Mailing List Archive

Mailing List: techdiver

Banner Advert

Message Display

From: "Sean T. Stevenson" <ststev@un*.co*>
To: "David Reinhard" <reinhard@oc*.co*.au*>,
     "techdiver@aquanaut.com"
Date: Mon, 22 Nov 1999 21:28:05 -0800
Subject: Re: Legalities of purging someone
I am forced to agree that the extra time spent performing EAR in water,
if you are close to the boat or the shore, would be better spent
swimming your ass off to get the person to more effective care.  Having
said that, I would not entirely discount the second stage purging
thing, or any other attempt at treatment if I thought it could possibly
save a life.  This is just common sense, but is a call you have to make
when the situation arises.  As for getting a person onto the boat, the
swimmer should orient them head toward the hull.  Lower a basket
stretcher (preferably plastic or composite shell , rather than a wire
stokes litter) into the water vertically, so that it floats up
underneath the patient.  If there is high freeboard or other difficult
access, this provides you with a semi-stable platform to perform an
assesment, while another swimmer can set to securing the patient in the
basket stretcher for lift onto the deck.

-Sean


On Tue, 23 Nov 1999 11:17:09 -0800, David Reinhard wrote:

>Hi Bill,
>	thanks for your comments on this interesting issue. I have added some =
of
>my comments below.
>
>At 17:58 22-11-99 -0500, you wrote:
>>David,
>>
>>I have a mental image of you guys standing around the sputtering, cyan=
otic
>>and soon to be or already deceased =93victim=94 in your little white c=
oats in
>>the medical amphitheater. You pace back and forth worrying and specula=
ting
>>about whether to use the bag or bag and the mask or just the bag or ma=
ybe
>>just a little =93expired air=94. 
>
>Bill, you seem to have a strange impression of ambulance work! There is=
 no
>branch of medicine that is more practical than pre-hospital emergency
>medicine. The ability to assess a patient's needs and to rapidly instit=
ute
>life saving treatment is the hallmark of a good paramedic. Standing aro=
und
>dithering about what to next is not an option for us.
>	"white coats in the medical ampitheatre" is far removed from the
>environment in which I work. I have treated people in houses, in toilet=
s,
>in shops, in the street, down dark alley ways, in elevators, in wrecked=

>cars, in the middle of busy freeways, on beaches, at the base of cliffs=
, on
>boats, in planes, in stairwells, in bank vaults, in factories, stuck in=

>machinery, on roofs, at swimming pools, on piers, in baths, in trenches=
, on
>scaffolding, on trampolines, on ice skating rinks, in pouring rain, in
>blazing heat, etc (just a few that spring to mind) 
>
>
>>The point is that drowning is a hypoxic event where the onset of
>>irreversible cns damage occurs within short moments of oxygen deprivat=
ion.
>>We are talking about the resuscitation of divers (not your average acc=
ident
>>or heart attack victim) here and particularly those who have been invo=
lved
>>in some type of direct or tangential technical endeavor (that is what =
this
>>list is about after all).
>
>The basic principles of resuscitation (eg ABCs etc) remain the same
>irrespective of the cause of the problem. CPR is the same whether it is=
 a
>drowning, heart attack, electrocution or whatever. 
>
>  The most likely scenario is a diver who was using
>>a CCR (closed circuit rebreather) during which either the device faile=
d or
>>there was some sort of diver error or the diver had a precondition suc=
h as
>>diabetes or mental illness or a combination of mental and physical pro=
blems.
>>(the latter part of this statement is not serious and not humorous and=
 is
>>the subject of another thread)  There have been at least six deaths du=
ring
>>the past two years alone, involving the Inspiration rebreather, manufa=
ctured
>>in the UK several of which involved varying degrees of hypoxia.
>
>
>There are no doubt some genuine cases of divers drowning due to a medic=
al
>cause such as heart attack, stroke, fitting etc who have not been using=
 a
>Buddy Expiration!. 
>
> So the point
>>is that this sort of thing happens and the speed at which the diver=92=
s buddy
>>team can respond is very critical.
>>
>>In the case of a hypoxic diving accident there is an immediate and pre=
ssing
>>need to get oxygen into the alveoli to restore hemoglobin levels. Belo=
w 100
>>mm Hg there is a steep slope in the Hb-O2 saturation curve and the blo=
od
>>supply almost immediately becomes totally oxygen deficient.  A demand
>>regulator applied to an unconscious or drowned diver is the most immed=
iate
>>way to ventilate the lungs, providing the breathing passage is reasona=
ble
>>clear, to get oxygen to the blood.  Remember that anything you can get=
 into
>>the lungs at this point is better than the nothing that is already the=
re.
>
>Agreed.
>
>>Pure oxygen is vastly preferable to expired ventilatory gas, inasmuch =
as the
>>oxygen content of inspired gas has been displaced by co2 and moisture.=

