The next topic for discussion in the naemsp dialog will be Prehospital

Section of Emergency Medicine, University of Wisconsin, Madison, WI 53792,

USA. j...@medicine.wisc.edu

Abstract

INTRODUCTION: Ketamine has been used extensively for analgesia and

anesthesia in many situations, including disaster surgery where extra

personnel and advanced monitoring are not available. There are many features

of ketamine that seem to make it an ideal drug for prehospital use. The

reported use of ketamine in the prehospital environment is limited, however.

The purpose of this study is to review the experience in the use of ketamine

in a regional air ambulance service and suggest indications for its use in

the prehospital setting.

METHODS: This was a retrospective study of all patients transported by a

regional aeromedical program. Patients were included in this study if the

crew had used ketamine at any time during the flight. Data regarding the

transport collected included patient age, type of transport, indications for

ketamine use, and adverse reactions.

RESULTS: During the period studied, ketamine was used in 40 patients. The

age range was 2 months to 75 years. The indications and situations requiring

use were varied and included both trauma and medical patients. Hypotension

with need for analgesia, agitation or combativeness and intact airway, or

pain unresponsive to narcotic medications were the most common indications

for use. Ketamine was used both intravenous and intramuscular, even without

intravenous access. There were no adverse reactions.

CONCLUSIONS: Ketamine is an ideal drug for use in many prehospital

situations. Our experience suggests that it is safe, effective, and may be

more appropriate than drugs currently used by prehospital providers.

(Re-posted on Behalf of Charles Krin {to keep the discussion within

the same thread])
There is another problem with Nitronox rigs- the problem with scavenging the waste gases, the same problem that has caused Nitrous to go out of favor among dentists, despite 'laughing gas' being one of the best, and safest, dental analgesics known to humanity.
If waste gases are a problem in a 1000 plus square foot (figure 10 foot high ceilings, so 10,000 cubic feet) dental office with at least 5 changes of air per hour, how much more dangerous would it be in the back of a Type II or III ambulance, with maybe 100 cubic feet of space, especially during weather extremes, when ventilation of the rig may be limited?
Admittedly, in a moving ambulance, a scavenging system with an overboard dump is much simpler than in a fixed, often multi-office building. IIRC, the problem wasn't only with the 'laughing' effects on the dentist and techs, but there was also concern about long term effects, especially on pregnant females. Again, EMS would have the advantage of generally shorter periods of use.
as far as the need for a specialized regulator, it appears that Entonox/Nitronox can actually be stored in a single tank- from Wiki (yes, I know, not the best reference, but a quick one):
The gas is made of a mixture of fifty percent _nitrous oxide_ (http://en.wikipedia.org/wiki/Nitrous_oxide) (N2O or laughing gas)

and fifty percent _oxygen_ (http://en.wikipedia.org/wiki/Oxygen) (O2). The ability to combine _nitrous oxide_ (http://en.wikipedia.org/wiki/Nitrous_oxide) and oxygen at high pressure while remaining in the gaseous form is due to the

_Poynting effect_ (http://en.wikipedia.org/wiki/Poynting_effect) (after _John

Henry Poynting_ (http://en.wikipedia.org/wiki/John_Henry_Poynting) , an

English physicist).
The Poynting effect involves the dissolution of gaseous O2 when

bubbled through liquid N2O, with vaporisation of the liquid to form a gaseous

O2/N2O mixture.
Inhalation of pure nitrous oxide over a continued period would render a human _hypoxic_ (http://en.wikipedia.org/wiki/Hypoxia_(medical)) , and the 50% oxygen content prevents this from occurring. The two gases will separate at low temperatures (<4 _°C_ (http://en.wikipedia.org/wiki/Celsius) ), which

would permit administration of hypoxic mixtures. Therefore, it is

not given from a cold cylinder without being shaken (usually by cylinder

inversion) to remix the gases.

that Nitronox would be potentially be a very safe analgesic to add to

the capabilities of EMT Basics. It is even safer if the patient has one

hand free, and can cooperate with therapy:

To the best of my knowledge, unlike opiods, there is no histamine

release, and no one is allergic to this drug.
So, beyond medical and legal inertia, and the complaints of

ambulance companies at the initial costs of installation, is there any reason

why we can not urge our respective systems to allow our EMT-Bs and Paramedics to offer this simple method of pain relief?
Charles S. Krin, DO (ret)

EMS author and instructor, retired FP/EP.

