What are the indications and contraindications to platelet transfusion?

Alright, here's the case ... 46 y/o female s/p ventral hernia repair 1 week ago presents with swelling and slight discomfort below incision site that developed over the past several days. CT notes an underlying 2 x 2 cm fluid collection, likely hematoma. Labs notable for platelet count of 53,000; coags are normal. Is a platelet transfusion indicated?

Depends. If the hematoma is getting bigger suggesting ongoing bleeding then definitely; if not, one could probably do without and follow the patient closely.

Indications for platelet transfusion:

• active bleeding and platelets less than 100,000
  
• anticipated invasive procedure with potential for bleeding and platelets less than 50,000
  
• prophylaxis if platelets less than 10,000 or less than 20,000 with risk of bleeding secondary to dysfunctional platelets (uremia, aspirin)
  

Relative contraindications for platelet transfusion:

• TTP/HUS, HELLP, HIT. Primary treatment for a consumptive coagulopathy is to treat the underlying problem, not to transfuse platelets as they simply will be broken down and consumed. However, if the patient has marked thrombocytopenia, less than 20,000, or moderate thrombocytopenia, less than 50,000, and serious bleeding then platelet transfusion should be considered.

Source

Sabatine, M. MD. Pocket Medicine: The Massachusets General Hospital Handbook of Internal Medicine, 3rd ed. 2008.

Winshall, J. MD and Robert, L. MD. Tarascon Internal Medicine and Critical Care Pocketbook, 4th ed. 2007.