# Anticoagulation and Neuraxial Procedures: ASRA Guidelines

## The Risk: Epidural Hematoma

### Epidemiology

The estimated incidence of epidural hematoma is approximately 1:150,000 for epidural anesthesia and 1:220,000 for spinal anesthesia. The risk is higher in elderly patients, female patients, and those receiving anticoagulant therapy. The incidence may be increasing as the use of antithrombotic agents expands and the surgical population ages.

### Consequences

An epidural hematoma compresses the spinal cord or cauda equina, causing progressive motor and sensory deficits along with bowel and bladder dysfunction. Surgical decompressive laminectomy performed within 8-12 hours is critical for neurologic recovery. When decompression is delayed beyond 12 hours, permanent paraplegia occurs in more than 50% of cases.

### Risk Factors

The most common modifiable risk factor is anticoagulant or antiplatelet therapy. Other risk factors include coagulopathy from hepatic disease or DIC, thrombocytopenia, difficult or traumatic needle and catheter placement, an indwelling epidural catheter (which carries risk at removal as well as insertion), and anatomic abnormalities such as spinal stenosis or ankylosing spondylitis.

## ASRA Fourth Edition Guidelines (2018) -- Key Intervals

### Unfractionated Heparin (UFH)

#### Subcutaneous Prophylactic Dose (5,000 units BID/TID)

No specific time interval is required before neuraxial placement; the procedure may proceed if there is no clinical coagulopathy. The catheter may be removed 4-6 hours after the last dose, and heparin may be resumed 1 hour after needle or catheter manipulation.

#### Intravenous Therapeutic Dose

Intravenous heparin should be discontinued 4-6 hours before neuraxial placement, and the aPTT must be confirmed as normal. If the neuraxial procedure has already been performed, heparinization may begin 1 hour afterward. For catheter removal, heparin should be held for 4-6 hours with aPTT verification. If a bloody tap occurs in a patient scheduled for intraoperative heparinization (such as cardiac surgery), the situation should be discussed with the surgical team; delaying heparinization is preferable if possible, though a bloody tap is not an absolute contraindication.

### Low Molecular Weight Heparin (LMWH)

#### Prophylactic Dose (e.g., enoxaparin 40 mg daily)

A 12-hour interval is required after the last dose before neuraxial placement. The same 12-hour interval applies to catheter removal. The next LMWH dose should be given no sooner than 4 hours after needle or catheter removal.

#### Therapeutic Dose (e.g., enoxaparin 1 mg/kg BID)

A 24-hour interval after the last dose is required before neuraxial placement. The same 24-hour interval applies to catheter removal. The next dose may be given 4 hours after needle or catheter removal. Anti-Xa levels are not recommended for routine monitoring of timing decisions.

<image>Timeline diagram showing the ASRA-recommended time intervals for neuraxial procedures with common anticoagulants. The diagram uses a horizontal timeline with the neuraxial procedure in the center, showing required pre-procedure hold times to the left and post-procedure dosing intervals to the right. Separate rows are shown for: UFH (SC and IV), LMWH (prophylactic and therapeutic), warfarin, rivaroxaban, apixaban, dabigatran, clopidogrel, ticagrelor, prasugrel, and aspirin. Each interval is clearly labeled in hours or days.</image>

### Direct Oral Anticoagulants (DOACs)

#### Rivaroxaban (Xarelto)

Rivaroxaban should be held 72 hours before neuraxial placement and may be resumed 6 hours after needle or catheter removal.

#### Apixaban (Eliquis)

Apixaban should be held 72 hours before neuraxial placement and may be resumed 6 hours after removal.

#### Dabigatran (Pradaxa)

Dabigatran should be held 120 hours (5 days) before neuraxial placement if creatinine clearance exceeds 50 mL/min, and even longer if clearance is 30-50 mL/min. It may be resumed 6 hours after removal. Idarucizumab (Praxbind) reverses dabigatran but does not make immediate neuraxial placement safe.

#### Edoxaban (Savaysa)

Edoxaban should be held 72 hours before neuraxial placement and may be resumed 6 hours after removal.

### Warfarin

Warfarin should be discontinued 5 days before neuraxial placement. The INR must be checked on the day of the procedure and must be 1.4 or below (ideally 1.2 or below). For catheter removal, the INR must also be 1.4 or below. Warfarin may be resumed postoperatively, but the INR should be monitored daily while the catheter remains in place. If the INR rises above 1.4 with the catheter still in situ, warfarin should be held and the INR rechecked.