(Re-posted on behalf of Craig McMillan [to keep the discussion in the

same thread])
Entonox (50% nitrous 50% oxygen) is readily available in New Zealand

and is the primary means of pain relief for BLS providers there. It is

available in a wide variety of tank sizes with a demand regulator

similar to a SCBA tank.

wide variety of patients, the only issue is that the tanks need to be

shaken prior to use as the gases tend to separate especially in cold

weather.

Former Kiwi, current American

Dr. Kim,

I will weigh in on your four questions.
1. I believe it is reasonable to initiate IV access and administer analgesia prior to moving a patient who has suspected fractures or is in a great deal of pain. I see this all the time especially when extrication is involved. Fentanyl is administered and then followed by Etomidate and the patient is moved while sedated. I don't know why this can't become the norm and not the exception of tangled patients.
2. I would certainly hope so. If they cannot, after multiple hours of training and multiple merit badge courses, then we need to go back to the drawing board on education standards. I have seen just the opposite. Too often, EMS personnel lean way to far to the "potentially unstable" side...and I cite the number of patients who are flown instead of ground-pounded (or run emergency to the ED) and then are released in a few short hours after arriving at the hospital. I have not seen any EMS personnel that would err to the side of delaying on scene care to provide analgesia on patients who could potentially be unstable.
3. See #2 only more so.
4. Now this is the core piece of the puzzle. The only issue is that with trauma, there are a number of variables that have nothing to do with the condition of the patient that may or may not make analgesia or sedation prior to moving or packaging the patient desirable. It isn't just what data or outcomes, we have to include the other mitigating factors (location of patient, entanglement, scene security, etc) as well.
Thanks for the time,
Dudley Wait

Schertz EMS

I would also like to point out that fentanyl can be given IN as well without IV access. This is perfect for a child with a broken arm who just needs a "sniff" of medication for comfort and not the torture of the IV. IN fentanyl is also great for trauma where IV access may delay care and arguably worsen outcomes.

Medical Director

Mercy EMS

Mercy Catholic Medical Center

Department of Emergency Medicine

501 South 54th Street

Philadelphia, PA 19143

215.748.9740

215.748.9208 (fax)

The first paper used an analgesic dose of 0.1 mg/kg IV and 1 mg/kg IM.

The second paper used an analgesic dose of 1 mg/kg IV and 5 mg/kg IM.

Quite the difference between the 2 dosages.

Kaweah Delta Medical Center

I found the study.
Prehosp Emerg Care. 1998 Oct-Dec;2(4):304-7.

Emergency medical services transport of patients with headache: mode of arrival may indicate serious etiology.

Nemer JA, Tallick SA, O'Connor RE, Reese CL.

Department of Emergency Medicine, University of Pittsburgh School of Medicine, Pennsylvania, USA.

Abstract

OBJECTIVE: To determine whether mode of arrival is associated with seriousness of etiology and use of diagnostic testing in patients treated in the emergency department for headache.

METHODS: This observational, retrospective study was conducted by consecutive review of the records of patients presenting to the emergency department with a chief complaint of headache from December 1994 through May 1995. Patients with altered mental status or seizures were excluded. Mode of arrival was classified as either by EMS or other (e.g., private vehicle). Patients with a final diagnosis of meningitis, intracranial hemorrhage, or central nervous system tumor were classified as having serious causes, whereas those with headache due to migraine, tension headache, or headache that was otherwise unspecified were classified as nonserious. The use of diagnostic studies, such as lumbar puncture or CT scan, and their results, was recorded. Patients were included in the category of patients having serious intracranial pathology even if the diagnosis was delayed. Statistical analysis was performed using the Yates-corrected chi-square test, and by determining odds ratios (ORs) with 95% confidence intervals.

RESULTS: For 967 patients presenting with a chief complaint of headache, 837 charts were included in the analysis. A total of 102 patients arrived by EMS, and 735 arrived by other means. Patients arriving by EMS had a higher rate of serious cause of headache than did those arriving by other means (OR = 18.5, p < 0.0001). EMS patients tended to undergo additional diagnostic testing (OR = 4.4, p < 0.0001), and those tests were more likely to be abnormal than for those arriving by other means (OR = 9.4, p < 0.0001). Males had a somewhat higher rate of serious diagnosis (OR = 2.6, p < 0.05).

