Hypothermia (Hyperthermia) Dr. Stella Yiu Staff Emergency Physician

LMCC objectives List clinical findings of hypothermia Investigate Initiate resuscitation for severe hypothermia

1. Clinical findings of hypothermia

Normal temp: 36.5 – 37.5 C

Effects By Patrick J. Lynch, medical illustrator (Patrick J. Lynch, medical illustrator) [CC-BY-2.5 ( via Wikimedia Commons Image credit: US public domain

Mild (32-35C)

Moderate (28-32C) Image credit: James Heilman, MD

Moderate (28-32C)

Severe (<28C) Image credit: jer5150, Wikimedia commons, Jeffrey Bary, Flickr creative commons

What precipitates hypothermia?

Increased heat loss Alcohol Sepsis Burn

Exposure EM Ottawa 14 Photo credit: Jonathan Snyder, U.S. Air Force, UNC - CFC – USFK, CC by 2.0, via Flickr creative commons

Impaired thermostat Metabolic (Cirrhosis, uremia, DM, Hypothyroid) CNS (stroke, trauma, MS, Parkinson) Drugs (Barbituates, TCAs)

2. Investigations

CDMQ: 25 M found passed out on street. Core temp 30C. Name 4 investigations.

Investigations CBC, Cr, Lytes, Coag profile (DIC) TSH EKG

Osborn J waves

3. Resuscitation

Mild (32-35C): Passive external rewarm

Mod (28-32C): Active external rewarm

EM Ottawa 23 By Patrick J. Lynch, medical illustrator (Patrick J. Lynch, medical illustrator) [CC-BY-2.5 ( via Wikimedia Commons Warm humidified Oxygen

Severe (<28) Warm every cavity but Gentle handling EM Ottawa 24

CDMQ: How do we do active core rewarming in severe hypothermia? (6)

Airway Intubate Warm humidified oxygen

Circulation Warm intravenous fluids

Pleural space By Patrick J. Lynch, medical illustrator (Patrick J. Lynch, medical illustrator) [CC-BY-2.5 ( via Wikimedia Commons

Bladder By User:Lennert B [GFDL ( CC-BY-SA-3.0 ( sa/3.0/) or CC-BY-2.5 ( via Wikimedia Commons

Dialysis By National Kidney and Urologic Diseases Information Clearinghouse, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, USA [Public domain], via Wikimedia Commons Photo credit: becre8tv, CC by 2.0, via Flickr Creative commons

Bypass By Van Meurs, K, Lally, KP, Peek, G, Zwischenberger, Extracorporeal Life Support Organization, Ann Arbor [CC-BY-2.5 ( via Wikimedia Commons

MCQ 3: Patient is lethargic and bradycardic. Most appropriate warming method? A. Pleural lavage B. Bladder irrigation C. Intubation D. Dry blanket and a snack E. Blanket with forced warm air

MCQ 4: 12 M found in snow. After 2hrs CPR and warming, asytolic. Core temp 27.5C. What is the most appropriate step? A. Stop resuscitation B. Defibrillation C. Continue CPR and warming D. Warm water immersion E. Stop warming

Not dead until warm (>30-32) and dead

Hyperthermia

LMCC objectives List predisposing illnesses List clinical findings Select investigations Manage patient by various cooling methods

Causes Environment Decreased heat dissipation Metabolic heat

1. Predisposing illness

Metabolic causes: Heat production Metabolic heat Thyroid, pheochromocytoma Malignant hyperthermia NMS Sepsis

Decreased heat loss: Drugs Decreased heat dissipation Obesity Drugs (anticholinergics, serotonin)

2. Clinical findings

Case: The rave girl

Heat stroke: Hot + confused T> 40 Orthostatic BP,  HR CNS: Confusion, ataxic, cerebral edema, seizure CVS: CHF, pulmonary edema, CV collapse

Lab findings: Liver, Renal Liver: necrosis Rhabdomyolysis DIC

3. Cooling methods

Basic cooling: Photo credit: Kenneth Lu, Flickr creative commons

Photo credit: yellowcloud, flickr creative commons

More aggressive cooling GI/Peritoneal lavage Cardiac bypass

Stop cooling when temp < 40

LMCC objectives List predisposing illnesses List clinical findings Select investigations Manage patient by various cooling methods