Chapter 12: Resuscitation in Special Circumstances Flashcards
What happens to potassium in acidosis?
- Serum K+ increase as it moves from cells to serum
- H+/K+ pump
How is hyperkalaemia defined and what classifies as severe?
K+>5.5 mmol/L
Severe >6.5 mmol/L
What can cause hyperkalaemia?
- Renal failure
- Acidosis
- DKA
- Drugs - Spironolactone, ACEi, amiloride, ARB, NSAID’s, B blockers, trimethoprim
- Endocrine - Addison’s disease
- Tissue breakdown - rhabdomyolysis, TLS, haemolysis
How may hyperkalaemia present?
Arrhythmia
Weakness - flaccid paralysis, paraesthesia, depressed tendon reflexes
What ECG changes do you see with hyperkalaemia?
- Absent/small p waves
- Prolonged PR
- Wide QRS
- Can see ST segment depression
- S and T merging
- Tall tented T waves
- VT
- Bradycardia
- Cardiac arrest
How is hyperkalaemia treated?
- STOP DRUGS/K+ fluids
- IV Calcium chloride - 10ml/10% over 2-5 mins
- Insulin/Dextrose - 10 units in 250ml of 10% 15-30min
- Sodium bicarbonate - 50mmol IV bolus - severe acidosis or renal failure
- Salbutamol nebulised 10-20mg
- Dialysis
- K+ binder - calcium resonium 15-30g or Sodium Polystyrene Sulfonate
What do you do for each stage of hyperkalaemia?
Mild: 5.5-5.9
1. Address cause
2. Calcium resonium or sodium polystyrene sulfonate
Mod: 6.0-6.4
1. Insulin dextrose
2. As above
Severe: 6.5+
1. Expert help
2. Calcium chloride
3. Shifting agents
4. Remove K+ - dialysis
What are the main risks associated with hyperkalaemia treatment?
- Hypoglycaemia - monitor BM
- Tissue necrosis - secondary to extravasation of intravenous calcium salts - Ensure secure vascular access
- Intestinal necrosis and obstruction - K+ exchange resin - avoid prolonged use and give laxative
- Rebound hyperkalaemia - after drug treatment warn off - monitor for at least 24hr
What is important to know about cardiac arrest in haemodialysis patients?
- Sudden cardiac death most common cause
- Usually ventricular arrhythmia
- Stop ultrafiltration, give fluid and return pt blood volume
- Disconnect dialysis machine
- Use dialysis access for drugs
- Early defib
How is hypokalaemia defined?
- < 3.5mmol/L
- Severe = < 2.5mmol/L
What can cause hypokalaemia?
- GI losses
- Alkalosis
- Drugs - loop diuretics, thiazides, laxatives, steroids
- Renal losses
- Cushings/hyperaldosteronism
- Mg depletion
- Poor intake
- Overtreated High K+
How can you recognise hypokalaemia?
- R/O in all arrhythmia/cardiac arrest
- Seen at end of haemodialysis or in peritoneal dialysis
- Symptoms: Fatigue / Weakness / Leg cramps / Constipation
- If severe: Rhabdomyolysis / Ascending paralysis / Resp difficulties
What ECG features are seen in hypokalaemia?
- ST segment changes
- Small T waves
- U waves
- Arrhythmia
- Cardiac arrest
How should K+ be replaced?
- Gradually
- Max 20mmol/L per hour
- More rapid infusion indicated in unstable arrhythmia - 2mmol/L/min for 10 mins then 10mmol over 5-10 mins
What can cause hypercalcaemia?
- Primary/tertiary hyperparathyroidism
- Malignancy
- Sarcoid
- Drugs
How does hypercalcaemia present?
- Abdo pain
- Hypotension
- Weakness
- Confusion
- Arrhythmia
- Cardiac arrest
What ECG changes are seen in hypercalcaemia?
- Short QT
- Wide QRS
- Flat T waves
- AV block
- Cardiac arrest
How is hypercalcaemia treated?
- Fluid replacement
- Furosemide - 1mg/kg
- Hydrocortisone 200-300mg
- Pamidronate 30-90mg
- Rx underlying cause
What can cause hypocalcaemia?
- Chronic renal failure
- Pancreatitis
- CCB OD
- Toxic shock syndrome
- Rhabdomyolysis
- TLS
How does hypocalcaemia present?
- Paraesthesia
- Tetany
- Seizures
- AV block
- Cardiac arrest
What ECG changes are seen for hypocalcaemia?
- Prolonged QT
- T wave inversion
- Heart block
- Cardiac arrest
What can cause hypermagnasaemia?
- Renal failure
- Iatrogenic
How does hypermagnasaemia present?
- Confusion
- Weakness
- Resp. depression
- AV block
- Cardiac arrest
What ECG changes are seen for hypermagnasaemia?
- Prolong PR
- Prolonged QT
- T wave peak
- AV block
- Cardiac arrest
How is hypermagnasaemia managed?
- Calcium chloride 10ml 10%
- Saline diuresis - furosemide 1mg/kg + 0.9% saline
- Ventilatory support if req.
- Haemodialysis
What can cause hypomagnasaemia?
- GI loss
- Malabsorption
- Starvation
- Alcohol
- Polyuria
How does hypomagnasaemia present?
- Tremor
- Ataxia
- Nystagmus
- Seizures
- Arrhythmia - torsades
- Cardiac arrest
How does hypomagnasaemia present on ECG?
