Drugs in Emergencies

7/27/2019 Drugs in Emergencies

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Drugs in Emergencies

Dr U I HapuarachchiDepartment of Surgery

Faculty of Medicine, Galle


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Learning objectivesAt the end of this lecture, you should be

able to demonstrate; Commonly used drugs

Indications

Routes of administration

Common adverse effects


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ContentVasoconstrictors

Anti-arrhythmic drugs

Inotropes

Vasodilators Opioid antagonists


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Adrenaline 1 mg/ml

1:1000 concentration

Brown colour ampoule

Mode of Action

& effects


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AdrenalineIndications

Cardiac arrest VF or Pulseless VT -iv

Anaphylaxis im or iv

Inotrope - iv

Laryngospasm - nebulization

Local infiltration with LAvasoconstrictor


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AdrenalineDose 1:1000 im anaphylaxis

1:10000 iv Anaphylaxis & cardiac arrest 1:200000 infiltration

0.05-0.5 g/kg/min - infusion

Side effects

myocardial O2 consumption

heart rate

Pro arrhythmic


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Vasopressin

20 iu/ml 1 ml clear ampoule

Mode of action Smooth muscle V1 receptor stimulation

Intense vasoconstriction

Indications

Septic shock resistant to other vasoconstrictors

Variceal bleeding


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VasopressinDose

0.03 iu/min as an infusion in sepsis

20 iu over 15 min in variceal bleeding

Side effects

Headache

Myocardial and peripheral ischaemia

Nausea & vomiting


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Amiodarone 150 mg/ml 2 ml ampoule

Brown colour ampoule

Mode of Action

Membrane stabilizing anti-arrhythmic duration of action potential & refractory period

Mild negative inotrope

blockage


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AmiodaroneIndications

VF or pulseless VT cardiac arrest just before4th shock

Unstable tachycardia (narrow/broad complex)

Stable broad complex tachycardia

Stable narrow complex tachycardia


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Amiodarone

Dose

300 mg bolus diluted in 20 ml of 5% Dextrose

(unstable- 10-20 min, stable 20-60 min) 900 mg infusion over 24 hours

Side effects

Hypotension & bradycardia

Prolonged use photosensitivity, abnormal thyroidfunction, peripheral neuropathy, pulmonary fibrosis,

hepatic dysfunction


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Atropine 1 mg/ml or 0.6 mg/ml vial

Clear colour ampoule

Mode of action

Blocks the parasympathetic neurotransmitteracetylcholine (anti-muscarinic)


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AtropineIndications

Cardiac arrest Asystole of PEA Bradycardia

With neostigmine in reversal of muscle paralysis

Antisialogogue


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AtropineDose

0.5 mg iv

0.02 mg/kg in reversal

Side effects Blurred vision, dry mouth

Urine retention

Acute confusion state


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Adenosine 3 mg/ml vial 2 ml

Mode of action

Naturally occuring purine nucleoside

transmission across AV node Extremely short half life 10-15 sec


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Adenosine

Indications

Stable narrow complex tachycardia notterminated by vagal maneuvers

Can be given in undiagnosed VT

If SVT - ventricular rate

If VT no change in ventricular rate


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Adenosine

Dose

6 mg > 12 mg > 12 mg in SVT

Side effects

Negative inotrope hypotension Nausea, flushing

Chest discomfort

Bronchospasm


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Verapamil

2.5 mg/ml 2 ml vial

Mode of action Slows conduction / refractoriness in AV node

Indications Stable narrow complex tachycardia not

terminated by vagal maneuvers / adenosine

Control of ventricular rate in patients with AF

or Atrial flutter


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Verapamil

Dose

2.5-5 mg iv over 2 min

Repeat 5-10 mg every 15-30 min

Maximum < 20 mg

Side effects

Headache, flushing

Hypotension due to myocardial contractility


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Digoxin

250 g/ml 2 ml vial

Mode of Action

vagal tone

sympathetic activity by suppression of

baroreceptors

Prolong AV node refractory period


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Digoxin

Indications

AF with fast ventricular rate

Side effects

Nausea, diarrhoea, anorexia Confusion, dizziness


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Digoxin

Toxicity increased by

Hypokalaemia

Hypomagnesaemia

Hypoxia

Hypercalcaemia

Renal failure

hypothyroidism


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Dobutamine

Mode of Action

1, 2 effects

Indications

Inotrope of choice in post resuscitation Useful when pulmonary oedema is

present


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Dobutamine

Dose

5-20 g/kg/min as infusion

Side effects

Tachycardia Arrhythmias

Exacerbate myocardial ischaemia


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Noradrenaline

Mode of action

Potent agonist

Mild effect

Indications Severe hypotension with low peripheral vascular

resistance

Septic shock


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Noradrenaline

Dose

0.05-0.5 g/kg/min as infusion

Side effects

Headache

Bradycardia

Arrhythmias

Peripheral ischaemia


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Dopamine

D1, D2, 1, 1 &2 effects

Dose 1-20 g/kg/min

Renal dose Dopamine ?

Indicated for hypotension in the absenceof hypovolaemia

May cause cardiac arrhythmias, myocardial O2 demand & worsen

ischaemia


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Naloxone

Used for opiate overdose

Competitive antagonist at opioid

receptors

Reverses all effects of opioids

Duration of action < opioids

Need frequent boluses or infusion

400 g/ml 1 ml vial


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Others

Calcium chloride

Ephedrine

Magnesium sulphate

Sodium bicarbonate

Beta adrenergic blockers Nitrates


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References

Bennett PN, Brown MJ.

Chapter 22- Adrenergic mechanisms & Drugs. ClinicalPharmacology- 9thEdition Pg 447-455

Bennett PN, Brown MJ.

Chapter 24- Cardiac arrhythmias & Cardiac failure. ClinicalPharmacology- 9thEdition Pg 497-513

Richards D, Aronson J.

Anti-arrhythmic drugs. Oxford Hand Book of Practical DrugTherapy Pg 77-103

Richards D, Aronson J.Adrenoceptor agonists & Anti-muscarinic Drugs. Oxford HandBook of practical Drug Therapy Pg 190-199

http://www.resus.org.uk

Guidelines, medical information & reports > Resuscitation

Guidelines 2005 > Adult & paediatric Advanced life Support
http://www.resus.org.uk/http://www.resus.org.uk/


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Thank You

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Drugs in Emergencies