1、The new england journal of medicinen engl j med 355;15 www.nejm.org october 12, 2006e16ThoracentesisTodd W. Thomsen, M.D., Jennifer DeLaPena, M.D., and Gary S. Setnik, M.D.From the Department of Emergency Medi-cine, Mount Auburn Hospital, Cambridge, MA (T.W.T., G.S.S.); the Department of Emergency M
2、edicine, Beth Israel Deacon-ess Medical Center, Boston (J.D.); and the Division of Emergency Medicine, Harvard Medical School, Boston (T.W.T., J.D., G.S.S.). Address reprint requests to Dr. Thomsen at the Department of Emergency Medi-cine, Mount Auburn Hospital, 330 Mount Auburn St., Cambridge, MA 0
3、2238, or at tthomsenmah.harvard.edu.N Engl J Med 2006;355:e16.Copyright 2006 Massachusetts Medical Society.INDICATIONSThoracentesis is a valuable diagnostic procedure in a patient with pleural effusion of unknown causation. Analysis of the pleural fluid will allow its categorization as either a tran
4、sudate (a product of unbalanced hydrostatic forces) or an exudate (a product of increased capillary permeability or lymphatic obstruction) (Table 1). If the effusion seems to have an obvious source (e.g., in an afebrile patient with con-gestive heart failure and bilateral pleural effusions), diagnos
5、tic thoracentesis may be deferred while the underlying process is treated. The need for the procedure should be reconsidered if there is no appropriate response to therapy.1Thoracentesis, as a therapeutic procedure, may dramatically reduce respiratory distress in patients presenting with large effus
6、ions.CONTRAINDICATIONSThere are limited data on the safety of thoracentesis in patients who are using an-ticoagulant medications or those with coagulopathy or thrombocytopenia. One small study suggests that the procedure is safe and that fresh-frozen plasma is not needed in patients with mild elevat
7、ions of the prothrombin time or partial-throm-boplastin time (0.5Ratio of pleural fluid LDH to serum LDH0.6Pleural fluid LDH 2/3 upper limit of normal for serum* Data are from Light.1LDH denotes lactate dehydrogenase.videos in clinical medicineDownloaded from www.nejm.org on December 18, 2007 . Copy
8、right 2006 Massachusetts Medical Society. All rights reserved. thoracentesisn engl j med 355;15 www.nejm.org october 12, 2006Thoracentesis must be performed with extreme care in patients who are receiv-ing mechanical ventilation, because positive-pressure ventilation may bring the lung close to the
9、thoracentesis needle, thus theoretically increasing the risk of tension pneumothorax. Ultrasonography may be beneficial in these situations.Thoracentesis should be deferred in patients with severe hemodynamic or re-spiratory compromise until the underlying condition can be stabilized. In patients wi
10、th small or loculated effusions, the procedure should be performed by an expe-rienced clinician, ideally with ultrasonographic guidance.The thoracentesis needle should not pass through sites of cutaneous infection (such as cellulitis or herpes zoster) on the chest wall. If such a lesion is present,
11、another entry site should be sought.EQUIPMENTNumerous prepackaged thoracentesis kits (e.g., Safe-T-Centesis Catheter Drainage Tray, Cardinal Health) are commercially available. You should become familiar with the specific devices available at your institution. You will need the following items: anti
12、septic solution (chlorhexidine or povidoneiodine), sterile gauze, a sterile drape, sterile gloves, a small syringe for anesthetic injection, 25- and 22-gauge needles for anesthetic injection, and local anesthetic (e.g., lidocaine).You will also need the following items on hand: an 18-gauge over-the-
13、needle catheter, a large syringe (35 to 60 ml) for the aspiration of pleural fluid, a three-way stopcock, high-pressure drainage tubing, sterile occlusive dressing, specimen tubes, and one or two large evacuated containers. In this video, we use a standard intra-venous over-the-needle catheter and o
14、ther equipment that is commonly available.PREPARATIONExplain the procedure to the patient, and obtain written informed consent. You should also complete the three preparatory steps outlined by the Universal Protocol of the Joint Commission on Accreditation of Healthcare Organizations: verify the pat
