CONTENTS
- General considerations
- Approach to warfarin reversal
- Approach to DOAC reversal
- Reversal of other agents
- Pharmacology of procoagulant agents
- Pre-procedure coagulation management for common procedures
how coagulopathic is the patient?
- Critically ill patients often have several coagulopathies (e.g., thrombocytopenia plus supratherapeutic INR on warfarin). Consider all medications and coagulation labs in order to get a global sense of how coagulopathic the patient is.
- For patients with cirrhosis or disseminated intravascular coagulation (DIC), traditional coagulation parameters (e.g., INR) don't necessarily reflect the true coagulation state. In this situation, thromboelastography (TEG) may be more accurate.
pharmacology specifics
- Review all medications the patient is taking which may affect coagulation (including over-the-counter aspirin or aspirin-containing products).
- Determine what doses of medication the patient is on, and when is the last time a dose was taken.
why was the patient initially anti-coagulated?
- Most patients are anti-coagulated for atrial fibrillation or deep vein thrombosis. Short-term interruption is generally fine.
- Some patients are anti-coagulated for higher risk conditions (e.g. a mechanical mitral valve, which has a high risk of thrombosis). This may shift the risk/benefit ratio.
how important is it to reverse the anticoagulation?
- Life-threatening bleeding requires aggressive normalization of coagulation parameters, but minor bleeding may respond to local measures.
- There is little evidence that moderately elevated INR correlates with post-procedural bleeding after many procedures (e.g., ultrasound-guided central line placement or thoracentesis). Anticoagulation reversal for minor procedures is generally unnecessary.
rapid reference for warfarin reversal
- Investigation:
- INR
- ⚠️ For intracranial hemorrhage in a patient on warfarin, PCC should be given immediately without waiting for the INR to result.(35579034)
- Reversal
assessment & target
- Assessed by measuring INR.
- For patients with intracranial hemorrhage, follow INR every 3-6 hours to ensure adequate reversal.(33288539)
intravenous vitamin K
- Probably the most important intervention to reverse warfarin is vitamin K.
- 10 mg should be given intravenously, as soon as possible (infused over 30 minutes).
- FFP or PCC will work only for ~8 hours.
- Vitamin K will do the job after the FFP/PCC wears off. It takes Vitamin K 6-12 hours to start working, so vitamin K must be given simultaneously with FFP or PCC.
- Intravenous vitamin K may theoretically cause an anaphylactoid response if infused rapidly.
- This is exceedingly rare (~1/30,000 patients).(22315259)
- This is an anaphylactoid reaction (not anaphylactic), so it can be avoided by infusing the vitamin K slowly (e.g., over 30 minutes).
- An anaphylactoid reaction is due to a drug's directly stimulating mast cells to release histamine – unlike an anaphylactic reaction, which involves IgE antibodies. Anaphylactoid reactions can present similarly to anaphylactic reactions and may be treated similarly. However, anaphylactoid reactions are generally less severe and can be avoided by infusing a drug slowly.
- Fear of this reaction should never be a barrier to giving intravenous vitamin K to patients who need it.
- If you're absolutely terrified about this reaction, then infuse the vitamin K incredibly slowly (e.g. over an hour). An anaphylactoid reaction is rate-related, so the likelihood of a severe adverse reaction at this slow of a rate is really zero.
- Other routes are inferior for emergent reversal:
- Subcutaneous administration has erratic absorption.
- IM administration may cause hematoma formation.
- PO administration has slower absorption.
- 💡 For emergent reversal of anticoagulation, there is only one dose & one route of vitamin K that should be used: 10 mg IV vitamin K.
Patients with supratherapeutic INR without bleeding are commonly encountered. Below is a general rubric that may help guide management. However, this isn't based on strong evidence. Most importantly, management should be individualized based on patient-specific factors (e.g., risk factors for bleeding/clotting etc.).
- INR 3-5 without bleeding:
- Hold warfarin.
- Resume at a lower dose when INR is therapeutic.
- INR 5-9 without bleeding:
- Hold 1-2 doses of warfarin.
- Vitamin K 1-2.5 mg PO/IV if risk for bleeding.
- Resume warfarin at lower dose then INR is therapeutic.
- INR >9 without bleeding:
- Hold 1-2 doses of warfarin.
- Vitamin K 2.5-5 mg PO/IV.
- Repeat vitamin K in 24 hours if INR remains elevated.
- Resume warfarin at lower dose when INR therapeutic. (Bojar 2021)
rapid reference for dabigatran reversal
- Investigation:
- PTT and thrombin time (if available).
- Reversal:
- Idarucizumab 5 g.
- If ingested in <2 hours may consider activated charcoal 50 grams.
lab assessment of drug levels
- Crude assay = PTT
- Normal PTT argues against clinically significant dabigatran effect, but doesn't exclude this possibility.
- Better assay = Thrombin Time (TT)
- Good correlation with dabigatran levels, but may be unmeasurably elevated at therapeutic dabigatran concentrations.
- Normal thrombin time excludes clinically significant dabigatran effect.(31339254)
- Availability may vary; often cannot be run STAT.
pharmacology
- Half-life: 12-17 hours (doubles if GFR <30 ml/min).
- Renal excretion: 80%.
- Removal by dialysis: ~65%.
tx: idarucizumab (PRAXBIND) 💊
- Monoclonal antibody binds and inactivates dabigatran.
- Possible indications for reversal:
- (1) Major bleeding or planned high-risk procedure.
- (2) Last dose taken within <12-24 hours (with normal renal function). For patients with intracranial hemorrhage, reversal may be considered if the last dose was within <5 half-lives (i.e., within the past 2-4 days.(Albin 2022)
- (3) Significantly abnormal PTT and/or thrombin time (especially thrombin time >25 seconds).
- Dose
- A total of 5 grams is usually sufficient. This is typically provided as two separate 2.5-gram doses no more than 15 minutes apart.
- However, for patients with an unusually high level dabigatran (e.g., new-onset renal failure with drug accumulation), there is a possibility that additional doses might be needed.
- Monitoring
- Follow PTT (or thrombin time if available) at baseline, 2-4 hours after idarucizumab, and 12-24 hours later.
- A small proportion of patients may have a rebound of dabigatran levels >12 hours after reversal due to drug redistribution out of adipose tissue, which may associate with bleeding. Redosing idarucizumab may be considered.(Albin 2022)
- Side-effects may include hypokalemia, delirium, pyrexia, and bankruptcy.
- Little high-quality evidence is available regarding this drug.
- If idarucizumab is unavailable, four-factor PCC may be used as an alternative, second-line treatment.(33403486)
tx: hemodialysis
- Due to its low percent protein binding, dabigatran can be removed by dialysis (whereas other DOACs cannot be).
