Complete obstruction of an endotracheal tube due to an unexpected blood clot in a patient with a hemo-pneumothorax after repositioning of the patient for lumbar spine surgery

Corresponding author: Hyun Kyoung Lim, M.D., Department of Anesthesiology and Pain Medecine, Inha University Hospital, 7-206, Sinheungdong 3-ga, Jung-gu, Incheon 400-711, Korea. Tel: 82-32-890-3968, Fax: 82-32-881-2476, E-mail: [email protected] This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http:// creativecommons.org/licenses/by-nc/3.0/), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. CC Endotracheal intubation is widely used to maintain the airway during general anesthesia. Intraoperative endotracheal tube obstruction can be caused by biting, kinking, external compression, and secretions or other intraluminal material [1]. We experienced a case of complete obstruction of the endo tracheal tube due to a blood clot during surgery with a patient in the prone position who had a hemo-pneumothorax. A 40-year-old male with bilateral multiple rib fracture associated with a hemo-pneumothorax without hemoptysis, L2 spine fracture and left distal tibia medial malleolar fracture were the result of an accident in which the patient fell down 3 meters. On the seventh day of hospitalization, posterior lumbar interbody fusion was scheduled to correct the L2 spine fracture. Intubation was performed with an 8.0 mm armored tube, and vital signs were stable: blood pressure, 100-120 systolic and 60-70 diastolic; heart rate, 75-90 beats/min; the electrocardiogram showed a normal sinus rhythm with 99-100% oxygen saturation: ETCO2, 34-36 mmHg; peak inspiratory pressure, 18-22 cmH2O. After repositioning the patient for spinal surgery from the supine to the prone position, there was a slight increase in the peak inspiratory pressure to 23-25 cmH2O, but there was no change in both lungs sound and in rib cage movement during mechanical ventilation. Thirty minutes after maintaining the patient in the prone position, a sudden rise in the peak inspiratory pressure and ETCO2 were detected at 32-35 cmH2O and 43-45 mmHg, respectively, with a change in the capnograph indicating an obstructive pattern. Endotracheal suction was done immediately, but was unsuccessful in relieving the pressure. Mechanical ventilation was turned off and manual ventilation was performed, during which progressive increases in resistance were sensed. Eventually, the capnograph was flattened with a gradual decline in oxygen saturation to 75%. Based on suspicion of endotracheal tube obstruction, a bronchoscopy was done using a flexible bronchoscope while intermittent manual ventilation with 100% O2 was carried out. In addition, we confirmed the presence of total occlusion of the endotracheal tube at the distal end by a blood clot. Without delay, the patient was turned back to the supine position and the endotracheal tube was extubated, at which point, the blood pressure was between 160-170 systolic and 95-110 diastolic; the heart rate was 120-130 beats/min and the oxygen saturation was at 45%. Immediate mask ventilation was performed until pulse oximetry Oxygen saturation rose up to 95% and the patient was re-intubated with a 7.5 mm armored tube. The formally extubated tube was fully obstructed with a huge blood clot at the distal end to the cuff site (Fig. 1). The vital signs became stable after re-intubation, and the ETCO2 and peak inspiratory pressure were maintained between 34-36 mmHg and 18-22 cmH2O, respectively. The surgery was completed without further incidence, and the patient was transferred to the general ward without any sequelae, and eventually discharged at POD 21. There are several reported cases on airway obstruction due to blood clots. Arney et al. [2] reported on the cleansing,