Thursday, December 19, 2013

IO: For More Than Just CPR Medications

"An IO for you, and an IO for me..."

It is amazing how a series of tweets regarding a topic of interest can inspire a literature hunt leading to a blog post. Case in point:

 


 

This exchange led me to wonder about other medications, besides those that we typically use for cardiopulmonary resuscitation (CPR) that can be effectively administered via the intraosseous (IO) route. After conducting a rather extensive literature search on the topic, I was surprised to find that there were a whole lot more medications reportedly given via this route than I imagined. Below is a table that lists these medications with respective references, along with whether these medications have been evaluated in animal models and/or clinical cases as well as reported cases administered to pediatric and/or adult patients.

Medications That Have Been Administered Via the IO Route, As Reported in the Literature
Medication
Animal Model
Clinical Setting
Adult
Pediatrics
Antidotes1
Atropine
Y


Digoxin immune FAB
Y


Hydroxocobalamin
Y


Methylene blue


Y
Pralidoxime
Y


Scorpion antivenom


Y
Antiseizure Medications2
Diazepam
Y


Fosphenytoin
Y


Phenobarbital
Y


Phenytoin
Y

Y
Fibrinolytics3
Alteplase

Y

Tenecteplase

Y

Paralytic Agents4
Rocuronium

Y

Succinylcholine
Y
Y
Y
Vecuronium


Y
Miscellaneous Agents5
Adenosine*
Y
Y
Y
Dexamethasone

Y

Etomidate

Y

Fentanyl

Y

Hypertonic saline
Y


Insulin


Y
Ketamine
Y

Y
Mannitol

Y

Methylprednisolone

Y

Midazolam

Y

Morphine

Y

Propofol
Y


Propranolol
Y


Radiocontrast dye

Y

Recombinant factor VIIa
Y


   Note: Y: Yes; indicates studied in these settings

The asterisk associated with adenosine in the table above indicates somewhat mixed results in terms of its effectiveness when administered via the IO route. Although one animal study and one case report demonstrated its effectiveness in cessation of supraventricular tachycardia, a recently published case series of two pediatric patients showed that the IO route was unreliable for the purposes of converting such arrhythmias to normal sinus rhythm. 

Selected references (by PubMed ID): 
  1. Antidotes:
    • Atropine/pralidoxime: 22738685
    • Digoxin immune FAB: 1985666
    • Hydroxocobalamin: 22738685
    • Methylene blue: 9867898
    • Scorpion antivenom: 20728778
  2. Antiseizure medications: 
    • Diazepam: 2752998; 9065255
    • Fosphenytoin: 12813289
    • Phenytoin: 2331255; 2757281; 3778598
    • Phenobarbital: 2757281
  3. Fibrinolytics:
    • Alteplase: 20947209; 24054882
    • Tenecteplase: 20522435
  4. Paralytic agents:
    • Rocuronium: 16382512
    • Succinylcholine: 2216931; 2602189; 8437069; 9885697; 15636659
    • Vecuronium: 1352102; 9065255
  5. Miscellaneous agents: 
    • Adenosine: 8193689; 8780485; 22217855
    • Dexamethasone: 19741408
    • Etomidate: 16382512
    • Fentanyl: 9065255; 21334506
    • Hypertonic saline: 11791047; 15359091
    • Insulin: 18326143
    • Ketamine: 8362509; 9065255; 18028968; 21334506
    • Mannitol: 8437069; 15636659
    • Methylprednisolone: 19741408
    • Midazolam: 21334506
    • Morphine: 8437069; 15636659; 18082778
    • Propofol: 9426788; 22720990
    • Radiocontrast dye: 21111513; 23726677
    • Recombinant factor VIIa: 19317190