- Dialysis may be considered if idarucizumab is unavailable.
lab assessment of XaBAN drug levels
- Crude assay = INR
- Rough assay
- Normal INR argues against a significant drug level but doesn't exclude this entirely. (31317796)
- Better assay = Anti-Factor Xa level
- Anti-Xa activity correlates well with drug level but not necessarily with anticoagulant effect. (31339254)
- Normal anti-Xa level excludes the presence of clinically relevant Xa inhibitors. Any anti-Xa assay may be used (e.g., assays designed for use with unfractionated heparin or low molecular-weight heparin) – the key issue is whether there is any detectable anti-Xa activity. (30916798)
- With anti-Xa levels increasingly being used to titrate heparin infusions, this laboratory's availability and turn-around time is improving.
- Best assay = Apixaban level (discussed in the section below).
pharmacology
- ApiXaBAN:
- Half-life ~12 hours (ranging ~9-14 hours).
- Clearance: ~55% in stool; ~25% renal excretion.
- Protein binding: ~90% (not dialyzable).
- RiveroXaBAN:
- Half-life 6-9 hours (11-13 in elderly).
- Clearance: 70% renal excretion.
- Protein binding: ~95% (not dialyzable).
- EdoXaBAN:
- Half-life 10-14 hours.
- Clearance: 50% renal excretion.
- Protein binding: ~50% (somewhat dialyzable).
reversal of XaBANs
- [1] 4-factor PCC (KCENTRA) 💉
- [2] If ingested within <2 hours, may consider activated charcoal 50g.
- [3] If INR is elevated, consider 10 mg IV vitamin K to exclude vitamin K deficiency.
- (Adnexanet Alfa may be considered if available. However, clinical data is mixed and the price is extremely high.)
Apixaban level is a chromogenic anti-Xa level that is calibrated to evaluate the level of apixaban. The assay's mechanics are identical to an anti-Xa level used to dose-adjust a heparin infusion. As such, an apixaban level will only be a valid measurement of the apixaban level in the absence of any other medications that inhibit factor X.
potential indications for checking an apixaban level
- [1] Active hemorrhage.
- [2] Need for an emergent/urgent procedure.
- [3] Expected abnormal pharmacokinetics, e.g.:
- Extremes of weight.
- Elderly.
- Renal impairment.
- Drug-drug interactions are expected to affect apixaban levels.
- [4] Clinical failure with breakthrough thrombosis.
- [5] Evaluation of medication adherence.
test limitations
- Other medications that will elevate the measured apixaban level:
- Heparins (unfractionated or LMWH).
- Fondaparinux.
- Any other Xa inhibitors (e.g., rivaroxaban, edoxaban).
- Falsely low anti-Xa/apixaban levels may occur with: (35080509)
interpretation of levels
normative levels during treatment of AF
- Peak level (2-4 hours after dose); median (5th-95th percentile)
- 2.5 mg (twice daily): 123 (69-221) ng/mL.
- 5 mg (twice daily): 171 (91-321) ng/mL.
- Trough level (10-12 hours after dose); median (5th-95th percentile)
- 2.5 mg (twice daily): 79 (34-162) ng/mL
- 5 mg (twice daily): 103 (41-230) ng/mL.
normative levels during treatment of DVT/PE
- Peak level (2-4 hours after dose); median (5th-95th percentile)
- 2.5 mg (twice daily): 67 (30-153) ng/mL.
- 5 mg (twice daily): 132 (59-302) ng/mL.
- 10 mg (twice daily): 251 (111-572) ng/mL.
- Trough level (10-12 hours after dose); median (5th-95th percentile)
- 2.5 mg (twice daily): 32 (11-90) ng/mL.
- 5 mg (twice daily): 63 (22-177) ng/mL.
- 10 mg (twice daily): 120 (41-335) ng/mL.
very rough cutoff values
- >50 ng/mL: roughly correlates with a therapeutic level
- >30 ng/mL: roughly correlates with some drug activity
thrombolytic reversal: immediate management
- Order INR, PTT, and fibrinogen levels (but don't wait for the lab result before giving reversal for an actively bleeding patient).(32224752)
- Essential interventions:
- Optional interventions:
- Fresh frozen plasma, for example ~2 units (may help manage fibrinogen degradation product coagulopathy).
- Platelet transfusion may be considered, especially in ongoing or life threatening bleeding with borderline thrombocytopenia or receipt of antiplatelet agents.
thrombolytic reversal: followup care
- Repeat coagulation studies (complete blood count, INR, PTT, fibrinogen, and ideally TEG). Provide additional products as needed to address deficiencies. In particular:
- Targeting a fibrinogen level >150-200 mg/dL is essential (for intracranial hemorrhage, >200 mg/dL may be desirable).(33952393) Each 10 units of cryoprecipitate will increase fibrinogen by ~50 mg/dL.(36333037)
- If the TEG shows ongoing hyperfibrinolysis, then administration of additional tranexamic acid or aminocaproic acid should be strongly considered.
- If INR >1.6, fresh frozen plasma should be considered.(36333037)
- Thrombocytopenia should be treated (with a platelet target depending on the location and severity of hemorrhage).
pharmacology of alteplase
- Alteplase has a very short half-life, so it is gone from the blood within minutes.
- Even after alteplase has left the bloodstream, levels of many clotting factors (especially fibrinogen) are profoundly reduced. Therefore, the effects of alteplase last much longer than the tPA molecules themselves.
- tPA has profound effects on numerous components of coagulation.(discussed further here) Reconstructing coagulation takes more work than might initially be expected.
general approach
- Protamine may cause anaphylaxis or pulmonary hypertension.
- In most cases of bleeding due to a heparin infusion, discontinuing the infusion alone is adequate.
- Protamine may be considered for severe bleeding (e.g., heparin-associated intracranial hemorrhage).
- ⚠️ Excessive protamine may cause coagulopathy.
protamine dose 💊
- General guidance:
- Usually avoid giving more than 50 mg at once.
- Give slowly over 15 minutes (rapid administration may cause hypotension, bradycardia, and anaphylactoid reaction).
- Reversal of heparin given via bolus:
- Heparin given within <30 minutes: 1 mg protamine per 100 units heparin.
- Heparin given 30-60 minutes ago: 0.5-0.75 mg protamine per 100 units heparin.
- Heparin given 60-120 minutes ago: 0.375-0.5 mg protamine per 100 units heparin.
- Heparin given 2-6 hours ago: 0.25-0.375 mg protamine per 100 units heparin.
- Reversal of heparin infusion:
- Determine the amount of heparin infused over the last two hours (usually the infusion rate multiplied by two).
- Give 1 mg protamine per 100 units of heparin which the patient has received over the last two hours.
- Post-cardiac surgery heparin rebound:
- May start with 25-50 mg protamine.
- Reversal of enoxaparin:
- Enoxaparin within <8 hours: 1 mg protamine per 1 mg enoxaparin. If bleeding continues, may give additional 0.5 mg protamine per mg enoxaparin.
- Enoxaparin given 8-12 hours previously: 0.5 mg protamine per 1 mg enoxaparin.
- Enoxaparin given >12 hours previously: Protamine less likely to be beneficial.
- Reversal of dalteparin or tinzaparin:
- Dalteparin or tinzaparin given within <4 hours: 1 mg protamine per 100 units of dalteparin or tinzaparin. May repeat half this dose four hours later.
- Given 4-8 hours previously: 0.5 mg protamine per 100 units dalteparin or tinzaparin.
- Monitoring
- Protamine lasts for about two hours so that multiple doses may be required (especially for low molecular weight heparin).
- Reversal of unfractionated heparin: monitor PTT 10 min after protamine is given, then again in 2-8 hours.
- Reversal of enoxaparin:
- Follow Xa level after giving protamine and then q2hr. Protamine neutralizes at most ~60-75% of enoxaparin, so don't expect normalization of anti-Xa level.(Albin 2022) May consider re-dosing at 0.5 mg protamine per mg enoxaparin if bleeding persists or anti-Xa level is rising (max 25 mg).
- Note that protamine will reverse enoxaparin only by ~50%.
protamine reactions
- A range of adverse reactions can occur, including:
- Hypotension and/or pulmonary vasoconstriction.
- Anaphylactoid reactions, including bronchospasm.
- Noncardiogenic pulmonary edema.
- Risk factors:
- History of fish allergy or nonprotamine medication allergy.
- Prior exposure to protamine.
- Rapid protamine administration.
- Protamine reactions generally occur within minutes of administration.
- Treatment varies depending on the clinical manifestation and severity.
rapid reference for antiplatelet reversal
- Investigation: Platelet function assays (if available).
- Reversal
- Desmopressin (DDAVP) 0.3-0.4 ug/kg, infuse over 20-30 minutes.
- Consider targeting a higher fibrinogen level than usual.
- (If desperate: Might consider addition of tranexamic acid.)
- (Platelet transfusion is generally not supported by evidence.)
overview of approaching antiplatelet agents
- Medications seem to be the safest, fastest, and most effective strategy:
- (2) Tranexamic acid may improve platelet function as well. Evidence is of fair quality, albeit not robust. However, tranexamic acid is inexpensive, generally safe, and widely available.
- Fibrinogen or cryoprecipitate – Targeting a slightly higher level than usual might be helpful, but evidence on this is scant.
assessment of anti-platelet medication effects
- This is impossible to do with most assays. Specifically, platelet agents will not affect conventional coagulation tests or standard thromboelastography (TEG).
- Numerous assays exist to evaluate platelet function, but most have poor availability or prolonged turn-around time. The most useful assays for emergent use might be the following:
- In practice, decisions about reversal agents often need to be made in the absence of any laboratory data regarding platelet function. Thus, the best approach to assessment may be a clinical history of whether the patient is adherent with antiplatelet agents and when the last dose was taken.
Rx #1: Desmopressin (DDAVP) improves platelet function
- More on this below. 💉
Rx #2: Target a slightly higher fibrinogen level ??
- Platelets cooperate together with fibrinogen to form a clot. Thus, to a certain extent, increased activity of either platelets or fibrinogen may compensate for a deficiency of the other.
- Evidence regarding the use of fibrinogen to reverse anti-platelet agents is nearly nonexistent. However, one study which investigated this confirmed that increasing the fibrinogen level may increase clot firmness in blood treated with antiplatelet agents, as measured by thromboelastography. (28159767)
- The optimal fibrinogen target in a bleeding patient is controversial (different guidelines recommend values ranging between ~150-200 mg/dL). For a patient on antiplatelet agents who is hemorrhaging, it might be sensible to target a slightly higher fibrinogen target than usual (if you're on the fence about whether to give fibrinogen).
Rx #3: Tranexamic acid (TXA) ? 💉
- Tranexamic acid inhibits the conversion of plasminogen into plasmin. Tranexamic acid is generally conceptualized as an inhibitor of fibrinolysis, but it's actually a lot more than that. For example, plasmin is involved in bradykinin generation, so tranexamic acid may have a role in the treatment of bradykinin-mediated angioedema.🌊 Plasmin also degrades the glycoprotein Ib receptors on the surface of platelets, impairing their ability to interact with von Willebrand Factor.(30474416) By preventing this interaction, tranexamic acid could potentially improve platelet function.
- Several studies suggest that tranexamic acid could improve platelet function, particularly in the context of anti-platelet agents:
- Two studies involving CABG patients found that tranexamic acid improved in vitro platelet function among patients who had received antiplatelet therapy.(20962655, 27388281)
- Three prospective RCTs involving CABG patients have demonstrated that tranexamic acid can reduce operative blood loss among patients on antiplatelet medications. (31363394, 22033349, 23426385)
- Tranexamic acid isn't widely recommended to reverse antiplatelet medications. However, it is widely available, relatively inexpensive, safe, and overall has a favorable track record for use in a variety of types of bleeding. The risk/benefit ratio is probably more favorable for tranexamic acid than for platelet transfusion (more discussion on both of these therapies below).
platelet transfusion & why it's generally not a wise idea
when might we expect exogenous platelets to help reverse antiplatelet agents?
- From a pharmacological standpoint, platelet transfusion would make the most sense if the following conditions were met:
- (#1) The anti-platelet drug should cause permanent inhibition of platelet function (drugs which do this include aspirin, clopidogrel, and prasugrel).
- (#2) The anti-platelet drug itself should already be cleared from the body (otherwise, residual drug may cause inhibition of the new platelets).
- (#3) Immediate hemostasis is essential (e.g. for an intracranial hemorrhage).
- Based on these principles, we can theoretically stratify the predicted effectiveness of platelet transfusion for common antiplatelet agents as follows:
- #1 = Most effective for aspirin. This drug causes permanent inhibition of platelet function and has a short half-life.
- #2 = Intermediate effect for clopidogrel. This drug causes permanent inhibition of platelet function, but it has a moderate half-life of 6 hours. Thus, if the patient took a dose of clopidogrel within the past 6-12 hours, residual drug could interfere with transfused platelets.
- #3 = Minimal effect for ticagrelor. Ticagrelor is a reversible platelet inhibitor, so platelet inhibition is a reflection of the real-time serum drug levels of ticagrelor. Transfused platelets will be inhibited by ticagrelor along with native platelets – adding little benefit.(30395148)
clinical evidence: PATCH trial
- This is a multi-center RCT regarding the use of platelet transfusion in patients with spontaneous intracranial hemorrhage who were taking antiplatelet agents. ~90% of the patients were taking aspirin, with relatively few patients using P2Y12-inhibitors. In short, this is precisely the situation where we would expect platelet transfusion to be beneficial.
- The study found no benefit from platelet transfusion – in fact, patients receiving platelets had worse neurologic outcomes and a trend towards more bleeding.
- This is an enormously important trial, which reminds us that we cannot assume that platelet transfusion will reverse anti-platelet drugs.
- More platelets doesn't equate with a better outcome.
- Patients undergoing neurosurgery were excluded from the trial, so this is one potential limitation.
understanding the PATCH trial: why doesn't platelet transfusion improve clinical outcomes in patients prescribed anti-platelet drugs
- The PATCH trial was a bit surprising, but in retrospect perhaps it shouldn't have been. There are numerous signals in the literature that platelet transfusion isn't great for reversal of anti-platelet drugs. The following are some reasons that platelet transfusion may fail to work clinically.
- (1) Many patients who are prescribed anti-platelet agents don't experience clinical platelet inhibition:
- (a) Some patients are non-adherent and simply aren't taking the medications.
- (b) Some patients may have altered drug metabolism, causing the anti-platelet agent to be ineffective (particularly in the case of clopidogrel).
- (2) Among patients whose platelets are truly inhibited, platelet transfusion often doesn't cause a substantial improvement in platelet function! This result has been found by several studies. (30814031, 27653814, 26553698, 24256671) This might be explained as follows:
- (a) Especially with newer antiplatelet drugs, longer half-life may lead to the persistence of drug in the body. Residual anti-platelet medication may cause dysfunction of transfused platelets.
- (b) Transfused platelets may not be as effective as normal platelets, due to changes which occur during storage.
- (c) It's conceivable that even if functional platelets are transfused into the patient, the dysfunctional platelets still get in the way and impair coagulation.
- (3) Platelet function is only one of many determinants of clinical outcome. Other factors may be more important (e.g. fibrinogen levels, blood pressure, features of the anatomic lesion which is bleeding).
- (4) Platelet transfusion has several risks (e.g. transfusion reaction, TRALI, cytokine release, infection, suppression of native platelet synthesis). These may serve to counterbalance any potential benefit.
possible prerequisites for platelet transfusion
- The final word remains to be written regarding the use of platelet transfusion to reverse anti-platelet medications. Routine use of platelet transfusion certainly seems misguided. However, there may be situations where platelet transfusion is reasonable (e.g. a surgeon or interventional consultant strongly feels that platelets are needed).
- Four prerequisites are suggested which could define patients who might potentially benefit from a platelet transfusion:
- (1) Patient is taking an antiplatelet agent which causes permanent platelet inhibition (e.g., aspirin, clopidogrel, or prasugrel).
- (2) The last dose of medication should ideally be >3 half-lives previously. Otherwise, residual drug may inhibit transfused platelets (this is discussed further above).
- (3) There is some laboratory evidence that the patient's platelets are inhibited (if platelet function labs are available and time permits this evaluation).
- (4) There is significant ongoing hemostatic stress (e.g. active bleeding or planned procedures).
use
- Warfarin reversal:
- Massive transfusion protocol (replacement of numerous factors and blood).
- Antithrombin deficiency.
- 🛑 Plasma should not be used in an attempt to reverse NOACs. (33403486)
dosing (1 unit = 250 ml)
- General dosing:
- 2-4 Units is often used as a dose of FFP.
- 4 units will increase clotting factors by ~10% which is considered necessary to improve coagulation. (Bojar 2021)
- Dosing for warfarin reversal based on INR:
- INR 2-3.9: 10 ml/kg
- INR 4-6: 12-15 ml/kg
- INR >6: 15-20 ml/kg.
- Follow the INR and consider additional FFP as needed.
what is in FFP?
- FFP contains clotting factors at their normal concentration in the plasma (it doesn't contain concentrated levels of clotting factors). This makes it impossible to restore the patient's INR to a 1.0 (this would require an infinite amount of FFP). In practice, it's impossible to achieve an INR below ~1.7.🌊
- When cryoprecipitate is obtained from the same unit of blood, FFP will have low levels of factors I, VIII, XIII, von Willebrand factor, and fibronectin. (Bojar 2021)
contraindications to PCC
- Heparin-induced thrombocytopenia (contains small amounts of heparin). In this situation, may consider either: fresh frozen plasma 💉 or Factor IX complex concentrates 💉.
pharmacokinetics, rebound, & monitoring of PCC
- PCC works immediately.
- The duration of effect is ~6-8 hours.
- Some DOACs will outlast this effect, causing rebound bleeding.
- Warfarin reversal requires IV vitamin K plus PCC, to avoid rebound bleeding when PCC wears off.
- The effect is generally monitored in terms of INR.
- For anti-Xa reversal, follow INR after giving PCC and then subsequently q6hr. Rebounding INR might indicate the waning effectiveness of PCC (but this remains unclear).
basics of four-factor prothrombin complex concentrate (PCC) – specifically KCentra 💊
- Contains a lot of stuff:
- Clotting factors (II, IX, X, and VII).
- Endogenous anticoagulants (Protein C, Protein S, and antithrombin-III)
- Very small amount of heparin.
- The inclusion of endogenous anticoagulants reduces the risk of thrombosis. This may explain studies that found no increase in thrombosis risk with PCC when compared to fresh frozen plasma. (33403486)
- PCC includes all the vitamin K-dependent coagulation factors, ideally suited to reverse warfarin. PCC is the preferred agent for warfarin reversal in major bleeding. (22315259) Advantages include:
- Lower volume, which reduces the risk of volume overload.
- Faster reversal (low volume of PCC allows for complete reversal in <30 minutes).
- More consistent reversal than fresh frozen plasma.
- There is no need to be thawed and cross-matched before administration.
- No risk of transfusion-related acute lung injury (TRALI).
dosing of PCC
dosing: warfarin reversal
- Traditional dosing (might be preferable for intracranial hemorrhage):
- INR 1.5-2: 15 units/kg (max 1500 units).(35579034) AHA/ASA guidelines suggest reversal if the INR is 1.3 or higher, but the benefit of reversing an INR of 1.3-1.4 is dubious.
- INR 2-4: 25 units/kg (max 2,500 units).
- INR 4-6: 35 units/kg (max 3,500 units).
- INR >6: 50 units/kg (max 5,000 units).
- Fixed dose PCC
- Uses include:
- (1) May reduce cost for patients with non-CNS bleeding that isn't immediately life-threatening.
- (2) May be applied immediately in situations where the INR is unknown.
- Initial dose:
- If weight >95 kg or INR is known to be >7.5, give 2,000 units.
- Otherwise give 1,500 units.
- Repeat INR STAT after 30 minutes. If the INR is >1.4, give additional PCC.
- Uses include:
dosing: anti-Xa (XABAN) reversal
- Many algorithms recommend 50 units/kg (max 5,000 units). (27894493, 33403486) This may be ideal for CNS bleeding.
- An alternative dosing strategy is to give 25 units/kg absolute body weight (max 2,500 units), and then follow clinically and repeat INR. This dose may be repeated if hemostasis is not achieved.
- Fixed dosing with 2,000 units may be used. This strategy has the advantage that it is simple and also has the best evidentiary support.(30916798) Additionally, fixed-base dosing may be ordered immediately rather than awaiting laboratory tests.
dosing: other coagulopathies
- The usual dose is often 20-40 IU/kg, depending on coagulation tests.
- Cardiac surgery: 20 IU/kg IBW may be used. (33251719)
indications include
- Hypofibrinogenemia.
- von Willebrand disease.
- Factor XIII deficiency with hemorrhage.
- Uremic patients with hemorrhage refractory to other interventions.
factors contained within a unit of cryoprecipitate (from 1 donor unit of plasma)
- Factor VIII (80–150 units).
- von Willebrand factor (100–150 units).
- Factor XIII (50–75 units).
- Fibrinogen (150–250 mg). (Dabbagh 2018)
dosing
- Cryo is often provided in 5-unit “pools.”
- Two 5-unit pools will raise the fibrinogen level by ~70-100 mg/dL. (Flynn 2020)
- The number of units of cryoprecipitate required may be estimated as follows: (Bojar 2021)
# Units = (Desired increase in fibrinogen in mg/dL)(Weight in kg)/500
- Benefits compared to cryoprecipitate:
- Doesn't require ABO blood matching.
- Doesn't require thawing.
- Reduced risk of pathogen transmission.
- Contains a known amount of fibrinogen.
- Lower amount of volume administration.
- Drawbacks compared to cryoprecipitate:
- Fibrinogen concentrate doesn't deliver von Willebrand factor (which can be problematic among patients on ECMO or status post cardiopulmonary bypass who have acquired von Willebrand syndrome).
- Dose:
- 30-60 mg/kg.
- As a rule of thumb, for a 70-kg patient, 3-4 grams of fibrinogen will increase the plasma level of fibrinogen by 100 mg/dL. (Dabbagh 2018, Flynn 2020)
basics of Factor IX complex – specifically Profilnine SD 💊
- Contains factors II, IX, X, and a small amount of VII.
- ⚠️ Unlike KCentra, does not include any endogenous anticoagulants. This gives Factor IX complex a greater tendency to promote thrombosis.
- Factor IX concentrate be used as an alternative to KCentra in patients with a history of heparin-induced thrombocytopenia. However, it is probably riskier and is supported by less evidence, when compared to KCentra.
pharmacokinetics
- Onset is essentially immediate.
- Duration of action is 12-24 hours.
dosing
- Emergent warfarin reversal in patients with a history of heparin-induced thrombocytopenia (HIT):
- 25 units/kg absolute body weight (max 2,500 units) combined with one unit of fresh frozen plasma.
- Maximal daily dose is 5,000 units.
mechanism of action
- DDAVP stimulates the release of von Willebrand Factor and factor VIII from the endothelium. Von Willebrand factor binds the GPIIb-IIIa receptor on platelets, causing platelet aggregation.
- This improves platelet function in a nonspecific fashion. However, DDAVP may be especially effective in patients with a deficiency of von Willebrand Factor or factor VIII.
general indications 💊
- Uremic platelet dysfunction. (25933676)
- Reversal of antiplatelet agents:
- DDAVP is arguably the front-line agent to improve platelet function. Evidence shows platelet function improvement among patients on antiplatelet medications, including P2Y12 inhibitors. (18068065, 1434725, 8330156)
- Among patients with intracranial hemorrhage on antiplatelet therapy, a retrospective study found that DDAVP use correlated with lower rates of hemorrhage expansion. (31567345) Neurocritical care guidelines suggest consideration of a single dose of DDAVP for patients with intracranial hemorrhage on antiplatelet agents. (26714677) 2022 AHA-ASA guidelines suggest that DDAVP may be utilized (with a level 2B recommendation). (35579034)
- Von Willebrand Disease:
- Congenital (Type I).
- Acquired:
- Chronic aortic stenosis.
- ECMO.
- Post-CT surgery patients with cardiopulmonary bypass time >140 minutes. (Dabbagh 2018)
- Hemophilia A.
- Patients with inherited platelet disorders. (Dabbagh 2018)
dose
- 0.3-0.4 micrograms/kg IV infused over 15-30 minutes to avoid vasodilation:
- 0.3 mcg/kg may be used for Hemophilia, Von Willebrand Disease, or antiplatelet reversal. (35579034)
- 0.4 mcg/kg may be used for uremic platelet dysfunction.
- In practice, DDAVP is usually given only as a one-time dose. DDAVP may be repeated q12hr for up to 6 doses, but this is usually not utilized for a few reasons:
- [1] DDAVP stimulates vWF release but doesn't increase its synthesis. Consequently, vWF stores are depleted, leading to tachyphylaxis.
- [2] Hyponatremia may become increasingly problematic over time.
side effects
- Hyponatremia: DDAVP blocks renal excretion of free water, which may lead to hyponatremia. This can be avoided by limiting the administration of water while administering desmopressin.
- Hypotension does seem to occur – this has been demonstrated in a meta-analysis. (27893176) In a critical care setting, this is manageable; the main problem may be incorrectly attributing the hypotension to hemorrhage (e.g., using it as a trigger to initiate a massive transfusion). Hypotension might be prevented or mitigated by slower administration.
- Thrombosis is a theoretical risk. However, the most recent meta-analysis detected no increase in thrombotic events.(27893176)
basics
- Both agents have the same mechanism of action: fibrinolysis inhibition due to competitive binding to plasminogen.
- Tranexamic acid is ten times more potent than aminocaproic acid. (Dabbagh 2018)
indications
- Trauma (CRASH-2 trial).
- Postpartum hemorrhage (WOMAN trial).
- Perioperative bleeding (especially cardiothoracic and orthopedic surgery).
- Laboratory evidence of hyperfibrinolysis.
- Accelerated Intravascular Coagulation and Fibrinolysis (AICF) in cirrhosis.📖
- Bleeding after receiving fibrinolytic therapy (e.g., alteplase).📖
- Massive transfusion protocol. 📖
- Possibly: Reversal of antiplatelet agents. 📖
cautions & relative contraindications
- Seizure history (may reduce seizure threshold). Seizure seems to be less common with aminocaproic acid than with tranexamic acid. (35747005)
- Patient at high risk of venous thromboembolic disease.
- End-stage renal disease.
- Aminocaproic acid and tranexamic acid are indicated for hyperfibrinolysis but are contraindicated in disseminated intravascular coagulation. Further discussion of sorting out DIC vs. hyperfibrinolysis is here: 📖
- Contraindicated in active hematuria from the upper urinary tract (may promote clot formation within the kidney or ureter).
choice of tranexamic acid vs. aminocaproic acid
- Overall, tranexamic acid and aminocaproic acid are very similar agents. Realistically, the selection of one agent may relate to factors such as availability and cost.
pharmacology
- Tranexamic acid:
- Excreted unchanged in the urine.
- Half-life of ~3 hours.
- Aminocaproic acid:
- Clearance is predominantly renal.
- Half-life of ~2 hours and a duration of action of ~3-4 hours.
- Oral bioavailability is 100%, with absorption within 1-2 hours.
dosing of IV tranexamic acid
- Loading dose:
- Loading dose is typically one gram as a slow IV push over 10 minutes, but it may range over 10-30 mg/kg. (Dabbagh 2018)
- The CRASH trials utilized one gram infused over 10 minutes.
- IV tranexamic acid must be infused slowly over 10-20 minutes (to avoid hypotension).
- Maintenance infusion:
- Maintenance infusion is typically 125 mg/hour (often formulated as one gram infused over 8 hours, repeatedly).
dosing of aminocaproic acid
- Intravenous administration:
- Loading dose of 4-5 grams IV during the first hour.
