Background
Thoracentesis (thoracocentesis) is a core procedural skill for hospitalists, critical care physicians, and emergency physicians. With proper training in both thoracentesis itself and the use of bedside ultrasonography, providers can perform this procedure safely and successfully. [1, 2] Before the procedure, bedside ultrasonography can be used to determine the presence and size of pleural effusions and to look for loculations. [3] During the procedure, it can be used in real time to facilitate anesthesia and then guide needle placement.
Indications
Thoracentesis is indicated for the symptomatic treatment of large pleural effusions (see the images below) or for treatment of empyemas. It is also indicated for pleural effusions of any size that require diagnostic analysis. [4, 5, 6]
Contraindications
There are no absolute contraindications for thoracentesis. Relative contraindications include the following:
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Uncorrected bleeding diathesis
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Chest wall cellulitis at the site of puncture
Technical Considerations
A 2017 review of literature on preprocedure, intraprocedure, and postprocedure aspects of thoracentesis suggested the following [7] :
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Preprocedure - Physician training and maintenance of skills (eg, simulation with direct observation); moderate coagulopathy (eg, international normalized ratio < 3, platelet count >25,000/μL) and mechanical ventilation do not increase risk of postprocedural complications
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Intraprocedure - Ultrasonography is associated with a lower risk of pneumothorax; pleural manometry can help identify nonexpanding lung and may reduce risk of reexpansion pulmonary edema
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Postprocedure - Routine chest radiography is not warranted because bedside ultrasonography can identify pneumothorax
Complications
Complication rates for thoracentesis performed by experienced clinicians are not available. However, data on complications that develop after thoracentesis performed by residents learning the procedure are available. [1, 8]
Major complications include the following:
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Pneumothorax (11% [9] )
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Hemothorax (0.8%)
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Laceration of the liver or spleen (0.8%)
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Diaphragmatic injury
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Tumor seeding
Minor complications include the following:
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Pain (22%)
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Dry tap (13%)
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Cough (11%)
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Subcutaneous hematoma (2%)
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Subcutaneous seroma (0.8%)
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Vasovagal syncope
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Image of a 48-year-old woman with cancer and large left pleural effusion (2.5 liters were removed). The patient was tachypneic, hypoxic, and reported pleuritic chest pain.
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Ultrasound image using curvilinear probe. Image shows chest wall and large volume of pleural fluid.
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Chest radiograph after thoracentesis of the cancer patient shown above.
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Ultrasound image in M-mode showing sinusoidal wave pattern. This is created by the lung moving within the large pleural effusion during respiration. The depth of the lung and the amount of fluid between the parietal pleura (adherent to the chest wall) and visceral pleura (adherent to lung tissue) are easily measured with ultrasonography.
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One option for proper positioning of patient. Easy access to the 7-9 rib space along the posterior axillary line.
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Application of chlorhexidine solution.
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Sterile drape with fenestration and adhesive strip placed over puncture site, with sterile towels draping a large work area.
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Administering anesthesia to the skin, subcutaneous tissue, rib periosteum, intercostal muscle, and parietal pleura.
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Advancing the device over the superior aspect of the rib.
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Nicking the skin with scalpel to reduce skin drag as the catheter is advanced through the skin.
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Feeding the catheter over the needle introducer.
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The 5-cm mark is at the level of the skin.
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The catheter is fed all the way to the hub.
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Use the manual syringe pump method or a vacuum bottle. The syringe pump method (shown here) is more labor intensive and can cause thumb neurapraxia in the operator.
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Sterile towels on the bed, creating a large sterile work space.
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Ultrasound image using the linear probe. Image demonstrates 2 ribs with their associated acoustic shadows, rib interspace, pleural fluid, and the presence of the diaphragm rising up into this rib interspace.
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Video clip of ultrasound using the linear probe. Image demonstrates 2 ribs with their associated acoustic shadows, rib interspace, pleural fluid, and the presence of the diaphragm rising up into this rib interspace.
