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