Routine Chest Radiographs after Uncomplicated Thoracentesis

CXRs might be helpful in certain scenarios, even when a complication is not suspected. For example, a postprocedure CXR to detect nonexpandable lung or evaluate the rate of recurrence may guide definitive management of patients with recurrent or malignant pleural effusion. Determining completeness of drainage may also assist with planning for palliative measures such as pleurodesis or indwelling pleural catheter placement. A postprocedure CXR is also helpful in patients with a technically difficult procedure or in those with symptoms during or immediately after the procedure. This recommendation is consistent with the 2010 British Thoracic Society guidelines, which recommend CXRs for procedures where air was withdrawn, the procedure was difficult, multiple needle passes were required, or the patient became symptomatic.¹⁴ The Society of Hospital Medicine’s recent Position Statement concurs with these guidelines and recommends against routine chest radiography in asymptomatic patients when sliding lung is visualized by postprocedure ultrasound.¹⁰

Hospitalists should not rountinely obtain post-thoracentesis CXRs in asymptomatic patients. Clinical monitoring with subsequent symptom-guided evaluation lowers costs, avoids unnecessary radiation exposure, and has been shown to be successful in a large case series of more than 9,300 patients.¹⁵ Some coughing should be expected with all large-volume thoracenteses as a normal response to re-expansion of atelectatic lung. The coughing should not persist past the immediate postprocedure period. If symptoms arise or if a complication is expected, the test of choice is either CXR or, if the hospitalist is a competent sonographer, bedside sonography. Bedside sonography is a low-cost, noninvasive method and has been well studied in the diagnosis of post-thoracentesis pneumothorax.¹⁶ CXRs may still be needed to confirm findings by sonography, to investigate postprocedural symptoms in those with pleural adhesions or other lung/pleural diseases (because ultrasonography is less reliable in these patients), or if reexpansion pulmonary edema or other complications are suspected. A robust quality improvement strategy to reduce unnecessary post-thoracentesis CXRs could result in cost savings and spare patients from radiation exposure, because a recent study of almost 1,000 thoracenteses performed at an academic medical center demonstrated that internal medicine residents, pulmonologists, and interventional radiologists order a CXR following 95% of thoracenteses.¹⁷ For a hypothetical hospital that orders 100 unnecessary post-thoracentesis CXRs annually, hospitalists could avoid approximately $7,000 in wasted expense per year.¹⁸

• Do not routinely order post-thoracentesis CXRs.
• Order a post-thoracentesis CXR if (1) the patient had new chest pain, dyspnea, or persistent cough during or after the procedure; (2) procedural features suggest increased risk of a complication (multiple needle passes, aspiration of air, difficulty obtaining fluid); or (3) a definitive palliative procedure will be arranged based on lung expansion.
• If qualified, use bedside sonography as a first step in the diagnosis of pneumothorax, reserving CXRs for those patients in whom accurate sonography is not possible, an alternative diagnosis is suspected, or when sonography findings are equivocal.