Matthias Arlt

Pumpless extracorporeal interventional lung assist in patients with acute respiratory distress syndrome: a prospective pilot study

IntroductionPumpless interventional lung assist (iLA) is used in patients with acute respiratory distress syndrome (ARDS) aimed at improving extracorporeal gas exchange with a membrane integrated in a passive arteriovenous shunt. In previous studies, feasibility and safety of the iLA system was demonstrated, but no survival benefit was observed. In the present pilot study we tested the hypothesis that timely initiation of iLA using clear algorithms and an improved cannulation technique will positively influence complication rates and management of lung protective ventilation.MethodsiLA was implemented in 51 patients from multiple aetiologies meeting ARDS-criteria (American-European Consensus) for more than 12 hours. Initiation of iLA followed an algorithm for screening, careful evaluation and insertion technique. Patients with cardiac insufficiency or severe peripheral vascular disease were not considered suitable for iLA. Arterial and venous cannulae were inserted using a new strategy (ultrasound evaluation of vessels by an experienced team, using cannulae of reduced diameter). The incidence of complications and the effects on tidal volumes and inspiratory plateau pressures were primary outcome parameters, while oxygenation improvement and carbon dioxide removal capabilities were secondary study parameters.ResultsInitiation of iLA resulted in a marked removal in arterial carbon dioxide allowing a rapid reduction in tidal volume (≤ 6 ml/kg) and inspiratory plateau pressure. Adverse events occurred in 6 patients (11.9%). The hospital mortality rate was 49%.ConclusionsThe use of an indication algorithm for iLA in early ARDS, combined with a refined application technique was associated with efficient carbon dioxide removal and a reduced incidence of adverse events. iLA could serve as an extracorporeal assist to support mechanical ventilation by enabling low tidal volume and a reduced inspiratory plateau pressure.

Extracorporeal membrane oxygenation in severe trauma patients with bleeding shock.

AIM OF THE STUDY Death to trauma is caused by disastrous injuries on scene, bleeding shock or acute respiratory failure (ARDS) induced by trauma and massive blood transfusion. Extracorporeal membrane oxygenation (ECMO) can be effective in severe cardiopulmonary failure, but preexisting bleeding is still a contraindication for its use. We report our first experiences in application of initially heparin-free ECMO in severe trauma patients with resistant cardiopulmonary failure and coexisting bleeding shock retrospectively and describe blood coagulation management on ECMO. METHODS From June 2006 to June 2009 we treated adult trauma patients (n=10, mean age: 32+/-14 years, mean ISS score 73+/-4) with percutaneous veno-venous (v-v) ECMO for pulmonary failure (n=7) and with veno-arterial (v-a) ECMO in cardiopulmonary failure (n=3). Diagnosis included polytrauma (n=9) and open chest trauma (n=1). We used a new miniaturised ECMO device (PLS-Set, MAQUET Cardiopulmonary AG, Hechingen, Germany) and performed initially heparin-free ECMO. RESULTS Prior to ECMO median oxygenation ratio (OR) was 47 (36-90) mmHg, median paCO(2) was 67 (36-89) mmHg and median norepinephrine demand was 3.0 (1.0-13.5) mg/h. Cardiopulmonary failure was treated effectively with ECMO and systemic gas exchange and blood flow improved rapidly within 2 h on ECMO in all patients (median OR 69 (52-263) mmHg, median paCO(2) 41 (22-85) mmHg. 60% of our patients had recovered completely. CONCLUSIONS Initially heparin-free ECMO support can improve therapy and outcome even in disastrous trauma patients with coexisting bleeding shock.

A new miniaturized system for extracorporeal membrane oxygenation in adult respiratory failure.

IntroductionMortality of severe acute respiratory distress syndrome in adults is still unacceptably high. Extracorporeal membrane oxygenation (ECMO) could represent an important treatment option, if complications were reduced by new technical developments.MethodsEfficiency, side effects and outcome of treatment with a new miniaturized device for veno-venous extracorporeal gas transfer were analysed in 60 consecutive patients with life-threatening respiratory failure.ResultsA rapid increase of partial pressure of arterial oxygen/fraction of inspired oxygen (PaO2/FiO2) from 64 (48 to 86) mmHg to 120 (84 to 171) mmHg and a decrease of PaCO2 from 63 (50 to 80) mmHg to 33 (29 to 39) mmHg were observed after start of the extracorporeal support (P < 0.001). Gas exchange capacity of the device averaged 155 (116 to 182) mL/min for oxygen and 210 (164 to 251) mL/min for carbon dioxide. Ventilatory parameters were reduced to a highly protective mode, allowing a fast reduction of tidal volume from 495 (401 to 570) mL to 336 (292 to 404) mL (P < 0.001) and of peak inspiratory pressure from 36 (32 to 40) cmH2O to 31 (28 to 35) cmH2O (P < 0.001). Transfusion requirements averaged 0.8 (0.4 to 1.8) units of red blood cells per day. Sixty-two percent of patients were weaned from the extracorporeal system, and 45% survived to discharge.ConclusionsVeno-venous extracorporeal membrane oxygenation with a new miniaturized device supports gas transfer effectively, allows for highly protective ventilation and is very reliable. Modern ECMO technology extends treatment opportunities in severe lung failure.

