Cardiac arrest in special circumstances Flashcards
What is the most likely rhythm in asphyxia cardiac arrests
PEA or asystole
Three causes of asphyxia cardiac arrest
Hanging
Drowning
Asthma
Normal range for serum potassium
3.5-5.0mmol/L
Serum range for severe hyperkalaemia?
> 6.5 mmol/L
What happens to serum potassium levels in acidaemia?
Increase in serum potassium
Three causes of hyperkalaemia ?
Renal failure (C/A) Drugs Tissue breakdown
Three drugs ass. w/ hyperkalaemia?
ACEI, beta blockers, NSAIDS
ECG abnormalities associated with hyperkalaemia
Tall tented T waves (T>R in >1 lead)
Flat/absent P waves
S&T wave merging
What is used to shift potassium into cells? What should be monitored?
Glucose (25g) + insulin (10 units) solution. or nebulised (10-20mg) of salbutamol (severe). Monitor glucose and K
What is used for cardiac protection in hyperK
IV Calcium chloride or calcium gluconate
What can be used to remove potassium in
a) mild hyperK
b) sever hyperk
a) calcium resonium
b) dialysis
How is hypokalaemia defined?
<3.5mmol/L
Three causes of hypokalaemia
GI losses, endocrine disorders, dialysis
Symptoms and signs of hypoK?
Mild- weakness, fatigue, cramps
Severe- rhabdomyolysis, ascending paralysis
2 ECG changes ass. w/hypoK?
U waves & flat T waves
What other electrolyte might be important to give in hypoK?
Magnesium
What temperature is classified as severe hypothermia?
28-24 C
What should be used to diagnose hypothermia?
Low reading thermometer placed in the lower third of the oesophagus
What is the rationale behind therapeutic hypothermia?
Cellular demand for oxygen reduces by 6% for every 1 C drop in temperature. Inducing hypothermia-> better neurological outcomes
What CPR sequence should be used in patients:
a) temp <28 C
b) temp <20 C
a) Continuous CPR (or CPR 5 mins/ 5 min break repeat)
b) CPR 5 mins/break 10 mins repeat
When would you hesitate to resuscitate a hypothermic patient?
Asystole, snow obstructing airway, signs of irreversible death, if hypothermia unlikely to be primary cause of CA
When should the rescuer give a hypothermic patients drugs? How should these drugs be given?
Drugs (and shocks) withheld until temp >30 C. When temp >30 C, interval between doses should be doubled. Revert to standard when >35 C
Which is the only rhythm that should be shocked in hypothermic patients?
VF- shock 3x and if failed, wait until temp >30 C before starting.
In PHM- how are hypothermic patients rewarmed?
Remove p from cold environment. Passive rewarming e.g. blankets and aluminium foil. Active external e.g. heats pads.
In hospital, how are hypothermic patients rewarmed?
If not severe- warm IV fluids & humidified air.
If severe can consider VA-ACMO with warm fluids.
Why do hypothermic patients required so much fluid during rewarming?
Vasodilation during hypothermic increases intravascular space.
How is heat stroke differentiated from heat exhaustion?
Heat stoke - change in mental status, temperature >40 C, SIRS and varied organ dysfunction
What are some risk factors for heat stroke?
Elderly age, specific drugs e.g. anticholinergics, hyperthyroidism, skin conditions
What is the treatment for hyperthermia?
Fluid & electrolyte correction & rapid cooling e.g. cold IV fluids, cold packs, drinking cold fluids
What is malignant hyperthermia?
Genetic condition. Calcium homeostasis of skeletal muscle. Hypermetabolism & muscle contracture caused by specific anaesthetics and muscle relaxants
Treatment of malignant hyperthermia?
Dantrolene, stop trigger, active cooling, oxygen, correct acidosis & electrolytes