CONCLUSIONS: In this EMS system, patients with headache who arrive by EMS are more likely to have serious causes. Mode of arrival may be of use to the clinician in assessing risk of serious illness among patients with headache. Whether this observation represents an element of self-triage or a combination of other factors remains to be determined.

With that said. I'd like to see the numbers from our colleague in Alaska. If there are that many "frequent flyers" causing problems then perhaps something needs to be addressed locally as Tarrant County did.

http://www.wfaa.com/news/local/Tarrant-ambulance-service-reaches-out-...
Keith Wesley, MD

Hello Mic!

Any chance of uploading this article for download?
DTK

David T. Kim, M.D., FACEP

Idaho Emergency Physicians, P.A.

Life Flight Network

Boise, ID

Thank you, Dr. Wu for providing a copy of the article by Svensen & Abernathy (American Journal of Emergency Medicine (2007) 25, 977–980). I believe Mic Gunderson will be posting a copy for download on the dialog resource page.

within 60 seconds after a single IV dose and within 3 to

5 minutes for an IM dose. This sedation lasts approximately

10 to 15 minutes for IV doses and 20 to 30 minutes for IM

doses [15]. These kinetics have both advantages and

disadvantages for prehospital care. First, the duration of

analgesia and anesthesia are long enough for many transports,

and so, the patient is not overly sedated or dissociated

on arrival in the emergency department and can be

adequately examined by the staff. On the other hand, the

duration is short enough that repeated doses may be

necessary."

Idaho Emergency Physicians, P.A.

Life Flight Network

Boise, ID

Hi
In France we have a prehospital emergency system has 2 level:

first level fire man for BLS (as paramedic). They do not have medication.

Second level ambulance with emergency physician and nurse

If fire man are front of a painful patient (trauma for example) and they can not move him, they call the second level.
So we can do every kind of treatment from simple analgesia to anaesthesia.

- For a trauma patient for example, we begin with titrated morphine:0,1mg/kg IV then 3 mg every each 5 minute; Goal: VAS or NRS = or< 3/10; no maximum dose. Limitation are side effects (nausea, vomiting, apnea). for the mobilisation we add nitrous oxide. The onset of action is 5 minutes so we have to wait 5 minutes before the patient mobilisation. The advantage with morphine is that there is an antidote (naloxone).

CNRD

Hôpital Armand Trousseau

26, av Arnold Netter

75571 Paris Cédex 12

Tel : +33 144735426

Secrétariat: +33 144735421

Hi
About ketamine

CNRD

Hôpital Armand Trousseau

26, av Arnold Netter

75571 Paris Cédex 12

Tel : +33 144735426

Secrétariat: +33 144735421

Yes, Yes, and Yes,

There are now several articles posted on the resource page for this

topic at http://groups.google.com/group/naemsp-dialog/web/topic-4---prehospita....
One of our objectives here is to provide a collection of resources

useful to everyone researching the topic of prehospital pain

management. If you have links, files, etc. that you think should be

included, please send them to me at mic.gunder...@gmail.com.

--- Mic

Editor / Moderator, NAEMSP Dialog;

President, IPS

I know I'm jumping in here a little late, but not only do I think that

parenteral pain management means ALS, but I think it's one significant

argument for the existence of ALS EMS. Think about what proportion of our

patients present with some type of pain versus what proportion presents with

the most studied prehospital complaint--cardiac arrest. Has anyone studied

the quality of pain management as a key performance measure for an ALS (or

BLS, for that matter) EMS system? Admittedly, pain management doesn't

usually appear to influence mortality like cardiac arrest or STEMI

management, but is it not as "worthy" a KPI? I think that every patient in

pain would think so!
Laurie
Laurie A. Romig, MD, FACEP

Medical Director

Pinellas County EMS

Hi again to all,

Paramedic Research Fellow/Intensive Care Paramedic,

Ambulance Research Institute

Ambulance Service of New South Wales

0429 129 908 / 9779 3858

Dr. Talbot,

require that your paramedics justify NOT giving pain medicine to

patients?
If that is the case, that is excellent. Too many places put too many

unrealistic and unnecessary restrictions on treatment of prehospital

pain.
Tim Noonan.

