IV or IO in cardiac arrest: Does it matter?

Reading Time: 3 minutes

Ambulance 212 is en route with a 55 y/o male in cardiac arrest. They state it was a witnessed cardiac arrest, and the patient was found in PEA. They placed a supraglottic airway and were unable to obtain IV access. The call was 2 minutes away, so they decided to scoop and run. Upon arrival, the patient has a supraglottic airway in place and remains pulseless with no cardiac activity on POCUS Echo. CPR remains in progress.

The question now is what access do you want?

The Pre-brief

When discussing out-of-hospital cardiac arrest (OHCA) management, I am often asked what my preference is, IO or IV? I have for years asked for two routes of access, a humeral IO and a large-bore IV. I love how fast fluid can be administered through a humeral IO, and the proximity to the central circulation of the humoral site is advantageous when compared to the tibial IO. Also, I think that a large-bore IV catheter is ideal during a code as it can sometimes be more reliable than an IO. Peripheral IVs can sometimes be challenging to get depending on the proceduralist and the patient’s anatomy. Seldom will I place a central line for a code initially, as they are cumbersome, time-consuming, and add no significant value to the initial code management.  I prefer multiple peripheral lines before doing a central line if at all possible. I’ve even used multiple IO’s in a code before placing a central line (not trying to be a central line hater).

So, does the data shed any light as to which route is better?

A few recent and notable papers provided some possible thoughts.

Article by Kawano T et al., Intraosseous vascular access is associated with lower survival and neurologic recovery among patients with out-of-hospital arrest. Ann Emerg Med 2018 (DOI: 10.1016/j.annemergmed.2017.11.015)     

This paper compared the outcomes of patients in OHCA that either received an IV or IO. However, reviewing the paper’s data, there was no randomization, and the patients who received the IO were often sicker and had poor prognostic indicators in the first place. Plus, the IO placement location (humeral, sternal, or tibial) was not noted. The authors’ conclusion, “In adult out of hospital cardiac arrest patients, intraosseous vascular access was associated with poorer neurologic outcomes than intravenous access.” I didn’t feel comfortable with this paper’s outcome as the data collection was not ideal, and without randomization, I felt like the conclusion was weak.

Another paper:

 Zhang Y et al. Intravenous Versus Intraosseous Adrenaline Administration in Out of Hospital Cardiac Arrest: A retrospective cohort study. Resuscitation 2020 (DOI: 10.1016/j.resuscitation.2020.01.009 )   

Essentially, the authors wanted to know if IV or IO routes led to different outcomes when patients were provided with prehospital epinephrine. This paper is retrospective, and again, this means there was no randomization. Patients were often sicker in the IO group, and the IO location was also not recorded. The author’s conclusion: “Compared with the IO approach, the IV approach appears to be the optimal route for adrenaline administration in advanced life support for OHCS during prehospital resuscitation.” Again, I don’t feel like the conclusion is strong enough to say that IO is inferior.

Other papers such as this one:

 Daya et al. Survival after intravenous versus intraosseous amiodarone, lidocaine, or placebo in out-of-hospital shock-refractory cardiac arrest. Circulation 2020 (DOI: 10.1161/CIRCULATIONAHA.119.042240 )also has similar issues and similar outcomes, with IV leaning to be more advantageous than IO.

The Debrief

So, if all these papers popo IOs, why do I like adding them into my cardiac arrest management? 

Many of the studies that compared the two routes are retrospective studies, which show association and not causation. There are no papers to my knowledge that have compared IO sites (humeral vs tibial)  in cardiac arrests. Additionally, most IV’s in American prehospital system are placed in the upper extremities, and most IO’s are placed in the lower extremities. It would be useful to compare outcomes of IVs vs. IOs that are placed on the same body region. Finally, There doesn’t seem to be a significant data set that randomizes IO vs. IV. In my own experience, a well placed humeral IO flows just as well as a peripheral IV, and it’s relatively simple in most patients to place. There is still much to discover on this topic. I prefer IV access if possible, but if there is going to be a delay for whatever reason, I have no hesitation in utilizing a humeral IO in my arrest management. Please leave a comment if you have an opinion on this topic. I’d love to hear from you.


More Posts

Related Posts

Would love your thoughts, please comment.x