Article - Regional Anesthesia in Pt Receiving Antithrombotics Flashcards
Recommended time interval between catheter removal and subsequent low-molecular weight heparin administration
4 hours
Preoperative instructions for patient on warfarin prior to elective procedure using regional
Discontinue at least 5 days prior
INR preoperative goal in warfarin patients
What do you do if goal is not met?
<1.5
Consider 1-2 mg oral Vitamin K if >1.5
Many new oral anticoagulant medications have been approved by the FDA since the last regional consensus article. Nearly all of these drugs have a black box warning for what adverse effect?
Spinal hematoma
What 3 time intervals are important to understand for anticoagulants when using regional anesthesia?
- Time between discontinuation of anticoagulant and a surgical procedure or neuraxial block
- Timing of epidural catheter after administration of anticoagulant
- Timing of subsequent dosing following neuraxial catheter removal
How do you reverse warfarin in patient presenting for urgent surgery? For immediate reversal?
Urgent reversal: Consider 2.5-5 mg oral or IV vitamin K
Immediate reversal: PCCs, FFP
Instructions for bridging preoperative patients at high risk for thromboembolism when discontinuing warfarin for procedure
Bridge with therapeutic SC LMWH (preferred) or IV UFH
When should last dose of preoperative LMWH be administered before surgery? How should dose be adjusted?
24 hours before
Only give half the daily dose
When should IV heparin be discontinued before surgery?
4-6 hours
Is bridging necessary for patient at low risk for thromboembolism?
Nope
When to resume warfarin postoperatively for patient at low risk of thromboembolism?
POD??
When to resume LMWH for patient at high risk of thromboembolism after minor surgical procedure?
After high risk procedure?
24 hr postoperatively
48 hr postoperatively
-
-
What should you assess when considering timing of resumption of LMWH or UFH therapy?
Bleeding risk and adequacy of hemostasis
What 2 drugs do all patients with bare metal or drug eluting stents require for varying durations?
Aspirin Thienopyridine derivatives (Clopidigrel aka plavix)
Instructions for preoperative patients on antiplatelet therapy at high risk of cardiac events (exclusive of coronary stents)
- Continue aspirin throughout periop period
- Discontinue clopidigrel 5 days prior to surgery
- Resume thienopyridine 24 hours postoperatively
Instructions for preoperative patients on antiplatelet therapy at low risk of cardiac events
- Discontinue dual anti-platelet therapy 7-10 days prior to surgery
- Resume antiplatelet therapy 24 hours postoperatively
How long should elective surgery be postponed if aspirin and thienopyridine therapy bust be discontinued for patients with bare metal stents and drug-eluting stents?
Bare metal stents- 6 weeks
Drug eluting stents- 6 months
If a patient is on antiplatelet therapy for coronary stents and needs surgery that cannot be postponed, what should be done about medications?
Continue dual anti-platelet therapy throughout perioperative period
In patients scheduled to receive thrombolytic therapy, the patient should be queried and medical record reviewed for what recent intervention?
Lumbar puncture, spinal cord or epidural anesthesia, or ESI
Guidelines detailing contraindications suggest that thrombolytics should be avoided for how long following puncture of non-compressible vessels?
10 days
Patients who have received fibrinolytic or thrombolytic therapy should not undergo what interventions
Performance of spinal or epidural anesthetics except in highly unusual circumstances
While no clear data clearly outlines length of time neuraxial puncture should be avoided after discontinuation of lytics, what minimum time interval should be observed and what lab values recorded?
48 hours
Normalization of clotting studies including fibrinogen
What is one of the last clotting factors to recover?
FIbrinogen
What clotting factor should be measured before removing neuraxial catheters in patients who unexpectedly received lytic therapy during neuraxial catheter infusion?
Fibrinogen
What lab value is typically used to monitor anticoagulant effect of heparin in therapeutic doses?
aPTT
Which lab offers improvements over aPTT for accurate measurement of heparin levels?
Anti-factor Xa
Which lab value is used to monitor higher doses of anticoagulant given during CP bypass?
