Sam The Dog Can't Breath Flashcards
What is wrong here?
Retracted lung lobe
The lung lobes are pulled back from the thoracic wall (retracted) when there is fluid or air in the pleural space - this is fluid, look back at your notes if you cannot remember what air in the space would look like.
What is wrong here?
Top right - Retracted lung lobes: The lung lobes are again retracted as there is fluid in the pleural space.
Big bottom right box - Obscured cardiac silhouette and diaphragm
The cardiac silhouette and diaphragm are obscured by the pleural effusion which is sitting in the ventral pleural space.
Little bottom right box - Fissure line
This is a fissure line showing fluid between the lung lobes which highlights the edge of the two lung lobes which are usually of the same opacity therefore not distinguishable.
How to perform thoracocentesis? (this is long)
*The two most common techniques are the “butterfly” catheter or fenestrated plastic catheter. The technique utilized depends on the size and body condition of the patient, the presence of air versus fluid, quantity of the pleural effusion, and the clinician’s preference. In cats and small dogs, the “butterfly” technique is recommended. A 19- to 23-gauge “butterfly” catheter is attached to a three-way stopcock and syringe (10 to 20 mL). In larger or obese dogs, the fenestrated catheter is preferred. An 18- to 22-gauge 1½- to 2½-inch catheter is attached to an extension set, three-way stopcock, and syringe (10 to 20 mL).
The animal is most commonly placed in sternal recumbency or standing. In most cases, sedation is not required to perform the procedure. In some cases, especially when larger-gauge catheters are used, local anesthesia can be given. Lidocaine 2% can be used to infiltrate the skin, subcutaneous tissues, intercostals muscles, and pleura. The tap is performed at the seventh or eighth intercostal space. The needle is inserted just cranial to the rib to avoid the intercostal vessels and nerves. If air is being aspirated, the tap should be performed from the mid to the dorsal third of the intercostal space. If fluid is being aspirated, the tap should be performed at the costochondral junction. If the sample is difficult to obtain due to either pocketing or small volumes, ultrasound guidance may be helpful. The site of the thoracocentesis is clipped and surgically scrubbed. Whenever possible, gloves should be worn to maintain aseptic technique. During the introduction of the needle into the thoracic cavity, gentle suction is initiated to maintain slight negative pressure. Once the position of the needle is satisfactory and air or fluid is freely obtained, the needle should be oriented either ventrally or laterally along the body wall. This technique will help reduce the risk for laceration of the adjacent lung lobe. The needle should be removed if unexpected hemorrhagic fluid or air is obtained, or if the patient is moving excessively. If using the over-the-needle catheter technique, frequent kinking of the catheter may occur with patient movement. To help stabilize the catheter, the hand that is holding the catheter can be rested against the animal to try to prevent excessive movement.
Samples should be saved for analysis if the etiology of fluid is in question. In some cases, the fluid can be saved pending further diagnostic imaging. The sample can be saved in an EDTA tube (cytology, cell count, and total protein), red-top tube (biochemical analysis), and culture tube. Following thoracocentesis and stabilization of the patient, repeat thoracic radiographs and ultrasound imaging can be used to assess the previously obscured intrathoracic structures and amount of remaining fluid and to identify an iatrogenic pneumothorax if present.*
Chose a diagnoses based on the fluid results you have got back
Chylothorax
Which test can you do to confirm that this is a chylothorax, and what result do you expect from it?
You need to do a fluid to serum triglyceride ratio check; you would expect the effusion fluid to be higher in triglyceride than the serum.
See the WikiVet link below to get a bit of background on development of chylothorax, or look at the In Practice article.
Which of the following would be a sensible next step to manage Sam’s pleural effusion?
Place chest drains - Good idea. Drain enough to make him stable for a quick general anaesthetic then place chest drains to allow much more simple management of the pleural fluid. Dogs have a fenestrated mediastinum so in theory you could place just one drain allowwing you to empty both sides. However, often the medisatinum becomes clogged with debris so you need to place one on each side.
