ALS MODULE 7

Pharmacology

Relates to HLT404C Apply Advanced Resuscitation Techniques

Introduction “There are no studies that addressed the order of drug administration. There is inadequate evidence to define the optimal timing or order for drug administration.” ARC Guideline 11.5 December 2010 page 2. The administration of drugs will almost certainly be used in cardiac arrests and should be prepared and given in accordance with the hospital guidelines and health care protocols whilst awaiting the orders and/or arrival of the doctor.

Introduction Drugs used in cardiac arrest can be

categorised according to therapeutic objectives. •  To increase perfusion pressure and enhance contractility

e.g. Adrenaline •  To correct arrhythmias e.g. Amiodarone •  Restore electrolyte balance e.g. Magnesium, Potassium

Chloride, Calcium Chloride •  To correct acidosis e.g. Sodium Bicarbonate

Specific Resuscitation Drugs Adrenaline Classification:

•  Sympathomimetic Actions:

•  Activates an adrenergic receptive mechanism on affected cells and imitates all actions of the sympathetic nervous system “Fight or Flight”

•  Acts on both alpha and beta receptors and is the most potent alpha receptor activator causing peripheral vasoconstriction, increased heart rate & myocardial contractility

Specific Resuscitation Drugs Adrenaline Dosage:

•  10ml of 1:10,000 solution = 1 mg •  1ml of 1:1000 solution = 1mg

•  add 9mls N/saline to make 1:10,000 •  Can repeat every 3-5 minutes •  No maximum dose

Method of Administration: •  IV/IO/ETT

Specific Resuscitation Drugs Adrenaline Indications:

•  Ventricular Fibrillation/pulseless Ventricular Tachycardia after initial counter shocks have failed (after 2nd shock then after every second cycle).

•  Asystole and electromechanical dissociation (pulseless electrical activity) in initial cycle (then every second cycle).

•  Relief of hypersensitivity reactions to drugs and other allergens – given either IM or SC

Specific Resuscitation Drugs Adrenaline Adverse effects:

•  Tachyarrhythmias •  Severe hypertension after resuscitation •  Tissue necrosis if extravasation occurs •  Other adverse effects such as arrhythmias,

headache and increase in myocardial oxygen demand

Specific Resuscitation Drugs Amiodarone Classification:

•  Antiarrhythmic

Actions: •  Suppresses SA node function •  Decreases speed of conduction through AV node,

refractoriness of AV node •  Prolongs PR, QRS and QT intervals •  Increases the action potential of contractile fibres, e.g.

effects Na, K and Ca channels to slow the speed of conduction system

Amiodarone Dosage:

•  300mg Bolus •  Additional bolus of 150mg could be considered •  Maybe followed by an infusion – refer to local

protocols Method of Administration:

•  Draw up gently/slowly to prevent froth •  Slow push into either IV or IO

Specific Resuscitation Drugs

Specific Resuscitation Drugs Amiodarone Indications:

•  Ventricular Fibrillation (VF) •  Pulseless Ventricular Tachycardia (VT) •  Conscious Ventricular Tachycardia - infusion •  Rapid Atrial Fibrillation and Flutter - infusion

Specific Resuscitation Drugs Amiodarone Adverse effects:

•  Hypotension •  Bradycardia •  Heart Block •  Torsades de Pointes •  GIT disturbances

This is why we give it as a SLOW PUSH

Specific Resuscitation Drugs Calcium Classification:

•  Electrolyte

Actions: •  Essential for normal muscle and nerve activity •  It transiently increases myocardial excitability and

contractility and peripheral resistance. Dosage:

•  5-10mls of 10% calcium solution •  Suggest dilute (20mls N/Saline) to minimise extravasation

effects. Please check your local protocols.

Specific Resuscitation Drugs Calcium Method of Administration:

•  Slow push into either IV or IO Indications:

•  Hyperkalaemia •  Hypocalcaemia •  Overdose of calcium channel blocking drugs

•  e.g. Verapamil, Nifedipine

Specific Resuscitation Drugs Calcium Adverse effects:

•  Increased myocardial and cerebral injury by mediating cell death

•  Tissue necrosis with extravasation •  Rapid IV administration causes flushing, burning

sensation and cardiac arrest

Specific Resuscitation Drugs Lignocaine Classification

•  Antiarrhythmic Actions:

•  Suppresses discharge from ectopic foci by blocking sodium channel, inhibits re-entry arrhythmias that lead to VT/VF

•  Reduces action potential production which results in slowed cardiac conduction

