A 58-year-old woman suffered from blunt thoracic, pelvic fracture, and right lower limb fracture because of falling from approximately 6 meters high by accident. She was transferred to the nearest hospital and admitted into intensive care unit (ICU) immediately. Emergency CT examination showed bilateral pulmonary contusion, right pleural effusion, bilateral multiple rib fractures, right clavicle fractures, lumbar two–four vertebral spinous process fractures, right iliac bone fractures, and right femoral shaft fractures. The patient received single-lumen intubation and mechanical ventilation (MV) because of refractory tachypnea and hypoxemia. In addition, chest X-ray showed right large hemothorax with atelectasis (Figure 1). The patient presented hemorrhagic shock due to hemothorax and multiple fractures. The patient was treated with closed drainage of the right thoracic cavity, enhanced MV support, fixation and traction of the right lower limb, and fluid and blood transfusion resuscitation. After these treatments, blood pressure could be maintained with low-dose vasopressors, but no alleviation of hypoxemia was observed. Therefore, the patient was transferred to our ICU department on day 2.
On arrival, the patient had severe dyspnea with paradoxical breathing, respiratory rate at 35 breaths per minute, tachycardia at 130 beats per minute, and arterial pressure of 122/68 mmHg with norepinephrine infusion at 0.1 μg/Kg/min. Breathing sounds decreased, oxygenation saturation was 90% with ventilator set as fraction of inspiration oxygenation (FiO2) 1.0, pressure control (PC) 25 cmH2O, positive end expiratory pressure (PEEP) 15 cmH2O, and tidal volume (VT) 300 ml; arterial blood gas analysis showed that pH was 7.32, PaO2 was 53 mmHg, and PCO2 was 72 mmHg. Meanwhile, the bedside bronchoscopy showed that the main bronchus was almost obstructed by foreign bodies, which may be blood clots caused by bronchial hemorrhage (Figure 2). When the PaO2/FiO2 ratio (PFR) was 53 mmHg, removing the blood clots was dangerous, and threatened bleeding would recur after blood clots were removed. Moreover, mechanical ventilation and respiratory distress can aggravate lung injury and lead to persistent pulmonary hemorrhage. Therefore, we decided to establish veno-venous (V-V)-ECMO, and insert catheter via the right jugular vein (19-F cannula for inflow) located at the right atrium and the right femoral vein (21-F cannula for outflow) located at the inferior vena cava. Blood was drawn out from the inferior vena cava to the ECMO device (Maquet, ROTAFLOW Console), and it was infused into the right atrium after oxygenation. We did not use any anticoagulation drugs because of bronchial bleeding, right hemothorax, and other unstable organ injury. The pump was set at 3800–4000 rpm to maintain a blood flow rate of approximately 4.0 L/min, which may prevent thrombus formation, and the gas flow rate at 3–5 L/min and FiO2 1.0. After ECMO was established, mechanical ventilation parameter was declined to prevent barotrauma with remediation of respiratory distress. Arterial blood gas analysis showed that pH was 7.45, PaO2 was 163 mmHg, and PCO2 was 30 mmHg with ventilator set as PC 14 cmH2O, PEEP 10 cmH2O, VT 200 ml, and FiO2 0.4. The patient was stable with respiratory rate of 12 breaths per minute, heart rate of 80 beats per minute, and arterial blood pressure of 110/60 mmHg without any vasopressor. Further CT scan showed that the bilateral lung consolidation and trachea were almost obstructed completely (Figure 3). With ECMO support, we performed bronchoscopy with cryotherapy to clear the foreign bodies in the main segments of bronchopulmonary, and the pathology results showed that the foreign bodies were blood clots (Figure 4.).
When the clots were removed, the ventilator parameters were the same as the previously set condition, and VT was augmented from 200 ml to nearly 400 ml. Chest CT scan was obtained prior to the withdrawal of ECMO, showing that the clots in the trachea disappeared and pulmonary atelectasis improved (Figures 5). We weaned ECMO support by decreasing oxygen supply on day 3 and removing ECMO when the oxygen supply stopped for 24 hours on day 6 with ventilator set to PC 13 cmH2O, PEEP 8 cmH2O, and PFR>300 mmHg because of non-heparinization. No ECMO-related infection and bleeding were observed during the course. Prothrombin time (PT), activated partial thromboplastin time (APTT), and D-dimer were monitored four times each day during ECMO ongoing to evaluate ECMO thrombogenicity. We removed the right thoracic drainage tube on day 5 and the left thoracic drainage tube on day 6. The patient underwent tracheostomy on day 10, MV stopped on day 13, and bronchial bleeding totally stopped on day 15. The right femoral shaft and pelvic fracture underwent reposition and osteosynthesis on day 18. The patient was extubated on day 24, transferred to traumatology ward on day 28, and discharged on day 35.