Heparin-free extracorporeal membrane oxygenation in a patient with severe pulmonary contusions and bronchial disruption.

Pulmonary contusion complicated with endobronchial hemorrhage is potentially life-threatening, particularly in patients with tracheobronchial tree disruption and severe airway bleeding after blunt trauma, and pose a high mortality risk. In such cases, extracorporeal membrane oxygenation (ECMO) can be used as a salvage treatment modality. However, the use of ECMO for moribund trauma patients with respiratory failure may be limited for several reasons, such as intractable bleeding. In this case report, we describe a patient with severe bilateral pulmonary contusions with tracheobronchial tree disruption that was successfully treated using heparin-free venovenous ECMO.

INTRODUCTION

Extracorporeal membrane oxygenation (ECMO) is a useful rescue treatment for patients with respiratory failure. However, the use of ECMO in trauma patients with bleeding has been limited because of the risk of systemic heparinization. In selected trauma patients with endobronchial hemorrhage due to severe contusion, heparin-free ECMO may be used successfully [1]. In this case report, we report the use of heparin-free ECMO to support a patient with tracheobronchial tree disruption and bilateral pulmonary contusions complicated with alveolar hemorrhage due to a blunt trauma.

CASE REPORT

A 48-year-old man who had sustained traumatic hemopneumothorax after being trapped between a forklift and a truck was transferred from a local hospital after bilateral closed thoracostomy. His initial vital signs were as follows: blood pressure, 160/100 mmHg; pulse rate, 104 beats/min; respiratory rate (RR), 32 breaths/ min; oxygen saturation, 92%; body temperature, 36.5°C; and Glasgow coma scale, 15 points.

Initial arterial blood gas analysis performed under mechanical ventilation with a fraction of inspired oxygen (FiO2) of 0.6 showed a pH of 7.22, PaCO2 of 50 mmHg, PaO2 of 64 mmHg, and HCO3 of 22 mmol/L. Contrast-enhanced computed tomography of the chest and abdomen-pelvis revealed a grade 2 liver laceration, multiple thoracic spine fractures involving the transverse and spinous processes, bilateral multiple rib fractures, and severe bilateral lung contusions with suspicious injury of the right lower lobar bronchus. The injury severity score was 43 points (Fig. 1).

Fig. 1.

Computed tomography of the chest in a 48-year-old man who sustained blunt chest trauma. (A,B) There is a suspicious bronchial injury (arrow) on the right lower lobe and severe bilateral lung contusions.

After 4 hours, continuous air leakage through the right-sided chest tube was observed. The patient’s ventilatory parameters were incompatible with survival, with a PaO2/FiO2 ratio of 56 at FiO2 of 1.0. Venovenous ECMO (Maquet Rotaflow Centrifugal Pumps with Quadrox-D oxygenators; Maquet, Rastatt, Germany) was promptly established using the Seldinger technique. A 17-Fr arterial catheter was inserted into the right jugular vein and a 19-Fr venous catheter (Bio-medicus; Medtronic, Minneapolis, MN, USA) was inserted into the right femoral vein. Initial heparin loading was not performed. After ECMO, the ventilatory status and follow-up arterial blood gas analysis were as follows: FiO2 of 0.4, RR of 12 breaths/min, peak inspiratory pressure of 20 mmHg, positive end-expiratory pressure of 10 mmHg, PaO2 of 98 mmHg, and PaCO2 28 of mmHg. Under ECMO, we performed a bronchoscopy to evaluate the extent of the bronchial injury and then decided to perform emergency surgery.

Surgery was performed under venovenous ECMO, with one-lung ventilation and lung protection strategies implemented to keep the tidal volume below 150 mL and FiO2 below 0.4. A right posterolateral thoracotomy was performed to remove the large hematomas. A circumferential tear of more than 80% was observed in the right lower lobar bronchus, with laceration of the right lower lobe that was irreparable (Fig. 2A); hence, a right lower lobectomy was performed (Fig. 2B). Thereafter, the displaced right sixth and seventh ribs were fixed using an 8-hole straight plate (SternaLock; Biomet Microfixation, Jacksonville, FL, USA).

Fig. 2.

Intraoperative findings in a 48-year-old man who sustained blunt chest trauma. (A) Bronchial tear and crushing injury to the right lower lobe of the lung are shown. (B) After right lower lobectomy, the specimen shows a more than 80% circumferential tear in the right lower lobar bronchus.

ECMO was maintained without anticoagulation, and meticulous lung care with suctioning of the blood clot was continued. The ECMO system was successfully removed 59 hours postoperatively. The patient was eventually weaned off mechanical ventilation on day 4 and was discharged without any complaints.

DISCUSSION

ECMO has been a proven rescue modality to treat patients with reversible respiratory failure. Currently, early initiation of ECMO is acknowledged to improve the survival of trauma patients with respiratory failure due to ventilator-associated pneumonia or systemic inflammatory response syndrome [1]. However, ECMO support in patients with bronchial injury and/or severe lung contusion is not recommended. Pulmonary contusion with alveolar hemorrhage and tracheobronchial injury can be managed without ECMO through lung isolation using a double-lumen endotracheal tube and suctioning of the blood clot and strategies that range from repair to pneumonectomy [2-4]. However, these treatment modalities may not be sufficient for stabilizing patients with bronchial injury complicated with bilateral lung contusions and endobronchial hemorrhage. In particular, one-lung ventilation during surgery could pose high mortality and morbidity risks because of acute lung injury, and conventional treatment might not be adequate for maintaining hemodynamic and respiratory stability [5]. In such cases, ECMO could be a useful rescue treatment.

In general, the use of ECMO entails anticoagulation to prevent life-threatening thrombosis in the extracorporeal circuit. On the other hand, inappropriate anticoagulation may result in excessive bleeding due to consumptive coagulopathy [6]. According to one report, among 15 patients, 6 had hemorrhagic complications and 4 had thromboembolic complications [1]. These results imply a limitation of ECMO support in moribund trauma patients with bleeding. Recently, heparin-coated circuits and oxygen membranes have been developed. According to another case report, short-term heparin-free venovenous ECMO in patients with contraindications to therapeutic anticoagulation could be an effective treatment modality without thromboembolic complications [7-9]. In this patient who presented with active bleeding, which manifested as pulmonary contusion complicated with alveolar hemorrhage, hemothorax, and liver laceration, the use of high-flow (more than 3.5 L/min) and short-term ECMO, instead of anticoagulation, successfully weaned him off mechanical ventilator support 59 hours postoperatively, without thromboembolic complications. As this is a case report, the use of heparin-free venovenous ECMO for patients with bleeding needs to be proven, with more cases and studies undertaken. Nevertheless, our experience with this case suggests that heparin-free ECMO may be a valuable treatment option for trauma patients with contraindications to anticoagulation.

ECMO is an invasive procedure with significant risks for complications, such as thrombosis and hemorrhage. In addition, ECMO support may not be the first treatment option in patients with bronchial injury or traumatic lung contusion with alveolar hemorrhage, and its use is even contested in injured, bleeding patients. However, in a patient with severe traumatic bronchial injury and alveolar hemorrhage with intractable hypoxemia and hypercapnia, ECMO merits consideration and may be key to survival in this situation.