Specific Resuscitation Drugs Lignocaine Dosage

•  1mg/kg body weight Bolus •  Can give additional bolus of 0.5mg/kg

Method of Administration: •  IV /IO/ETT

Indications •  VF and pulseless VT where Amiodarone cannot be

used •  Prophylaxis in the setting of recurrent VF or VT

Specific Resuscitation Drugs Lignocaine Adverse effects:

•  Slurred speech •  Altered consciousness •  Muscle twitching •  Seizures •  Hypotension •  Bradycardia •  Heart block •  Asystole

Specific Resuscitation Drugs Magnesium Classification:

•  Electrolyte •  Antiarrhythmic

Actions: •  Magnesium is an electrolyte essential for membrane stability. •  Hypomagnesaemia causes myocardial hyperexcitability

particularly in the presence of hypokalaemia and digoxin. •  Anticonvulsant

Specific Resuscitation Drugs Magnesium Dosage:

•  Bolus of 5mmol. •  Suggest dilute (20mls N/Saline) to minimise extravasation

effects. •  Infusion (20mmols over 4 hour) Please check your local

protocols

Method of Administration: •  Slow push into either IV or IO •  Infusion

Specific Resuscitation Drugs Magnesium Indications:

•  Torsades de Pointes •  VF/pulseless VT (usually administered when

refractory to defibrillator shocks and a vasopressor) •  Known hypokalaemia •  Known hypomagnesium •  Cardiac arrest from Digoxin toxicity

Specific Resuscitation Drugs Magnesium Adverse Effects:

•  Hypotension •  Bradyarrhythmia •  Respiratory failure •  Muscle weakness •  Flushing

Specific Resuscitation Drugs Potassium Chloride Classification:

•  Electrolyte Actions:

•  Potassium is an electrolyte essential for membrane stability.

•  Low serum potassium, especially in conjunction with digoxin therapy and hypomagnesaemia, may lead to life threatening ventricular arrhythmias.

Specific Resuscitation Drugs Potassium Chloride Dosage:

•  Bolus of 5mmol •  Suggest dilute (20mls N/Saline) to minimise extravasation

effects. Please check your local protocols

Method of Administration: •  Slow push into either IV or IO

Indications: •  Persistent VF due to documented or suspected

hypokalaemia

Specific Resuscitation Drugs Sodium Bicarbonate

•  Use only with adequate ventilation and CPR •  Consider if arrest is over 15 minutes or in known

metabolic acidosis - take an ABG/VBG for pH if no return of spontaneous circulation (ROSC)

•  Prolonged arrest can result in lactic acid build up (acidosis), which can lead to depression of cardiac contractility.

Specific Resuscitation Drugs Sodium Bicarbonate Dosage:

•  1mmol/kg infused over 2-3 minutes then guided by ABG’s or VBG’s

Adverse Effects: •  Metabolic alkalosis, hypokalaemia, hypernatraemia

and hyperosmolality. •  Sodium bicarbonate and adrenaline or calcium

when mixed together may inactivate each other, precipitate and block the IV line.

Specific Resuscitation Drugs Atropine Classification:

•  Anticholinergic Actions:

•  Parasympathetic antagonist that accelerates sinus or atrial pacemakers

•  Increases atrioventricular conduction •  Increases heart rate, •  Conduction & cardiac output

Specific Resuscitation Drugs Atropine Dosage:

•  600mcg – 1mg •  Repeated as necessary every 3-5 min up to a total dose of 3 mg

Method of Administration: •  IV/IO/ETT

Indications: •  Symptomatic bradycardia (see guideline 11.9): -

•  systolic BP < 90 mmHg •  heart rate < 40/min •  ventricular arrhythmia •  heart failure

Specific Resuscitation Drugs Atropine Adverse effects:

•  Tachycardia •  Rebound bradycardia if given too slowly or dose too

small •  Blurred Vision •  Delirium •  Hyperthermia in large doses

Summary Asystole – Adrenaline

VT/VF - Defibrillation +/- Amiodarone

Hyperkalaemic arrest – Bicarbonate and Calcium

Electrolytes – Known/suspected U+E’s imbalance

Protracted arrest/acidosis - Sodium Bicarbonate

Bradycardia - Atropine

ALL FLUSHED WITH 20 - 30MLS OF NORMAL SALINE

http://www.eremotelearning.com.au/moodle/file.php/11/ALS_Flowchart_Adults.pdf

To view PDF file, Click Here

Pharmacology Further Reading/Resources

•  ARC Guidelines December 2010 – Guideline 11.5 and 11.9 www.resus.org.au

•  Australian Injectable Drug Handbook, 4th Edition 2009, SHPA

•  Australian Medicines Handbook 2009 •  Rapid ACLS, Barbara Aehlert, RN. Mosby Inc 2007 •  The Merck Manual Online Medical Library, http://

www.merck.com/mmpe/index.html

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