List Archives

Thu, 9 Jan 2003 14:23:35 +0100

Chris,

to the best of my knowledge there has been no change in the guidelines =
for
prehospital management of severe brain trauma. These guidelines state =
that
hyperventilation can be used in patients who show signs of brain stem
hernination. The mechanism is DECREASE (not increase) of blood flow to =
the
brain, and thus, reduction of intracranial blood volume. This leads to
decrease in intracranial pressure, although ischemia might be =
worsened!!
(This is the reason why hyperventilation is now rarely used on ICUs).

You may take a look at the guidelines; the reference is:
	Guidelines for the management of severe head injury. Brain Trauma
Foundation, American Association of Neurological Surgeons, Joint =
Section on
Neurotrauma and Critical Care.
	J Neurotrauma. 1996 Nov;13(11):641-734. No abstract available.
	PMID: 8941879 [PubMed - indexed for MEDLINE]
Best wishes

Walter Mauritz

	-----Urspr=FCngliche Nachricht-----
	Von:	Cotton, Chris (SAAS)
[mailto:cotton.chris@saambulance.com.au]
	Gesendet am:	Donnerstag, 9. Januar 2003 14:00
	An:	'trauma-list@trauma.org'
	Betreff:	The coning patient

	We call it "coning" colloquially in Australia - not sure what it is
known as
	elsewhere. I suppose to some it would mean smokin' a pipe, to others
(as
	mentioned) it might mean having an ice cream. I reckon either would
be
	better than the medical condition, but ...   ;o)

	"Coning" is herniation of the brain stem through the Foramen Magnum.
A
	condition for which there is little chance of survival. It is the
result of
	a vicious cycle of brain swelling from hypoxia that reduces cerebral
blood
	flow and leads to worsening ischaemia, which in turn leads to
swelling of
	more brain tissue, compression of cerebral vasculature, further
compromising
	of blood flow and hence the spiral continues (usually downward)
until death
	ensues.=20

	In extremis, the theory goes that mild hyperventilation (ie. blowing
off
	CO2) increases blood flow to the brain tissue (which in one way is
not
	really what you want, as this increases ICP) and can possibly help
overcome
	the ischaemia by increasing the flow. This is, by best estimations
theory
	and is probably just taught because their is bugger all you can
really do on
	the roadside once they're in this state and it sounds reasonable.=20

	The reason for my post is to check whether there has been any change
to this
	approach. I thought there had been in light of this recent paper i
saw
	somewhere, but for the life of me - i can't remember where i saw it.
Thought
	someone here might be able to help me out.

	Chris Cotton
	Intensive Care Paramedic
	South Australia.

	From: James A. Johnson [mailto:J.Johnson@Valley-hosp.com]=20
	Sent: Wednesday, January 08, 2003 5:28 PM=20
	To: 'trauma-list@trauma.org'=20
	Subject: RE: The coning patient=20

	NOT TO SOUND IGNORANT BUT WHAT IS CONING?=20

	--
	trauma-list : TRAUMA.ORG
	To change your settings or unsubscribe visit:
	http://www.trauma.org/traumalist.html

List Archives

For your convenience, find the Trauma List Archive Below

AW: The coning patient