>
>Agreed, provided this is achievable. EAR done properly is preferable to=

>100% O2 blasting out the exhaust ports of a reg.
>
>>Obviously, the airways must be open and the direct leakage of respirat=
ory
>>gas to the external environment must be controlled.
>>
>>In an operating theater or an ambulance masks and bags may be appropri=
ate;
>>however  on the surface of the ocean
>
>Clearly a bag and mask is unsuitable for in-water resuscitation. The on=
ly
>viable option here is EAR or rapid removal from the water.
>	
>	(Incidently how many of you out there have practised removing "patient=
s"
>from the water into a boat? This can be tough. The best way to do it wi=
ll
>vary from boat to boat depending on the design. It is well worth having=
 a
>go at this before you get caught with a real incident.)
>
>
>
> or the sinkhole the most immediate
>>action must be taken in the timeliest of fashions to spare the victim =
his
>>life or his future functionality.
>
>Bill, you and George are very keen to promote the DIR concept in diving=
..
>Let us apply the DIR principle to resuscitation. I know of no agency th=
at
>teaches resuscitation using a regulator, irrespective of what "level" o=
f
>instruction is being undertaken. It would truly be wonderful if a reg w=
as a
>useful resuscitation device, and if so I would be the first to advocate=
 it,
>I can assure you. Lets face it - every diver has one! However I have st=
rong
>reservations about its use, and if it was regarded as medically apropri=
ate
>I am sure some one would have caught onto this long ago and would be
>teaching its use. I don't believe that a reg is part of DIR resuscitati=
on,
>but if anyone can prove me wrong then I would happily reconsider. 
>
>
>Safe Diving,   David
>
>>
>>Best regards,
>>
>>Bill Mee
>
>>
>>-----Original Message-----
>>From: David Reinhard <reinhard@oc*.co*.au*>
>>To: techdiver@aquanaut.com <techdiver@aquanaut.com>
>>Date: Monday, November 22, 1999 8:41 AM
>>Subject: Re: Legalities of purging someone
>>
>>
>>>Dear List,
>>> sorry to have come in rather late on this discussion but I have been=
 away
>>>from my computer for a few days. I am sure there are many people on t=
his
>>>list who are better able to discuss legal issues than me, so i will s=
tick
>>>to the medical side of this debate. There are a number of points that=
 need
>>>to be considered.
>>>
>>> Firstly, any resuscitation system requires an interface between that=

>>>system and the patient. With resuscitators of any type this generally=

>>>invoves a face mask, which encloses both mouth and nose, and has a so=
ft
>>>rubber/silicone cushion designed  to seal against the face. The abili=
ty to
>>>achieve a good seal with this mask is probably the most important ski=
ll in
>>>using a resuscitator. Without a good seal it will not be possible to
>>>ventilate the lungs. Air/O2 will obviously follow the path of least
>>>resistance so if the seal is not perfect (or near to perfect) then ga=
s will
>>>simply escape via that leak to the atmosphere and not into the patien=
ts
>>lungs.
>>> If using a scuba regulator as a resuscitation device this principle
>>>obviously still applies. It would be necessary to place the mouthpiec=
e into
>>>the mouth in such a way that a perfect seal is obtained. Not having d=
one
>>>this on an unconscious person I cannot comment on whether or not this=
 would
>>>be easy to achieve. When pressing the purge button with the aim of
>>>inflating the chest the gas will still of course follow the path of l=
east
>>>resistance. This means that the gas will predominantly vent out the e=
xhaust
>>>ports since the resistance in the airways and the need to expand the =
chest
>>>will be much greater than the passage of gas out of the ports. It wou=
ld
>>>then be necessary to block both ports in order to achieve lung inflat=
ion.
>>>If this was done manually it would obviously require two hands. Since=
 the
>>>nose also provides a path of lower resistance than the airways in the=
 lungs
>>>the nose must be pinched closed. To achieve this (ie blocking both ve=
nts,
>>>pinching the nose) while pushing the purge button will require at lea=
st two
>>>operators.
>>> "Positive pressure ventilators" that work on a similar principle to =
a
>>>"purge button" also require a pressure relief valve (typically set at=