Venovenous extracorporeal membrane oxygenation for acute lung failure in adults

BACKGROUND Acute lung failure (ALF) is an increasing problem that can be treated with venovenous extracorporeal membrane oxygenation (vv-ECMO). This report summarizes prospectively collected data of an institutional experience with vv-ECMO. METHODS From January 2007 to December 2010, 176 patients (mean age, 48 ± 16; range, 14-78 years) with ALF refractory to conventional therapy were supported with vv-ECMO. The general indication for vv-ECMO was a partial oxygen pressure/fraction of inspired oxygen (Fio(2)) < 80 mm Hg under a Fio(2) of 1.0, a positive end-expiratory pressure of 18 cm H(2)O, and refractory respiratory acidosis (pH < 7.25), despite optimization of conservative therapy. RESULTS All patients underwent peripheral cannulation. In 59 cases, vv-ECMO was placed in another facility with ECMO transport by helicopter or ambulance. The mean vv-ECMO support interval was 12 ± 9.0 days (range, 1-67 days). During ECMO, 12 patients (7%) could be extubated and stepwise mobilized. Cannula-related complications during long-term support occurred in 14%, which was mostly minor bleeding. Overall survival was 56%: 58 patients (33%) died during mechanical support, and 20 (11%) died after weaning from the system. The best outcome was noted in trauma patients. Risk factors were mainly advanced age and multiorgan failure. CONCLUSION Modern vv-ECMO is an excellent treatment in patients with severe ALF and should be more liberally used.

Bridge to lung transplantation through a pulmonary artery to left atrial oxygenator circuit.

BACKGROUND There is no mechanical device available to support patients with end-stage lung failure for weeks and months until appropriate donor organs for lung transplantation are available. METHODS In a 38-year-old female patient with primary pulmonary hypertension a paracorporeal artificial lung (PAL) system was placed parallel to the pulmonary circulation with connections to the pulmonary artery and to the left atrium. The key component of the PAL was a low-resistance membrane oxygenator. RESULTS After institution, the PAL had a blood flow of 3.5 L/min and created a PaO(2)/fraction of inspired oxygen ratio of 270, while the oxygenator was provided with oxygen 3 L/min. The pulmonary artery pressure declined by almost 50%. The PAL worked well over 62 days until appropriate donor lungs were available. With resuming more physical activity, an increased flow through the native lung augmented the fraction of unsaturated blood arriving at the left atrium, which mandated increasing oxygen flow to the PAL. CONCLUSIONS The data obtained with this case encourage further research into PAL systems, which may hopefully serve as a bridge to lung transplant device in appropriate patients in the future.

First experiences with a new miniaturised life support system for mobile percutaneous cardiopulmonary bypass

AIM As a result of healthcare changes, interhospital transfer has become common in the care even of patients with severely deteriorated cardiopulmonary function. This study describes experience with the use of a specially downsized, lightweight extracorporeal circulation system (Emergency-MECC) which enables percutaneous cardiopulmonary bypass support in resistant cases of severe cardiac and cardiopulmonary failure. METHODS Between March 2006 and June 2007, the Emergency-MECC system, consisting of a centrifugal pump and a membrane oxygenator, was used to facilitate interhospital transfer of five adults. The technique included percutaneous cannulation, femoro-femoral venoarterial (n=4) and femoro-jugular venovenous (n=1) life support by extracorporeal membrane oxygenation. RESULTS Bedside cannulation was uneventful and the extracorporeal circulation support achieved adequate systemic blood flow and oxygen delivery in all cases. Vasopressor support could be immediately reduced and hypoxaemia was treated effectively. During interhospital transfer (air ambulance in three and ground ambulance in two cases), no technical complication occurred. Hospital survival rate was 80%. CONCLUSIONS The Emergency-MECC system is safe, rapid and highly effective in restoring blood flow and oxygen delivery. Interhospital transfer on cardiopulmonary bypass was made possible without extended technical or personnel support.

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.

Out-of-hospital extracorporeal life support for cardiac arrest—A case report

We report the use of out-of-hospital extracorporeal life support (ECLS) in cardiac arrest. We treated a 9-year-old girl with cardiac arrest after warm-water drowning with percutaneous venoarterial extracorporeal membrane oxygenation (ECMO) using a new portable Mini-ECMO system. A beating-heart circulation was reestablished on ECMO, but, unfortunately, our patient did not survive. This case shows that Mini-ECMO support can be used to restore an effective circulation and gas exchange in the out-of-hospital setting.

Emergency Use of Extracorporeal Membrane Oxygenation in Cardiopulmonary Failure

Severe pulmonary and cardiopulmonary failure resistant to critical care treatment leads to hypoxemia and hypoxia-dependent organ failure. New treatment options for cardiopulmonary failure are necessary even for patients in outlying medical facilities. If these patients are in need of specialized center treatment, additional emergency medical service has to be carried out quick and safely. We describe our experiences with a pumpless extracorporeal lung assist (PECLA/iLA) for out-of-center emergency treatment of hypercapnic respiratory failure and the use of a newly developed hand-held extracorporeal membrane oxygenation (ECMO) system in cardiac, pulmonary, and cardiopulmonary failure (EMERGENCY-LIFE Support System, ELS System, MAQUET Cardiopulmonary AG, Hechingen, Germany). Between March 2000 and April 2009, we used the PECLA System (n = 20) and the ELS System (n = 33) in adult patients. Cannulation was employed using percutaneous vessel access. The new hand-held ELS System consists of a centrifugal pump and a membrane oxygenator, both mounted on a special holder system for storing on a standard patient gurney for air or ground ambulance transfer. Bedside cannulation processes were uneventful. The PECLA System resulted in sufficient CO(2) removal. In all ECMO patients, oxygen delivery and systemic blood flow could be restored and vasopressor support was markedly down. Hospital survival rate in the PECLA group was 50%, and 61% in the ECMO group. Out-of-center emergency treatment of hypercapnic pulmonary failure with pumpless extracorporeal gas exchange and treatment of cardiac, pulmonary, and cardiopulmonary failure with this new hand-held ECMO device is safe and highlyeffective. Patient outcome in cardiopulmonary organ failure could be improved.