Evidence Shmevidence

Todd Fraser on 08-03-2013

So it seems I started a bit of a firestorm this week.

I posted the results of the new OSCILLATE and OSCAR trials on the social media networks, and the descriptors used might be considered slightly inflammatory (only a little). I suggested that high frequency ventilation modes "don't work".

Well, that gotem fired up! What I didn't appreciate fully was that there are lovers of HFOV who were a bit put out that I suggested it wasn't useful, and provided me (fairly reasonably) that the trials did not exclude the possibility that it might work in very severe ARDS.

This raises the very difficult issue of the "evidence free zone". It seems that there are always going to be holes in the evidence, and since clinical trials are by their very nature "controlled", and we live in a very UN-controlled, real world, the evidence is always going to require interpretation. It seems that in most cases, you can interpret the data to suit your position.

A great example is the findings of the SAFE study. The albumin proponents can now quite honestly argue that Albumin is as safe (pardon the pun) as saline, so its safe to use. Those against say that the study has proven that Albumin has no redeeming qualities.

We'll never ever have a full set of data. How then do we overcome this discrepency in practice?

We probably won't, but at least that leaves me with the comforting knowledge that the art of our specialty will never fully be replaced with the science.

8 Comments

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Mike from United States Of America wrote 03-10-2013 12:21:25 pm
I think you've hit the nail on the head. While much of what we do can be protocolized or pathwayed, our data will NEVER be 100% definitive. There will never be one-size-fits-all solutions to the mysteries and puzzles we face. As clinicians, we must remain flexible enough to try new things, creative enough to re-try or adapt old things in new circumstances, and analytical enough to know in which cases to do those things (specifically, by recognized what studies are and are not telling us).

Con from Greece wrote 03-10-2013 01:15:10 pm
Agree with Mike - we are too concerned with the literature and forget how to apply common sense.

Dr Di from Darwin from Australia wrote 03-10-2013 06:57:31 pm
It is my theory that the passion for and against a particular treatment in intensive care medicine is inversely proportional to the evidence for that treatment - it is seen with HFOV, ECMO, hypothermia, albumin and steroids - to name a few.
ICM is an art - we all conduct a slightly different orchestra but as long as the music is equally good for our patients - viva la difference!!

Gordon West from United Kingdom wrote 03-12-2013 01:05:06 pm
Case for the defence.

I don't think it is so unreasonable that a highly expensive intervention is subjected to more scrutiny before it is widely adopted. This has been a continual problem in clinical medicine.

While I can understand the emotive rationale for a "rescue therapy", how many billions of pounds have been wasted on unproven therapies?

Veeru wrote 03-18-2013 02:19:28 am
a point to add
: is the proficiency of the (icu)units using the HFOV in the ossilate trial, considering it is a very complex strategy to apply and maintain even in the most expereinced of units. the OSCAR answered it to some extent by their training but still HFOV is a difficult to master treatment which might get better with time

Myrenek from Australia wrote 03-21-2013 11:23:44 pm
Just adding on from Di - the evidence for efficacy of an intervention in ICU seems to be inversely proportional to the cost or complexity of the intervention.......ECMO, ECCO2removal,Prone, NO, surfactant, inhaled prostacyclin and now HFOV.

What seems to work is good supportive ventilation practice with tight control of tidal volumes and higher PEEPs as demonstrated in OSCILLATE. I wonder of OSCAR would also have shown a better outcome in the control goup if their standard ventilation practices had not been so variable and their PEEPs had been higher.

Dghdoc from United Kingdom wrote 06-18-2013 05:24:34 am
And now there's Proseva! Oh man

Todd Fraser from Australia wrote 06-18-2013 08:42:52 am
Hey Dghdoc, don't leave it there! Come on, out with it...