In this VETgirl online veterinary continuing education video, we demonstrate how to perform a thoracocentesis. This is a 12-year-old, male neutered, DSH presenting for tachypnea. On presentation, the cat had muffled lung sounds ventrally and had a short, shallow breathing pattern consistent with pleural space disease. As dyspneic cats are very fragile, gentle, limited handling should be used to minimize stress. Immediate triage, flow by oxygen therapy, rapid targeted physical examination (e.g., perfusion parameters, auscultation) and prompt therapy is warranted in a step-wise manner. Placement of an intravenous (IV) catheter is not necessary and is too stressful for the dyspneic patient. Rather, focus on triage and stabilization, while the therapeutic and diagnostic treatment plan is initiated. This may include low-dose butorphanol intramuscularly (IM), rapid Thoracic Focused Assessment with Sonography for Trauma (T-FAST) ultrasound, and placement into an oxygen cage.

With the dyspneic cat, chest radiographs should be avoided until the patient is more stable. When in doubt, a diagnostic/therapeutic thoracocentesis should be performed first. If pleural effusion is detected on initial T-FAST ultrasound, the patient should be clipped, scrubbed and prepared for a life-saving thoracocentesis immediately. A thoracocentesis should be performed between the 7-9th intercostal spaces (ICS) to avoid the heart (3-5th ICS) or liver (caudal to the 9th ICS). A short cut approach to this rib space is to trace your finger up from the end of the sternum at the xyphoid, which is approximately at the 8th ICS. A thoracocentesis should be performed cranial to the rib, as the blood vessels and nerves lie caudal to the rib (e.g., “hiding” behind the rib). An appropriately sized needle (1.5” 22-gauge needle, depending on the size of the cat), a 3-way stopcock, and a 12-20 ml syringe should be used. In this cat, approximately 200 mls of pleural effusion was removed; further diagnostics including chest radiographs and thoracic ultrasound revealed a mediastinal mass. Check out our other VETgirl videos to learn more!