Pleur-evac use in a dog with spontaneous pneumothorax | VETgirl Veterinary Continuing Education Videos
In this VETgirl online veterinary CE video, a 2-year-old, female-spayed, German Shepherd was presented in acute respiratory distress. The patient had pronounced abdominal effort and muffled left -sided lung sounds. Thoracic radiographs showed a severe pneumothorax, with atalectic left cranial and caudal lung lobes. Thoracocentesis was attempted, but negative pressure was unable to be obtained, even after several liters of air was removed; the dog was diagnosed with a spontaneous pneumothorax.
Spontaneous pneumothorax is a relatively uncommon cause of respiratory distress in dogs. The most common cause of spontaneous pneumothorax is a bullae (or multiple bullaes or blebs), but can also occur secondary to a mass, abscess, foreign body migration (e.g. porcupine quill), neoplastic mass, etc. Surgical treatment of a ruptured bullae is considered standard of care, typically within 24 hours of diagnosis. Advanced imaging (e.g., CT) is typically recommended to localize and identify the severity of lesion(s), and to help guide surgical exploratory, typically via a median sternotomy. In this patient, a low-profile Mila chest tube was placed with minimal sedation, and was connected to a Pleur-evac® for continuous suction. To see how to set up a Pleur-evac®, see this YouTube video here.
A Pleur-evac® is single use drainage system used for continuous suction of the pleural space, for either pleural effusion or spontaneous pneumothorax. A water column is used to regulate the suction, as well as an in line regulator, both set to 20 mmHg. The fluid in the Pleur-evac® air leak meter is used to monitor the amount of air removed from the pneumothorax. In this patient, you can see the air removed by the Pleur-evac® with each breath. Unless there is an air leak, you would not expect to see these bubbles when using the Pleur-evac® for pleural effusion. If fluid is collected, rather than air, there are measurement markings in the fluid collection chamber to be able to quantify the pleural effusion removed. The limitation of the Pleur-evac® is that it cannot quantitate the amount of air being removed from the chest – only fluid.
After several hours of Pleur-evac® suction, negative pressure was obtained in this patient (as evidenced by the lack of air bubbles in the chamber). At this point, the patient was breathing comfortably, which allowed time to plan for a CT and thoracic surgery. In this patient, a large bullae was identified in the left cranial lung lobe. The patient was taken to surgery and the bullae was successfully removed.
So what can you do if you don’t have a Pleur-evac® and continuous suction? Ideally, patients with a spontaneous pneumothorax would be transferred to a referral specialty hospital for care. Chemical pleurodesis with intra-pleural doxycycline is not as effective in dogs as it is in people, so is not recommended. Blood patching, which involves injecting the patient’s fresh whole nonanticoagulated blood into the pleural space, has been used to form temporary clots, and may provide a short term solution to allow for referral in extremely unstable patients. Blood patching should not be considered a long term solution, however. This patient recovered from a thoracotomy and lung lobectomy, was able to maintain negative thoracic pressure, and was later discharged home.