>>>around 50-70cm H2O) to avoid overpressure injury to the lungs. This o=
f
>>>course is not present on a scuba regulator. The air flow from many
>>>regulators (the Oceanic showerheads are a good example) is quite rema=
rkable
>>>and would pose a significant risk to the lungs. It would also be diff=
icult
>>>at these extraordinary flow rates to judge when to stop pressing the
>>>button, since chest inflation would be very rapid. Another path of le=
ast
>>>resistance, especially if the airway is not fully opened (a very comm=
on
>>>fault with unskilled operators), is via the oesophagus to the stomach=
..
>>>Inflation of the stomach would, I believe, be highly likely using a s=
cuba
>>>regulator in this fashion. Inflation of the stomach has two adverse e=
ffects
>>>1) increased likelihood of regurgitation with possible inhalation of
>>>stomach contents (potentially fatal) and 2) an inflated stomach puts
>>>pressure on the diaphragm and thus limits the excursion of the lungs
>>>reducing the ability to ventilate the lungs effectively.
>>> The use of positive pressure ventilators has been gradually phased o=
ut
>>>over the last ten years or so (in Australia anyway) in favour of bag =
and
>>>mask systems. Bag and mask systems are capable of delivering close to=
 100%
>>>O2 with greater contol over ventilation volumes and at generally lowe=
r
>>>pressures than positive pressure ventilators.
>>> Options for divers when treating a non-breathing patient  are probab=
ly
>>>primarily 1) bag and mask with or without O2, 2) EAR via a "pocket ma=
sk
>>>with or without O2, 3) straight EAR (eg mouth to mouth. (EAR =3D Expi=
red Air
>>>Resucitation)
>>> While I have been involved in probably several hundred resuscitation=

>>>attempts I have never done mouth to mouth. I would personally find it=
 very
>>>difficult to place my mouth over someone elses especially when covere=
d with
>>>vomit. Many of the people i have resuscitated have been heroin ODs an=
d
>>>quite frankly I would not take the risk of acquiring the diseases tha=
t
>>>these people often carry. I have utilised a "pocket mask" for EAR whe=
n I
>>>have not had equipment immediately available and found this to be a
>>>relatively easy technique which would be well suited to a "lay person=
" with
>>>minimal training. However, normally I use a bag and mask system which=
 I
>>>feel is the best alternative for a trained operator. However if you h=
ave
>>>not been well trained, and maintained your skills with regular practi=
ce,
>>>the bag and mask may not be appropriate.
>>> While it is desirable to deliver high O2 concentrations to a non-bre=
athing
>>>patient do not disregard the value of EAR just because it delivers on=
ly
>>>around 17% O2. Many lives have been saved by EAR. It is far better to=

>>>effectively ventilate the lungs with 17% O2 than to improperly utiliz=
e
>>>equipment (whether a properly designed ventilator or an improvisation=
 with
>>>a scuba regulator) and achieve little if any ventilation, or put the
>>>patient at risk of further harm by lack of training/experience.
>>> It is my opinion that from a medical viewpoint a scuba regulator has=
 many
>>>disadvantages that would exclude its use as a resuscitation device. I=
 would
>>>not personally use it. In fact you are probably taking a legal risk u=
sing
>>>any device that you have not been properly trained for. So unless you=
 have
>>>received traning in the use of a scuba regulator for resuscitation (w=
hich
>>>is highly unlikely!!) leave it alone.
>>>
>>> For those of you who think credentials are important I have been an
>>>instructor in CPR and O2 use for over twenty years (accredited by the=

>>>National Heart Foundation and the Royal Lifesaving Society of Austral=
ia), I
>>>have worked as a professional ambulance paramedic for 16 years, the l=
ast
>>>five of which have been on Mobile Intensive Care Ambulances. Despite =
that I
>>>do however recognize that my opinions are potentially fallible and I =
remain
>>>open to anyones viewpoint if they can demonstrate any flaws in what I=
 have
>>>written above.
>>>
>>>
>>>Regards,  David Reinhard.
>>>
>>>
>>>
>>>
>>>
>>>
>>>-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=

>>>Ocean Internet - "The Quality ISP"
>>>http://www.ocean.com.au/info.html
>>>
>>>--
>>>Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com=
'.
>>>Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.co=
m'.
>>>
>>
>>
>-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-
>Ocean Internet - "The Quality ISP"
>http://www.ocean.com.au/info.html
>
>--
>Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'.=

>Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'=
..
>


--
Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'.
Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'.

Navigate by Author: [Previous] [Next] [Author Search Index]
Navigate by Subject: [Previous] [Next] [Subject Search Index]

[Send Reply] [Send Message with New Topic]

[Search Selection] [Mailing List Home] [Home]