Lumbar puncture and antithrombotic therapy

Created 07/02/2022, last revision 05/11/2023

lumbar puncture (LP), also known as a spinal tap, is an important and commonly performed invasive procedure to obtain cerebrospinal fluid (CSF) for diagnostic testing
the procedure carries some risk of spinal bleeding (most often in the form of an epidural hematoma)
high-risk conditions include:
- coagulopathies (including pharmacologically induced)
- advanced age
- multiple puncture attempts
- spinal pathology
the potential benefit of the procedure must outweigh the risk of bleeding
avoid repeated puncture attempts in high-risk patients
spinal hematoma should be suspected if sudden sensorimotor and/or sphincter deficits or severe low back pain occur after puncture ⇒ perform MRI immediately and consult a neurosurgeon ( after > 8h, the prognosis is already unfavorable despite successful surgery!) [Herlocker, 2010]

on the other hand, periprocedural discontinuation of antithrombotic medication is associated with an increased risk of thromboembolism
- aspirin withdrawal precedes up to 10.2% of acute cardiovascular syndromes (Burger, 2005)
the potential benefit of lumbar puncture must always outweigh the risk of thrombosis
bridging therapy may be required in high-risk patients
consultation with the specialist who prescribed the antithrombotic therapy and a hematologist is recommended

Routine coagulation and CBC

routine CBC + coagulation tests are performed prior to lumbar puncture; however, this is not explicitly stated in the recommendations for patients with a negative history of bleeding or hepatopathy
always perform in patients:
- with known coagulopathy or a history of bleeding
- on anticoagulant therapy
- with hepato- or nephropathy
consult a hematologist if pathological results are obtained

Thrombocytopenia

the procedure is considered safe if:
- lumbar puncture: Tr > 40×10⁹/L
- epidural/spinal anesthesia: Tr > 80×10⁹/L [Van Veen, 2009]
individually assess the risk-benefit ratio and consider concomitant risk factors (antiplatelet drugs, etc.)
- lumbar punction: – Tr 20-40×109/L
- epidural/spinal anesthesia: Tr 40-80×10⁹/L
consider preprocedural consultation with a hematologist and administration of platelet concentrate

Inherited coagulopathies

always manage such patients in collaboration with a hematologist
caution is necessary for patients with a positive family history who have not yet been diagnosed

Aspirin

low-dose ASA (100 mg) does not increase the risk of bleeding in minor procedures (incl. lumbar puncture)
it has also not been found to increase the risk of bleeding during epidural anesthesia (when ASA was given for pre-eclampsia) ⇒ no need to discontinue low-dose ASA
only high doses (> 300 mg) probably increase the risk of bleeding

P2Y12 inhibitor monotherapy

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Dual antiplatelet therapy (DAPT)

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GP IIb/IIIa antagonists

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Others

discontinue cilostazol 42 hours before the procedure and restart after 5 hours [Gogarten, 2010]
dipyridamole has a half-life of 10-12 hours; no special precautions are needed and it can be resumed after 6h

prophylactic reversal of antiplatelet therapy is not a routine procedure and should generally be avoided due to the risk of thrombosis
2-3 units of platelets may be considered to provide functional, circulating platelets; consult a hematologist
- studies have shown mixed results regarding the benefit of this practice; there is no standard dose, and no effect was shown in the PATCH trial
desmopressin (ddAVP) OCTOSTIM – 0,3 ug/kg +100 mL of NS, infused over 15-30 minutes
- the benefit of using desmopressin before lumbar puncture remains unproven; data are only available for general surgery (where reduced need for transfusion was reported) (Desborough, 2016)

Warfarin

it is safe to perform a lumbar puncture if INR is ≤ 1.4
discontinue warfarin 4-5 days before the procedure; the drop in INR is individual and difficult to predict
- the rapid fall in INR in the first 3 days after warfarin discontinuation reflects an increase in factor VII activity. However, hemostasis may remain compromised due to deficiencies in factors II and X (which take longer to normalize) [Herlocker, 2010]
- if early LP is required, administer KANAVIT 5 mg IV > 6-8 h before the procedure, then recheck INR
- in urgent cases, administer KANAVIT + PCC (PROTHROMPLEX. FEIBA) → see here
check INR before the procedure
restart warfarin after 12-24h; standard maintenance dose or double dose can be used

DOAC

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LMWH

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Fondaparinux

high risk of hematoma is present at the therapeutic dose (5-10 mg/d); the risk at a prophylactic dose (2.5 mg/d) is relatively low
discontinue fondaparinux at a prophylactic dose (2.5 mg) 36-42 h before the puncture and resume it 6-12 hours later
there are no strict recommendations for discontinuing a full therapeutic dose (probably > 48h)
specific tests are available to detect the residual activity of fondaparinux → fondaparinux

Heparin

heparin half-life is 1-2 h
a lumbar puncture can be performed > 4-6h (according to different recommendations) after the last heparin application, provided that the APTT ratio is normal (≤ 1.2)
heparin can be restarted 1-2 h after LP (Dodd, 2018)

Thrombolysis

hemostatic dysfunction may persist for up to 24 hours following tPA administration (via IVT, IAT, or intrasinus thrombolysis)
- postpone lumbar puncture for > 24h
- fibrinogen levels can be helpful (fibrinogen is the last of the coagulation factors to normalize after thrombolysis)
IVT administration < 10 days after a dural puncture is a relative contraindication – consider the risk-benefit ratio (AHA/ASA 2019 IIb/C)

warfarin
- consider bridging only in high-risk patients (see table below)
- meta-analyses have not shown a clear benefit of bridging, only an increased risk of bleeding
- BRIDGE trial in Afib patients showed non-inferiority of no therapy vs. LMWH bridging (only a few patients with CHADS2 ≥ 5 were enrolled in this trial; CHA2DS2-VASc score was not used)
- in patients with VTE > 3 months, a prophylactic dose of LMWH may be selected for bridging and should be discontinued 12 hours before surgery
- LMWH at therapeutic dose in high-risk patients should be started when INR < 2 (usually 36h after warfarin discontinuation) and discontinued ≥ 24h before surgery/procedure
- after the procedure, restart LMWH in 12-24h (at a therapeutic dose)
DOAC
- bridging therapy during DOAC discontinuation is not necessary, given the drug’s half-life and short discontinuation period

High-risk patients ⇒ consider LMWH bridging
DVT (deep vein thrombosis / PE)	DVT/PE < 3 months high-risk patient with a previous DVT on warfarin with a target INR of 3.5
Atrial fibrillation	stroke/TIA < 3 months stroke/TIA > 3 months + risk factors (CHA₂DS₂-VASc score ≥ 3) heart failure hypertension with BP > 140/90 mm Hg age > 75 years diabetes
Mechanical valve