http://roguemedic.com/

Laurie,
Well said. I completely agree. Pain is the most common complaint in EMS and

in my experience most patients satisfaction is based more on whether or not

their pain was treated then whether or not the field "diagnosis" was

correct, what was the paramedics interpretation of the EKG, or how thorough

an exam was completed by the paramedic.

points (Initial and Final Pain Scores and treatment with opioids or other

treatment modalities) as key performance indicators, to look at how well we

treat pain statewide. It would be interesting to compare those regions of

the state without ALS to those with ALS. I certainly believe that every EMS

patient deserves pain management as early as possible. The question will be

how to facilitate pain management in those rural areas that just DO NOT have

ALS.
This is such an important topic and I thank all of you who are involved in

this discussion. Hopefully, by sharing these discussions we can dispel many

of the myths and help improve pain management in EMS worldwide.

Arthur Kanowitz MD FACEP

State Medical Director

Emergency Medical and Trauma Services Section

Health Facilities and Emergency Medical Services Division

Colorado Department of Public Health and Environment

4300 Cherry Creek Drive South

Denver. Colorado 80246-1530

office 303 692-2984

mobile 720 641-3540

There is a paper on misidentifying drug seekers that I sent to Mic

Veysman BD.

Acad Emerg Med. 2009 Apr;16(4):367-8. Epub 2009 Mar 6. No abstract

available.

PMID: 19298618 [PubMed - indexed for MEDLINE]
> Many of the people we care for are having nausea and are experiencing fear along with their pain. It would be nice to hear what people thing about managing mixed manifestations of suffering.
There should not be a need for anti-nausea medication for most

patients, but there is a discussion of giving diphenhydramine with

morphine in this podcast at EMCrit
Dr. Edward Gentile talking about the very aggressive morphine protocol

they use without problems:

http://blog.emcrit.org/podcasts/gentile-pain/

The follow-up post explaining the routine use of diphenhydramine:

http://blog.emcrit.org/blogpost/comments-on-pain-protocol/
> As we expand our pharmaceutical options in this domain the issue of drug diversion and the addicted clinician arise. It would be interesting to hear about systems to make sure medications go into patient veins not provider veins.
It amazes me that I have never been asked to take a urine drug test,

other than as part of standard pre-employment testing.

I generally give doses of morphine over 20 mg/fentanyl over 200 mcg a

couple of times per year. I have track marks (although they are from

frequent platelet donations). I am regularly questioned about the need

for such large doses of morphine/fentanyl. Doctors act as if they are

doing ME a favor by allowing me to appropriately treat my patient's

pain. If they are truly concerned that this is too much, why has

nobody ever expressed any concern about diversion? I have joked with

my boss, that if I ever come in with my whole body shaved, he should

be suspicious (the visible parts - get your minds out of the gutter).
Tim Noonan.

http://roguemedic.com/

> I see the issue breaking down into the following areas

> 1. Appreciation for the role of pain management

treatment of prisoners, not treating the pain of prehospital patients,

putting them in the back of a truck, often on a hard piece of plastic,

and driving them over bumpy roads will often exceed the pain delivered

to those being intentionally tortured.
Why do so many of us not oppose torturing the people we are supposed

to be caring for?

this kind of treatment?

with the patient describing pain in their own words. If only the

patient knows what their pain is, why do we feel the need to force

them to use our pain scale to describe something that they do not feel

is properly described by our pain scale?
If the patient says that he/she would like more pain medicine, is

there a good reason for us to say "No"?

off quickly.

truck ride on a hard board on top of the rear axle may be over-

medicated for laying on a thick mattress in the emergency department

with nurses assigned to several patients. In the ambulance, the medic

is closer to the patient than I am to my keyboard, right now. If the

medic cannot recognize side effects from that distance, then maybe the

medic should not be allowed to work as a medic.
The onset is less important than the rate at which it wears off.

If something is being treated, where the assessment may be affected by

the medication, having the medication wear off as the patient is

arriving in the emergency department should satisfy the fears of those

worried about narcosis.
Two relevant papers on this -
Appeal for fentanyl prehospital use.

Braude D, Richards M.

Prehosp Emerg Care. 2004 Oct-Dec;8(4):441-2. No abstract available.

PMID: 15626010 [PubMed - indexed for MEDLINE]

pain management.

Kanowitz A, Dunn TM, Kanowitz EM, Dunn WW, Vanbuskirk K.