15、ients identity, ensure that the needle-insertion site is correctly marked, and take a time-out immediately before the procedure for final verification by all mem-bers of the care team that the patient, the procedure, and the site are all correct. (More information is available at http:/www.jointcomm
16、ission.org/patientsafety/universalprotocol.)Thoracentesis is a sterile procedure, and you should wash your hands before the procedure and wear sterile gloves during the procedure. Enlist the help of one or two assistants. They will be needed to help position and monitor the patient and fill the evac
17、uated container and specimen tubes.Place the patient in a sitting position on the edge of the bed, leaning forward, with his or her arms resting on a bedside table. If the patient is unable to sit up-right, the lateral recumbent or supine position may be used. The level of the effusion should be est
18、imated on the basis of diminished or absent sounds on auscultation, dullness to percussion, and decreased or absent fremitus. You should insert the needle one or two intercostal spaces below the level of the effusion, 5 to 10 cm lat-eral to the spine. To avoid intraabdominal injury, do not insert th
19、e needle below the ninth rib. Mark the appropriate site, and then prepare the skin with antiseptic solution and apply a sterile drape.Anesthetize the epidermis overlying the superior edge of the rib that lies below the selected intercostal space, using 1% or 2% lidocaine and a small (25-gauge) needl
20、e. Insert a larger (22-gauge) needle and then “walk” it along the superior edge ARibHemithoraxmidlineNeedle entry sitePositioning of the patient and anatom-ical landmarksDownloaded from www.nejm.org on December 18, 2007 . Copyright 2006 Massachusetts Medical Society. All rights reserved. The new eng
21、land journal of medicinen engl j med 355;15 www.nejm.org october 12, 2006of the rib, alternately injecting anesthetic and pulling back on the plunger every 2 or 3 mm to rule out intravascular placement and to check for proper intrapleural place-ment. To avoid injury to the intercostal nerve and vess
22、els, the needle must not touch the inferior surface of the rib. Once pleural fluid is aspirated, stop advancing the needle and inject additional lidocaine to anesthetize the highly sensitive parietal pleura. Note the depth of penetration before withdrawing the needle.ASPIRATION OF PLEURAL FLUIDAttac
23、h an 18-gauge over-the-needle catheter to a syringe, and advance the needle along the superior surface of the rib to the predetermined depth while continuously pull-ing back on the plunger. Once pleural fluid is obtained, stop advancing the needle, carefully guide the catheter over the needle, and t
24、hen remove the needle. You must cover the open hub of the catheter with a finger to prevent the entry of air into the pleural cavity.Attach a large syringe with a three-way stopcock to the catheter hub. With the stopcock open to the patient and the syringe, aspirate approximately 50 ml of pleural fl
25、uid for diagnostic analysis and then close the stopcock to the patient. If additional fluid is to be removed for therapeutic purposes, one end of high-pressure drainage tubing can be attached to the third port of the stopcock and the other end to a large evacuated container. The stopcock should then
26、 be opened to the patient and the container, and the fluid should be allowed to drain. No more than 1500 ml of fluid should be removed.When the procedure has been completed, remove the catheter while the patient holds his or her breath at end expiration, cover the site with an occlusive dressing, an
27、d remove any remaining antiseptic solution from the skin. Make sure that all needles are placed in appropriate safety containers.ANALYSIS OF PLEURAL FLUIDAspirated fluid should immediately be placed in appropriate specimen tubes and analyzed without delay. A tube without additives should be submitte
28、d for the mea-surement of protein and lactate dehydrogenase levels. The comparison of these values with those for serum protein and lactate dehydrogenase obtained at about the same time will allow a transudate to be distinguished from an exudate (Table 1). If the effusion is a transudate, usually no