### Antiplatelet Agents

#### Aspirin (ASA)

Aspirin as monotherapy does **not** contraindicate neuraxial anesthesia. It may be continued perioperatively for neuraxial procedures. The risk assessment changes, however, when aspirin is combined with other antiplatelet agents.

#### Clopidogrel (Plavix)

Clopidogrel should be held 5-7 days before neuraxial placement.

#### Ticagrelor (Brilinta)

Ticagrelor should be held 5-7 days before neuraxial placement.

#### Prasugrel (Effient)

Prasugrel should be held 7-10 days before neuraxial placement.

#### Dual Antiplatelet Therapy (DAPT)

When aspirin is combined with a P2Y12 inhibitor, the bleeding risk is substantially higher. The P2Y12 inhibitor must be held for the appropriate interval, while aspirin alone may continue. If a patient has a recent coronary stent and the mandatory DAPT window has not elapsed, a multidisciplinary discussion weighing the cardiac risk of holding DAPT against the neuraxial bleeding risk is essential.

#### GP IIb/IIIa Inhibitors

Abciximab should be held 48 hours before neuraxial placement. Eptifibatide and tirofiban should be held 8 hours.

### NSAIDs

Nonselective NSAIDs such as ibuprofen and naproxen do not pose additional concern for neuraxial procedures. COX-2 inhibitors do not increase bleeding risk.

### ASRA Time Intervals Summary

| Anticoagulant | Hold Before Neuraxial | Resume After Needle/Catheter Removal |
|---|---|---|
| UFH (SC prophylactic) | No specific interval | 1 hr after removal |
| UFH (IV therapeutic) | 4–6 hr (check aPTT) | 1 hr after removal |
| LMWH (prophylactic) | 12 hr | 4 hr after removal |
| LMWH (therapeutic) | 24 hr | 4 hr after removal |
| Warfarin | 5 days (INR ≤1.4) | After removal (monitor INR) |
| Rivaroxaban | 72 hr | 6 hr after removal |
| Apixaban | 72 hr | 6 hr after removal |
| Dabigatran | 120 hr (CrCl >50) | 6 hr after removal |
| Edoxaban | 72 hr | 6 hr after removal |
| Clopidogrel | 5–7 days | After removal |
| Ticagrelor | 5–7 days | After removal |
| Prasugrel | 7–10 days | After removal |
| Aspirin (monotherapy) | No contraindication | Continue perioperatively |

### Herbal Supplements

Garlic, ginkgo, and ginseng theoretically increase bleeding, but there is no specific ASRA recommendation to delay neuraxial procedures based on their use. Discontinuation 7 days before the procedure is reasonable when possible.

## The PAUSE Trial (DOACs)

### Design

The PAUSE trial was a prospective cohort study examining perioperative DOAC management for elective surgery and procedures, using a standardized interruption protocol based on the specific DOAC, renal function, and procedure bleeding risk.

### Key Findings

The study demonstrated that a simple, standardized DOAC interruption protocol without bridging anticoagulation is safe. For apixaban and rivaroxaban, a 2-day hold is adequate for low-bleed-risk procedures and a 3-day hold for high-bleed-risk procedures. For dabigatran, a 2-day hold suffices for low-bleed-risk procedures with creatinine clearance of 50 mL/min or higher, while a 4-day hold is needed for high-bleed-risk procedures or reduced clearance. The thromboembolism rate was below 1% and the major bleeding rate below 2%. The critical practical takeaway is that **bridging anticoagulation is not necessary for DOACs** because their predictable pharmacokinetics and short half-lives allow simple hold-and-resume protocols.

## Platelet Count Thresholds for Neuraxial

### General Recommendations

A **platelet count of 80,000/mcL or above** is generally considered safe for epidural placement and removal. A count of **50,000-75,000/mcL** may be acceptable for single-shot spinal anesthesia, where the smaller needle and single pass reduce the risk. A count **below 50,000/mcL** generally contraindicates neuraxial procedures. Platelet function, not just the count, should be considered in conditions such as preeclampsia, ITP, and liver disease. The trend in the platelet count is important: a rapidly falling count may reach critically low levels before catheter removal is needed.

