Magnesium Sulfate in Prehospital
Magnesium sulfate is also used, generally
ous case studies show dramatic reversal of
in the hospital setting, for acute MI with
By Michael Silverman, EMT-P
class IIb (acceptable, possibly helpful) when
admissions in that group of patients.
given prophylactically, although the literature
suggests the latter treatment offers little to no
in the healthcare setting for many years.
benefit.9–11 It is unlikely that magnesium
Group concluded that although indiscrimi-
Over-the-counter (OTC) products like mag-
would be used in the prehospital setting for
nate use was not warranted in the ED set-
ting, there was “sufficient evidence to sup-
(magaldrate, Antiflux, Lowsium, Riopan) are
identify and articulate to on-line medical
port its use in a subgroup of patients experi-
control that the MI patient uses or misuses
encing severe asthma who appear to respond
(Doan’s pills, Magan, Mobidin) are used as
diuretics, and has poor dietary intake and
differently to the administration of magne-
sium. These patients benefited both in terms
salts (Milk of Magnesia) are used for consti-
of admission rates and improved pulmonary
pation.1 This article focuses on the more pro-
tory VF/VT (cardiac arrest) is 1 or 2 grams
function.”14 The researcher later said, “It
gressive uses of intravenous magnesium sul-
(magnesium sulfate) costs virtually nothing
fate that are beginning to appear in prehos-
and is incredibly safe, especially in the doses
pital care protocols and trial studies, specifi-
higher doses up to 5–10 grams have been
we use for acute asthma.” In the prehospital
used. The dose for acute MI is 1–2 grams
setting, any patient who does not respond to
over 5–60 minutes. Prehospital dosage for
the initial beta-agonist dose should be classi-
cardiac arrest tends to be IV push or as an
fied as severe and a candidate for intra-
infusion over a period up to three minutes.
being well tolerated. Side effects at these
pendently, reached similar conclusions. The
only significant difference was that this
that occurs during pregnancy and can cause
hypotension, absent or decreased deep ten-
headaches, vision problems, abdominal pain,
don reflexes, respiratory depression, circula-
nausea, vomiting and sudden swelling of the
tory collapse, diaphoresis and drowsiness.
Although this treatment will generally not
face, hands or feet. Eclampsia, a Greek word
for “bolt from the blue,” can present with
monary function, given the potential benefit
seizures—the hallmark of eclampsia—along
The use of magnesium sulfate for treating
of this medication, low incidence of side
with agitation, altered level of consciousness
effects, cost-effectiveness and its presence in
Although not a primary therapy in the pre-
most paramedic drug inventories, it should
hospital setting, it may prove useful in the
be routinely used in prehospital care when a
port, oxygen therapy, large-bore IV with NS
patient presents with severe asthma and ini-
should be aware of this secondary potential-
tial therapies are not effective. If your assess-
the patient in the left lateral position. Seizure
ment indicates the patient is not improving
activity is typically treated with intravenous
after initial beta-agonist treatment and the
magnesium sulfate, 4 grams over three min-
tion in asthma is well known, prehospital
patient has a history of intubation and/or
utes. In the prehospital setting, diazepam
care tends to focus on bronchodilation using
hospital admission after similar episodes, this
(Valium) or midazolam (Versed) can be used
beta-agonists such as albuterol and epineph-
would be an excellent candidate for magne-
rine (in extremis), and anticholinergic agents
sium sulfate. The optimal dose is 25–100
seizure.7 The only definitive treatment for
such as ipratropium bromide. Some systems
nisolone to treat airway edema, as well as
period.14 Treating acute asthmatic patients
chemical sedation should intubation become
with a less dramatic history should not be
Magnesium deficiency is associated with a
“high frequency of cardiac arrhythmias,
symptoms of cardiac insufficiency and sud-
acetylcholine release and muscle excitability.
Magnesium Sulfate and Stroke
den cardiac death.” As a result, many pre-
It is known that acute temporary elevation of
Acute stroke is the third-leading cause of
hospital protocols include the use of magne-
serum magnesium can result in bronchodila-
death in the United States, after heart attack
sium sulfate for treating refractory VF/VT
and cancer, and the leading cause of long-
or the presence of torsade de pointes: Class
patients with normal magnesium levels.