29、 further evaluation is required and the underly-ing medical condition should be treated (Table 1).Additional tubes and a heparinized syringe on ice (for pH determination) will be required for additional testing if the effusion is found to be exudative (Table 2).1COMPLICATIONSPneumothorax is rare aft
30、er thoracentesis and, when present, seldom requires the placement of a chest tube.3Although chest radiographs are commonly obtained after thoracentesis, they are not required after simple, uncomplicated procedures. Radi-ography of the chest should be performed if air was aspirated during the procedu
31、re; if chest pain, dyspnea, or hypoxemia develops; if multiple needle passes were required; or if the patient is critically ill or receiving mechanical ventilation.4Other complications of thoracentesis include pain, coughing, and localized infec-tion. More serious complications include hemothorax, i
32、ntraabdominal-organ injury, air embolism, and postexpansion pulmonary edema. Postexpansion pulmonary edema is rare and can probably be avoided by limiting therapeutic aspirations to less than 1500 ml.5BACProper use of the three-way stopcockBPlacement of the needle to avoid inter-costal vessels and n
33、ervesDownloaded from www.nejm.org on December 18, 2007 . Copyright 2006 Massachusetts Medical Society. All rights reserved. thoracentesisn engl j med 355;15 www.nejm.org october 12, 2006ReferencesLight RW. Pleural effusion. N Engl J Med 2002;346:1971-7.McVay PA, Toy PTCY. Lack of increased bleeding
34、after paracentesis and thoracen-tesis in patients with mild coagulation ab-normalities. Transfusion 1991;31:164-71.Colt HG, Brewer N, Barbur E. Evalua-tion of patient-related and procedure-relat-ed factors contributing to pneumothorax following thoracentesis. Chest 1999;116:134-8.Petersen WG, Zimmer
35、man R. Limited utility of chest radiograph after thoracen-tesis. Chest 2000;117:1038-42.Trachiotis GD, Vricella LA, Aaron BL, Hix WR. As originally published in 1988: reexpansion pulmonary edema. Ann Tho-rac Surg 1997;63:1206-7.Copyright 2006 Massachusetts Medical Society.1.2.3.4.5.To avoid complica
36、tions, follow these six directions. First, make sure you fully understand the equipment you are using, especially if you are using a prepackaged thoracentesis tray with specialized devices. Improper use of the three-way stop-cock may lead to pneumothorax. Second, firmly establish the level of the ef
37、fusion by conducting a careful physical examination. Lateral decubitus radiography is useful in determining whether the effusion is “free-flowing” (i.e., not loculated). Small or loculated effusions are best approached by an experienced operator with ultrasonographic guidance. Third, check for coagu
38、lopathy or thrombocytopenia before performing thoracentesis. Fourth, always advance the needle along the su-perior surface of the rib, to avoid intercostal vessel injury. Fifth, limit therapeutic drainage to less than 1500 ml, to avoid postexpansion pulmonary edema. Sixth, always remove the needle w
39、hile the patient is at end expiration. Negative intratho-racic pressure during inspiration may lead to pneumothorax.No potential conflict of interest relevant to this article was reported.Table 2. Additional Tests for the Evaluation of Exudative Effusions.*Test Submission Method CommentsCell count a
40、nd differentialcountEDTA-treated tube Polymorphonuclear-cell predominance suggestive of acute process, such as parapneumonic effusion or pulmonary embolism; mononuclear-cell predomi-nance suggestive of chronic process, such as cancer or tuberculosis Grams stain and culture Syringe for Grams stain; c
41、ulture bottles for cultureConsider use of special stains or cultures in specific sce-narios (e.g., acid-fast bacilli smear and culture for lymphocytic-predominant exudative effusions)Hematocrit EDTA-treated tube Value 120% of serum value suggestive of cancer, pul-monary embolus, or trauma; value 50%
42、 of serum value suggestive of hemothoraxGlucose measurement Tube without additives Level 110 mg/dl (1.2 mmol/liter) suggestive of chylo-thoraxAmylase measurement Varies Elevated level suggestive of pancreatic disease or esoph-ageal rupture* Data are from Light.1 Check with your laboratory.Downloaded from www.nejm.org on December 18, 2007 . Copyright 2006 Massachusetts Medical Society. All rights reserved.
