[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Anaesthesia and ICU](https://durgical.com/en/anaesthesia/) › [Preoperative assessment](https://durgical.com/en/anaesthesia/areas/preop/) › Anticoagulants, antiplatelets and neuraxial blocks

# Anticoagulants, antiplatelets and neuraxial blocks

- Concept

Blood thinners must be paused for the right time before a spinal or epidural and its catheter removal, to avoid bleeding around the spinal cord.

Updated Nov 13, 2026

## Key points

- Catheter removal is as risky as insertion: time both against the last anticoagulant dose and delay the next dose after each.
- Aspirin or NSAIDs alone do not prevent a neuraxial block; the risk rises when they are combined with other antithrombotic drugs.
- Warning signs: new back pain, leg weakness or numbness beyond the expected block, or bladder and bowel dysfunction; image at once.
- Outcome depends on time: decompression within about eight hours of symptoms gives the best chance of recovery.
- Common hold times: prophylactic LMWH 12 h, therapeutic LMWH 24 h, warfarin about 5 days with normal INR, clopidogrel 5–7 days.

On this page

- The basics Key points
- What it is
- Key points
- Components
- Typical intervals from consensus guidance (check the current local protocol)
- In practice
- Next step
- Memory aid
- Elsewhere in DurgiPedia

- Study Test yourself

- Connections Connections

## What it is

A spinal or epidural haematoma is rare but can compress the spinal cord or cauda equina and leave permanent paralysis. The risk rises when a needle or catheter enters the neuraxis while clotting is impaired, so every neuraxial block and every catheter removal is timed against the anticoagulant or antiplatelet the patient takes. Consensus guidance from regional anaesthesia societies sets intervals based on each drug's half-life and kidney clearance: aspirin and NSAIDs alone add little risk; P2Y12 inhibitors (clopidogrel, ticagrelor, prasugrel) are stopped several days before; warfarin is stopped days before with a normal INR on the day; heparins and direct oral anticoagulants have intervals in hours to days. Removing a catheter carries the same risk as inserting it, and the next anticoagulant dose is delayed after both. Deep blocks near non-compressible vessels follow the same rules. When the intervals cannot be met, the team chooses general anaesthesia or another analgesic technique. Pregnant patients on heparin need a delivery plan made in advance so that labour analgesia stays possible.

## Key points

- Risk factors for haematoma: older women, kidney impairment, traumatic or repeated punctures, an indwelling catheter and combined antithrombotic drugs.
- Intervals depend on the drug and kidney function; dabigatran in particular is prolonged when kidney function is reduced.
- Unfractionated heparin subcutaneous prophylaxis: a few hours' gap and, after longer courses, a platelet count for heparin-induced thrombocytopenia.
- Direct factor Xa inhibitors are usually held about three days before a neuraxial block at standard intervals; check local guidance.
- Low platelets: obstetric consensus considers neuraxial block usually acceptable above about 70 × 10⁹/L if stable and no other bleeding risk.

## Components

- The drug: its mechanism, half-life, last dose time and whether it is prophylactic or therapeutic.
- The patient: kidney function, platelet count, other antithrombotic drugs and bleeding history.
- The block: single-shot spinal, epidural catheter or deep peripheral block near a non-compressible vessel.
- The clock: hold time before puncture, timing of catheter removal, and gap before the next dose.

## Typical intervals from consensus guidance (check the current local protocol)

| Drug | Stop before block | Restart after puncture or catheter removal |
| --- | --- | --- |
| Aspirin, NSAIDs (alone) | No need to stop | No restriction |
| Clopidogrel / ticagrelor / prasugrel | 5–7 days / 5–7 days / 7–10 days | After catheter removal |
| Warfarin | About 5 days; INR normal on the day | After catheter removal |
| LMWH prophylactic / therapeutic | 12 h / 24 h | Prophylaxis about 12 h after puncture; 4 h after catheter removal |
| Subcutaneous unfractionated heparin (prophylaxis) | About 4–6 h | About 1 h after puncture or removal |
| Apixaban, rivaroxaban, edoxaban | About 72 h | About 6 h after puncture or removal |
| Dabigatran | About 72–120 h by kidney function | About 6 h after puncture or removal |

## In practice

- A traumatic or bloody puncture delays the first anticoagulant dose afterwards; it is written down and handed over.
- Patients with an epidural catheter receive prophylactic doses timed so the catheter comes out at the trough, not the peak.
- Pregnancy: therapeutic heparin is often switched to a shorter-acting form or held before planned induction so labour analgesia is possible.
- Never bridge with heparin just to allow a block; choose another technique if the drug cannot be stopped safely.
- Check regularly for motor block in the legs while an epidural catheter is in place and for a day after removal.

## Next step

- Before any neuraxial block, record the drug, the last dose time and the platelet count, and compare with the local interval table.
- Call a senior if intervals are not met, the puncture was traumatic, or the patient takes two antithrombotic drugs.
- If back pain, new weakness or numbness, or bladder or bowel dysfunction appear, stop the epidural infusion and request urgent MRI and neurosurgery.
- Plan catheter removal with the ward: time it to the trough and note when the next anticoagulant dose may be given.
- Follow neurological checks after removal and tell the patient which symptoms need urgent attention.

## Memory aid

Drug, Dose time, Do the kidneys clear it, Device out: four D's before any needle or catheter near the spine.

## Test yourself

Think of the answer, then tap the question to see it.

## Why is removing an epidural catheter timed as carefully as inserting it?

Pulling the catheter can tear epidural veins just as insertion can, so it is done when the anticoagulant effect is lowest and the next dose is delayed.