term disability. Public awareness campaigns
Evidence also shows that magnesium acts as
emphasizing “brain attack” education, early
(acceptable, probably useful and effective)
a competitive antagonist with calcium and
and class I (useful and effective) for tor-
reduces the neutrophilic burst associated
sade.8,11 Since this medication is far down the
with the inflammatory response in asthma.14
Regardless, the beneficial effect of magne-
longer just supportive. Early recognition
sium is controversial because a large clinical
opens the door for more effective interven-
trial has not been done, even though numer-
stroke. For example, early recognition of ischemic stroke allows
Early Recognition of Stroke
providers to consider thrombolytic treatment, although the benefit-to-
There are two well-known tools to help a prehospital
risk ratio due to intracerebral hemorrhage and overall effectiveness is
provider rapidly and reliably identify a stroke patient: the Los
quite controversial.17,26 Prehospital providers need not focus on these
Angeles Prehospital Stroke Screen20 (LAPSS) and the
controversial treatment issues. Rather, we should focus on supportive
Cincinnati Prehospital Stroke Scale (CPSS).25
care and rapid transportation to the most appropriate facility.
Magnesium is well known as a neuroprotective agent. A $16 million
Phase 3 trial titled “FAST-MAG” has just been funded at the
If all of the following criteria are met, the patient is identified
University of California, Los Angeles (UCLA) to demonstrate “that
as meeting the LAPSS criteria for a “code stroke.” The last
paramedic initiation of IV magnesium sulfate within two hours of
known time the patient was at baseline or deficit-free and
symptom onset improves the long-term functional outcome of hyper-
acute stroke patients.”18 The initial pilot study, conducted between
May 2000 and January 2002, showed that “paramedics initiated the
• History of seizures or epilepsy absent
drug much more quickly compared to the usual approach of waiting
until the patient was in the hospital, and patients tended to make a bet-
• At baseline, patient not wheelchair-bound or bedridden
Patients in the UCLA trial study met the following criteria: age
40–95; identified in the Los Angeles stroke screen criteria; identified
within two hours of onset of symptoms; continued to have symptoms
Arm strength—normal, drifts down or falls rapidly
Patients excluded from the study met the following criteria: coma;
Based on above exam for asymmetry, patient has only unilat-
rapidly improving; SBP <90 or >220; severe renal dysfunction (on
eral weakness. If the above are yes or unknown, the patient
dialysis); severe respiratory distress (oxygen saturation <90%); sec-
ond- or third-degree heart block; major head trauma in the last 24hours; stroke within the last 30 days.
A critical part of the study was reliable identification of stroke
The CPSS does not include criteria for acute stroke therapy,
patients using the Los Angeles Prehospital Stroke Screen (LAPSS)
but is a good screening tool to identify stroke patients.
described in the sidebar.19 The trial study selected a prehospital mag-
nesium sulfate dosage of 4 grams over 15 minutes, followed by a
Action: Have patient show teeth or smile.
maintenance infusion of 16 grams over 24 hours in the hospital set-
Normal: Both sides of face move equally well.
Abnormal: One side of face does not move as well as the
Although there are a number of neuroprotective agents, extensive
clinical experience with magnesium demonstrates patients’ ability to
tolerate it safely. Magnesium increases cerebral blood flow to ischemic
Action: Have patient close both eyes and hold both arms out.
brain areas by dilating blood vessels and prevents damaging calcium
Normal: Both arms move the same or both arms do not move
buildup in injured nerve cells.20,21,22 If the outcome of this trial is posi-
tive, it has the potential to significantly change our approach to stroke
Abnormal: One arm does not move or one arm drifts down
treatment in the prehospital and emergency department settings.
Although potential routine treatment of stroke with intravenous
magnesium sulfate is many years away, prehospital care providers
Action: Have the patient say, “You can’t teach an old dog new
should now concentrate on early recognition, supportive care and
rapid transport of suspected stroke patients to the most appropriate
Normal: Patient uses correct words with no slurring.
facility. Many prehospital protocols now support rapid transport of
Abnormal: Patient slurs words, uses inappropriate words or is
stroke patients to the most appropriate facility with a “stroke team”
rather than the closest facility, especially when patients meet specific
criteria such as baseline health status and known time of onset.20,23,24,26
3. Abbott J. Complications related to pregnancy. Emergency Medicine: Concepts and
Another Potential Application
, 3rd Ed. St. Louis, MO: Mosby, 1992.
