Peri-arrest and Second Line Drugs Flashcards
Action of atropine
Anticholinergic muscarinic receptor blocker
Blocks action of vagal nerve on the heart
Reduces refractory period of SA and AV node, increasing rate of discharge and enhancing conduction
Indications of atropine
Severe bradycardia with haemodynamic compromise
NO LONGER RECOMMENDED ASYSTOLE
Dosage of atropine
Symtomatic bradycardia 0.5-1mg
Dosage of atropine (paediatric)
20mcg/kg
40mch/kg ETT
Administration atropine
IV or IO bolus
can repeat every 3-5 minutes
Max 3mg
Administration atropine (paediatric)
IV or IO bolus
can repeat evert 5 minutes
Max 600mcg
Contraindications of atropine
Glaucoma
Adverse effects of atropine
Anticholinergic effects
Dries secretions
Urinary retention
Dilated pupils
Hyperthermic (large doses)
Delirium
Excitement
Tachycardia
Atropine considerations
Doses given too slowly or <0.5mg in adults can cause transient paradoxical slowing of heart rate and may cause arrythmias
Avoid large doses in coronary patients as excessive tachycardia can occur, aggravating myocardial ischemia and/or precipitating ventricular arrythmias
Action of lignocaine
1b antiarrhythmic
Sodium channel blocker, reducing action potential, slowing cardiac conduction
also LA effect
Indications of lignocaine
Failure of defibrillation and adrenaline to revery pulseless VT/VF
Can be used as prophylaxis in setting of recurrent VT/VT
Conscious VT
Dosages of lignocaine
1mg/kg
0.5mg/kg may be considered as additional bolus
2mg/kg ETT
administered between 3rd and 4th shock
Dosages of lignocaine (paediatric)
1mg/kg
2mg/kg ETT
Administration of lignocaine
IV/IO bolus 25-50mg/min
Max 300mg
Adverse effects of lignocaine
Hypotension
Bradycardia
Heart block
Seizures
Asystole
Slurred speech
Altered consciousness
Muscle twitching
Action of magnesium
Smooth muscle relaxation and cell membrane stabilisation through inhibition of calcium channels resulting in reduced intracellular calcium
Indications of magnesium
Torsades de Pointes
Hypomagnesaemia (particularly when associated with hypokalemia)
Documented hypokalemia
Cardiac arrest due to digoxin toxicity
May be requested in event of defib and adrenaline failure to revert VF and pVT
Dose of magnesium
5mmol - can repeat once
Dose of magnesium (paediatrics)
0.1-0.2mmol/kg
Administration of magnesium
IV/IO bolous
consider 10-20mmol infusion over 1-2hr per electrolytes
Administration of magnesium (paediatrics)
IV/IO bolus
followed by 0.3mmol/kg infusion
Contraindications of magnesium
AV blocks
Magnesium toxicity
Adverse effects of magnesium
Muscle weakness
Respiratory depression/fatigue
Hypotension
Magnesium considerations
1g calcium gluconate to reverse hypermagnesemia
Action of potassium
Essential for stability of cell membranes
Indications of potassium
Persistent VF/VT due to documented hypokalemia
Hypomagnesemia
Dosage of potassium
5mmol
Dosage of potassium (paediatric)
0.05mmol/kg
Administration of potassium
Slow IV or IO bolus
Contraindications of potassium
N/A
Adverse effects of potassium
Hyperkalemia
Bradycardia
Hypotension
Tissue necrosis with extravasation
Action of sodium bicarbonate 8.4%
Alkalizing solution, combines hydrogen ions to form carbonic acid to reverse acidosis
Indications of sodium bicarbonate 8.4%
Hyperkalemia
Documented metabolic acidosis (pH<7/0 or BE>-10,,ol/L)
Overdose of tricyclic antidepressants or phenobarbitone
Protracted cardiac arrest lasting >15minutes
