Pumpless extracorporeal lung assist in severe blunt chest trauma

Pumpless Extracorporeal Lung Assist as Supportive Therapy in a Patient with Diffuse Alveolar Hemorrhage

Our 18-year old female patient suffered from microscopic polyangiitis. After invasive diagnostics, a diffuse alveolar hemorrhage occurred, leading to acute lung failure. In spite of differential ventilation, respiratory insufficiency and lactate-acidosis increased quickly. Due to the massive hemorrhage, a pumpless extracorporeal lung assist was implanted and, after six hours, low-dose heparinization was started. In response to this therapy, hypercapnia and acidosis improved quickly and were completely eliminated within 24 hours. Simultaneously, treatment with prednisolon and cyclophosphamid was started. After 7 days, the patient's conditions allowed weaning from the pumpless extracorporeal lung assist and after 9 days she was extubated.

In conclusion, the pumpless lung assist was shown to be a very practical option to treat the most serious forms of hypercapnia, especially for patients disposed to diffuse bleeding.

The contribution of arterio-venous extracorporeal lung assist to gas exchange in a porcine model of lavage-induced acute lung injury

This prospective large-animal study was performed to evaluate the contribution of arterio-venous extracorporeal lung assist (AV-ECLA) to pulmonary gas exchange in a porcine lavage-induced acute lung injury model. Fifteen healthy female pigs, weighing 50.39±3.8 kg (mean±SD), were included.

After induction of general anaesthesia and controlled ventilation, an arterial line and a pulmonary artery catheter were inserted. Saline lung lavage was performed until the PaO2 decreased to 51±16 mmHg. After a stabilization period of 60 min, the femoral artery and vein were cannulated and a low-resistance membrane lung was interposed. Under apnoeic oxygenation, variations of sweep-gas flow were performed every 20 min in order to evaluate the membrane lung's efficacy, in terms of carbon dioxide (CO2) removal and oxygen (O2) uptake. Although AV-ECLA is highly effective in eliminating CO2, if combined with apnoeic oxygenation, normocapnia was not achievable. AV-ECLA's contribution to oxygenation during severe hypoxemia was antagonized by a significant increase in the pulmonary shunt fraction.

Extracorporeal membranous oxygenation (ECMO) in polytrauma: what the radiologist needs to know

The purpose of this article is to review the spectrum of severe traumatic injuries treatable with ECMO and their imaging features, considerations for cannula placement, and complications that may arise in polytraumatized patients on extracorporeal life support. Recent major advances in miniaturization and biocompatibility of ECMO devices have dramatically increased their safety profile and expanded the application of ECMO to patients with severe polytrauma.

Extracorporeal lung support in trauma patients with severe chest injury and acute lung failure: a 10-year institutional experience

Introduction

Severe trauma with concomitant chest injury is frequently associated with acute lung failure (ALF). This report summarizes our experience with extracorporeal lung support (ELS) in thoracic trauma patients treated at the University Medical Center Regensburg.

Methods

A retrospective, observational analysis of prospectively collected data (Regensburg ECMO Registry database) was performed for all consecutive trauma patients with acute pulmonary failure requiring ELS during a 10-year interval.

Results

Between April 2002 and April 2012, 52 patients (49 male, three female) with severe thoracic trauma and ALF refractory to conventional therapy required ELS. The mean age was 32 ± 14 years (range, 16 to 72 years). Major traffic accident (73%) was the most common trauma, followed by blast injury (17%), deep fall (8%) and blunt trauma (2%). The mean Injury Severity Score was 58.9 ± 10.5, the mean lung injury score was 3.3 ± 0.6 and the Sequential Organ Failure Assessment score was 10.5 ± 3. Twenty-six patients required pumpless extracorporeal lung assist (PECLA) and 26 patients required veno-venous extracorporeal membrane oxygenation (vv-ECMO) for primary post-traumatic respiratory failure. The mean time to ELS support was 5.2 ± 7.7 days (range, <24 hours to 38 days) and the mean ELS duration was 6.9 ± 3.6 days (range, <24 hours to 19 days). In 24 cases (48%) ELS implantation was performed in an external facility, and cannulation was done percutaneously by Seldinger's technique in 98% of patients. Cannula-related complications occurred in 15% of patients (PECLA, 19% (n = 5); vv-ECMO, 12% (n = 3)). Surgery was performed in 44 patients, with 16 patients under ELS prevention. Eight patients (15%) died during ELS support and three patients (6%) died after ELS weaning. The overall survival rate was 79% compared with the proposed Injury Severity Score-related mortality (59%).

