Leopold Rupprecht

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.

Pumpless Extracorporeal Lung Assist: A 10-Year Institutional Experience

BACKGROUND Pumpless extracorporeal lung assist (PECLA) was developed to support pulmonary function in patients with severe respiratory insufficiency. METHODS Since 1996, 159 patients with an age ranging from 7 to 78 years were provided with a PECLA system. Fifteen patients were referred to us by air or ground transport after insertion of the system in a peripheral hospital. RESULTS Main underlying lung diseases were acute respiratory distress syndrome (70.4%) and pneumonia (28.3%). Pumpless extracorporeal lung assist lasted for 0.1 to 33 days, mean 7.0 +/- 6.2 days; cumulative experience was greater than 1,300 days. Successful weaning and survival to hospital discharge was achieved in 33.1% of patients after a mean PECLA support of 8.5 +/- 6.3 days. During PECLA therapy, 48.7% of patients died, mainly as a result of multiorgan failure after a mean interval of 4.8 +/- 5.1 days. Inability to stabilize pulmonary function was noted in 3% of patients only. After PECLA, 30-day mortality was 13.6%. In a subgroup analysis, best outcome was obtained in patients after trauma. CONCLUSIONS Pumpless extracorporeal lung assist is a simple and efficient method to support patients with deteriorating gas exchange for prolonged periods to allow the lung protective ventilation and transportation. Best indication for use of PECLA is severe hypercapnia and moderate hypoxia.

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.

Minimal Extracorporeal Circulation : An Alternative for On-Pump and Off-Pump Coronary Revascularization

BACKGROUND Coronary artery bypass surgery employing minimal extracorporeal circulation (MECC) was compared with standard extracorporeal circulation (ECC) and off-pump coronary artery bypass graft surgery (OPCABG) with regard to the perioperative course. METHODS From January 2004 to December 2007, 1,674 patients (n = 558 MECC, n = 558 ECC, n = 558 OPCABG) who underwent coronary bypass surgery were studied. The primary end point was in-hospital mortality; secondary end points were perioperative variables, intensive care, and in-hospital course. RESULTS Demographic data, comorbidity, and the European System for Cardiac Operative Risk Evaluation score (MECC 3.0%, ECC 3.5%, OPCABG 3.2%) were similar among the groups, but in-hospital mortality for elective and urgent/emergent patients was lower in the MECC and OPCABG groups (MECC 3.2%, OPCABG 3.7%, ECC 6.9%; p < 0.05). The number of distal anastomoses was lowest in the OPCABG group, but comparable for MECC and ECC patients. Postoperative ventilation time, release of creatinine kinase, catecholamine therapy, drainage loss, and transfusion requirements were lower in the MECC and OPCABG groups, whereas stay in the intensive care unit was shorter only in the latter (p < 0.05). CONCLUSIONS Minimal extracorporeal circulation is an easy and safe procedure for coronary artery bypass graft surgery. In selected patients, the advantages of MECC equal those of OPCABG. MECC should be considered as an alternative to OPCABG and standard ECC procedures.

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.

Percutaneous Cannulation for Extracorporeal Life Support

BACKGROUND Extracorporeal life-support systems are valuable tools to treat patients with acute cardiopulmonary failure in intensive care facilities, and are highly suitable for the interhospital transfer of critically ill patients to specialized centers. This article reviews the cannulation strategies and associated vascular complications in our institution. METHODS Between January 2004 and December 2009, 464 extracorporeal life-support systems were implanted via percutaneous cannulation at our institution. The type and incidence of adverse events related to the percutaneous access to femoral, subclavian vessels and the jugular vein were retrospectively analyzed. The primary focus was on bleeding and limb ischemia. RESULTS 464 patients (340 male, 124 female) with isolated pulmonary or combined cardiopulmonary failure were connected to extracorporeal gas exchange systems. Most patients (n = 196) were connected to a PECLA system; 158 patients to a veno-arterial ECMO. Use of a veno-venous ECMO system was necessary in 110 cases. Thirty-two patients (6.9 %) suffered bleeding complications after cannula insertion, predominantly after PECLA placement (3.9 %). After implantation, limb ischemia developed in 15 cases (3.2 %), mostly in the veno-arterial ECMO group (n = 13). Demographic data and cannula size show no significant difference between patient groups with and without ischemic complications ( P = 0.57). A prophylactic fasciotomy was performed in the 15 cases with limb ischemia. Survival was independent of ischemic (leg) complications. CONCLUSION With proper vessel visualization, exposure and cannulation, and accurate cannula placement, optimal flows and minimal complication rates can be achieved, rendering percutaneous extracorporeal life support a safe procedure.

Temporary percutaneous right ventricular support using a centrifugal pump in patients with postoperative acute refractory right ventricular failure after left ventricular assist device implantation

OBJECTIVE Acute right ventricular (RV) failure is a life-threatening condition with a poor prognosis, and sometimes the use of mechanical circulatory support is inevitable. In this article, we describe our experience using a centrifugal pump as a temporary percutaneous right ventricular assist device (RVAD) in patients with postoperative acute refractory RV failure after left ventricular assist device (LVAD) implantation. METHODS We retrospectively reviewed eight consecutive patients with acute RV failure who underwent temporary percutaneous RVAD implantation using a centrifugal pump after LVAD implantation between April 2008 and February 2011. A Dacron graft was attached to the main pulmonary artery and passed through a subxiphoid exit, where the outflow cannula was inserted. The inflow cannula was percutaneously cannulated using Seldingers technique in the femoral vein. The chest was definitely closed. The technique allowed bedside removal, avoiding chest re-opening. RESULTS The median patient age was 52 years (range: 41-58). The median duration of support was 14 days (range: 12-14). RV systolic function improved; central venous pressure and mean pulmonary artery pressure decreased significantly after RVAD support. In three patients, an oxygenator was integrated into the RVAD due to impaired pulmonary function. Six patients were successfully weaned. Five patients survived to hospital discharge. Technical problems or serious complications concerning decannulation were not observed. CONCLUSION This report suggests that implantation of temporary percutaneous RVAD using a centrifugal pump is a safe alternative in the treatment of postoperative acute refractory RV failure. Ease of device implantation, weaning, explantation, and limited number of complications justify a liberal use.