Fatal tracheo-innominate artery fistula after tracheostomy in a patient with Pelizaeus-Merzbacher disease.

Tracheo-innominate artery fistula (TIF) is a serious, life-threatening complication following tracheostomy. We report a fatal TIF in a 15-year-old girl with Pelizaeus-Merzbacher disease. She received a tracheostomy for prolonged translaryngeal intubation due to acute respiratory failure without a trial of noninvasive ventilatory support before intubation. Severe hemorrhage from the TIF occurred 6 months after tracheostomy; immediate resuscitation failed. Antemortem fiberoptic bronchoscopy showed tracheal stenosis accompanied by granulation tissue, and postmortem examination revealed TIF with ulcerative granulation. Preventive intervention is required to avoid catastrophic TIF due to its high mortality rate. Moreover, to avoid prolonged translaryngeal intubation leading to tracheostomy, noninvasive ventilatory support before translaryngeal intubation, if applicable, is beneficial.

Effects of direct haemoperfusion through fibres immobilizing polymyxin B and nafamostat mesilate on endotoxaemia in conscious Guinea-pigs.

1. Direct haemoperfusion through a network of fibres immobilizing polymyxin B (PMX-B) is used for the treatment of septic shock, but the mechanism underlying its clinical benefits remains unclear. The aims of the present study were to assess the actions of direct haemoperfusion through fibres immobilizing PMX-B (PMX-DHP) on the effects of exogenously administered endotoxin in conscious guinea-pigs and to examine the difference in the effects of heparin compared with nafamostat mesilate (NM) used as an anticoagulant. Although nafamostat is widely used in Japan, the agent cannot necessarily be used elsewhere in the world. Therefore, the study aimed to investigate and elucidate the effectiveness of NM compared with heparin. 2. Colonic motion was monitored continuously via telemetry using a force transducer attached to the taenia caecum, whereas blood pressure was monitored using a carotid artery catheter. To establish a haemoperfusion circuit in each freely moving and conscious guinea-pig, catheters were implanted in the carotid artery and the jugular vein, tunnelled subcutaneously, exteriorized at the back of the neck in contact with a lightweight tethering spring and attached to a swivel device at the top of the cage. On the day after the operation, lipopolysaccharide (LPS; Escherichia coli, O111:B4; 1 mg/kg) was administered i.v. and PMX-DHP was conducted for 2 h. Heparin (50 IU/h) or NM (0.4 mg/h) was used as the anticoagulant. Furthermore, guinea-pigs were administered a lethal dose of LPS (10 mg/kg) and the survival rate was examined for animals undergoing PMX-DHP compared with control animals. 3. In guinea-pigs treated with PMX-DHP, relaxation of colonic longitudinal muscle caused by LPS was significantly suppressed, as were decreases in blood pressure. Of the two anticoagulants used, NM was more effective than heparin. In addition, PMX-DHP significantly increased the survival rate of guinea-pigs that received potentially lethal doses of LPS. 4. In conscious and unrestrained guinea-pig endotoxaemia model, PMX-DHP significantly improved intestinal paralysis and decreases in blood pressure. These effects were augmented more by NM than by heparin when an anticoagulant was used in the perfusion process. These findings suggest that haemoperfusion using PMX and NM performed in the early stage of endotoxaemia is an effective treatment.

Elimination of 2-arachidonoylglycerol action by direct hemoperfusion through immobilized polymyxin B fibers: an experimental study in conscious guinea pigs.

Direct hemoperfusion through a network of immobilized polymyxin B fibers is used for the treatment of septic shock, but the mechanism underlying the clinical benefits remains unclear. The aims of the present study were to assess the actions of direct hemoperfusion through immobilized polymyxin B fibers on effects of exogenous endotoxin or 2-arachidonoylglycerol in conscious guinea pigs; and to examine the underlying mechanisms. In the present study, colonic motion was monitored continuously by telemetry using a force transducer attached to the taenia caecum, while blood pressure was monitored with a carotid artery catheter. To establish a hemoperfusion circuit in a freely moving, conscious guinea pig, catheters were implanted in the carotid artery and the jugular vein, tunneled subcutaneously, exteriorized at the back of the neck in contact with a lightweight tethering spring, and attached to a swivel device at the top of the cage. On the day after the operation, lipopolysaccharide (Escherichia coli, O111:B4; 1 mg/kg) or 2-arachidonoylglycerol (1 mg/kg) was given intraperitoneally (i.p.) and direct hemoperfusion through immobilized polymyxin B fibers was carried out for 2 h. The results showed that in guinea pigs treated with direct hemoperfusion through immobilized polymyxin B fibers, relaxation of colonic longitudinal muscle caused by lipopolysaccharide or 2-arachidonoylglycerol was significantly suppressed, as were decreases in blood pressure. We conclude that the actions following exogenous administration of 2-arachidonoylglycerol were eliminated by direct hemoperfusion through immobilized polymyxin B fibers. These results suggest that effectiveness of direct hemoperfusion through immobilized polymyxin B fibers in endotoxemia involves elimination of 2-arachidonoylglycerol action.