Feb 01, 2002
Thoracentesis indications The indications for emergency thoracentesis are straight forward. They are the following:
The area selected is clipped, prepped and, if the patient is apprehensive or painful, sedated and oxygen is provided. A good combination that I like to use is butorphenol at .05 to .15 mg/kg and acetylpromazine at .001 to .01 mg/kg. This combination is given intravenously. Lidocaine 1 percent and sodium bicarbonate in a one to five mixture is used as a local anesthesia if there is time (two or three minutes Photo 1). It should be instilled in the skin and down to the pleura. An 18-gauge needle is inserted into the skin with the bevel facing caudally (Photo 2) and a small bleb of saline is placed in the hub of the needle (Photo 3). The needle is slowly advanced (Photo 4) until the saline is sucked inward (negative intrathoracic pressure) or expelled outwards (tension pneumothorax). Needle advancement is stopped and the needle is angled caudally so that the needle is lying along the chest wall "locked" between the ribs with the bevel facing toward the lungs (Photo 5). This helps minimize the likelihood of iatrogenic lung trauma from the needle. The needle can be held in this position by pushing in toward the rib thus "locking it down". An assistant then attaches an extension set (Photo 6) and three-way stopcock and starts aspirating on the needle (Photo 7). If no assistant is immediately available, the operator can begin aspiration. To maintain a safe "locked" position on the needle so it does not move, an assistant must be available to manipulate the syringe and stopcock. Mild adjustments may have to be made to facilitate good flow through the needle. Without the bleb of saline being moved by the pressure within the pleural space, it would literally be impossible to tell when the needle has entered the pleural space. That has cost past lives when clinicians have relied on a "pop" to tell them they were "in the pleural space" and in actuality they were not and tension pneumothorax was missed!
In March, we will disucss the placement and indicuations for chest tubes.