Often in the ED we are faced with a patient who is on anticoagulation and needs an urgent procedure. Lumbar puncture is a very safe procedure overall, but it’s particularly dicey in the setting of anticoagulation because of the possibility of spinal hematoma and subsequent neurologic sequelae. Let’s take a look at what the guidelines and evidence have to say about this problem.

Turns out there’s not much data on the subject, as bleeding from LP is relatively rare – most of the data comes from spinal anesthesia, in which estimates range from 1 to 220,000 patients.  What evidence we have suggests that LPs are safe with mild to moderate thrombocytopenia, and not much else. 

  • A recent review including over 1500 LPs in thrombocytopenia (including 39 with platelet count below 10000!) revealed no bleeding complications.
  • There’s no good data to suggest a threshold for INR above which LP is safe.
  • A review from the 80s showed that 2 percent of patients on anticoagulant therapy developed a spinal hematoma; interestingly these patients received anticoagulation after undergoing LP.
  • There are case reports of patients with bleeding diatheses (hemophilia, von willebrand’s), who developed hematomas after LP.
  • There is no literature to assess the risk of bleeding with LP on novel oral anti-coagulants.

Because of the paucity of data, current expert recommendations are to AVOID LP in these patients;

  • platelet count <50-80K
  • INR > 1.4
  • patients with bleeding diatheses (unless the missing component is corrected to normal levels; this will not happen in the ED)
  • I would add novel anticoagulant use as well, given the lack of data

If your patient comes in with a high INR, can you just give FFP? Probably not worth your time – a recent study in Journal of Emergency Medicine suggests that FFP transfusion is very unlikely to bring your INR below that 1.4 threshold.

Another thing to point out is that the older study mentioned above suggests the risk of bleeding persists for some time after LP, so hold off on that anticoagulation. Recommendations suggest something in the vicinity of one hour.

The good news for us is that the cases in which an LP is critically important are rare to non-existent in the ED. Treat for dangerous pathologies (like meningitis), and admit or observe until either 1. the anticoagulant wears off or 2. the LP can be done fluoroscopically, which theoretically reduces the chance of injury to small blood vessels.

 

References:

Abdel-Wahab OI, Healy B, Dzik WH. Effect of fresh-frozen plasma transfusion on 9 prothrombin time and bleeding in patients with mild coagulation abnormalities. 10 Transfusion. 2006;46(8):1279-1285.

Wolfe, Krysta and John Kress. Contemporary Reviews in Critical Care Medicine: Risk of Procedural Hemorrhage. Chest. In press. 
Kimberly Jonhson, et al. Lumbar Puncture: Technique, indications, contraindications, and complications in adults. UpToDate.