How To Do It: Thoracentesis
A 40 year-old female with a history of leukemia presents to the ED complaining of 3 days of progressively worsening RIGHT sided pleuritic chest pain with associated SOB. She denies fever and chills.
BP: 130/70, HR: 133, RR: 18, O2 Sat 98% on room air
General: Alert and oriented. No acute distress.
Pulm: Decreased lung sounds on the RIGHT. No accessory muscle use, no intercostal/subcostal retractions, speaking in full sentences
CXR: Significant for large RIGHT sided pleural effusion
CT angio: Shows no pulmonary embolus. Confirms right sided pleural effusion.
Plan: Perform A Thoracentesis
Is it indicated?
Therapeutic (SOB, CP, tachycardia, hypotension, hypoxia)
Diagnostic (new malignancy? new infection?) 20-30cc
How do we do it?
Position - Midaxillary or posterior midscapular line
Placement - 1-2 rib spaces below superior aspect of effusion, superior to rib
When do we stop?
1500 ccs - Poor evidence stemming from 1982 study that quotes mortality rate up to 20% due to re-expansion edema
Vague chest discomfort or tightness - More recent literature quotes “vague chest discomfort or tightness” as the primary indication to stop
Pleuritic chest pain - Reflects irritation from the catheter and is not an indication to stop the procedure.
Coughing - Normal lung tissue re-expansion and is not an indication to terminate the thoracentesis procedure
What are the complications?
Re-expansion pulmonary edema (RPE)/ Reperfusion Injury
Expansion pulmonary edema was believed to be caused by removal of large volume (>1 - 1.5L) thoracentesis creating a negative intrathoracic pressure thereby drawing fluid from the pulmonary vasculature into the pleural space
More recent theories suggest that RPE may be due to an ischemia-reperfusion injury with subsequent cytokine release and increased capillary permeability
If it does happen, how do we manage it?
Re-expansion pulmonary edema is rare and generally manageable with supplemental oxygen +/- BiPAP.
Take Away #1
Thoracentesis should be performed diagnostically whenever the fluid is of unknown etiology or therapeutically when the volume of fluid is causing significant clinical symptoms.
Take Away #2
Re-expansion pulmonary edema is likely due to ischemia reperfusion injury with subsequent cytokine release and increased capillary permeability.
Take Away #3
If pulmonary edema occurs, supplemental O2 and BIPAP are likely to resolve issue.
Daniel Brodmerkel, DO is a current second year resident at Stony Brook Emergency Medicine.
Edited by Bassam Zahid, MD