Dosage of sodium bicarbonate 8.4%
1mmol/kg
Dosage of sodium bicarbonate 8.4%
1mmol/kg
Administration of sodium bicarbonate
IV/IO bolus over 2-3min
Then as guided by ABG usually pH<7.1
Administration of sodium bicarbonate (paediatrics)
IV/IO bolus over 2-3min
Then as guided by ABG usually pH<7.1
Contraindications of sodium bicarbonate
Nil
Adverse effects of sodium bicarbonate
Hypernatremia and hyperosmolality
Hypokalemia
Paradoxical cerebral acidosis
Depressed cardiac contractility
Metabolic alkalosis shifts O2/hb curve to left
Sodium bicarbonate considerations
INCOMPATIBLE WITH ALL OTHER DRUGS - requires dedicated IV line in the prolonged arrest >15min
May be indicated after confirmation of severe acidosis (ABG)
Action of calcium
Electrolyte essential for normal muscle and nerve activity
Increases myocardial excitability, contractility and peripheral resistance
Indication of calcium
Hyperkalemia
Hypocalcaemia
Overdose of calcium-channel blockers
Hypermagnesiumaemia
Dosage of calcium
5-10ml of 10% calcium chloride or calcium gluconate
Dosage of calcium (paediatric)
0.2ml/kg of 10% calcium chloride OR
0.7ML/KG OF CALCIUM GLUCONATE
Administration of calcium
IV/IO bolus (adults and paediatrics)
Contraindications of calcium
N/A
Adverse effects of calcium
Possible increased myocardial and cerebral injury by mediating cell death
Tissue necrosis by extravasation
Calcium considerations
Incompatible with range of drugs - may precipitate in IV lines
Action of isoprenaline
Acts exclusively on beta-adrenergic receptors
B1 effects include increased cardiac contracility and heart rate
B2 effects include bronchodilation and vasodilation
Indications of isoprenaline
Symptomatic bradycardia - particularly when originating below AV node
AV blocks unresponsive to atropine
Pharmacological pacing in Torsades de points
Dosage of isoprenaline
Bolus 20mcg - 60mcg
Infusion 0.5-10mcg/min
Dosage of isoprenaline (paediatric)
Bolus not recommended
Infusion 0.05-2mcg/kg/min
Isoprenaline infusion
3mg in 50ml 5% dextrose
OR
6mg made up to 100ml 5% dextrose = 60mcg/ml
Administration routes of isoprenaline
IV/IO adults and paeds
Contraindications of isoprenaline
N/A
Adverse effects of isoprenaline
Tachyarrhythmia
Hypotension - diastolic BP may fall due to reduction in peripheral vascular resistance
Myocardial iscaemia
Considerations of isoprenaline
Sometimes referred to as “pharmacological pacing”
Use continuous cardiac monitoring when administering
Action of adenosine
Depresses node activity, slowing conduction AV nod, causing transient AV block, interrupting re-entry circuit - allows restoration normal sinus rhythm
Indications of adenosine
SVT - acute treatment
Diagnostic aid for broad and narrow complex tachycardia
Wolfe Parkinson White Syndrome
Dosage of adenosine
Initial: 3mg rapid IV bolus
If unsuccessful after 1-2min: rapid 6mg bolus
If unsuccessful after 1-2min: rapid 12mg bolus
Dosage of adenosine (paediatric)
All ages
1st dose 0.1mg/kg (max 6mg)
2nd 0.2mg/kg (max 12mg)
3rd 0.3mg/kg (max 12mg)
Administration of adenosine
IV/IO bolus (adults and paeds)
Administer into large IV cannula rapid IV bolus
followed by rapid N/S flush
Contraindications of adenosine
N/A
Adverse effects of adenosine
Bradycardia
Chest pain
Dizziness
Nausea
“Impending doom”
Facial flushing
Headache
Considerations of adenosine
ECG during drug administration is required due to transient AV block determining atrial activity