Resuscitation in Special circumstances Flashcards
What is the normal range for extracellular potassium?
3.5-5
When serum pH decreases what happens to serum potassium and why?
It increases because potassium shifts from cellular to vascular space
What usually causes hyperkalaemia?
Increased potassium release from cells or impaired excretion by the kidneys
What is the definition of hyperkalaemia?
> 5.5
What is the definition of severe hyperkalaemia?
> 6.5
What are the causes of hyperkalaemia?
- renal filure
- drugs
- tissue breakdown
- metabolic acidosis
- endocrine disorders
- diet
- spurious
Which drugs cause hyperkalaemia?
ACE-I
ARB
potassium sparing diuretics
NSAIDS
b-blockers
trimethoprim
What are the causes of tissue breakdown contributing to hyperkalaemia?
Tumour lysis
Rhabdomyolysis
Haemolysis
Which endocrine disorders might cause hyperkalaemia?
Addison’s disease
What may be the presentation of hyperkalaemia?
Weakness progressing to flaccid paralysis
Paraesthesia
Depressed deep tendon reflexes
At what level does hyperkalaemia tend to cause ECG changes?
6.7
What are the ECG changes that might be seen in hyperkalaemia?
- first degree heart block
- flattened/absent P waves
- tall, peaked (tented) T waves
- ST depression
- S and T wave merging- sine wave
- widened QRS
- Ventricular tachycardia
- bradycardia
What are the 5 key steps in treating hyperkalaemia?
- Cardiac protection
- Shifting potassium into cells
- removing potassium from the body
- monitoring serum potassium and glucose concentration
- prevention of recurrence
What are the main risks associated with treating hyperkalaemia?
- hypoglycaemia
- tissue necrosis
- rebound hyperkalaemia
Why can tissue necrosis occur after treatment of hyperkalaemia?
2ry to extravasation of IV calcium salts
What is the treatment of mildly elevated K?
5.5-5.9
- address cause
- if treatment is indicated then use potassium binders (Calcium resonium) 15-30g
What is the treatment of a moderately elevated K- without ECG changes?
6.0-6.4
- shift K intracellularly with glucose/insulin
- 10 units short-acting insulin and 25g of glucose IV over 15-30 minutes
- follow up with 10% glucose infusion at 50ml h for 5 h in patients with a pre treatment BM of <7
- remove potassium with calcium resonium
What is the treatment of severe hyperkalaemia >6.5 without ECG changes?
- seek expert help
- give glucose/insulin
- give salbutamol 10-20mg nebulised
- remove k from the body, consider dialysis, sodium zirconium cyclosilicate and/or patiromer
- consider cardiac monitoring
What is the treatment of severe hyperkalaemia with ECG changes?
Protect the heart with calcium salts: 6.8mmol Ca via 10mL calcium chloride IV over 2-5 minutes or 30mL 10% calcium gluconate over 15min
Use shifting agents- glucose+insulin/salbutamol
Remove K
Start cardiac monitoring
Calcium salts protect the heart by reducing the risk VF/pVT
What is the treatment of severe hyperkalaemia during CPR?
10mL calcium chloride 10% by rapid IV bolus
give insulin/glucose 10 units short acting insulin and 25g glucose IV by rapid injection
Give sodium bicarbonate 50mmol (50ml of 8.4% solution) IV by rapid injection if severe acidosis or renal failure
Consider dialysis
What is the definition of hypokalaemia?
<3.5
severe <2.5
What are the causes of hypokalaemia?
- GI losses
- drugs
- renal losses
- endocrine disorders
- metabolic acidosis
- magnesium depletion
- poor diet
Which drugs cause hypokalaemia?
diuretics, laxatives, steroids
Which conditions/procedures cause renal losses of k?
renal tubular disorders
diabetes insipidus
dialysis
Which endocrine conditions may cause K loss?
Cushings, hyperaldosteronism
What are the symptoms of hypokalaemia?
- fatigue
- weakness
- leg cramps
- constipation
- rhabdomyolysis
- ascending paralysis
- respiratory difficulties
What are the ECG features of hypokalaemia?
U waves
T wave flattening
ST segment changes
arrythmias
What is the maximum recommended dose of iv K?
20mmol h
When is a higher dose of K indicated?
When cardiac arrest is imminent
- 2mmol /min for 10 minutes followed by 10mmol over 5-10 min
Which other mineral is essential for K uptake?
Mg
What is the definition of hypercalcaemia?
> 2.6mmol
ionised calcium is usually measured on blood gas machines
Normal ionised Ca is 1.1-1.3
What are the causes of hypercalcaemia?
