Unless anyone has any decent quality research in the last year looking at
sensible outcomes, I'd reckon the Cochrane review still gives us the best
guide as to outcome: Lafuente-Lafuente C, Melero-Bascones M. Active chest
compression-decompression for cardiopulmonary resuscitation (Cochrane
Review). In: The Cochrane Library, Issue 1, 2003. Over 4,000 patients in the
various studies. No significant difference in any outcome measure
(particularly, confidence intervals for relative risk taking survival to
discharge from hospital were 0.98- 1.01).
There are a number of means of improving cardiac output during cardiac
arrest that have been shown to be effective when cardiac output (or a proxy
such as EtCO2) is taken as an outcome measure. Despite extensive research in
some cases, none of these methods have been shown to improve neurologically
acceptable outcome. Of course, if you believe that the patient in front of
you belongs to a subgroup too small to be picked up by the studies but who
would benefit from a measure to improve output, the best way is probably
invasively by either bypass (Ref 1); open chest CPR (Ref 2, 3); or possibly
the minimally invasive direct massage device (I'm not even going to bother
citing a reference here. Basically a bit of kit that transfers money from
the healthcare system to its manufacturer, but has never been shown to
improve patient outcome in any way).
Of these, open chest CPR is the cheapest to institute; but with all of them,
evidence is based on case series with a few survivors (and because of the
heterogeneity of non traumatic cardiac arrest it is not sensible to compare
to historical series), rather than RCTs.
> A US firm called CPRx holds the patent for the ResQ-valve
> which fits between
> the bag/valve & ET tube.
And I'm sure they can site you plenty of data looking at proxy measures and
case series. But can they give you a RCT showing improved neurologically
intact survival from this device (or if such a trial has not taken place,
are they supporting it)?
> Although the ACD device is not cleared for US use, there is research
> proposed by the Medical College of Wisconsin of the
> ResQ-valve with standard
> CPR recording both survival data & haemodynamics (with invasive BP
> monitoring).
I've got a sneaking suspicion that the survival data is going to be all case
series stuff. Unless there's been something since I last checked, the only
RCT was a French paper showing no difference in survival to hospital
discharge.
The interesting point from all this is that while it is undoubtedly possible
to improve haemodynamics during CPR, this does no translate to improved
outcomes (with the best research coming from use of the ACD- cardiopulmonary
bypass studies are mainly small series; and despite the wholesale change
from open chest to closed chest CPR, this has not been subject to anything
much in the way of RCTs). A useful question would be why this is the case.
The practical point is that there are a number of proprietary devices on the
market. However, in the absence of evidence of improved outcomes with them
you might be better spending your money elsewhere.
Matt Dunn
Warwick
References:
1. Martin GB, Rivers EP, Paradis NA, Goetting MG, Morris DC, Nowak RM.
Emergency department cardiopulmonary bypass in the treatment of human
cardiac arrest. Chest. 1998 Mar;113(3):743-51. Instituted on average after
half an hour downtime, restored outputn no long term survivors- this is in
line with animal studies showing no good neurological outcome with bypass
after over 15 minutes downtime and no long term survivors after 20
2. Calinas-Correia J, Phair I. Physiological variables during open chest
cardiopulmonary resuscitation: results from a small series- 7 patients, no
survivors
3. Hachimi-Idrissi S, Leeman J, Hubloue Y, Huyghens L, Corne L. Open chest
cardiopulmonary resuscitation in out-of-hospital cardiac arrest.
Resuscitation. 1997 Oct;35(2):151-6- 2 survivors out of 33 patients in whom
standard resuscitation had not restored output
This email has been scanned for viruses by NAI AVD however we are unable to
accept responsibility for any damage caused by the contents.
The opinions expressed in this email represent the views of the sender, not
South Warwickshire General Hospitals NHS Trust unless explicitly stated.
If you have received this email in error, please notify the sender.
|