Thoracentesis
Michael L. Barretti
Mark M. Wilson
Richard S. Irwin
I. GENERAL PRINCIPLES
A. Thoracentesis is the introduction of a needle, cannula, or trocar into the pleural space to remove accumulated fluid or air.
B. History (cough, dyspnea, or pleuritic chest pain) and examination (dullness to percussion, decreased breath sounds, and decreased tactile fremitus) suggest that an effusion is present. Chest radiograph (CXR) or ultrasonography (US) is essential to confirm the clinical suspicion.
C. Analysis of pleural fluid yields clinically useful information in >90% of cases.
D. The most common causes of pleural effusions are congestive heart failure, parapneumonic, malignancy, and postoperative sympathetic effusions.
II. INDICATIONS AND CONTRAINDICATIONS
A. Consider thoracentesis for pleural effusions in patients with pleurisy, who are febrile or are suspect for infection, whose clinical presentation is atypical for congestive heart failure, or whose course does not progress as anticipated.
B. Relative contraindications include those settings in which a complication from the procedure may prove catastrophic (i.e., known underlying bullous disease, the presence of positive end-expiratory pressure, a patient with only one functional lung).
C. Absolute contraindications include an uncooperative patient, the inability to identify the top of the rib at the planned puncture site clearly, operator inexperience with the procedure, and coagulopathy that cannot be corrected.
D. For pleural fluid present in only small quantity (less than half a hemidiaphragm obscured on an upright posterior-anterior [PA] CXR) or when the fluid is not freely flowing (i.e., loculated), directed guidance with dynamic (real-time) US or computed tomography is necessary to minimize the risk for serious complications.
III. PROCEDURE
A. Technique for needle-only or catheter-over-needle removal of freely flowing fluid.
1. Whenever available, US imaging of the thoracic cavity should be utilized (by qualified personnel) to identify the pleural fluid pocket as well as visceral structures both above and below the diaphragm.
2. If US is not available or the operator is inexperienced in chest sonography, obtain a lateral decubitus CXR to confirm a free-flowing pleural effusion.
3. Obtain informed written consent for the procedure and follow the universal precautions procedures.
4. Follow your institution-specific policy to ensure and document that you have the “correct patient, correct procedure, correct site.”
5. With the patient sitting, arms at side, mark the inferior tip of the scapula on the side to be tapped. This approximates the eighth intercostal space, the lowest level that may be safely punctured unless US determines a lower interspace can safely be entered.
6. Position the patient sitting at the edge of the bed, leaning forward over a pillow-draped bedside table, with arms crossed in front to elevate and spread the scapulae. An assistant should stand in front of the table to prevent any unexpected movements.
7. Percuss the patient’s posterior chest for the highest point of the effusion. The interspace below this should be entered in the posterior axillary line. Mark the superior aspect of the rib with your fingernail (the inferior border of each rib contains an intercostal artery and should be avoided).
8. Using sterile technique, cleanse and drape the area surrounding the puncture site.