- primary or tertiary hyperparathyroidism
- malignancy
- sarcoidosis
- drugs
What are the symptoms of hypercalcaemia?
- abdominal pain
- confusion
- weakness
- hypotension
- arrhythmias
- cardiac arrest
What are the ECG signs of hypercalcaemia?
- short QT interval
- prolonged QRS
- flat T waves
- AV block
- cardiac arrest
What are the treatments for hypercalcaemia?
- fluid replacement IV
- furosemide 1mg kg
- hydrocortisone 200-300mg iV
- pamindronate 30-90mg iV
What is hypocalcaemia?
<2.1 total calcium
What are the causes of hypocalcaemia?
- chronic renal failure
- acute pancreatitis
- calcium channel blocker overdose
- toxic shock
- rhabdomyolysis
- tumour lysis syndrome
What are the symptoms of hypocalcaemia?
Paraesthesia
Tetany
Seizures
AV block
Cardiac arrest
What are the ECG signs of hypocalcaemia?
- prolonged QT
- T wave inversion
- heart block
- cardiac arrest
What is the treatment of hypocalcaemia?
Calcium chloride 10% 10-40mL IV
1-2g 50% Magnesium Sulfate (2-4ml 4-8mmol) IV if neccesary
What is hypermagnesaemia?
> 1.1
What are the causes of hypermagnesaemia?
Renal failure
Iatrogenic
What are the symptoms of hypermagnesaemia?
Confusion
Weakness
Respiratory depression
AV- block
cardiac arrest
What are the ECG changes in hypermagnesaemia?
prolonged PR interval
T Wave peaking
AV block
arrest
When should treatment for hypermagnesaemia be considered?
> 1.75
What is the treatment for hypermagnesaemia?
Calcium chloride 10% 5-10mL IV
Ventilatory support if neccessary
Saline diuresis 0.9% saline with furosemide 1mg per kg
HD
What is hypomagnesaemia?
<0.6
What are the causes of hypomagnesaemia?
- GI loss
- polyuria
- starvation
- alcoholism
- malabsorption
what are the sympoms of hypomagnesaemia?
- tremor
- ataxia
- nystagmus
- seizures
- arrhythmias -TDP
- cardiac arrest
What are the ECG changes in hypomagnesaemia?
Prolonged PR and QT
ST depression
T wave inversion
Flattened p waves
increased QRS duration
tdp
What is the treatment for hypomagnesaemia?
Severe or symptomatic
- 2g 50% magnseium sulphate (4mL; 8mmol) IV over 15 mins
TDP
- 2g 50% magnseium sulphate (4mL; 8mmol) IV over 1-2 mins
Seizure
- 2g 50% magnseium sulphate (4mL; 8mmol) IV over 10 mins
How much more likely are HD patients to suffer an OOH cardiac arrest?
20 x
What are the risk factors for cardiac arrest in HD patients?
electrolyte disturbance
fluid shift
medical comorbidities
What should you do if someone on a HD machine arrests?
- stop dialysis and return the patients blood volume with fluids
- disconnect form the maching unless defibrillation proof
- leave dialysis access open for drug administration
- provide prompt management of hyperkalaemia
How can sepsis be identified?
SOFA score
What is septic shock?
Sepsis requiring vasopressors to maintain a MAP > 65 and a serum lactate >2 mmol despite fluid resus
What is in the 1 hour care bundle for sepsis?
- Give high flow 02
- blood cultures and any other sampling required
- give broad spectrum abx
- initiate fluid resus
- measure lactate
- measure urine output
B- Blood culture
U- urine output
F- fluids
A- antibiotis
L- lactate
O- o
What is the fluid regimen in sepsis?
Give fluid challenges in boluses of 250-500ml of crystalloid to maximum volume of 30ml/kg body weight in patients with hypotension, high lactate, or other signs of low urine output
If the MAP is still less than 65 despite fluids then escalation for vasopressors is required
How do you work out the MAP
Mean Arterial Pressure = 1/3(SBP) + 2/3(DBP)
Who should you consider giving a single dose of activated charcoal to?
A patient hwo has ingested a potentially toxic amount of a toxin known to be absorbed by activated charcoal, up to one hour previously
Multiple doses may be beneficial in poisoning with carbamazepine, dapsone, phenobarbital, quinine and theophylline
When should whole bowel irrigation be considered?
Potentially toxic ingestion of sustained release or enteric-coated drugs, oral iron poisoning and the removal of whole packets of ingested drugs
When is urine alkalinisation used and how?
Give IV sodium bicarbonate in moderate to severe salicylate poisoning
What kind of drugs can haemodialysis remove?
Removes drugs or metabolites with low molecular weight, low protein binding, small volumes of distribution and high water solubility
What does opioid poisoning cause?