Activated clotting time (ACT)
Options for labs that show adequate therapeutic anticoagulant effect in patients with VTE or unstable angina
- PTT prolongation between 1.5-2.5 times baseline value
- Heparin level of 0.2-0.4 U/ml
- Anti-factor Xa level of 0.3-0.7 U/ml
What is the advantage of heparin related to its reversal?
Can be rapidly reversed with protamine
Each mg of protamine can neutralize how much heparin?
100 U
What time interval between needle placement and heparinization in surgery decreases risk of significant bleeding? what else decreases risk?
1 hour
Avoidance of other hemostasis altering drugs
What is an associated factor in approximately 50% of spinal hematomas?
Bloody tap or traumatic regional block
In patients who have undergone systemic heparinization, heparin should be discontinued for how long before removal of catheter to reduce risk of hematoma?
2-4 hours
Also assess coag status
What should be avoided in a patient with known coagulopathy from any cause?
Neuraxial blocks
LETS BEAT THE DEAD HORSE
How long should surgery be delayed in the event of a traumatic tap?
24 hours
Time from instrumentation to systemic heparinization
Should be greater than 60 minutes
When should epidural catheters be removed?
When coagulation is restored
What should you monitor for after catheter removal?
Signs and symptoms of hematoma formation
What lab value should be checked prior to neuraxial block or catheter removal in patients receiving IV or SC UFH heparin for more than four days?
What disorder are you monitoring for?
- Platelet count
- heparin induced thrombocytopenia
When should you discontinue heparin infusion prior to neuraxial blockade?
4-6 hours
Also verify normal coag status
Delay heparin administration for how long after needle placement?
1 hour
How long should you wait to discontinue neuraxial catheter after last heparin dose and assessment of coag status? When can you reheparinize?
D/C after 4-6 hours
Reheparinize after 1 hour
How long should you wait before performing neuraxial block on patients on the following drugs? (*still always assess coag status)
- Preoperative low dose SC UFH for thromboprophylaxis (5000 U BID or TID)
- Preoperative higher dose SC UFH for thromboprophylaxis (7500-10,000 U BID or daily dose <20,000 U)
- Preoperative therapeutic UFH (individual dose >10,000 U SC per dose or >20,000 U total daily dose)
- 4-6 hours
- 12 hours
- 24 hours
For patients taking the following doses of enoxaparin, placement or removal of neuraxial catheter should be delayed for how long after administration?
- Prophylactic doses such as those used for prevention of DVT (30 mg BID or 40 mg once daily)
- Higher therapeutic doses (1 mg/kg BID or 1.5 mg/kg once daily)
- At least 12 hours
2. 24 hours
When should post-procedure dose of enoxaparin be given after catheter removal?
No sooner than 4 hours
When bridging anticoagulation, it is critical that the last preoperative dose occur when?
at least 24 hours before surgery
What two combination of drugs increases risk of spinal hematoma?
Anti-platelet or oral anticoagulant administered in combination with LMWH
When should needle placement occur in patient receiving prophylactic LMWH?
At least 12 hours after admin
Can a patient who received LMWH 2 hours ago receive neuraxial techniques?
No, because needle placement would occur close to peak anticoagulant activity
In patients receiving higher therapeutic doses of LMWH when can catheter placement occur?
Delay at least 24 hours
In patients receiving higher therapeutic doses of LMWH, what lab value should you consider checking, particularly in elderly and renal insufficiency patients? What is an acceptable level?
Anti-factor Xa
TRICK QUESTION: An acceptable level of residual anti-factor Xa activity to proceed with neuraxial remains undetermined
In single daily prophylactic dosing of LMWH, how long must you wait between catheter/needle placement before the first dose?
- Second?
- Other considerations?
- When can catheter be removed?
- Then when can you give another dose?
- 12 hours before first
- Second dose no sooner than 24 hours after first dose
- Indwelling catheters represent no increased risk and may be maintained
- No additional hemostasis altering meds allowed
- Remove catheter 12 hours after last dose
- Give at least 4 hours after catheter removal
When can single or BID THERAPEUTIC LMWH dosing be resumed after non-high-bleeding risk surgery?
