A recent cohort study using the Danish nationwide medical registry demonstrates that the incidence of a spinal or epidural hematoma from lumbar punctures in patients with pre-existing thrombocytopenia (Platelets<150 K) or coagulopathy (INR>1.4 or aPTT>39 seconds) is not significantly higher than the rates in control patients. The study investigators analyzed 83,711 lumbar punctures in 64,730 separate patients between January 1, 2008 until December 31, 2018. Of the total cohort, they found that 7875 patients had thrombocytopenia, 1393 patients had an elevated INR level and 2604 patients had a prolonged aPTT. The study investigators then determined how many patients developed a spinal hematoma within 30 days of a lumbar puncture (primary outcome) and how many patients had a traumatic tap (secondary outcome) defined as >300 x 10^6 RBC/L.
The results as summarized below surprisingly did not show an increase in spinal hematoma with either thrombocytopenia or coagulopathy:
Platelets #hematomas/total % (95% CI)
>150K 103/51,132 0.2% (0.16-0.24%)
101-150K 13/3914 0.33 (0.18-0.57)
51-100K 4/2065 0.19 (0.05-0.5)
31-50K 1/789 0.13 (0-0.7)
11-30K 2/886 0.23 (0.03-0.81)
1-10 0/221 0 (o-1.66)
Total <150 K 20/7875 0.25%
INR #hematomas/total % (95% CI)
0-1.4 106/43,771 0.24 (0.2-0.29)
1.5-2.0 1/957 0.1 (0-0.58)
2.1-2.5 0/224 0 (0-1.63)
2.6-3.0 0/100 0 (0-3.62)
3.1-4.0 0/61 0 (0-5.87)
4.1 0/51 0 (0-6.98)
Total >1.4 1/1393 0.07%
aPTT #hematomas/total % (95% CI)
0-39s 59/19561 0.30 (.023-0.39)
40-60s 5/2282 0.22 (0.07-0.51)
61s 0/322 0 (0-1.14)
Total >40s 5/2604 0.19%
+ coagulopathy 24/10,371 0.23% (0.15-0.34%)
– coagulopathy 99/49,526 0.20% (0.16-0.24%)
This data suggest that thrombocytopenia or coagulopathy was not a significant risk factor for the development of lumbar puncture-associated spinal hematomas/epidural hematomas. The independent risk factors identified for the development of spinal hematomas were male sex [HR = 1.72] and age 41-80 [HR = 2.1]
The incidence of traumatic lumbar punctures was more frequent in patients with elevated INR (~40%) vs 28% for patients with normal INR or prolonged aPTT levels (~26%) vs 21% incidence in patients with a normal aPTT level.
This study does NOT mean that it is safe to perform a lumbar puncture without pre-procedure correction of platelet counts in the setting of thrombocytopenia or coagulopathy if the INR>1.5 or the aPTT exceeds 1.5x upper limit of normal However, the risk of epidural hematoma/spinal hematoma may not be as high as clinicians previously thought under these circumstances. More large population-based studies are needed to see if this data are reproducible to inform decisions about the safety of lumbar punctures in patients with a bleeding diathesis.
Reference: