Reversal of Oral Anticoagulation

On one of my recent shifts, I met an alcoholic liver cirrhosis gentleman who was on an unknown "blood thinner."  As he spoke to me, I hoped he would never come in as a trauma notification. I hope this never happens, but incase it does here's a refresher on anticoagulation reversal and a side note on those with liver cirrhosis.

Vitamin K Antagonists/ Coumadin

• Limits synthesis of Factors II, VII, IX, X, and the anticoagulant proteins C and S

• Reversal: 5-10 mg IV Vitamin K; Onset is 2-6 hours

• Reversal: 10-15 ml/kg Fresh frozen plasma (FFP), which contains all coagulation factors in non-concentrated forms.  

  • Be careful in HF patients; because of the large volumes needed of this drug it can significantly increase intravascular volume

  • Usually people do 2U FF for ICH and 4U FFP for extracranial hemorrhages

• Reversal: 4 Factor Prothrombin Complex Concentrate (PCC) =Kcentra contains factor VII, and non- activated factor II, IX, and X. Proteins C and S are also mixed in.  

  • Initial dose 25-50 IU/kg for significant bleeds

  • In patients with concern for increasing intravascular volume, PCC (although costly) is less volume

  • Faster time to INR reversal

Direct Thrombin Inhibitors (DTIs)

• Dabigatran (Pradaxa), Argatroban, Ximelagatran...

• Inhibits both free thrombin and clot bound thrombin

• Reversal: No specific agents, however transfusion of PRBCs and FFP is recommended. PCC could be helpful, but no definitive evidence yet. 

• For Dabigatran only, hemodialysis has been recommended as it possesses low plasma protein binding properties and thus is easy to dialyze out. 

  • Also, an antibody, Idarucizumab, has been created however costs $3500 

Factos  Xa Inhibitors:

• Rivaroxaban (Xarelto), Apixaban (Eliquis), Fondaparinux (Arixtra)

• Inhibits factor Xa

• Reversal: No specific reversal agents

• 4 Factor PCC has shown some promising results

• Second line reversal: TXA: 1 gm over 10 minutes and then 1 gm over the next 8 hours if 4 Factor PCC is ineffective 

This is the quick and dirty reference, however there are many considerations such as patients with liver failure, time of last anticoagulation use, severity of bleed, compliance of patient to anticoagulation. 

A bit about cirrhosis patients...

In patients with cirrhosis the provider may use the INR and PT to assess synthetic function of the liver but not to assess hemorrhagic risk.The evidence supports a “watchful waiting” approach to the transfusion of platelets and fresh-frozen plasma with a bedside assessment of the patient’s actual hemorrhagic risk. 

INR is not entirely meaningless in the setting of cirrhosis, but rather it may function a bit like a D-dimer. If the INR is normal then coagulation is intact. However, if the INR is elevated, then it reveals NOTHING about coagulation. 

POTD Trauma Tuesdays: Fish Hook Removal

FISH HOOK REMOVAL

Introduction
▪ Most fishhooks consist of an eyelet at one end, a straight shank, and a curved portion that ends in a barbed point on the inner curve that points away from the hook’s tip. By design, it is constructed to prevent the hook from dislodging once it engages tissue
▪ Fish hooks are most often caught on hands and feet
▪ ED physicians may remove superficially embedded hooks but those embedded in vital structures (eyes, testicles, carotid artery, etc) should be referred to the appropriate surgical specialist covering that organ

How do I prepare to remove it?
▪ Stabilize the hook with a hemostat and remove any attachments, such as lures, fishing lines, sinkers, etc.
▪ Cleanse with betadine
▪ Use local anesthesia
▪ Children may need procedural sedation
▪ Pain control
▪ Tetanus prophylaxis

What methods are used for removal?
▪ Back out technique
⁃ If the hook is barbless, this is the easiest method.
⁃ As the name implies, back the hook out with a hemostat.

▪ Push through technique
⁃ Use when the tip of the hook is near the skin surface.
⁃ Push the hook through until you break the skin, and then use a wire cutter to cut the tip off.
⁃ Then back out the remainder of the hook.

