Extracorporeal membrane oxygenation in severe respiratory failure resulting from burns and smoke inhalation injury

Abstract

Extracorporeal membrane oxygenation (ECMO) is one of the most frequent forms of extracorporeal life support (ECLS) and can be used as rescue therapy in patients with severe respiratory failure resulting from burns and/or smoke inhalation injury. Experience and literature on this treatment option is still very limited, consequently results are varied. We report a retrospective analysis of our experience with veno-venous (VV) ECMO in burn patients. All five patients, three male and two female (age: 28–37 years) had flame type burns and smoke inhalation injury. Their Murray scores ranged between 3.25 and 3.75, and their revised Baux scores between 62 and 102. The mean pre-ECMO conventional ventilation time was 7.4 days (3–13). The mean ECMO duration was 18 days (8–35). Three patients were cannulated with dual lumen, two with separate cannulae. One oxygenator had to be changed due to technical issues and two patients needed two parallel oxygenators. Four patients had renal replacement therapy. All patients needed vasoconstrictor support, antibiotics and packed red blood cells (5–62 units). Three had steroid treatment. All five patients were successfully weaned from ECMO. One patient died later from multi-organ failure in the ICU, the other four patients survived. VV-ECMO is a useful rescue intervention in patients with burns related severe respiratory failure. Patients in our institution benefit from having both burns and ECMO centres with major expertise in the field under one roof. The results from this small cohort are encouraging, although more cases are needed to draw more robust conclusions.

Introduction

Pulmonary injury resulting from burns and/or acute smoke inhalation presents with multifaceted pathophysiology. The profound inflammation of airways with pulmonary shunting as well as augmented micro-vascular pressure gradient often results in hypoxemic respiratory failure [1], [2], [3]. Acute lung injury (ALI) as a result of smoke inhalation contributes significantly to the overall morbidity and mortality of fire victims. Thirty years ago, Shirani et al. [4] described additive effects on mortality in patients with burns and inhalation injury. The authors reported increased mortality of burn patients of approximately 20% with smoke inhalation, up to 40% from pneumonia, and up to 60% if both were present (at the midrange of age and burn size) [4], [5].

Extracorporeal membrane oxygenation (ECMO) is a relatively new technology that emerged about 50 years ago and today is routinely used in specialized centres for neonatal, pediatric, and adult respiratory and cardiac failure [7]. It was used for the first time in a burn patient in 1994 [6]. ECMO can be used in veno-venous configuration (VV-ECMO) to provide adequate extracorporeal gas exchange in isolated refractory respiratory failure of numerous causes, or in veno-arterial configuration (VA-ECMO), when support for cardiac and/or circulatory support is required [8]. The overall goal of ECMO in patients with severe respiratory failure is to achieve adequate gas exchange, and to allow a reduced intensity of mechanical ventilation, thereby decreasing the potentially deleterious effects of ventilator-induced lung injury prior to recovery. Consequently, ECMO may be considered the definitive rescue therapy for refractory life-threatening hypoxemia, since pulmonary gas exchange is not required [5], [9].

The use of ECMO in neonatal respiratory failure has been established for decades and is supported by randomized trials [10]. Use in adult respiratory failure is more controversial given poor outcomes in early randomized trials [11], [12]. The CESAR trial from 2009 [13] and various case series have shown improved outcomes with survival rates between 75% and 85% in patients with refractory respiratory failure who were referred to an ECMO centre [14], [15]. To date, only a few studies assessing ECMO in the field of burn and/or acute smoke inhalation injury have been published. This retrospective study reports our experience with five patients requiring ECMO for severe hypoxemic respiratory failure post-burn and smoke inhalation injury.