About Imaging: Bleeding Risk and Assessment

Bleeding Risk and Assessment

Indiscriminate coagulation screening prior to surgery or other invasive procedures to predict postoperative bleeding in unselected patients is not recommended. 1
A bleeding history including detail of family history, previous excessive post-traumatic or postsurgical bleeding and use of anti-thrombotic drugs should be taken in all patients preoperatively and prior to invasive procedures. 1 Patients without evidence of historical risk factors or physical findings suggestive of a bleeding disorder have a low risk for peri- and postoperative hemorrhage. 2
If the bleeding history is negative, no further coagulation testing is indicated. 1
If the bleeding history is positive or there is a clear clinical indication (e.g. liver disease), a comprehensive assessment, guided by the clinical features is required. 1 Preoperative testing with the partial thromboplastin time, prothrombin time, and platelet count is warranted for patients with clinical evidence to suggest a bleeding disorder. 2
Coagulation testing may delay surgery inappropriately and cause unnecessary concern in patients who are found to have 'abnormal' tests. In addition it is associated with a significant cost. 1 Although some defend it as a means of avoiding litigation, it has been demonstrated that 30-95% of unexpected laboratory results from screening tests are either not documented or not pursued further. Therefore, random screening could potentially increase rather than reduce the risk of litigation. 5,6

Significant bleeding after percutaneous biopsy is exceptionally rare. 3
In most cases, percutaneous biopsy can be performed in patients taking aspirin. 3
In those patients undergoing elective, nonurgent deep organ biopsy, scheduling the biopsy 10 days after the last dose of aspirin is a reasonable, but not a necessary, precaution. 3
The decision to cease or continue aspirin in the setting of percutaneous biopsies will be dependant on a variety of factors including patient factors, operator choice and local practice.

A systematic review of the published literature provides little evidence that preprocedure elevation of the INR or PT predicts an increased risk of bleeding at the time of an invasive diagnostic procedure. 4
Central vein cannulation and femoral arteriography are expected to be as safe in patients with an elevated INR as in patients with normal preprocedure test results, although the degree of INR elevation to which this applies is unclear. 4
Transjugular liver biopsy may also be safe in patients with an elevated INR, and possibly also plugged liver biopsy, although there is much uncertainty surrounding the estimates of bleeding rates. 4
Similarly, elevated coagulation test results also appear not to predict an increased risk of bleeding after percutaneous liver biopsy although the limited literature suggests that bleeding complications may be more frequent than with transjugular liver biopsy. 4
A very limited data suggests that elevated clotting tests do not predict increased bleeding during bronchoscopy. 4
There is not enough data to date to draw conclusions about paracentesis, thoracocentesis, lumbar puncture, or kidney biopsy. 4
The decision to perform invasive procedures in the setting of abnormal coagulation will be dependant on clinical factors like patient status, urgency of procedure and operator choice. Local practice and availability of resources can also influence the decision making process.