A 47-year-old male patient, who has no specific past medical history, suffered severe thoracic trauma in a forklift accident 14 h before he was transferred to our hospital. After having his chest crushed by a forklift, the patient instantly had hemoptysis and showed serious signs of respiratory distress. At the local hospital, the physical examination revealed pulse oxygen was at approximately 80%; there was subcutaneous emphysema in the neck and chest; breathing was inaudible by auscultation in the left lung; and, there were moist rales in the right lung. The patient immediately received single-lumen intubation and mechanical ventilation (MV). The CT scan showed left-side pneumothorax, right-side pneumo-hemothorax, bilateral traumatic wet lung, and multiple rib fractures. The bronchoscopy also indicated a left main bronchial rupture. Therefore, the patient was treated immediately with bilateral closed thoracic drainage, fluid infusion, and immobilization of the chest wall.
Treatment notwithstanding, there was no alleviation of the patient’s symptoms, and his pulse oxygen remained consistently low (approximately 80%). Consequently, he was transferred directly to our department. The minute ventilation volume was only 2 to 3 L/min by single-lumen mechanical ventilation. Therefore, the single-lumen tube was replaced with a double-lumen tube, with ventilation only to the right lung to prevent leakage. Nevertheless, the patient’s pulse oxygen remained low, with no remediation of his respiratory distress. On admission, after running the necessary checks and analyses, with his APACHE II score at 25, the predicted odds of mortality was 51%. His blood gas revealed both respiratory acidosis and metabolic acidosis, with both exacerbating gradually. Figure 1 exhibited the chest x-rays at different times, before pneumonectomy (Fig. 1a) and after the withdrawal of ECMO (Fig. 1b).
At that critical moment, ECMO was initiated without delay. Upon selection of the veno-venous (V-V) ECMO model, catheters were inserted into the right jugular vein (arterial catheter, the tip nearly reached right atrium) and right femoral vein (venous catheter, the tip located at inferior vena cava). Specifically, blood was drawn out from the right atrium to the ECMO device (Maquet, ROTAFLOW Console), after oxygenation it was infused into the right femoral vein, with the gas flow at 4-6 L/min, fraction of inspiration O2(FiO2) at 100% and the pump operating at 3480—3610 rpm. Upon receipt of ECMO and MV, the patient’s oxygenation stabilized; his pulse oxygen rose to 97%—100%; and his respiratory distress was alleviated significantly, thus permitting urgently needed surgery. With the consent of his family members, the patient had an emergency, video-assisted thoracoscopic exploratory thoracotomy. The edema and consolidation of the entire left lung were severe. 1 cm from the tracheal carina, the postero-lateral wall of the left main bronchus experienced an 8 cm long and irregular rupture, which spread to the distal end of the secondary bronchus of the upper and inferior lobes. The rupture was unable to be ordinarily repaired and anastomosed, so the patient required a total left lung resection. The thoracoscopic pictures during the surgery are exhibited in Fig. 2.
After left lung resection, with the support of ECMO, the parameters of ventilator (PURITAN BENNETT 840) were set as follows, mode: Synchronized Intermittent Mandatory Ventilation (SIMV), Frequency(F): 12 times/min, VT:200 ml, FiO2: 40%, and positive end expiratory pressure (PEEP): 8cmH2O. Gradually, with ECMO and low tidal volume (VT) MV (VT 200 ml) as the main therapy, assisted by anti-inflammatories, antibiotics, sedatives, and analgesics, the patient made a recovery. ECMO was sustained up to the 10th day, and MV until the 20th day, post-operation. After the initiation of ECMO, heparin was micro-pump injected (125u-750u/hour), and activated clotting time (ACT) was monitored every 2 h. ACT was expected to remain between 160 s to 180 s, which was fluctuating between 130 s to 210 s without severe bleeding complication occurring. After the initiation of ECMO, arterial and venous blood gas were tested every 6 h; 24 h before the patient’s ECMO weaning, the gas flow was reduced to 2 L/min; 6 h before weaning to 0 L/min; FiO2 was reduced to 80%, the O2 and CO2 partial pressure of blood gas were dynamically stable, then ECMO was weaned and the related catheters were removed. During the ECMO treatment, infections such as catheter-related bloodstream infection or ventilator associated pneumonia (VAP) should be anticipated, and antibiotics for most gram-negative and some of the sensitive gram-positive bacteria should be applied. In this case, the culture of sputum samples and broncho-alveolar lavage fluid or blood samples were all negative. In the first week after the operation, piperacillin-sulbactam was used to prevent possible lung infections, later to be replaced by imipenem and levofloxacin when the fever and white blood cell count climbed. Ulinastatin, a glycoprotein found in human urine and blood, proved to be a multivalent, Kunitz-type serine protease inhibitor and exhibited moderate anti-inflammatory effects without any immunosuppression side-effects ; it was used for immuno-modulation and anti-inflammation in our case. Because the invasive double-lumen intubation and right-side multiple rib fractures caused considerable pain, appropriate analgesics and sedatives were essential for the post-op compliance of the patient. The combination of dexmedetomidine and fentanyl or midazolam and morphine were used alternatively for sedation and analgesia. The alteration reduced the risk of drug accumulation while keeping a satisfying effectiveness. Finally, considering the subcutaneous emphysema in the neck and the edema of bronchial local tissue, a tracheotomy was not performed in the early phase, but a double-lumen tube was retained until the 10th day to cope with possible leakage in the bronchial stump.