Prehosp Emerg Care. 2006 Jan-Mar;10(1):1-7.

PMID: 16418084 [PubMed - indexed for MEDLINE]
> 4. Determining what the goal is for pain relief
The goal is a level of pain that is tolerable to the patient.

As long as the patient says that they want more pain relief, we should

not be deciding that 50 mg morphine, or whatever other dose, is too

much. If the patient is in pain, we should treat it.

initial medication does not appear to be effective for that patient.

A short acting benzodiazepine (midazolam) is an excellent addition to

morphine/fentanyl. it wears off quickly, so any sedative issues should

be wearing off as the patient is arriving at the emergency department.

If it wears off sooner, more can be given.

metabolize medication quickly.

a therapeutic dose of morphine, or fentanyl, or dilaudid (other than

for procedural sedation)?
Anyone?
Ever?
> 5. Addressing the special needs of pediatrics
It is not any more ethical to torture children, cute little innocent

children, than it is to torture big mean adults.

> 1. Pain management alters the physical exam

truly is experiencing narcosis.

> consent for additional treatment

Dr. Dailey is well aware. Dr. Dickinson wrote about that in this paper

-

Refusal of base station physicians to authorize narcotic analgesia.

Prehosp Emerg Care. 2001 Jul-Sep;5(3):293-5. No abstract available.

PMID: 11446548 [PubMed - indexed for MEDLINE]
> 3. Is there a role for holistic measures such as bio-feedback,

> acupressure, aroma therapy, etc.

placebo, having somebody hold their hand will be much more effective

than the acupressure/acupuncture placebo - even if their hand is being

held by a scary guy like me.

http://roguemedic.com/

Tim Noonan

> My name is Erik and I am new to the discussion group. I have been in the

> Pennsylania Emergency Medical Services for twenty-three years with the last

> seventeen years as a Nationally Registered Paramedic. I am very interested

> in learning about the constant changes that are occuring in pre-hospital

> medicine.

> I am happy that pain management has become a priority in the pre-hospital

> management of a patient even though it was way overdue. However, I think the

> biggest issue that faces pre-hospital providers are the "drug-seekers" and

> the concern of an Emergency Room physician/nurse saying "oh this guy is a

> drug-seeker how did you fall for that?"
I ask them to show me some well done research that shows how to

identify which patients are certain to be just junkies seeking drugs

for recreational purposes.
There is no such research. They are only fooling themselves, if they

claim to be 100% accurate. That is nothing but witchcraft/voodoo/

alternative medicine/BS.
Ask them - How many patients with genuine pain are you willing to

torture to prevent some junkies from getting high?

If they want to work for the Philly PD, they will take a huge cut in

pay, but they may be providing better patient care than they are as

the local Misery Cop/Nurse.
> Unfortunately, people who frequently abuse the system will create

> stereotypes and fear which results in hesitation on performing pain

> management. My question is how do we train our younger providers,

> physicians, and nurses to overcome this stereotype and at the same time

> recognize someone who is abusing the systems and is attempting to feed into

> an addiction?

people scamming the system to get some drugs?

acting drug, like fentanyl, is not going to be very satisfying for

someone looking to get well. It wears off too quickly.
Tim Noonan.

http://roguemedic.com/

> Dr. Isenberg's concern about patient's needing pain management and being

> triaged to BLS is a valid concern.
Erik Davis,

This is especially a concern in Philadelphia. Dr. Mechem (is he still

the medical director for the fire department?) has shown no interest

in pain management. When I would teach ACLS in city hospitals, the

medics would tell me that they were issued a maximum of 20 mg morphine

in a 5 pack of 4 mg syringes. They stated that they were not permitted

to restock anything until they were down to 4 mg morphine. If what I

have been told by a bunch of different medics is true, that is

horrible. what happens when they have a fire fighter - one of their

own - with serious burns?

directors?

the suburbs, but you hope for something better from someone working at

HUP.
> Personally, I think that it is a way of thinking that needs to be changed

> both with the BLS and ALS providers. . . .

and isolated extremity fractures should be treated under standing

orders. Obviously, for those operating with even worse (none) standing

orders, we need to do something about the insanity of Mother-may-I

medical direction.
One of the other problems with short transport times is that some

medical command physicians will ask the completely irrelevant question

- How far are you from the hospital?
I answer that it depends on how quickly I get orders for pain

management - and I may have to call back several times if they are

stingy with the pain medicine.
I can always talk to the patient, for informed consent, and explain

that the doctor at the closest hospital does not want them to have

pain medicine. Would they like me to call somewhere else?