After high-bleeding-risk-surgery?
Can you give this while the catheter is in?
- 24 hours after non-high-bleeding risk
- 48-72 hours after high-bleeding risk surgery
- No, give no sooner than 4 hours after catheter removal or at least 24 hours after placement whichever is greater
Best method to assess rivaroxaban
Use of chromogenic anti-factor Xa assays developed for measurement of direct fact Xa inhibitors using specific rivaroxaban calibrators
If a neuraxial block is considered in patients treated with prophylactic rivaroxaban (<10 mg/d), what time interval should be observed between last dose and subsequent neuraxial puncture and/or catheter manipulation/withdrawal?
22-26 hours
In apixaban-treated patients, after a cautious risk-benefit analysis there is justification to proceed with neuraxial block after at least how long?
26-30 hour time frame
Are there specific antidotes that reverse anticoagulant effects of anti-factor Xa agents?
Nope, still lacking
Are there antidotes for thrombin inhibitors (Agratroban, angiomax, disirudin)?
No, the antithrombin effects cannot be reversed pharmacologically
Can you perform neuraxial techniques on patients receiving parenteral thrombin inhibitors?
Nope not recommended
What to use as bridge when warfarin is stopped before a neuraxial or surgical procedure?
LMWH
INR goal associated with normal coagulation & low risk of spinal bleeding if not on warfarin
<1.5
Recommendation on concurrent use of medications that affect clotting mechanism/increase risk of bleeding for patients recieving oral anticoagulants and do so without influencing INR
What are these meds?
Dont take these meds concurrently
Include: NSAIDs, thienopyridiines, UFH, and LMWH
When taking warfarin, when to remove catheter?
When INR is less than 1.5
When undergoing elective procedure where antiplatelet effect is not desired, AACP recommends D/C of clopidigrel and prasugrel for how many days prior to surgery?
5 days
How long do Oral P2Y12 inhibitors need to be stopped before surgery?
5 days
Conditions or alterations of health that contribute to bleeding
History of bruising/excessive bleeding
Female sex
Increased age
Do NSAIDs represent added significant risk of development of spinal hematoma in patients having epidural or spinal anesthesia?
What about NSAIDs in combination with other meds affecting clotting mechansims such as oral anticoagulants, UFH, LMWH?
No
Yes, if combined with others you should use caution with neuraxial technique
When to D/C thienopyridines before neuraxial blockade
Ticlopidine?
Clopidigrel?
Prasugrel?
Ticlopidine 10 days
Clopidigrel 5-7 days
Prasugrel 7-10 days
Time to normal hemostasis after herbs:
Garlic?
Ginkgo?
Ginseng?
Is the stopping of these herbs MANDATORY before neuraxial?
Garlic - 7 d
Ginkgo - 36 h
Ginseng - 24 h
Nope not mandatory, but if they have been taking them avoid????? idk how it can be both?
Proactive measures in the obstetric patients upon onset of labor
- D/C anticoagulant therapy
- Use 5000 SC UFH BID for thrombo-prophylaxis in antepartum patients near delivery to facilitate neuraxial analgesia and anesthesia when feasible
When may prophylactic LMWH heparin be started or restarted after delivery?
6-12 hours after delivery and no sooner than 4 hours after epidural catheter removal (whichever is later)
Procedures at low risk of bleeding where patient may continue anticoagulants
- Superficial and compressible plexus/peripheral nerve blocks
- Joint injections
- SI joint and sacral lateral branch blocks
Procedures at intermediate risk of bleeding where patient may not continue anticoagulants
- Other procedurs based on compressibility, patient body habitus, comorbidities, and degree and duration of anticoagulation
- neuraxial injections
- facet procedures
- Visceral sympathetic blocks
- Pocket revision
Procedures at high risk of bleeding where patient may not continue anticoagulants
- neuraxial blocks
- deep and noncompressible plexus/peripheral nerve blocks
- spinal cord stimulator trial and implant
- intrathecal pump trial and implant
- vertebroplasty
- epiduroplasty
BASICALLY JUST ANYTHING WITH THE SPINE