Conclusion

Pumpless and pump-driven ELS systems are an excellent treatment option in severe thoracic trauma patients with ALF and facilitate survival in an experienced trauma center with an interdisciplinary treatment approach. We encourage the use of vv-ECMO due to reduced complication rates, better oxygenation and best short-term outcome.

Advances in therapy for acute lung injury

Despite advances in the therapy for acute lung injury and adult respiratory distress syndrome, mortality remains high. The iatrogenic risk of ventilator-induced lung injury might contribute to this high mortality because the lungs are hyperinflated. Low tidal volume and inspiratory pressure are surrogates for the stress and strain concept; but lung compliance, transpulmonary pressure, and chest wall elastance might differ in individual patients. In previous published studies, an increasing number of patients were treated successfully with extracorporeal support. Extracorporeal membrane oxygenation and interventional lung assist allow ultraprotective ventilation strategies. However, these assists have different technical aspects and different indications.

Advances in extracorporeal ventilation

Mechanical ventilation remains the signature tool of critical care; however, within the past decade, a growing body of evidence suggests that positive pressure ventilation in acute respiratory failure is a double-edged sword that is associated with life-threatening complications such as nosocomial pneumonia and low cardiac performance. Essentially, solutions are required to provide adequate gas exchange and stable acid-base status while optimizing and maximizing pulmonary as well as remote organ protection. Recently, the first commercially available extracorporeal membrane ventilator was approved for clinical lung support, the Interventional Lung Assist. This article gives an overview of the potential indications for this device and the current clinical evidence in extracorporeal ventilation.

[Pumpless extracorporeal lung assist]

The recently introduced pumpless extracorporeal lung assist (PECLA) is a remarkable alternative to the conventional extracorporeal membrane oxygenation in case of severe lung failure. By establishing a shunt between femoral artery and vein using the arterio-venous pressure gradient as a driving force through a low-resistance membrane oxygenator, PECLA provides highly effective gas-exchange by preserved cardiac function. Due to its closed system, reduced priming volume and low heparin demand, the unfavourable effects of extracorporeal membrane oxygenation can be effectively diminished. Hence the small technical, financial and personal input, the PECLA can be ideally used in district hospitals and during transport as well. Our short summary demonstrates the advantages and safety of the system proven over 123 cases.

Clinical experience with the iLA Membrane Ventilator pumpless extracorporeal lung-assist device

Extracorporeal gas exchange by extracorporeal membrane oxygenation has been established clinically in patients with acute lung failure. The interventional lung-assist (iLA) Membrane Ventilator device (Novalung) is a sophisticated representative of a new generation of pumpless extracorporeal lung-assist devices that are driven by the patient's cardiac output and therefore, do not require extracorporeal pump assistance. The system is characterized by a new membrane gas exchange system with optimized blood flow that is integrated in an arteriovenous bypass established by vascular cannulation. This particular pumpless extracorporeal lung-assist device was applied in 1800 patients for artificial lung assistance with easy use and low cost. This article reviews the present state of clinical Novalung device implementation focusing on encountered limitations and conceivable future developments in the field.

An Update on Interventional Lung Assist Devices and Their Role in Acute Respiratory Distress Syndrome

In recent years, pumpless arteriovenous systems for extracorporeal gas exchange have become a new therapeutic option for the treatment of patients suffering from acute respiratory failure. Experiences with the pumpless extracorporeal membrane lung in animal experiments and in patients with adult respiratory distress syndrome published in the current literature are reviewed. In addition this article presents a case of varicella pneumonia with persistent hypoxemia and hypercapnia under mechanical ventilation that showed a significant improvement with treatment with a pumpless extracorporeal lung assist using an arteriovenous shunt for eight days. The patient made a complete recovery. This is the first report of a patient with a life-threatening varicella pneumonia successfully treated with pumpless extracorporeal lung assist device. This review provides an update on interventional lung assist devices and a critical discussion of their advantages and limitations.