Friday 1 December 2017

Incorporating point-of-care ultrasound into ACLS: Does cardiac activity predict survival?

From the Journal of No Shit comes this study looking at whether cardiac activity on ultrasound during ACLS is associated with improved survival.

This observational study was conducted in 20 ED’s in North America in patients presenting to the ED in PEA or asystole. Ultrasound was performed at the beginning at the end of ACLS and they looked at several outcomes.

793 patients were enrolled. 13 (1.6%) patients survived to hospital discharge (no mention if they were neurologically intact.)

For what it is worth, cardiac activity on initial ultrasound was the variable with the strongest association with survival at every endpoint investigated. In addition, they found 34 pericardial effusions and some patients with suspected pulmonary embolism.

Caution is in order as 3 patients with no initial cardiac activity on ultrasound survived to hospital discharge.

Of course, there could have been some bias as the decision to terminate resuscitative efforts was probably influenced by the ultrasound. In today’s environment, I don’t think blinding the ultrasound would have been ethical.

I think the most valid conclusion is PEA and asystole are extremely terrible prognostic signs regardless. Ultrasound without cardiac activity is also dismal (but not 100% perfect).

I have wondered why so much time & effort was put into answering a research question that seemed so obvious. It’s kind of up there with the parachute study… But I guess point-of-care ultrasound is still in the stage of trying to prove itself worthy.


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Intra-Articular Hematoma Block for Ankle Fracture Dislocation: an RCT

I recently listed to an episode of the Ultrasound Podcast featuring the guru of nerve blocks Dr Mike Stone. This guy sleeps with his ultrasound machine…

With this background, I was shocked to hear that he does not bother with using ultrasound or procedural sedation for reduction of ankle fracture dislocations. He just does a quick ankle hematoma block, “it’s what the orthopaedists would do…”

I’ve done hundreds of hematoma blocks of the distal radius but never considered the ankle. This prompted me to review the medical literature and find the best quality published evidence to support this practice.

Here we go…

This 2008 prospective RCT from New York City randomised patients with ankle fracture dislocations to either intra-articular block or procedural sedation.

What happened?

The authors concluded, “…an intra-articular lidocaine block provides a similar degree of analgesia and sufficient analgesia to achieve closed reduction of ankle fracture-dislocations.” In addition, the average time for reduction and stabilization was faster with the hematoma block.

So, ankle hematoma blocks are great!

Before we get too enthusiastic, consider the following limitations:
  • They only enrolled 42 patients. Yes, 42… Therefore, high risk for type II error and it cannot make adequate claims about safety.
  • It was sloppy; no specified primary outcome, no power calculation, CONSORT guidelines not followed, no mention of ethical approval, junior orthopaedic residents were “indirectly supervised,” some silly comments about “conscious sedation” etc.

So, this is really the best quality evidence we have?

Yes.

However, there is a wealth of published literature on hematoma & intra-articular blocks elsewhere and I think it is reasonable to conclude they are generally safe.

Subsequently, I have tried this technique a couple of times and had great outcomes; complete and long-lasting analgesia with wide awake happy patients. All the while not requiring a resuscitation room and all the resources of a procedural sedation.  I have an “n” of two. More poor-quality evidence?

I would encourage researchers to publish more on ankle hematoma blocks. To be honest, an RCT is probably not necessary to answer this research question. A large prospective case series should be adequate.

So, get injecting and pulling! (Please don’t quote me out of context)



To read more about ankle hematoma blocks, see paper referenced below. To hear Mike Stone talk about this on the Ultrasound podcast, check the link below and go to about the 11 minute mark.

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ECMO for refractory cardiac arrest: the Sydney experience

“Our study is the first multicentre study of ECPR outcomes in Australia. Thirty-seven patients between 2009 and 2016 underwent ECPR across two ECMO referral centres, with an overall survival rate of 35%, and excellent neurologic outcomes in survivors.”

Sounds great. Sign me up for ECMO!!!

But is there a downside?

This audit and medical record review took place over 7 years at two busy Sydney ED’s with a catchment area of 7 million. Both hospitals had developed ECMO response teams consisting of cardiothoracic surgery, anaesthetics, perfusionist and ICU personnel.

In the end, they had 13 good outcomes.

So, about 1 patient per year in each hospital…

In a system with limited healthcare resources, could these efforts been put to better use?

(Of course, ECMO can be used in other circumstances; support of cardiogenic shock post ROSC, overdose, hypothermia, etc.)

It is reasonable to conclude that ECMO currently is not ready for prime time in most centres. But perhaps we are in the ECMO infancy and it will become more feasible and important as the technology improves.

What do we conclude?

The current state of ECMO requires a lot of buck for little bang. It requires many resources and may have a role in the rare highly selected patient. But watch this space…

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Shared decision making in patients with low risk chest pain: empowering patients to go home

In patients presenting to the ED with very low risk chest pain, can a structured approach to shared decision making provide some benefit? Specifically, does it improve general comprehension and decrease resource utilization all in a safe manner?

In this study, 898 patients in the USA were randomised to a shared decision making facilitated by a decision aid or to usual care.

Inclusion criteria were:
  • Adults presenting to the ED with chest pain
  • Non-ischemic ECG
  • Negative initial troponin
  • No known prior coronary artery disease
  • Treating doctor wanted to admit to an observation unit to get a stress test or CTCA

(Yes… in many countries most of these patients would never have been admitted in the first instance. There are clearly some issues of external validity.)

Results?

With the decision aid, 15% more patients decided not to be admitted compared to usual care (52% vs. 37%).

Oh… and out of 898 patients, how many cardiac events were there?

Six.

This obviously begs the question as to why the vast majority of these patients could be sent home regardless of the decision aid.

Nevertheless, I think it does send the message that a structured approach to shared decision making may provide a better framework to educate our patients.


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