▪ String technique
⁃ Hook’s belly should be directly in front of you with the shank pointing in the opposite direction
⁃ Loop a piece of string or large silk suture (3-0) around the belly of the hook and then wrap the ends around your index finger
⁃ Push down on the shank and eye of the hook with your other hand to disengage the barb from the surrounding tissue
⁃ Pull string slowly until it is taut in the plane of the hook’s long axis
⁃ Keeping it taut, jerk it quickly and firmly in the same direction

▪ Cut it out technique
⁃ When all else fails, cut with a scalpel along the hook, and then blunt dissect down with a hemostat.

Should I give antibiotics?
▪ No trials have investigated antibiotic therapy for fish hook injuries
▪ Most superficial fish hook wounds heal well without sequelae
▪ Consider antibiotics if the fish hook is deeply embedded in an infection-prone area such as a fingertip or ear
▪ Most infections are caused by skin flora
▪ If hook is contaminated (touched sea water, fish, bait, etc), consider abx treatment
⁃ Cephalexin 500mg PO q6 or cefazolin 1g IV q8 or Clinda 300mg PO q6 or 600mg IV q8
⁃ Seawater? ADD Doxycycline 100mg q12
⁃ See recent guidelines for other specific situations

Baby, It's Cold Outside

In honor of Mariah Carey's performance in NYC yesterday and the start to our frigid temperatures, I figured I would talk about hypothermia. 

For simplicity purposes, hypothermia comes in 3 flavors:

1.     Mild Hypothermia: 32-35°C; Use insulating blankets on patient's core and they’ll usually warm 1°C/ hour and that’s a life saved.

2.     Moderate Hypothermia: 29-32°C or patients refractory to re-warming as expected. Consider other causes including hypoglycemia, malnutrition, ETOH, Addison’s, sepsis, and myxedema coma! Consider using active rewarming techniques (listed below).

3.     Severe Hypothermia: <29°C or those patients in cardiac arrest

So, lets talk about active rewarming techniques

After assessing ABC's in the hypothermic patient, you need core temperature monitoring via an esophageal probe (in the back of Resus 53) or a rectal probe! An esophageal probe is preferable given less breaks if compressions are needed and easier initiation of active rewarming.

Active Internal/ Core Rewarming:

1. Warm humidified oxygen will raise temperature 1°C/hr via NRB or 1.5°C/hr via ETT

2. Heated IVFs (40-42°C). Must use warm saline because room temperature saline can worsen hypothermia

3. Peritoneal irrigation, however this is less common given the chance of bowel injury unless there is ascites

4. Pleural irrigation with two 32F chest tubes on each side of the chest that can increase temperatures 3-6°C/hr
   
   Chest tube placement: one anterior and one posterior lateral on each side. With the anterior chest tube use the connector from a Salem sump and pump warm fluids into the anterior chest tube and then attach the pleura-vac connected to suction to the posterior lateral chest tube to allow continuous emptying
   

5. Extracorporeal blood rewarming

o   Venovenous

o   Hemodialysis

o   Continuous arteriovenous rewarming

o   Cardiopulmonary bypass

o   Extracorpeal Membrane Oxygenation (ECMO)

Termination of CPR should be considered if K >12 mmol or if asystole persists beyond 32°C

Lastly, since the in-service is coming, here a drop extra on arrhythmias in hypothermia… 

• Most common arrhythmia for mild hypothermia is bradycardia; Pacing is usually not necessary unless bradycardia persists after patient is rewarmed to 32-35°C

• In temperatures below 32°C, bradycardia-->atrial arrhythmias-->ventricular arrhythmias-->asystole

• If patient is in cardiac arrest, attempt defibrillation with single shock. If further defibrillation attempts are made, concurrent rewarming should be initiated.

• Modified ACLS guidelines:

  • AHA recommends 3 defibrillations and 3 rounds of epi with further dosing guided by clinical response

  • Recent consensus suggest only one defibrillation and round of ACLS meds → rewarm 5C → one defib/meds → Repeat

Classic test question:  ECG finding for hypothermia is an Osborn (J) Wave, which is a positive deflection at the J point. These waves are not pathognoromic. They also, have no prognostic value, like most tests (just kidding). However, the size of the wave correlates with the degree of hypothermia. 

Here is an example of mild hypothermia: 

That soon turned into moderate hypothermia:

Okay, all done. Stay warm to stay alive. Please feel free to ask questions and send feedback!