From the Guidelines
For a thoracentesis procedure in a patient on a heparin drip, the heparin infusion should be held approximately 4-6 hours before the procedure. This recommendation is based on the guidelines for managing antithrombotic therapy in patients undergoing invasive procedures, as outlined in the 2008 focused update incorporated into the ACC/AHA 2006 guidelines for the management of patients with valvular heart disease 1. After confirming the heparin has been discontinued, it is essential to check the patient's coagulation parameters (PTT or anti-Xa level) to ensure they have normalized before proceeding with the thoracentesis. Some key considerations for managing heparin therapy in this context include:
- The timing of heparin discontinuation and resumption may need to be adjusted based on the patient's specific clinical situation, bleeding risk factors, and the reason for anticoagulation.
- Communication with both the proceduralist and the primary team managing the anticoagulation is crucial to coordinate the timing of heparin discontinuation and resumption, ensuring patient safety.
- The heparin can typically be resumed 4-6 hours after the procedure if there are no signs of bleeding complications, as indicated by the guidelines 1. Key factors to consider when deciding on the timing of heparin hold and resumption include:
- The patient's individual risk factors for thromboembolism and bleeding
- The type of procedure being performed (in this case, thoracentesis)
- The patient's current coagulation status, as indicated by laboratory tests such as PTT or anti-Xa level.
From the Research
Holding Heparin Drip for Thoracentesis
- The decision to hold heparin drip for thoracentesis can be guided by studies that have evaluated the safety of performing thoracentesis in patients with uncorrected bleeding risk 2, 3.
- A prospective observational cohort study of 312 patients who underwent thoracentesis found no significant difference in pre- and postprocedural hematocrit levels in patients with a bleeding risk, and no patient developed a hemothorax as a result of the thoracentesis 2.
- A retrospective descriptive study of 292 patients who underwent thoracentesis found that 83% of patients were at risk of bleeding, but no bleeding events occurred, and medications such as clopidogrel, novel anticoagulants, and unfractionated heparin were not held prior to thoracentesis in many cases 3.
- A survey of 256 attending physicians found that most would perform a thoracentesis in patients receiving acetylsalicylic acid or prophylactic doses of unfractionated heparin or low molecular weight heparin, but there was variation in practice patterns regarding holding medications in patients with elevated bleeding risk 4.
- A study of 1,009 ultrasound-guided thoracenteses found that hemorrhagic complications were infrequent, and attempting to correct an abnormal INR or platelet level before the procedure was unlikely to confer any benefit 5.
Monitoring Heparin Therapy
- A study evaluating the accuracy of a point-of-care method for monitoring heparin therapy in patients with severe respiratory failure secondary to SARS-Cov-2 infection supported with VV-ECMO found that the method was not accurate enough to monitor heparin therapy 6.
- The study found poor agreement between the point-of-care test and laboratory methods, and correlation increased when results were normalized to platelet count and creatinine 6.
Guidance on Holding Heparin Drip
- Based on the available evidence, it appears that thoracentesis can be safely performed in patients with uncorrected bleeding risk, including those on heparin drip 2, 3.
- However, the decision to hold heparin drip should be made on a case-by-case basis, taking into account the individual patient's risk factors and the clinical judgment of the healthcare team.
- It is also important to note that monitoring heparin therapy is crucial to prevent thrombotic complications, and accurate methods for monitoring heparin therapy should be used 6.