Q: In Catheter-Directed Thrombolysis for Acute Limb Ischemia, what is the threshold to transfuse FFP (Fresh Frozen Plasma) for low fibrinogen level to avoid bleeding complication?

Answer:  100 mg/dL

Some vascular services monitor fibrinogen levels during catheter-directed thrombolysis for acute limb ischemia,  and may halt thrombolysis or give fresh frozen plasma if the value drops below 100 mg/dL. There is no strong evidence that it may decrease bleeding risk, so, many other vascular services do not monitor fibrinogen. Also, Fibrinogen level can be artificially high or normal in rtPA infusion due to accumulation of fragment X, one of several fibrin degradation products.

References: 

1. Catheter-Directed Thrombolysis for Acute Limb Ischemia - Semin Intervent Radiol. 2006 September; 23(3): 258–269.

2. The STILE Investigators Results of a prospective randomised trial evaluating surgery versus thrombolysis for ischaemia of the lower extremity. The STILE trial. Ann Surg. 1994;220:251–268.