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

Moderate (28-32C) Image credit: US public domain Photo credit: Greg O’Connell, Flickr creative commons

Moderate (28-32C) Image credit: James Heilman, MD Photo credit: Greg O’Connell, Flickr creative commons

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

What precipitates hypothermia?

Increased heat loss Alcohol Sepsis Burn

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

2. Investigations

CDMQ: 4 investigations

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

Osborn J waves

3. Resuscitation

Mild (32-35C): Passive external rewarm EM Ottawa 18

Mod (28-32C): Active external rewarm EM Ottawa 19 By U.S. Navy photo by Journalist 2nd Class J. Maurer. [Public domain], via Wikimedia Commons

Mod (28-32C): Active external rewarm EM Ottawa 20 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 21

Severe: Arrhythmia VF: CPR, defib x 1 If defib x 1 does not work, no defib (continue CPR) until >30C Not dead until warm and dead

CDMQ: What cavities for rewarming? (6)

Airway 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 confused and bradycardic. Most appropriate warming method? A. Pleural lavage B. Bladder irrigation C. Intubation D. Peritoneal dialysis E. Warm humidified oxygen

MCQ 4: 12 yo found in the snow. After 2hrs CPR and warming, asytolic and core temp is 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, sympathomimetics)

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 Tub immersion 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