Environmental Emergencies part 1 Dr Kirsty Dunn FACEM Ballarat Base May 2014
Environmental Emergencies
Heat and Cold Exposure
Burns, Electrical and Lightening injuries
Near Drowning and Submersion Syndromes
Barotrauma
Altitude
Envenomation
Heat & Cold Exposure
Febrile Pt has huge DDx:
• Infection / sepsis / SIRS
• Toxicological – drugs of abuse / serotonin syndrome / neuroleptic malignant syndrome / malignant hyperthermia / delirium tremens
• Exposure – NAI (mandatory reporting)
• Exertional – heat exhaustion / heatstroke
Hyperthermia
Heat Exhaustion
Heat Stroke
Heat Syncope
Heat Tetany
Heat Cramps
Prickly Heat
Heat Oedema
Heat Exhaustion
Most common heat-related illness
Water and salt depletion
Dehydration without adequate fluid intake (ave. adult only drinks 2/3 losses due to perspiration)
Salts – sweat replaced by hypotonic soln
• hyponatraemia, hypochloraemia, low urinary chloride and sodium
Body Temp near NORMAL
Heat Exhaustion
Ax- Lightheaded, fatigue, N, V, headache, myalgia, syncope, orthostasis, Sinus tachy, tachypnoea, diaphoresis, NORMAL mental status
Ix (not usually indicated) – transaminase elevn in 1-2000s eg marathon runners
Mx – rest out of sun, hydrolyte / Gatorade etc., ivf if vitals off. Home if young and well, admit if elderly for slow correction osmolarity 2 mOsm/hr
(cerebral oedema, hyponatraemia)
Heat Stroke
Medical EMERGENCY
Definition is a TRIAD • Core temp >40
c
• CNS dysfunction
• Anhydrosis
Epidemics common in Australia
Fatalities every year – poor, elderly, alcoholics, schizophrenics.
Predisposing RF’s Heat Stroke
Inc Heat Production
• Exertion, febrile illness, drugs (amphetamines, cocaine, aspirin)
External Heat Gain
• Hot and humid
Reduced ability to lose heat
• Dehydration, extremes age, obesity, neglect / inappropriate clothing
Heat Stroke in the ED
Ax – irritable, bizarre behaviour, combative, hallucination ,seizure, coma, death.
Vitals – tachy, hypoT, Right heart Failure, +/- sweating *doesn’t differentiate b’wn H. exhaustion and H. stroke.
ARDS, encephalopathic, MOF, DIC, rhabdo, shock liver.
Heat Stroke
Ix – FBC (haemoconcentration) • U&E )hyponatraemia, hypochloraemia, H/L
K, ARF
• LFT – transaminitis
• CK – rhabdo.
• FWT – myoglobinurea
• Coag’s – DIC
• Lactate – HAGMA
• ABG – resp. alkalosis
• CTB – r/o coagulopathic bleed / alternative Dx
Heat Stroke
Mx – ABC’s, IVC, IVF, active cooling, core temp, avoid shivering
AIM is only 39
C to avoid overshoot
HDU admit
(Do not immerse in ice bath)
Hypothermia
Mild 32-35
Moderate 28-32
Severe <28
Key Temps in Hypothermia <32
C Osborne waves and shivering artefact
<30
C Lose ability to shiver
<29
C ACS and pupillary dilation Bradycardia / slow AF w resistance to pressors / adrenaline / atropine
<28
C paralysis – knee jerk last to go / 1st return
<23
C no corneal reflex (or oculocephalic)
<22
C VF
18
C asystole
13
C lowest accidental hypothermia survived
ECG
Osborne /J waves. Nb T waves suggestive hyperK not reliable in
HypoThermia
Slow AF with slow ventricular response
Osborne Waves
Not pathognomonic for hypothermia
Also in SAH, cerebral injuries, myocardial ischaemia
Very similar to epsilon wave or ARVC
Modifications to ACLS for Hypothermia
A – warm (40
), humidified O2, intubate prn
B – Consider ICC’s pleural lavage (if ECMO>6/24 away)
C – IVF 40
C, unresponsive to antiarrhythmics, defib., external pacing
SB is physiological response – don’t pace
VF/VT – single defib. and 1Ad attempt only
CPR until core temp >30
C
D - ?neuroprotective
r/o 2nd hypothermia – ICH, AMI, toxicological
E – BSL may be H/L – must give some dextrose.
- use low reading core temp probe.
Pearls in Hypothermia
Ignore transient ventricular arrhythmias Leave slow AF and bradycardias Consider magnesium Gentle-handling over-emphasised Punctures will ooze (nb. post-CAGS pts) Ways to re-warm:
• External – heat lamp, bair hugger, warm blankets (4 x faster than passive alone)
• Invasive – severe hypothermia – warmed, humidified O2, IVF warmer (insulate lines), ECMO (10 x faster) – as effective as hot bath!
Note the AFTERDROP
Non-Salvable Hypothermia
K >12mmol/L
Core T <6 (<15 if CPR >2/24)
pH <6.5
ECMO unsuccessful
Clots in myocardium
**cannot terminate effort alone**
EMRAP Jan ‘14
Who is cold and salvageable and who is
cold and dead? There are 5 criteria you can use to determine if they are dead. • 1) A clear history of cardiac arrest prior to
cooling. • 2) If you have a core temperature greater than
32 degrees Celsius (89.6 degrees Fahrenheit) and they are in asystole, hypothermia is not the cause.
• 3) If they are frozen solid and the chest is not compressible.
• 4) They have potassium greater than 12 mEq/L. • 5) Special circumstances: trauma, drowning
and avalanche burial.
Don’t forget to seek and treat the following
T 65.5-4 Roppolo,
Rosen