- Maintenance infusion of 1 gram/hour.
- In severe renal failure, the maintenance infusion should be reduced (but no published dosing scheme is available).
- For ongoing hyperfibrinolysis, IV aminocaproic acid may be transitioned to oral aminocaproic acid (e.g., 3 grams PO q6hrs). (30986390) Given the possibility of rhabdomyolysis with extended use, the lowest possible dose that suppresses hyperfibrinolysis should be utilized. A dose of 1 gram PO four times daily may be effective for outpatients. (16393288, 16819496)
monitoring
- Serial coagulation studies should be monitored. The efficacy of aminocaproic acid in suppressing excessive fibrinolysis may be supported if the fibrinogen rises or stabilizes (stops dropping) during therapy. (26907195)
- Rhabdomyolysis may occur with extended use of aminocaproic acid, so following creatinine kinase may be advisable.
- Treatment of last resort for ongoing bleeding.
- The standard dose is 90 ug/kg, with a second dose considered after two hours.
- A lower dose (40 ug/kg) may be effective without exposing patients to an increased risk of adverse events. (33251719)
- There is a high risk of thrombotic events as compared to other blood products.
pitfalls in pre-procedure coagulation management for common critical care procedures
- (#1) We overestimate the risk of bleeding. Most bedside ICU procedures carry a very low risk of bleeding and don't require aggressive coagulation reversal (with the possible exception of lumbar puncture).
- (#2) We fail to consider the big picture. ICU patients are sometimes on a potpourri of anticoagulant medications, along with various other hemostatic challenges (e.g., uremic platelet dysfunction, thrombocytopenia). Although any single medication or abnormality may not be severe, the overall constellation may be quite problematic.
- (#3) We put excess faith in the INR. This is foolish, because INR interpretation depends on the clinical context. For example, an INR of 2.5 in the context of cirrhosis is likely to reflect rebalanced hemostasis without any increase in hemorrhage risk. Alternatively, an INR of 2.5 in a patient on apixaban suggests a high bleeding risk. Thus, any studies or guidelines based predominantly on INR values is fundamentally flawed.
- (#4) We try to push the INR to 1.0 using FFP. Please note the above discussion about the futility of giving FFP to patients with an INR of ≤1.7.📖 Additionally, in the context of cirrhosis, FFP will improve the INR but it generally doesn't improve clinical hemostasis.
how to avoid these pitfalls
- (#1) Recognize that most of our procedures are low-risk for hemorrhage. Note, for example, the below guidelines by the Society of Interventional Radiology.(31229333) Essentially every bedside procedure in the ICU is listed as a “low risk” procedure.🗞
- (#2) Try to consider the larger picture, including all coagulopathies and anticoagulant medications.
- (#3) Thromboelastography has a proven ability to guide hemostatic replacement in the operating room (including complex surgeries such as liver transplantation). When in doubt about whether factor replacement is needed, ordering thromboelastography may provide a “second opinion.”📖 TEG is especially useful in cirrhosis, where it clearly outperforms traditional coagulation tests such as INR.🌊
low-risk ICU procedures: central line placement, thoracentesis, paracentesis
- There is no evidence that any specific threshold exists for coagulation labs, below which these procedures are unsafe. For example:
- Varying guidelines recommend different platelet threshold targets prior to central line insertion (including >50, >30, >20 and >10).(31229333) The reality is probably that no threshold exists.
- The 2019 Society of Interventional Radiology Consensus Guidelines concluded that the risk of bleeding following thoracentesis or paracentesis is so low that “the need for prophylactic blood products before these procedures has been called into question.”(31229333)
- Ultimately, decisions about risk versus benefit of prophylactic blood product administration should be individualized, based on a holistic assessment of the patient's risk of bleeding. There are some situations where prophylactic transfusion may be beneficial, although on the whole it is grossly over-utilized.
- The key to minimizing risk is to avoid arterial injury. Some safety steps which may help in this regards are as follows:
- Central line:
- The procedure should be done by an expert operator using ultrasound guidance.
- Do not attempt the procedure if there isn't a favorable ultrasound view (e.g., clear visualization of the vein and separation between vein and artery).
- Use a shallow angle of approach and try not to backwall the vessel (i.e., avoid going through-and-through the vessel; ideally only the proximal vessel wall should be punctured).
- Thoracentesis:
- Avoiding thoracentesis near the spine (the intercostal artery position may be more variable there).
- Staying close to the upper edge of the rib.
- When possible, ultrasound may be used to visualize the intercostal artery. This allows for pre-procedure identification of aberrant vessels and avoidance of them.
- As the syringe is advanced, there should be continuous negative suction. If arterial blood appears in the syringe, pull out! Do not advance into the pleura (this may create an arterial-pleural fistula).
- Paracentesis:
- Use a very small-bore needle (e.g. 24-gauge lumbar puncture needle, with the stylet removed of course).
- Before performing the procedure, use ultrasound with doppler to make sure that there are no arteries in the vicinity. The inferior epigastric arteries should ideally be identified and avoided, as any trauma to these arteries may cause massive peritoneal hemorrhage.
lumbar puncture
- This is perhaps the most worrisome procedure commonly performed in an ICU, since an epidural hematoma might potentially compress the spinal cord and thereby cause permanent neurological damage.
- A platelet count >50 is generally recommended prior to lumbar puncture.(31229333)
- Some series suggest that lumbar puncture is safe among patients on single or dual antiplatelet therapy.(29573815, 31378231)
Follow us on iTunes
The Podcast Episode
Want to Download the Episode?
Right Click Here and Choose Save-As
To keep this page small and fast, questions & discussion about this post can be found on another page here.
- A common error is trying to reverse warfarin with PCC or FFP alone. If either of these is given without simultaneous vitamin K, it will wear off over several hours.
- For serious bleeding, vitamin K should be given intravenously (NOT im, sq, or orally).
- Vitamin K should never be given subcutaneously (erratic absorption) or intramuscularly (risk of hematoma).
- Beware of patients on NOACs who develop renal failure, but keep on taking their NOACs. They may accumulate drug and become severely supratherapeutic, without any screamingly abnormal lab values (unlike, for example, the patient on warfarin with an INR of 9 – who is quite obviously supratherapeutic).
- Aggressive reversal of anticoagulation prior to minor procedures (e.g. ultrasound-guided central line placement in a patient with a gigantic, superficial internal jugular vein).
- Don't try to correct the pre-procedure INR to <1.7 using FFP – this is impossible and dangerous.
Guide to emoji hyperlinks 
= Link to online calculator.
= Link to Medscape monograph about a drug.
= Link to IBCC section about a drug.
= Link to IBCC section covering that topic.
= Link to FOAMed site with related information.
- 🗞 = Link to PDF of an open-access journal article.
= Link to supplemental media.