- Flat p waves
- Prolong PR and QT
- Wide QRS
- ST depression
- T wave inversion
- Can get polymorphic VT - torsades
How is hypomagnasaemia managed?
- 2g 50% MgSo4 (4ml 8mmol/L)
- severe = over 15 mins
- torsades = over 1/2 mins
- Seizure = over 10 mins
How is septic shock defined?
- Lactate > 4mmol/L
- Hypotension unresponsive to fluid resus
50% mortality
What are the common causes for mortality in poisoning?
- Airway obstruction and respiratory arrest secondary to decreased conscious level - early tracheal intubation
- Drug induced hypotension - usually respond to IV fluids but may need vasopressor support
Electrolytes, BM and ABG’s should be checked as they commonly cause mortality
What modifications are required to resus in poisoning?
- Avoid mouth to mouth breathing in presence of cyanide, hyrogen sulphide, corrosives and organophosphates
- Check for hypo/hyperthermia
- Focus on correcting hypoxia, hypotension, acid/base and electrolytes
- Be prepared for long resus time and consider ECLS
- Seek expert advise and consult TOXBASE
What specific treatments are available for poisoning?
- Removal of clothes - skin exposure
- Gastric lavage and laxatives NOT used
- Activated charcoal - < 1hr and intact airway
- Whole bowel irrigation using polyethylene glycol
- Sodium Bicarb IV
- Haemodialysis
- Specific antidotes
Activated Charcoal (QuiT CPD) - carbamazepine, dapsone, phenobarbital, quinine and theophylline
Polyethylene glycol - sustained release/enteric coated drugs, oral iron poisoning, removal of ingested packets illicit drugs
Soda Bic - salicylate poisoning
Haemodialysis - Drugs with LMW, low protein binding, small VoD, high H2O solubility
What is the specific antidote for paracetamol?
1.N-acetylcysteine
What is the specific antidote for organophosphate poisoning?
- High dose atropine
What is the antidote for cyanide poisoning?
- Hydroxocobalamin
- 50% mortality thiosulphate
- Sodium nitrite
- Amyl nitrite
What is the antidote for digoxin poisoning?
- Digibind - digoxin specific Fab antibodies
What is the antidote for benzodiazepines?
- Flumazenil if no risk of seizure
What is the antidote for opioid poisoning?
-
Naloxone 400mcg IV, 800mcg IM, 800mcg SC or 2mg Intranasal
2.Non IV may be quicker - save time getting access - Duration of action not as long as respiratory depression persist- give increments until breathing adequately
What does opioid poisoning cause?
- Pinpoint pupils
- Resp depression
- Resp. arrest - Coma
What happens if opioids are withdrawn acutely in poisoning?
State of sympathetic excess leading to complications:
1. Severe agitation
2. Pulmonary oedema
3. Ventricular arrhythmia
Use naloxone cautiously in patients with dependence
What can a benzodiazepine OD cause?
- LOC
- Resp depression
- Hypotension
What can reversal of benzodiazepine OD with flumazenil lead to in patients with dependence or have coinjested pro-convulsants?
- Withdrawal syndrome
- Seizure
- Hypotension
- Arrhythmia
Is flumazenil used in comatose patients?
No
What can tricyclic antidepressant OD cause?
- Anti-cholinergic effects - mydriasis, fever, dry skin, delirium, tachycardia, ileus, retention
- Life-threatening arrhythmia - commonly shockable
- Hypotension
- Seizure
- Coma
What may indicate that a TCA overdose will lead to arrhythmia?
- Wide QRS
- Right axis deviation
Rx - Consider sodium bicarb
When can you get local anaesthetic toxicity?
- Regional anaesthesia - enters artery or vein
What issues can you get with local anaesthetic toxicity?
- Severe agitation
- LOC
- With or without tonic-clonic convulsions
- Sinus Bradycardia/ Conduction blocks/Asystole/VT
How can local anaesthetic toxicity be treated?
- Resus measures
- IV 20% lipid emulsion
- Initial 1.5mL/kg bolus in 1 min
- Give up to 3 boluses at 5 min intervals
- Followed by 15mL/kg/hr infusion
- Max 12mL/kg emulsion
What should you do following lipid emulsion rescue for local anaesthetic toxicity?
- Exclude Pancreatitis - daily amylase or lipase assays for 2 days
- Safe. transfer to clinical area
- Report cases to National Patient Safety Agency
What can cocaine toxicity cause?
Sympathetic overstimulation:
1. Agitation
2. Hyperthermia
3. Symptomatic tachycardia
4. Hypertensive crisis
5. Myocardial ischaemia with angina
What can be done to treat cocaine toxicity?
- Small dose IV benzo (midazolam, diazepam, lorazepam)
- GTN and phentolamine - reverse coronary vasoconstriction
- Can consider beta blockers and anti-arrhythmics - best unclear
- If arrest - use normal adreanline dose
How is drug induced severe bradycardia managed?
- Atropine - organophosphate, carbamate, nerve agent poisoning or acetylcholinesterase inhibitors
- 2-4 mg IV repeated doses
What can be used to treat bradycardia due to beta blockers or calcium channel blockers?
- Can use Isoprenaline at high dose if refractory bradycardia due to beta blockers
- Inotropes
- Vasopressors
- Calcium
- Glucagon
- Phosphodiesterase inhibitors
- High dose insulin-dextrose-potassium infusions