The evidence base for the safety of ultrasound-guided central line placement with thrombocytopenia or in patients with a bleeding diathesis is not robust. Nevertheless, based on the data available most procedural experts feels that an ultrasound-guided central venous catheter insertion is safe to perform without preprocedural transfusions for platelet counts >20x109/L or if INR<3 (even with patients on warfarin).
A meta-analysis of 1 RCT and 21 observational studies analyzed over 13,000 central venous catheter insertions. Of these central line insertions, 4,213 were in patients with a severe coagulopathy defined as a PLT<50K, INR>1.5 or a PTT>45 seconds. The overall risk of major bleeding (Hgb drop of 2 gm/dL or more) in this study was <0.01% and was not related to the presence of a bleeding diathesis. The authors concluded that ultrasound-guided central line placement was safe without preprocedural blood transfusions if the platelet count was over 20x109/L or if INR<3.1 In these studies, the administration of prophylactic platelets or FFP did not decrease the rate of major bleeding. Of note, all procedure operators were experienced and all catheter insertions were ultrasound-guided.
In addition, a Cochrane systematic review attempted to analyze whether there was a platelet transfusion threshold prior to central line insertion. There analysis concluded that there is "no evidence to determine if platelet transfusions are required prior to a central venous catheter insertion." Unfortunately, data were unavailable to guide clinical care.2
The final piece of information to examine is the platelet count threshold recommended prior to central venous catheter insertion in different countries. For example, in the United Kingdom the current threshold is 50 × 109 /L3, in Belgium the threshold is 30 × 109 /L4, in the United States the threshold is 20 × 109 /L 5, and in Germany the threshold is 10 × 109 /L, unless there are risk factors for bleeding.6 Obviously, there is no one international standard for a platelet transfusion threshold prior to central line insertion. The recommendations vary from platelet counts of 10K to 50K. The American Association of Blood Banks does recommend a 20 × 109 /L cut-off.
Unfortunately, there are no prospective randomized controlled trial data to provide the evidence base for central line insertion in patients with thrombocytopenia or coagulopathy, but we do have observational, retrospective studies to help guide clinicians. Based on this moderate quality evidence, the recommendations are that ultrasound-guided central venous catheter insertion is safe to perform without preprocedural transfusions if the platelet count was over 20x109/L and the INR<3.
5. Kaufman RM, Djulbegovic B, Gernsheimer T, Kleinman S, Tinmouth AT, Capocelli KE, et al. Platelet transfusion: a clinical practice guideline from the AABB. Annals of Internal Medicine. 2015; 162(3): 205–13.
6. The Board of the German Medical Association on the recommendation of the Scientific Advisory Board. Platelet transfusions. Transfusion Medicine and Hemotherapy. 2009; 36: 372– 82.