Emergency Medicine Flashcards
Define hypothermia?
- A reduction of core body temperature below 35°C (normal 37°C).
- Core temperature is measured with a rectal probe or through the esophagus
- Severe hypothermia is a core
temperature below 30°C.
Describe the clinical presentation for Hypothermia?
- Lethargy, confusion and weakness.
- Death usually occurs from arrhythmia because the cold alters cardiac conduction.
- Patients may have metabolic acidosis, respiratory acidosis, kidney injury and hyperkalemia.
How do you diagnose hypothermia?
- EKG shows an arrhythmia, either ventricular fibrillation or ventricular tachycardia.
- Elevation of the J point, known as Osborne waves.
- J wave elevation looks like ST-segment elevation
How do you treat hypothermia?
- Warm bed, bath or heated blankets.
- Warmed IV fluids or warmed humidified oxygen in severe cases.
- Caution because rapid heating may also cause arrhythmias.
- If arrhythmia presents, continue resuscitative measures until body temperature is >35°C (95 F)
Name three exertional heat disorders.
- Heat cramps
- Heat exhaustion
- Lethal heat stroke
Name two nonexertional heat disorders.
- Malignant hyperthermia
- Neuroleptic malignant syndrome
What are heat cramps and how are they treated?
- Occurs with fluid and electrolyte depletion
- Develop painful muscle contractions with muscle tenderness
- Patient is able to sweat normally with no neurological abnormalities.
- Treat with rest, oral rehydration and salt replacement.
What is heat exhaustion and how do you treat it?
- More severe exertional disorder .
- Patient is weaker, has systemic symptoms, body temperature is slightly elevated,.
- Neurologic symptoms include headache, nausea and anxiety.
- Death is unlikely but can progress to heat stroke if not treated.
- Patient can still sweat and remove heat from the body.
- Treatment is oral fluid rehydration and electrolyte replacement, may require IV.
What is a heat stroke and how do you treat it?
- Severe and potentially life threatening.
- Patients have lost ability to sweat and remove heat from the body.
- Body temperature may be elevated (>41°C or 105 F) resulting in confusion, disorientation, nausea, blurred vision and seizures.
- Labs may show hemoconcentration, rhabdomyolysis, elevated BUN, creatinine and white cell count.
- Anuria, DIC and lactic acidosis may develop.
- Treat with IV fluid replacement and rapid cooling off of the body such as placing in a cool environment and spraying with water and fanning to evaporate the fluid.
What is malignant hyperthermia?
Occurs as an idiotsyncratic reaction to the use of anesthetic agents such as halothane or succinylcholine (paralytic)
- May be caused by any anesthetic.
- Rhabdomyolysis may develop
How do you treat malignant hyperthermia?
Dantrolene
- Depresses excitation-contraction coupling in skeletal muscle by binding to the ryanodine receptor 1 and decreases intracellular calcium concentration.
What is neuroleptic malignant syndrome?
- Idiosyncratic reaction to a wide variety of phenothiazines or butyrophenones such as haloperidol.
- Muscular rigidity and rhabdomyolysis may occur.
- Treat with bromocriptine, stimulates dopamine receptors, specifically in the nigrostriatal pathway.
What is asystole?
- Complete absence of electrical activity in the heart
- Does not necessarily mean a flat line
- Usually due to ischemia
- Presents as unresponsive person with no pulse
- Treatment
1. CPR, obtain IV access and prepare for intubation
2. 1 mg epinephrine via IV push every 3-5 minutes
3 Reevaluate for atypical clinical features
Most common causes of asystole and other arrhythmias
Hypoxia Hypo/Hyperkalemia Hypothermia Hypoglycemia Hypovolemia Trauma Toxins (Includes overdose) Tamponade Tension Pneumothorax Thrombosis (coronary and pulmonary)
When is bicarbonate helpful in asystole?
When due to: Pre-existing acidosis: Tricyclic antidepressant (amitriptyline) Aspirin Hyperkalemia Diabetic Ketoacidosis
What is the recommended treatment for a patient that presents to the ED within 12 hours of an MI?
- Percutaneous coronary intervention (PCI)
- Preferred choice
- Lower rates of intracerebral hemorrhage and recurrent MI - Fibrinolysis
- Only if PCI not available
- Use tenecteplase or alteplase
- Contraindicated if GI bleeding or recent surgery
- It binds fibrin in the thrombus and converts entrapped plasminogen to plasmin
- Plasmin causes clot lysis and restores coronary flow
- Hemorrhage is most adverse therapy
