This VETgirl video demonstrates how to perform a thoracocentesis in a dyspneic cat. By using a TFAST ultrasound, one can rapidly identify the presence of pleural effusion. Once the presence of pleural effusion has been detected, a diagnostic and therapeutic thoracocentesis should be performed. A thoracocentesis is often life-saving, and should be performed immediately in any dyspneic patient that is suspected of having pleural effusion. The thoracocentesis should be performed cranial to the rib, as the blood vessels and nerves lie caudal to the rib (“hiding” behind the rib). Thoracocentesis should be performed at the 7th to 9th intercostal space (ICS) to avoid the heart (3-5th ICS) or liver (caudal to the 9th ICS). The patient should be shaved, scrubbed, and prepared for sterile technique. The use of a 3-way stopcock, extension tubing, an appropriately sized needle or catheter, and syringe should be used to collect air or fluid. Appropriate sterile collection tubes should be available for sample collection for cytology and/or culture purposes.
A short cut technique – rather than counting rib spaces in cases of severe emergency – is to draw an imaginary line caudal to the xiphoid along the lateral body wall. This is approximately the 8th ICS, and thoracocentesis can be performed in this area. If pleural effusion is present, the needle should be directed ventrally on the bottom 1/3 of the chest cavity; if abnormal air is present, the dorsal 1/3 of the chest cavity should be used for thoracocentesis.