- respiratory depression
- pinpoint pupuls
- coma and respiratory arrest
What are the initial doses of naloxone?
400 mcg IV, 800 mcg IM, 800mcg SC or 2mg IN
What dose of naloxone does large opiate overdose require?
Titration to dose of 10mg
What is the duration of action of naloxone?
45-70min
How long can respiratory depression last for after opioid overdose?
4-5h
What can acute withdrawal from opiates cause?
Sympathetic excess
* pulmonary oedema
* venticular arrhythmia
* severe agitation
What does overdose of benzodiazepines cause?
Loss of consciousness, respiratory depression and hypotension
When can flumazenil be used?
Reverse sedation caused by benzodiazepine overdose where there is no history or risk of seizures
When can use of flumazenil be dangerous?
Can cause significant toxicity (seizure, arrhythmia, hypotension, withdrawal syndrome) in patients with** benzodiazepine dependence** or co-consumption of proconvulsant medications such as TCA’s
What can overdose with TCAs cause?
- hypotension
- seizures
- coma
- life-threatening arrhythmia
How does TCA overdose cause VT?
Cardiac toxicity is mediated by anticholinergic and sodium channel-blocking effects
What are the anticholinergic effects?
- dilated pupils
- dever
- dry skin
- delirium
- tachycardia
- ileus
- urinary retention
What exacerbates hypotension in TCA overdose?
alpha-1 receptor blockade
What should be considered as a treatment for tri-cyclic induced ventricular conduction abnormalities?
Sodium bicarbonate
What can occur in local anaesthetic toxicity?
- severe agitation
- loss of consciousness
- tonic-clonic convulsions
- sinus bradycardia
- conduction blocks
- asystole
- ventricular arrhythmia
What can potentiate toxicity in local anaesthetic overdose?
Pregnancy
Extremes of age
Hypoxaemia
What might patients with cardiovascular collapse and cardiac arrest attributable to local anaesthetic benefit from?
IV 20% lipid emulsion in addition to ALS
give up to three boluses at 5 min intervals until stable or has had up t
Give initial bolus of 1.5mL kg 20% lipid emulsion followed by an infusion of 15ml kg h
What are common stimulants to cause overdose?
Cocaine
Amphetamine
What can happen in stimulant overdose?
- agitation
- symptomatic tachycardia
- hypertensive crisis
- hyperthermia
- myocardial ischaemia with angina
What is an effective 1st line for opiate overdose?
Small doses of benzodiazepine (midazolam, diazepam and lorazepam)
What can reverse cocaine-induced coronary vasoconstriction?
GTN and phentolamine
What can be lifesaving in organophosphate, carbamate or nerve agent poisoning?
Atropine
What doses of atropine may be required in drug induced brady?
2-4mg IV
What are features of severe asthma?
That might suggest a patient is at higher risk of a fatal attack
- a history of near fatal asthma requiring intubation and ventilation
- hospitalisation or ED attendance in the past year
- requiring three or more classes of asthma medications
- increasing use or reliance on b2 agonists
- adverse behavioural or psychological factors
- non-adherence, psychiatric illness, alcohol/drug dependence, learning difficulty
What causes the vast majority of asthma deaths?
Severe bronchospasm and mucous plugging leading to asphyxia
What is the commonest cause of asthma-related arrhythmia?
Hypoxaemia
What are the causes of cardiac arrest in asthma?
- asphyxia
- arrhythmia
- AutoPEEP
- tension pneumothorax
What is the treatment for asthma?
- salbutamol (5mg through an O2 driven nebuliser), repeated or continous dosing may be needed
- nebulised ipatropium bromide (500mcg 4-6 hourly)
- steroids - pred 40-50mg orally or hydrocortisone 100mg 6hrly
- IV magnesium sulfate 2g (8mmol) IV over 20 min
- consider IV salbutamol 250mcg IV slowly when inhaled therapy is not possible- bag-mask ventilation
- following senior advice consider giving aminophylline
oral steroids have a longer half life
If IV salbutamol is used what should you monitor?
Lactate
What is the dose of aminophyline?
5mg kg IV over 20min
followed by infusion of 500-700mcg kg h
maintain concentrations of less than 20mcg l
What can beta 2 agonists and steroids cause?
hypokalaemia
When should tracheal intubation be considered in asthma?
- deteriorating peak flow
- decreasing conscious level/coma
- persisting or worsening hypoxaemia
- deteriorating respiratory acidosis
- severe agitation- confusion and fighting the O2 mask
- progressive exhaustion
- respiratory or cardiac arrest
What is the risk of trying to ventilate an asthmatic without a TT?
gastric inflation due to increased airway resistance
