- INR
- Less than 2.0 for Therapeutic Thoracentesis (includes the use of drainage catheter-6.0 Fr from the Thoracentesis Kit)
- Less than 2.5 for Diagnostic Thoracentesis (includes the use of NEEDLE ONLY, but no catheter). Average amount drained with needle is 20mL (depends on the procedure staff)
- Platelet Count
- More than 50,000 for Therapeutic Thoracentesis (includes the use of drainage catheter-6.0 Fr from the Thoracentesis Kit)
- More than 25,000 for Diagnostic Thoracentesis (includes the use of NEEDLE ONLY, but no catheter). Average amount drained with needle is 20mL (depends on the procedure staff)
- Medications
- Heparin IV. Should be stopped 4 hours before thoracentesis.
- Low Molecular Weight Heparin. Should be stopped for at least 36 hours.
- Should be stopped for 5 days.
EXCEPTIONS to these requirements could be made depending on the case (risks vs benefits). For exceptional cases, there should be a direct communication with the procedure staff.
References:
- Transfusion 1991;31:164-171
- Am J Roentgenol. 2011 Jul; 197(1):W164-8
- Ann Am Thorac Soc 2013;10(4):336-341

If someone can help me understand this point:
If there is data regarding Safety of ultrasound-guided thoracentesis in patients with abnormal preprocedural coagulation parameters, why are we checking INRs prior to thoras or having cut offs?
http://journal.publications.chestnet.org/article.aspx?articleid=1667001#r2