## Which symptoms suggest a spinal epidural haematoma after a neuraxial block?

New or severe back pain, leg weakness or numbness beyond the expected block, and bladder or bowel dysfunction; urgent MRI and neurosurgical decompression follow.

## Does low-dose aspirin alone prevent a spinal anaesthetic?

No. Aspirin or NSAIDs alone do not add clinically important risk; the risk rises when they are combined with anticoagulants or other antiplatelet drugs.

## Why does kidney function change the hold time of dabigatran?

Dabigatran is cleared mainly by the kidneys, so its effect lasts longer when kidney function is reduced and the interval before a block is extended.

[Add to my cards (4)](https://durgical.app/estudiar/?add=/en/anaesthesia/anticoagulants-antiplatelets-and-neuraxial-blocks/)

## Elsewhere in DurgiPedia

- [The coagulation cascade](https://durgical.com/en/physiology/the-coagulation-cascade/)
- [Primary hemostasis and platelets](https://durgical.com/en/physiology/primary-hemostasis-and-platelets/)
- [Coagulation tests: PT/INR, aPTT, fibrinogen and D-dimer](https://durgical.com/en/clinical-skills/coagulation-tests-pt-inr-aptt-fibrinogen-and-d-dimer/)
- [Mechanical prevention of venous thromboembolism: stockings and intermittent compression](https://durgical.com/en/nursing/mechanical-prevention-of-venous-thromboembolism-stockings-and-intermittent-compr/)

## Connections

## Related 7

- [Which medicines to continue or stop before surgery](https://durgical.com/en/anaesthesia/which-medicines-to-continue-or-stop-before-surgery/)
- [Spinal anaesthesia](https://durgical.com/en/anaesthesia/spinal-anaesthesia/)
- [Epidural anaesthesia and analgesia](https://durgical.com/en/anaesthesia/epidural-anaesthesia-and-analgesia/)
- [Complications of neuraxial blocks: headache, hypotension, haematoma, infection](https://durgical.com/en/anaesthesia/complications-of-neuraxial-blocks-headache-hypotension-haematoma-infection/)
- [Peripheral nerve blocks in principle](https://durgical.com/en/anaesthesia/peripheral-nerve-blocks-in-principle/)
- [Labour analgesia](https://durgical.com/en/anaesthesia/labour-analgesia/)
- [Obstetric anaesthesia and caesarean section](https://durgical.com/en/anaesthesia/obstetric-anaesthesia-and-caesarean-section/)

## Related conditions 7

- [Epidural haematoma](https://durgical.com/en/conditions/epidural-haematoma/)
- [Deep vein thrombosis](https://durgical.com/en/conditions/deep-vein-thrombosis/)
- [Pulmonary embolism](https://durgical.com/en/conditions/pulmonary-embolism/)
- [Atrial fibrillation](https://durgical.com/en/conditions/atrial-fibrillation/)
- [Heparin-induced thrombocytopenia](https://durgical.com/en/conditions/heparin-induced-thrombocytopenia/)
- [Immune thrombocytopenia (ITP)](https://durgical.com/en/conditions/immune-thrombocytopenia/)
- [Von Willebrand disease](https://durgical.com/en/conditions/von-willebrand-disease/)

## In Pharmacology 15

- [Heparins](https://durgical.com/en/pharmacology/classes/heparins/)
- [Heparin](https://durgical.com/en/pharmacology/heparin/)
- [Enoxaparin](https://durgical.com/en/pharmacology/enoxaparin/)
- [Fondaparinux](https://durgical.com/en/pharmacology/fondaparinux/)
- [Warfarin](https://durgical.com/en/pharmacology/warfarin/)
- [Apixaban](https://durgical.com/en/pharmacology/apixaban/)
- [Rivaroxaban](https://durgical.com/en/pharmacology/rivaroxaban/)
- [Edoxaban](https://durgical.com/en/pharmacology/edoxaban/)
- [Dabigatran](https://durgical.com/en/pharmacology/dabigatran/)
- [Antiplatelet drugs](https://durgical.com/en/pharmacology/classes/antiplatelet-drugs/)
- [Acetylsalicylic acid](https://durgical.com/en/pharmacology/acetylsalicylic-acid/)
- [Clopidogrel](https://durgical.com/en/pharmacology/clopidogrel/)

## See all 15

- [Prasugrel](https://durgical.com/en/pharmacology/prasugrel/)
- [Ticagrelor](https://durgical.com/en/pharmacology/ticagrelor/)
- [Anticoagulant reversal agents](https://durgical.com/en/pharmacology/classes/anticoagulant-reversal-agents/)

[← All of anaesthesia](https://durgical.com/en/anaesthesia/)

Educational content; it does not replace supervised training, your institution's protocols or the anaesthetist's or intensivist's decision. It contains no doses and no ventilator or infusion settings.

Sources: [Perioperative Anticoagulation Management](https://www.ncbi.nlm.nih.gov/books/NBK557590/) (StatPearls (NCBI Bookshelf), 2023); [Anticoagulant Therapy In Pregnancy](https://www.ncbi.nlm.nih.gov/books/NBK606098/) (StatPearls (NCBI Bookshelf), 2026).

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Representative model, for educational purposes only.

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Source: https://durgical.com/en/anaesthesia/anticoagulants-antiplatelets-and-neuraxial-blocks/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/anaesthesia/anticoagulants-antiplatelets-and-neuraxial-blocks/