005, for death and MACE, respectively. CONCLUSIONS Serum levels of CA125 before and after TAVI independently predict death and MACE.

First experience with a paracorporeal artificial lung in humans.

Lung transplantation is the only treatment option for patients suffering form end-stage respiratory failure. To date, no mechanical device is available to support patients on the waiting list up to months. Here, we summarize our experience with our first two patients, who were supported with a paracorporeal artificial lung (PAL) placed in parallel to the pulmonary circulation with connection to the pulmonary artery and to the left atrium. A low resistance membrane oxygenator (iLA, Novalung, Hirrlingen, Germany) was attached in both patients. Our first patient suffering from a pulmonary veno-occlusive disease was supported for 18 days until he died due to severe sepsis. Our second patient with a primary pulmonary hypertension of unknown origin was supported 62 days followed by successful lung transplantation. In conclusion, the experience obtained with these first two patients under PAL encourages further studies and introduction of this promising concept into clinical practice.

Extracorporeal membrane oxygenation by single-vessel access in adults: advantages and limitations.

Veno-venous extracorporeal membrane oxygenation (vvECMO) conventionally requires the cannulation of two vessels. Here we report our initial experience with the “Wang-Zwische” (WZ) double-lumen cannula. In a group of n = 36 patients single venous cannulation for vvECMO was performed. A retrospective analysis was executed. A comparison of flow characteristics to standard two-vessel cannulation was performed. Mean age of the patient population was 48 ± 15 years (body mass index [BMI] 32 ± 13 kg/m2). In n = 32 patients (89%) the cannula was implanted percutaneously under echo or fluoroscopic guidance in less than 30 minutes. Nine patients were partially mobilized on extracorporeal membrane oxygenation (ECMO) support. Oxygenation (partial arterial oxygen tension [PaO2]/fraction of inspired oxygen [FiO2]) improved significantly in all patients from 66 mm Hg (interquartile range [IQR] 58–87 mm Hg) before ECMO to 117 mm Hg (IQR 95–195 mm Hg, p = 0.001) after 24 hours. In seven patients (19%) nonfatal adverse events occurred, including three dislocations, two partial cannula thrombosis, one ventricular perforation, and one retroperitoneal hemorrhage. The negative pressures for drainage at a flow of 2.5 L/min were significantly lower in a standard (S) two-vessel approach compared with a WZ approach (S: −9 mm Hg; IQR −3 to −24 mm Hg, vs. WZ: −23 mm Hg; IQR −4 to −40 mm Hg; p = 0.04). The WZ cannula offers sufficient gas exchange in addition to certain advantages over standard cannulation, including facilitated cannulation in selected patients and improved mobilization.