Extracorporeal membrane oxygenation in severe trauma patients with bleeding shock

Abstract

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 paCO₂ was 67 (36–89) mm Hg 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) mm Hg, median paCO₂ 41 (22–85) mm Hg. 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.

Introduction

Severe trauma is a leading cause of death in young adults.1, 2 Fatal injuries without any treatment option (e.g., cervical spinal injury and aortic rupture) result in immediate death at the scene. Life-threatening complications in the early course are bleeding shock and/or severe respiratory failure following chest trauma or massive blood transfusion. The early goal in trauma care is to combat shock. Bleeding shock can be treated effectively on scene by controlling the source of bleeding and rapidly initiating fluid resuscitation. In cases of severe trauma, early damage control surgery and extensive blood transfusion are immediately necessary.³ About 15% of polytrauma patients are in need of massive blood transfusion (MBT) defined as more than 10 units of packed red blood cells (PRBC). The prognosis of trauma patients receiving MBT is considered to be poor.4, 5, 6, 7, 8 Even if massive blood transfusion (MBT) is effective in the treatment of hemorrhagic shock, it is associated with potential complications9, 10 like severe acidosis and hypothermia. Hypothermia (body temperature < 34 °C) has deleterious effects on blood coagulation in trauma patients and when occurring in conjunction with metabolic acidosis can result in a mortality rate up to 90%.11, 12, 13, 14 MBT can overwhelm the patient's cardiocirculatory function resulting in the early decrease of cardiac output and pulmonary gas exchange. Late complications can appear as transfusion-related lung injury (TRALI) which magnifies the impairment of pulmonary gas exchange by blunt chest trauma and pulmonary contusions.¹² Both-, MBT and pulmonary contusion can lead to acute respiratory distress syndrome (ARDS). ARDS is most frequently observed in the early course of intensive care in patients with severe trauma and shock. The mortality rate in these patients reaches up to 40% despite advanced ventilatory treatment.15, 16 The use of extracorporeal membrane oxygenation (ECMO) as lifesaving treatment in respiratory failure was introduced by the pioneer work of Robert Bartlett in 1972¹⁷ and revolutionised the treatment of resistant hypoxemia in patients worldwide.18, 19 Depending on the site of cannulation, ECMO takes over the gas exchange function of the lung (veno-venous ECMO) or provides additional circulatory support (veno-arterial ECMO).17, 18, 19 Despite ongoing technical improvement of ECMO devices like centrifugal pumps and heparin coating of the circuits (which allows a reduction of systemic heparinisation), bleeding is still the most common complication in patients on ECMO. Bleeding can be induced by cannulation of the vessels, underlying coagulation disorders or the full-dose heparinisation commonly used.²⁰ Since the first ECMO in a trauma victim was performed by Hill et al.,²⁰ there have been several reports on ECMO in the subsequent course of post-traumatic respiratory failure in patients with blunt chest trauma.21, 22 However, the use of ECMO in severe trauma victims with preexisting bleeding shock is still unusual.²³ A recently published report on ECMO support in post-traumatic ARDS patients highlights the effort to extend this lifesaving technology to trauma patients.²³ We report our first experiences in application of initially heparin-free ECMO in severe trauma patients with resistant cardiopulmonary failure and coexisting bleeding shock. We reviewed our data retrospective and describe cannulation procedures and blood coagulation management during emergency v-v and v-a ECMO.