4. Hals G, Crump T. The pregnant patient: Guidelines for management of com-
Although this section has little to do with prehospital emergency
mon life-threatening medical disorders in the emergency department. Emerg Med
care, it was interesting to find that magnesium sulfate is being studied
to determine if prenatal use—specifically before preterm birth—can
5. Hansen WF. Problems in pregnancy. Emergency Medicine: A Comprehensive Study
improve pediatric outcomes, such as total mortality, reduction in neu-
, 4th Ed. New York, NY: McGraw-Hill Professional, 1996.
rosensory disability, motor dysfunction and cerebral palsy.27 Although
6. Rivers EP. Preeclampsia, eclampsia, and other hypertensive disorders of preg-
these studies are not strong enough to recommend widespread use,
nancy. The Clinical Practice of Emergency Medicine
, 2nd Ed., 1996.
7. Inland Counties EMS Agency. Obstetrical Emergencies. ALS Protocol
additional research may one day offer a treatment that can provide an
overall reduction in the prevalence of cerebral palsy.28
8. Dyckner T, Wester PO. Magnesium in cardiology. Acta Med Scand
9. Ebel H, Gunther T. Role of magnesium in cardiac diseases. J Clin Chem Clin
1. Mosby’s Nursing Drug Reference
. St. Louis, MO: Mosby, 2000.
2. Brooks MD. Pregnancy, eclampsia. www.emedicine.com/emerg/
10. Ceremuzynski L, Jurgiel R, Kulakowski P, Glbalska J. Threatening arrhyth-
mias in acute myocardial infarction are prevented byintravenous magnesium sulfate. Am Heart J
11. Advanced Cardiac Life Support. AmericanHeart Association, 1–20 and 1–55, 1997–1999. 12. Asthma and the Influence of Magnesium,www.asthmaworld.org/mag.htm.
13. Kirchner FT. Intravenous magnesium sulfateis effective in pediatric asthma. Amer Fam Phy
14. Rowe BH, Bretzlaff JA, Bourdon C, et al.
Intravenous magnesium sulfate treatment for acuteasthma in the emergency department: A systematicreview of the literature. Ann Emerg Med
15. Alter HJ, Koepsell TD, Hilty WM.
Intravenous magnesium as an adjuvant in acute bron-chospasm: A meta-analysis. Ann Emerg Med
16. Preventing Strokes Interactive Tutorial.
17. Muir KW. Br J Clin Pharmacol
18. Saver JL, Kidwell CS, Hamilton S, et al. TheField Administration of Stroke Therapy—Magnesium (FAST-MAG) Phase 3 Trial. AmericanStroke Association Conference, Jan. 2003.
19. Waddell A. Two hours to save a life: Strokestudy funded. UCLA Today
24:3, Oct 7, 2003.
20. Kidwell CS, Starkman S, Eckstein M, et al.
Identifying stroke in the field: Prospective validationof the Los Angeles prehospital stroke screen. Stroke
21. Muir KW, Lees KR. Dose optimization ofintravenous magnesium sulfate after acute stroke.Stroke
22. Bradford A, Lees KR. Design of the intra-venous magnesium efficacy in acute stroke trial. CurrControl Trials Med
23. National Stroke Association. Stroke: Acutetreatment and research. www.strokeassociation.org.
24. Hayes C. Stroke alert programs: Your patient’sstroke doesn’t have to be a “stroke of bad luck.”www.emsvillage.com. Dec. 10, 2001.
25. Kothari RU, et al. Cincinnati prehospital strokescale: Reproducibility and validity. Ann Emerg Med
33:373–378, Apr. 1999.
26. Ween JE. The inland empire regional strokeinitiative. Loma Linda University. www.llu.edu/llumc/neurosciences/ier-stroke.htm.
27. Crowther CA, Hiller JE, Doyle LW, HaslamRR. Effect of magnesium sulfate given for neuroprotection before preterm birth: A randomized con-trolled trial. JAMA
28. Tyson JE, Gilstrap LC. Hope for perinatal pre-vention of cerebral palsy. JAMA
Michael Silverman, EMT-P, is a paramedic for
American Medical Response in San BernardinoCounty, CA. Contact him at [email protected]
LES NEUROLEPTIQUES Ils sont essentiellement utilisés dans le traitement des psychoses. Les neuroleptiques (NL) sont des médicaments symptomatiques, c’est-à-dire qu’ils traitent les manifestations d’une psychose aiguë ou chronique. En améliorant l’état psychique ils: Récemment le terme « antipsychotique » a été introduit pour les nouveaux neuroleptiques. Action pharmacolo
Dosing Amphotericin B in Cryptococcal Meningitis William G. Powderly University College Dublin School of Medicine and Medical Science, Dublin, Ireland (See the article by Bicanic et al. on pages 123–30) It is salutary to note that, although for the0.3 mg/kg per day was effective when givenadvent of effective antiretroviral therapypast 50 years of therapeutics, amphoteri-led to a substa