What labs should be ordered for a patient who recently received a regional block?

Laboratory Testing After Regional Block

In most cases, routine laboratory testing is NOT required after an uncomplicated regional block in a patient with normal coagulation. 1

When Labs Are NOT Needed

For patients with normal baseline coagulation who received a regional block without complications, no routine laboratory monitoring is necessary. 1 The guidelines emphasize that:

• Routine coagulation screening in healthy patients without risk factors is not indicated 1
• The absence of clinical bleeding or neurological symptoms does not warrant reflexive laboratory testing 1

When Labs SHOULD Be Ordered

Laboratory testing after regional block is indicated only in specific high-risk scenarios:

Anticoagulant Exposure

• If the patient received anticoagulants while a neuraxial catheter was in place, check coagulation parameters before catheter removal 1
• For warfarin: verify INR ≤ 1.4 before catheter removal 1, 2
• For heparin infusion: confirm APTT ≤ 1.4 times normal and stopped > 4 hours before removal 1

Suspected Coagulopathy Development

Order labs if any of the following develop post-procedure:

• New neurological deficits (back pain, leg weakness, bowel/bladder dysfunction): Immediate coagulation screen (PT/INR, APTT, platelet count) 2
• Clinical bleeding from puncture site or elsewhere: CBC with platelet count, PT/INR, APTT 3
• Signs of sepsis or DIC: Full coagulation panel including fibrinogen 1

Obstetric Patients with Specific Conditions

• Pre-eclampsia with platelets 75-100: Repeat platelet count and coagulation screen within 6 hours if catheter remains in place 1
• Severe/HELLP syndrome: Check platelet count and coagulation studies immediately before catheter removal due to rapid changes 1
• Intrauterine fetal death: Verify coagulation parameters (PT, APTT, fibrinogen) before catheter manipulation 1

Trauma or Major Surgery Patients

• If regional block performed in trauma setting: Assess coagulation status (PT, APTT, platelet count, fibrinogen) before catheter removal due to trauma-induced coagulopathy 1

Critical Monitoring Without Labs

All patients recovering from neuraxial anesthesia should be tested for straight-leg raising at 4 hours from the last epidural/spinal dose, with Bromage scale documentation 2, 4. Inability to straight-leg raise at 4 hours requires immediate anesthesiologist assessment and consideration of urgent imaging, not just laboratory testing 2.

Common Pitfalls to Avoid

• Do not order routine "post-procedure coags" in uncomplicated cases—this increases costs without improving outcomes 1
• Do not delay catheter removal waiting for unnecessary lab results in low-risk patients 1
• Do not rely solely on labs to detect epidural hematoma—neurological examination is more sensitive and time-critical 2
• Do not assume normal pre-procedure labs remain valid if anticoagulation was given or clinical status changed 1