Drugs used in peri-arrest Flashcards
What is the indication for adenosine?
Paroxysmal SVT
What is the dose of adenosine?
6mg IV bolus
If initial dose of adenosine is not successful, what is the next step?
Give a further rapid bolus of 12mg after a 1-2 minute interval.
Give a third dose of 12 to 18mg after a further 1-2 minute interval.
What is adenosine?
A naturally ocurring purine nucleotide
What does adenosine do?
Blocks transmission through the AV node
Has little effect on other myocardial cells/conduction pathways
What is the half life of adenosine?
10-15 seconds
How should adenosine be given?
Give as a rapid bolus into a fast running IV infusion or followed by a saline flush
What should patients be warned of who are being given adenosine?
Transient, unpleasant side effects- nausea, chest pain, flushing
What is the indication for adrenaline outwith cardiac arrest?
Bradycardia (alternative to pacing)
Anaphylaxis
What is the dose of the treatment for Bradycardia?
adrenaline
2-10mcg min of adrenaline
An adrenaline infusion is also indicated in bradycardia associated with adverse signs and/or risk of asystole, which has not responded to atropine, if external pacing is unsuccessful/ not available
What is the dose of the treatment for anaphylaxis?
500mcg IM
50 mcg IV bolus titrated to effect whilst awaiting infusion
What are the indications for amiodarone in the peri-arrest period?
- control of HD stable monomorphic VT, polymorphic VT and wide-complex tachycardia of uncertain origin
- to control a rapid ventricular rate caused by an accessory pathway conduction in pre-exited atrial arrhythmias (AF) to achieve chemical cardioversion
- after unsuccessful electrical cardioversion to achieve chemical cardioversion or to increase the likelihood of further electrical cardioversion succeeding
What is the dose of amiodarone?
300mg IV over 10-60 min
Followed by an infusion of 900mg over 24h
What does amiodarone do?
Has effects on sodium, potassium and calcium channels as well as alpha- and beta-adrenergic blocking properties
What is preferable to other anti-arrhythmic drugs for atrial and ventricular tachyarrhythmias in patients with impaired heart function?
Amiodarone
What are the major adverse effects of amiodarone?
Hypotension and bradycardia
Caused by the solvent
Can be off-set by slowing infusion
Why should amiodarone be inserted into a CVC?
It causes thrombophlebitis when infused into a peripheral vein
Can be done in an emergency
What is the indication for aspirin?
ACS
What is the dose for aspirin?
300mg orally
crushed or chewed ASAP
What does aspirin do?
Improves the prognosis of patiets with acs
Anti-platelet activity and preventing early platelet thrombus formation
What is the indication for atropine?
Sinus, atrial or nodal bradycardia or AV block when the HD condition of the patient is unstable because of the bradycardia
What is the dose of atropine?
Repeated doses to a max of 3mg
What does atropine do?
Antagonises the action of parasympathetic neurotransmitter acetylcholine at muscarinic receptors
Blocks the effect of the vagus nerve on both the SA node and the AV node, increasing sinus automaticity and facilitating AV node conduction
What are the side effects of atropine?
Blurred vision, dry mouth, urinary retention, acute confusion
Dose dependent
Why is atropine not used in asystole/PEA?
It is usually caused by myocardial pathology rather than excessive vagal tone
no evidence that it works
What is the indication for beta-blockers?
Narrow-complex regular tachycardias not responding to vagal manoevres or adenosine in patients with preserved ventricular function
To control rate in atrial AF and atrial flutter when ventricular function is preserved
What are the options for beta blockers
atenolol
metoprolol
propranolol
esmolol
How to beta-blockers work?
Reduce the effects of circulating catecholamines and decrease heart rate and blood pressure
Cardioprotective effects for patients with ACS
What are the side effects of beta-blockers?
Bradycardia, AV conduction delay, hypotension and bronchospasm
What are the contraindications of beta-blockers?
second or third degree heart block and hypotension
used in extreme caution in patients with severe congestive heart failure and lung disease associated with bronchospasm
What is the dose for atenolol
5mg IV over 5 minutes, repeated if necessary after 10 minutes
What is the dose for metoprolol?
2.5mg IV at 5 minute intervals to a total of 15mg
What is the dose for propranolol?
100mcg kg IV slowly in three equal doses at 2-3 min intervals
What is the dose for esmolol?
IV loading dose of 500mcg kg over 1 min
What is the indication for verapamil?
Stable regular narrow-complex tachycardias uncontrolled or unconverted by vagal maneovres or adenosine
To control ventricular rate in AF or AFlutter and preserved ventricular function when the duration of the arrhythmia is less than 48h
What is the dose of verapamil?
2.5mg-5mg IV over 2 minutes
In the absence of therapeutic response or induced adverse event give repeated doses of 5-10mg every 15-30 min to a maximum of 20mg
What does verapamil do?
Calcium channel blocker that slows down conduction and increases refractoriness in the AV node
What might verapamil achieve?
Terminate re-entrant arrhythmias and control the ventricular rate and response rate in patients with atrial tachycardias (including AF and AFlutter)
Who should be given IV verapamil?
Patients with narrow-complex paroxysmal SVT or arrhythmias known with certainty to be supraventricular in origin
What might giving a patient with a ventricular tachycardia verapamil do?
Kill them
What might giving a patient with severe ventricular dysfunction do?
Decrease cardiac contractility and critically reduce cardiac output
Kill them
What is the indication for digoxin?
AF with fast ventricular response
What is the dose of digoxin?
250mcg-500mcg IV over 30 min
What is digoxin
Cardiac glycoside
What does digoxin do?
Slows ventricular rate by decreasing vagal tone, decreasing sympathetic activity by suppressing baroreceptors, prolonging AV node refractory period
What is the indication for vasopressors and inotropes
Hypotension in the absence of hypovolaemia
Cardiogenic shock
What are the doses of noradrenaline and dobutamine?
NA: 0.05mcg kg-1 min-1
DM: 5-20mcg kg-1 min-1
What is usually the treatment for myocardial dysfunction and inflammatory response after cardiac arrest?
noradrenaline and dobutamine
What are the effects of noradrenaline?
Potent vasoconstrictor but also a positive inotropic effect
What are the efects of dobutamine?
Inotropic and beta-agonist (increases heart rate and causes vasodilatation)
What is the indication for magnesium?
Digox tox
Polymorphic VT (torsades)
What is the dose of magnesium?
2g IV over 10 min
What does magnesium do?
Facilitates neurochemical transmission
Decreases acetylcholine release and reduces the sensitivity of the motor endplate
What are the indications for nitrates?
Prophylaxis or relief of angina
Unstable angina
MI
Acute and chronic left ventricular failure
What is the dose of GTN
1-2 doses of sublingual 300mcg tablet or 400mcg spray
What is the dose of a GTN infusion
10-200 mcg min
What is the dose of an isosorbide dinitrate infusion
2-10mg H
What is the mechanism of nitrates?
After conversion to nitric oxide, nitrates cause vascular smooth muscle relaxation
More marked on venous circulation than arterial and this reduces left ventricular diastolic pressure that is responsible for relieving angina
Also dilate the coronary arteries and relieve spasm in coronary smooth muscle
When are nitrates contraindicated?
Hypotension systolic <90