### Obstetric Considerations

Gestational thrombocytopenia (platelets 70,000-150,000) is generally considered safe for neuraxial if the count is stable. Most anesthesiologists will proceed with neuraxial anesthesia in preeclamptic patients with platelet counts above 70,000-80,000. In HELLP syndrome, the platelet count can change rapidly, and rechecking close to the time of the procedure is essential. There is no universal "hard cutoff"; clinical judgment must incorporate the trend, urgency of the procedure, and the risks of alternative anesthetic techniques.

<image>Clinical decision-making flowchart for neuraxial anesthesia in the anticoagulated patient. The flowchart begins with identifying the anticoagulant, then checks the time interval since last dose against ASRA guidelines, assesses coagulation status (INR, platelet count), and determines whether to proceed, delay, or choose an alternative technique. Decision points for catheter removal timing are also included with specific intervals for each anticoagulant class.</image>

## Catheter Removal Considerations

### Timing Is Critical

The risk of epidural hematoma exists at catheter **removal** as well as insertion. The same time intervals that apply to needle placement also apply to catheter removal. Catheter removal must be planned around the anticoagulation dosing schedule.

### After Catheter Removal

Neurological status should be monitored every 2 hours for at least 12-24 hours after catheter removal. Any new motor weakness, back pain, or bladder dysfunction demands urgent MRI and neurosurgical consultation. New neurologic deficits should never be attributed to residual epidural analgesia without thorough investigation.

## Special Situations

### Emergency Surgery in Anticoagulated Patients

When neuraxial anesthesia is the safest option in an anticoagulated patient requiring emergency surgery (for example, an emergency cesarean in a patient with a known difficult airway), the risk-benefit calculation changes. The clinical reasoning should be documented clearly. When neuraxial is contraindicated by anticoagulation, general anesthesia is usually the alternative.

### Thrombolytics and Fibrinolytics

Thrombolytics and fibrinolytics are an **absolute contraindication** to neuraxial procedures for 48 hours after administration. If a neuraxial catheter is already in place when thrombolytics are given, the catheter should not be removed. Fibrinogen should be checked, and the catheter removed only when fibrinogen exceeds 200 mg/dL and coagulation has normalized, with neurosurgical consultation.

### Fondaparinux

At prophylactic doses, neuraxial may be performed with caution, using a single-pass atraumatic technique. At therapeutic doses, neuraxial should be avoided. Data are limited, and ASRA advises caution.

## Clinical Pearls

The timing intervals are most critical at two points: needle or catheter insertion and catheter removal -- both carry hematoma risk. Aspirin monotherapy does not contraindicate neuraxial; neuraxial should not be delayed or cancelled for aspirin alone. DOACs do not require bridging with heparin perioperatively (PAUSE trial); their short, predictable half-lives allow simple hold-and-resume protocols. A bloody tap during epidural placement in a patient scheduled for intraoperative heparinization is a judgment call, not an absolute contraindication; the situation must be communicated clearly to the surgical team. The INR should always be checked on the day of the procedure in patients on warfarin rather than relying on the expected timeline alone. When in doubt, the most recent ASRA guidelines should be consulted, as anticoagulation pharmacology evolves and new agents are continuously introduced.

## References

- Horlocker TT, Vandermeuelen E, Kopp SL, et al. Regional anesthesia in the patient receiving antithrombotic or thrombolytic therapy: American Society of Regional Anesthesia and Pain Medicine Evidence-Based Guidelines (Fourth Edition). *Regional Anesthesia and Pain Medicine*. 2018;43(3):263-309.
- Douketis JD, Spyropoulos AC, Duncan J, et al. Perioperative management of patients with atrial fibrillation receiving a direct oral anticoagulant (PAUSE). *JAMA Internal Medicine*. 2019;179(11):1469-1478.
- Bateman BT, Mhyre JM, Ehrenfeld J, et al. The risk and outcomes of epidural hematomas after perioperative and obstetric epidural catheterization. *Anesthesia & Analgesia*. 2013;116(6):1380-1385.
- Leffert LR, Butwick AJ, Carvalho B, et al. The Society for Obstetric Anesthesia and Perinatology consensus statement on the anesthetic management of pregnant and postpartum women receiving thromboprophylaxis or higher dose anticoagulants. *Anesthesia & Analgesia*. 2018;126(3):928-944.