Читать книгу Canine and Feline Respiratory Medicine - Lynelle Johnson R., Lynelle R. Johnson - Страница 47

Thoracocentesis is performed as a diagnostic and therapeutic technique. It can be done before radiographs are performed when physical examination suggests a pleural disorder and the animal is in distress, after thoracic ultrasound demonstrates pleural disease, or after radiographs when pleural space disease is confirmed. The region of the seventh to ninth intercostal space is clipped and scrubbed in the ventral one‐third of the chest for fluid and in the dorsal one‐third for air. A 20 or 22 gauge butterfly needle is adequate for use in small dogs and cats when small pleural effusion or mild pneumothorax is present. A fenestrated 14–18 gauge catheter with extension set works well for larger dogs and can allow relatively rapid removal of large pleural effusions. Prior to entering the chest, an extension set, three‐way stopcock, and syringe should be assembled and ready for use to limit introduction of air into the pleural space after penetration with the needle or catheter. A large bowl, ethylenediaminetetraacetic acid (EDTA) and red‐top tubes, and a culturette swab should also be readily available to allow efficient specimen collection. In some animals, sedation is needed to perform a chest tap safely. Whenever possible, it is useful to have three people available to perform a chest tap.

A sterile preparation of the lateral thorax is completed and a site on the chest wall is chosen. The needle or catheter is advanced through tented skin and then walked off the cranial border of the rib to penetrate the pleural space at a perpendicular angle. This will avoid the vessels and nerves lying along the caudal rib margin. As soon as the pleura has been penetrated, the needle or catheter is directed downward to avoid injury to the lung parenchyma (Figure 2.23). The needle stylet is held stationary while catheter is advanced over the needle into the pleural space. When the catheter is fully in the chest, the needle is withdrawn, and the extension set is rapidly attached.

Figure 2.23 (a) To initiate thoracocentesis, the skin is tented and the catheter with needle is inserted perpendicularly between the rib spaces. (b) After the pleural space has been entered, the needle is directed ventrally and the catheter is advanced fully into the chest while the needle is held stationary.