This "doctor shopping" is discouraged, but that is only because it

makes the bad doctors look bad. OK. Not really. The bad doctors always

look bad, but this just points it out to the bad doctors. They do not

like that. conversations usually do not progress amicably beyond this

point. however, once I point out to the doctor that I will consult

with the patient about the doctor's recommendation for pain management

orders, they usually give more appropriate orders.

protecting him/her from malpractice suits and charges of negligence,

which I would be happy to assist the patient with pursuing. I do not

receive a lot of thank you cards from the doctors for this, but I do

not really do this for the doctors. I do patient care for the

patients.

http://roguemedic.com/

Laurie,

EMS Educator

Tucson, AZ

Gene,

Schertz EMS

Hi All,

System Development Coordinator

EMTS Section

Colorado Department

of Public Health & Environment

4300 Cherry Creek Drive South

Denver, Colorado 80246-1530

Office (303) 692-2916

Cell (720) 383-0250

Fax (303) 691-7720

Sean.Caff...@state.co.us

Hi to all

year prior to being replaced in the late 1990s by methoxyflurane.

cylinder. It was safe and effective, but little was written about it

from a research perspective. Methoxyflurane is commonly used in

Australia…administered through a lightweight inhaler held by the

patient, it is effectively self-administered at sub-anaesthetic

concentrations, generally with good effect, particularly in kids. One

of its downfalls is that it has to be constantly inhaled in order to

firstly achieve, then maintain analgesia. It also requires constant

instruction so ensure consistent breathing through the mouth and not

the nose! All clinical levels can administer methoxyflurane, with

many community first responders also being able to do so after

completing short courses.

Paul Simpson

Paramedic Research Fellow/Intensive Care Paramedic,

Ambulance Research Institute

Ambulance Service of New South Wales

And yet, Methoxyflurane has a slow onset/offset of effect, is a very

potent anesthetic (with a MAC listed as around 0.2%), a high degree of

lipid solubility, has to be consistently inhaled for proper effect, and

requires care by the medic to insure proper use.
sounds to me like it was a step backwards in safety to accommodate a

step forward in convenience for the ambulance operators.

Charles S. Krin, DO (ret)

EMS writer and educator, former FP/EP

Hi to all,

methoxyflurane had its limitations as most analgesics do, but I would

suggest that it is not at all a step backwards as suggested. In

clinical practice, with constant inhalation, methoxy actually has a

very rapid onset of effect and upon ceasing inhalation has a quick

‘washout’. As presented in our recent publication in Prehospital

Emergency Care (Middleton et al 2010;14;439-447), provides effective

analgesia in almost 60% of adult patients with moderate to severe pain

to whom it is administered, with a mean reduction in patient reported

pain score of 3.2 points (VNRS). There are few safety issues with

methoxy in the sub-anaesthetic doses used for analgesia. Sedation is

rare. It has an excellent safety profile as an analgesic.

patients to comply with instruction. Entonox however was not a whole

lot different as a comparison. It had a slower onset, a faster loss

of effect, and still required patients to constantly inhale in order

to maintain the effect, and cart around a heavy cylinder. For

patients who have difficulty using the inhaler and maintaining

constant inhalation, the inhaler can be attached to a standard resus

mask (in much the same way Entonox was administered) providing a

better effect.
The use of methoxy in our service is declining as we recommend it for

mild pain only these days. We advocate opioid analgesia for moderate

and severe pain. All paramedics, except those still undertaking basic

induction training over their first three years, within our 2 tiered

ambulance service can provide opioid analgesia using either IV morph

or IN fent. So use of methoxy has really dropped off in recent times,

which is fine, as patients are getting the more effective opiate based

analgesia more often when they need it.

prehospital analgesic, but it remains a very safe and reasonably

effective analgesic option that has a clear role amongst a multi-agent

approach to prehospital analgesia.

the discussion! As a first time participant in the forum, I am very

much enjoying the discussion!
Middleton PM. Simpson PM. Sinclair G. Dobbins TA. Math B. Bendall JC.

Effectiveness of morphine, fentanyl, and methoxyflurane in the

prehospital setting.