Cervical tracheal rupture with persistence of a pseudotrachea in a dog.

A dog was examined because of acute onset of respiratory distress following a cervical dog bite. Physical examination revealed a deep ventral cervical bite wound associated with localized mild subcutaneous emphysema. Thoracic radiographs showed moderate pneumomediastinum. Medical management consisting of oxygen therapy, antibiotics, and anti-inflammatories was initiated. After 2 days, respiratory distress suddenly worsened. Tracheoscopy showed a discontinuity between the tracheal rings of the cervical trachea; however, the inner tracheal wall appeared intact. Computed tomography scan revealed a ~3-cm complete rupture of all layers of the trachea. Surgical resection and anastomosis of the trachea were performed successfully. Follow-up 15 days after surgery showed complete resolution of respiratory signs, as well as subcutaneous emphysema. A mild ventral angulation of the trachea at the surgical site was noticed on thoracic radiographs. This is the first case report of a pseudotrachea in a dog. Persistence of a pseudotrachea may initially result in only minor clinical signs responsive to medical therapy despite tracheal rupture. In the presence of a pseudotrachea, tracheal rupture may be difficult to identify with tracheoscopy alone. Therefore, CT scan should be proposed in every patient with suspected tracheal trauma. Key clinical message: This case report highlights the importance of including a tracheal rupture in the differential diagnosis of cervical subcutaneous emphysema, even if the amount is small and not associated with significant respiratory signs. The presence of a pseudotrachea may result in less severe clinical signs than expected based on the actual degree of tracheal injury; however, the clinical status may rapidly deteriorate and become life-threatening. This case report also underlines the importance of a CT scan as a complement to tracheoscopy, which may not be sufficient to identify a tracheal rupture in the presence of a pseudotrachea.

Rupture trachéale cervicale avec persistance d'une pseudotrachée chez un chien. Un chien a été présenté pour une dyspnée aiguë modérée consécutive à des morsures cervicales par un autre chien. L'examen clinique révéla une plaie cervicale ventrale profonde associée à un emphysème sous-cutané localisé léger. Les radiographies thoraciques ont montré un pneumomédiastin modéré. Un traitement médical consistant en une oxygénothérapie, des antibiotiques et des anti-inflammatoires a été initié. Après deux jours, la dyspnée s'aggrava brutalement. Une trachéoscopie révéla une discontinuité entre les anneaux trachéaux malgré la persistance d'une paroi trachéale interne intègre. L'examen par tomodensitométrie montra une rupture trachéale cervicale complète dans toute son épaisseur, sur 3 cm de long. Une chirurgie de résection-anastomose de la trachée a été réalisée avec succès.Il s'agit de la première description de pseudotrachée chez un chien. La persistance d'une pseudotrachée peut initialement ne provoquer que des signes cliniques mineurs, notamment un emphysème sous-cutané léger et une dyspnée répondant au traitement médical, malgré une lésion trachéale en réalité importante. Par conséquent, un examen par tomodensitométrie de la trachée doit être envisagé chez tous les patients pour lesquels un traumatisme trachéal est suspecté.Message clinique clé :Ce cas souligne l'importance d'inclure une rupture trachéale dans le diagnostic différentiel de l'emphysème souscutané cervical, et cela même s'il n'est présent qu'en petite quantité et associé à faibles signes cliniques respiratoires. La persistance d'une pseudotrachée peut entraîner des signes cliniques moins importants qu'une rupture trachéale complète, cependant l'état respiratoire de l'animal peut rapidement s'aggraver et devenir une urgence vitale.Ce cas souligne de plus l'importance de l'examen par tomodensitométrie en complément de la trachéoscopie, qui peut parfois s'avérer insuffisante pour le diagnostic des ruptures trachéales, en particulier en présence d'une pseudotrachée.(Traduit par les auteurs).

Heparinized Saline Solution vs. Saline Solution (0.9% Sodium Chloride) for the Maintenance of Dorsal Pedal Arterial Catheter Patency in Dogs Undergoing General Anesthesia: A Pilot Study.

Heparin is widely used as an anticoagulant solution for maintaining arterial catheter patency. In humans, increasing evidence suggests that heparinized saline solution (HS) has no advantages over a saline (0.9% sodium chloride) solution (SS) in maintaining arterial catheter patency. To date, no studies have been conducted on the effectiveness of these solutions at maintaining arterial catheter patency in veterinary medicine. The objective of this pilot study was to determine the feasibility of a study and to report the treatment efficacy comparing HS and SS for the maintenance of the dorsal pedal arterial catheter patency during direct arterial blood pressure measurements in anesthetized dogs. Client-owned dogs undergoing abdominal surgery were allocated to two groups to receive either a continuous infusion of HS or SS through the dorsal pedal artery, and the arterial pressure waveform was monitored during general anesthesia. Our feasibility outcomes included the proportion of the screened veterinary patients that completed the study and the success rate of arterial catheter placement. The clinical outcomes were assessed by the number of catheter-flushing procedures, occlusion rate, the duration of the initial catheter-flushing procedures, and the duration of catheter occlusion. Of the 51 dogs screened, 41 (80.4%) completed the study. The success rate of arterial catheter placement in the HS and SS groups were 87.5 and 80.0%, respectively. There were no differences in the number of catheter-flushing procedures and occlusion rate between groups (28.6 vs. 20.0%, relative risk [RR]: 1.429, 95% confidence interval [CI]: 0.472-4.323, P = 0.719 and 14.3 vs. 15.0%, RR: 0.952, 95% CI: 0.217-4.179, P = 1.000, respectively). No differences were found in the probability of time to the initial catheter-flushing procedure and occlusion between groups assessed by the Kaplan-Meier method (P = 0.546 and P = 0.867, respectively). This study revealed the feasibility of a study comparing HS and SS for dorsal pedal arterial catheter patency during direct arterial blood pressure measurements in anesthetized dogs. Clinical outcome analyses were underpowered and thus, could not determine the meaningful differences in treatment efficacy between the groups. However, the information gained from this study provides insight for future study designs.