References
- 01434725 Gratz I, Koehler J, Olsen D, Afshar M, DeCastro N, Spagna PM, Ablaza SG, Larijani GE. The effect of desmopressin acetate on postoperative hemorrhage in patients receiving aspirin therapy before coronary artery bypass operations. J Thorac Cardiovasc Surg. 1992 Nov;104(5):1417-22 [PubMed]
- 08330156 Flordal PA, Sahlin S. Use of desmopressin to prevent bleeding complications in patients treated with aspirin. Br J Surg. 1993 Jun;80(6):723-4. doi: 10.1002/bjs.1800800616 [PubMed]
- 16393288 Gunawan B, Runyon B. The efficacy and safety of epsilon-aminocaproic acid treatment in patients with cirrhosis and hyperfibrinolysis. Aliment Pharmacol Ther. 2006 Jan 1;23(1):115-20. doi: 10.1111/j.1365-2036.2006.02730.x [PubMed]
- 16753596 Holland LL, Brooks JP. Toward rational fresh frozen plasma transfusion: The effect of plasma transfusion on coagulation test results. Am J Clin Pathol. 2006 Jul;126(1):133-9. doi: 10.1309/NQXH-UG7H-ND78-LFFK [PubMed]
- 18068065 Ranucci M, Nano G, Pazzaglia A, Bianchi P, Casana R, Tealdi DG. Platelet mapping and desmopressin reversal of platelet inhibition during emergency carotid endarterectomy. J Cardiothorac Vasc Anesth. 2007 Dec;21(6):851-4. doi: 10.1053/j.jvca.2007.05.009 [PubMed]
- 20962655 Weber CF, Görlinger K, Byhahn C, Moritz A, Hanke AA, Zacharowski K, Meininger D. Tranexamic acid partially improves platelet function in patients treated with dual antiplatelet therapy. Eur J Anaesthesiol. 2011 Jan;28(1):57-62. doi: 10.1097/EJA.0b013e32834050ab [PubMed]
- 22033349 Ahn SW, Shim JK, Youn YN, Song JW, Yang SY, Chung SC, Kwak YL. Effect of tranexamic acid on transfusion requirement in dual antiplatelet-treated anemic patients undergoing off-pump coronary artery bypass graft surgery. Circ J. 2012;76(1):96-101. doi: 10.1253/circj.cj-11-0811 [PubMed]
- 23426385 Shi J, Ji H, Ren F, Wang G, Xu M, Xue Y, Chen M, Qi J, Li L. Protective effects of tranexamic acid on clopidogrel before coronary artery bypass grafting: a multicenter randomized trial. JAMA Surg. 2013 Jun;148(6):538-47. doi: 10.1001/jamasurg.2013.1560 [PubMed]
- 23493971 Hibbert RM, Atwell TD, Lekah A, Patel MD, Carter RE, McDonald JS, Rabatin JT. Safety of ultrasound-guided thoracentesis in patients with abnormal preprocedural coagulation parameters. Chest. 2013 Aug;144(2):456-463. doi: 10.1378/chest.12-2374 [PubMed]
- 22315259 Holbrook A, Schulman S, Witt DM, Vandvik PO, Fish J, Kovacs MJ, Svensson PJ, Veenstra DL, Crowther M, Guyatt GH. Evidence-based management of anticoagulant therapy: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest. 2012 Feb;141(2 Suppl):e152S-e184S. doi: 10.1378/chest.11-2295 [PubMed]
- 24256671 Joseph B, Pandit V, Sadoun M, Larkins CG, Kulvatunyou N, Tang A, Mino M, Friese RS, Rhee P. A prospective evaluation of platelet function in patients on antiplatelet therapy with traumatic intracranial hemorrhage. J Trauma Acute Care Surg. 2013 Dec;75(6):990-4. doi: 10.1097/TA.0b013e3182a96591 [PubMed]
- 25933676 Kim JH, Baek CH, Min JY, Kim JS, Kim SB, Kim H. Desmopressin improves platelet function in uremic patients taking antiplatelet agents who require emergent invasive procedures. Ann Hematol. 2015 Sep;94(9):1457-61. doi: 10.1007/s00277-015-2384-1 [PubMed]
- 26553698 O'Connor SA, Amour J, Mercadier A, Martin R, Kerneis M, Abtan J, Brugier D, Silvain J, Barthélémy O, Leprince P, Montalescot G, Collet JP; ACTION Study Group. Efficacy of ex vivo autologous and in vivo platelet transfusion in the reversal of P2Y12 inhibition by clopidogrel, prasugrel, and ticagrelor: the APTITUDE study. Circ Cardiovasc Interv. 2015 Nov;8(11):e002786. doi: 10.1161/CIRCINTERVENTIONS.115.002786 [PubMed]
- 26714677 Frontera JA, Lewin JJ 3rd, Rabinstein AA, Aisiku IP, Alexandrov AW, Cook AM, del Zoppo GJ, Kumar MA, Peerschke EI, Stiefel MF, Teitelbaum JS, Wartenberg KE, Zerfoss CL. Guideline for Reversal of Antithrombotics in Intracranial Hemorrhage: A Statement for Healthcare Professionals from the Neurocritical Care Society and Society of Critical Care Medicine. Neurocrit Care. 2016 Feb;24(1):6-46. doi: 10.1007/s12028-015-0222-x [PubMed]
- 26907195 Buckley LF, Reardon DP, Camp PC, Weinhouse GL, Silver DA, Couper GS, Connors JM. Aminocaproic acid for the management of bleeding in patients on extracorporeal membrane oxygenation: Four adult case reports and a review of the literature. Heart Lung. 2016 May-Jun;45(3):232-6. doi: 10.1016/j.hrtlng.2016.01.011 [PubMed]
- 27388281 Van Aelbrouck C, Jorquera-Vasquez S, Beukinga I, Pradier O, Ickx B, Barvais L, Van Obbergh L, Faraoni D. Tranexamic acid decreases the magnitude of platelet dysfunction in aspirin-free patients undergoing cardiac surgery with cardiopulmonary bypass: a pilot study. Blood Coagul Fibrinolysis. 2016 Dec;27(8):855-861. doi: 10.1097/MBC.0000000000000485 [PubMed]
- 27653814 Teng R, Carlson GF, Nylander S, Andersson TL. Effects of autologous platelet transfusion on platelet inhibition in ticagrelor-treated and clopidogrel-treated subjects. J Thromb Haemost. 2016 Dec;14(12):2342-2352. doi: 10.1111/jth.13511 [PubMed]
- 27893176 Desborough MJ, Oakland KA, Landoni G, Crivellari M, Doree C, Estcourt LJ, Stanworth SJ. Desmopressin for treatment of platelet dysfunction and reversal of antiplatelet agents: a systematic review and meta-analysis of randomized controlled trials. J Thromb Haemost. 2017 Feb;15(2):263-272. doi: 10.1111/jth.13576 [PubMed]
- 27894493 Weinberger J, Cipolle M. Optimal Reversal of Novel Anticoagulants in Trauma. Crit Care Clin. 2017 Jan;33(1):135-152. doi: 10.1016/j.ccc.2016.08.005 [PubMed]
