We are performing a thoracentesis on a patient with a left-sided pleural effusion that has been seen on chest imaging. The patient has been consented for the procedure. We've reviewed their labs with no evidence of coagulopathy, and they are not on any blood thinners or dual antiplatelets. With our patient appropriately positioned, we will now proceed with identifying our optimal space for thoracentesis. Using a low-frequency probe, we will begin to palpate our structures and identify our entry site. On our ultrasound image, we should be able to identify lung, the dome of the diaphragm with the spleen underneath, and then our pocket of fluid to identify a safe entry site. This will also allow us to evaluate any characteristics of the fluid, such as loculations that might impair our ability to effectively drain. In this case, we see a small collection of fluid right above the diaphragm, and we choose the mid-scapular line about 7 centimeters below the tip of the scapula in this intercostal space. We start by sterilizing the entry area, which we defined on the mid-scapular line, about 7 centimeters below the tip of the scapula. Once the posterior left hemitorax is cleaned, we apply a drape to maintain sterility during the procedure. We could also use the accessory paper towel to further increase the sterile field. After draping our patient, we will now proceed with local anesthesia using 1% lidocaine without epinephrine. We will begin by numbing the subcutaneous tissues and then go perpendicular in the same path as our ultrasound to nub into the pleural space. So we feel the rib, always go above the rib, make a wheel, and then orient the needle perpendicular to the chest wall in the same direction as the ultrasound probe. We inject about a milliliter, advance and aspirate, inject, advance and aspirate over the rib, inject, advance and aspirate, inject, advance and aspirate. Our fluid is being withdrawn in the syringe. For a more proper pleural analgesia, we pull back about a milliliter and inject more lidocaine on the parietal pleura, which is usually responsible for pain during this procedure. Then the needle is removed. To allow more ease of entry of our 6-fringe thoracentesis catheter, we will begin by making a small incision at our entry site. This is done horizontally, parallel to the rib, at the prior site of local analgesia. It should not be too deep, but not too shallow, so usually about a third of the blade is inserted and a small nick is performed laterally. After our incision is made, we can now proceed with insertion of our thoracentesis catheter. In this setting, a 6-fringe thoracentesis catheter. The 6-fringe catheter over the needle is advanced through the incision with a syringe attached. Once the tip of the catheter is inside the incision, I remove my index finger from the patient's rib, I hold the catheter in between my thumb and my index, and I aspirate as I continue to advance the catheter. We continue to apply negative pressure while inserting, watching for evidence of pleural fluid. Once pleural fluid is encountered, we advance another 0.5 centimeters or so to assure that the white catheter is actually inside the pleural cavity, not just the needle, and then advance the catheter over the needle in the space while continuing to aspirate. It is not necessary to hub the thoracentesis catheter. And then the needle is removed. We will now proceed with drainage of pleural fluid with connection of our thoracentesis catheter to our drainage line using a three-way stopcock. A one-way valve is in place connected to a syringe to allow drainage, which drains into a collection bag. So the system is open. I like to personally use a small syringe for withdrawing and pushing fluid into the bag because it is easier than a larger syringe where more force needs to be applied. Manual drainage, of course, will take longer than draining to a vacuum bottle, but may be better tolerated by the patient. We will continue to drain pleural fluid until we've either reached a point where we can no longer withdraw any fluid or the patient develops symptoms such as pain in the chest, which would prompt discontinuation of drainage. At this point, we would prepare for catheter removal, preparing the patient to hum as we remove the catheter. An equivalent of humming would be to continue to aspirate as the catheter is being removed. And then pressure is applied to the insertion site. We would then apply a dressing, obtain a post-procedure chest x-ray as indicated, and send pleural studies to the lab, if desired.

thoracentesis

drain fluid

pleural space

ultrasound imaging

catheter insertion