- 28159767 Calmette L, Martin AC, Le Bonniec B, Zlotnik D, Gouin-Thibault I, Bachelot-Loza C, Gaussem P, Godier A. Ticagrelor reversal: in vitro assessment of four haemostatic agents. J Clin Pathol. 2017 Sep;70(9):733-739. doi: 10.1136/jclinpath-2016-204117 [PubMed]
- 28432428 Pabinger I, Fries D, Schöchl H, Streif W, Toller W. Tranexamic acid for treatment and prophylaxis of bleeding and hyperfibrinolysis. Wien Klin Wochenschr. 2017 May;129(9-10):303-316. doi: 10.1007/s00508-017-1194-y [PubMed]
- 29778325 Sprigg N, Flaherty K, Appleton JP, et al.; TICH-2 Investigators. Tranexamic acid for hyperacute primary IntraCerebral Haemorrhage (TICH-2): an international randomised, placebo-controlled, phase 3 superiority trial. Lancet. 2018 May 26;391(10135):2107-2115. doi: 10.1016/S0140-6736(18)31033-X [PubMed]
- 30395148 Senzel L, Ahmed T, Spitzer ED. Laboratory Monitoring of Platelet P2Y12 Receptor Inhibitors and Reversal of Antiplatelet Agents. Am J Clin Pathol. 2019 Jun 5;152(1):1-6. doi: 10.1093/ajcp/aqy151 [PubMed]
- 30474416 Mahla E, Tantry US, Prüller F, Gurbel PA. Is There a Role for Preoperative Platelet Function Testing in Patients Undergoing Cardiac Surgery During Antiplatelet Therapy? Circulation. 2018 Nov 6;138(19):2145-2159. doi: 10.1161/CIRCULATIONAHA.118.035160 [PubMed]
- 30741383 Hu W, Xin Y, Chen X, Song Z, He Z, Zhao Y. Tranexamic Acid in Cerebral Hemorrhage: A Meta-Analysis and Systematic Review. CNS Drugs. 2019 Apr;33(4):327-336. doi: 10.1007/s40263-019-00608-4 [PubMed]
- 30814031 Nagalla S, Sarode R. Role of Platelet Transfusion in the Reversal of Anti-Platelet Therapy. Transfus Med Rev. 2019 Apr;33(2):92-97. doi: 10.1016/j.tmrv.2019.01.002 [PubMed]
- 30916798 Cuker A, Burnett A, Triller D, Crowther M, Ansell J, Van Cott EM, Wirth D, Kaatz S. Reversal of direct oral anticoagulants: Guidance from the Anticoagulation Forum. Am J Hematol. 2019 Jun;94(6):697-709. doi: 10.1002/ajh.25475 [PubMed]
- 31069969 Gosselin RC, Adcock DM, Douxfils J. An update on laboratory assessment for direct oral anticoagulants (DOACs). Int J Lab Hematol. 2019 May;41 Suppl 1:33-39. doi: 10.1111/ijlh.12992 [PubMed]
- 31229333 Patel IJ, Rahim S, Davidson JC, Hanks SE, Tam AL, Walker TG, Wilkins LR, Sarode R, Weinberg I. Society of Interventional Radiology Consensus Guidelines for the Periprocedural Management of Thrombotic and Bleeding Risk in Patients Undergoing Percutaneous Image-Guided Interventions-Part II: Recommendations: Endorsed by the Canadian Association for Interventional Radiology and the Cardiovascular and Interventional Radiological Society of Europe. J Vasc Interv Radiol. 2019 Aug;30(8):1168-1184.e1. doi: 10.1016/j.jvir.2019.04.017 [PubMed]
- 31339254 Maher P, Taub E. Emergency department management of patients taking direct oral anticoagulant agents. Emerg Med Pract. 2019 Aug;21(8):1-28 [PubMed]
- 31317796 Desai NR, Cornutt D. Reversal agents for direct oral anticoagulants: considerations for hospital physicians and intensivists. Hosp Pract (1995). 2019 Aug;47(3):113-122. doi: 10.1080/21548331.2019.1643728 [PubMed]
- 31363394 Banihashem N, Khorasani M, Vaffai H, Naziri F, Khafri S, Seyfi S. The effect of low- dose tranexamic acid on postoperative blood loss in patients treated with clopidogrel and aspirin. Caspian J Intern Med. 2019 Spring;10(2):156-161. doi: 10.22088/cjim.10.2.156 [PubMed]
- 31396920 Rota E, Agosti S, Risso R, Morelli N. Lumbar puncture after direct oral anticoagulant (DOAC) reversal: a proposed algorithm for the emergency department. Intern Emerg Med. 2019 Oct;14(7):1175-1179. doi: 10.1007/s11739-019-02162-9 [PubMed]
- 31567345 Feldman EA, Meola G, Zyck S, Miller CD, Krishnamurthy S, Cwikla GM, Darko W, Jennings S, Sullivan R, Seabury R. Retrospective Assessment of Desmopressin Effectiveness and Safety in Patients With Antiplatelet-Associated Intracranial Hemorrhage. Crit Care Med. 2019 Dec;47(12):1759-1765. doi: 10.1097/CCM.0000000000004021 [PubMed]
- 32224752 Rabinstein AA. Update on Treatment of Acute Ischemic Stroke. Continuum (Minneap Minn). 2020 Apr;26(2):268-286. doi: 10.1212/CON.0000000000000840 [PubMed]
- 32455460 Koscielny J, Rutkauskaite E, Sucker C, von Heymann C. How Do I Reverse Oral and Parenteral Anticoagulants? Hamostaseologie. 2020 Jun;40(2):201-213. English. doi: 10.1055/a-1113-0557 [PubMed]
- 33403486 Milling TJ, Refaai MA, Sengupta N. Anticoagulant Reversal in Gastrointestinal Bleeding: Review of Treatment Guidelines. Dig Dis Sci. 2021 Jan 6. doi: 10.1007/s10620-020-06728-y [PubMed]
- 33952393 O'Carroll CB, Brown BL, Freeman WD. Intracerebral Hemorrhage: A Common yet Disproportionately Deadly Stroke Subtype. Mayo Clin Proc. 2021 Jun;96(6):1639-1654. doi: 10.1016/j.mayocp.2020.10.034 [PubMed]
- 35579034 Greenberg SM, Ziai WC, Cordonnier C, Dowlatshahi D, Francis B, Goldstein JN, Hemphill JC 3rd, Johnson R, Keigher KM, Mack WJ, Mocco J, Newton EJ, Ruff IM, Sansing LH, Schulman S, Selim MH, Sheth KN, Sprigg N, Sunnerhagen KS; American Heart Association/American Stroke Association. 2022 Guideline for the Management of Patients With Spontaneous Intracerebral Hemorrhage: A Guideline From the American Heart Association/American Stroke Association. Stroke. 2022 May 17:101161STR0000000000000407. doi: 10.1161/STR.0000000000000407 [PubMed] 📄
- Albin, C. S. W., & Zafar, S. F. (2022). The Acute Neurology Survival Guide: A Practical Resource for Inpatient and ICU Neurology (1st ed. 2022 ed.). Springer.