Emergency Medicine Flashcards
(237 cards)
causes of shock?
CHOD
Cardiogenic:
MI, arrhythmia
hypovolaemic:
haemorrhage- internal/ external
endocrine- addisionian crisis, DKA
excess loss- burns, diarrhoea, vomiting
third-spacing- pancreatitis
obstructive:
PE, tension pneumothorax, cardiac tamponade
distributive:
sepsis, anaphylaxis, neurogenic
mx of shocked patient?
if ECG unrecordable, mx as a cardiac arrest
->
ABCDE approach
->
raise foot of bed (unless cardiogenic)
->
IV access: 2 wide bore cannula in each Antecubital fossa
->
fast infusion of crystalloid to raise BP (unless cardiogenic)
initial monitoring of a shocked patient?
catheter to measure urine output
(>30ml/hr)
arterial line- monitor blood pressure directly and in real-time
central venous pressure line-
blood pressure in the venae cavae, near the right atrium of the heart. CVP reflects the amount of blood returning to the heart and the ability of the heart to pump the blood back into the arterial system.
what is anaphylactic shock?
type 1 IgE mediated hypersensitivity reaction
TH2 driven IgE production following primary allergen exposure
re exposure -> biphasic inflammatory response
early phase: mast cell degranulation -> histamine release
late phase: amplify and sustain the initial response
presentation of anaphylactic shock?
skin: urticaria, itching, oedema
breathing: wheeze, laryngeal obstruction, cyanosis
GI: D+V, abdo pain
sweating
CVS: tachycardia, hypotension
mx of anaphylactic shock
secure airway: give 100% O2
- consider intubation if respiratory obstruction
elevate the feet
IM adrenaline 0.5ml of 1:1000 (0.5mg)
- repeat every 5 min if needed
Secure IV access: IV 0.9% saline (500ml over 15 min)
IV 10mg chlorphenamine
IV 200mg hydrocortisone
Salbutamol nebs if wheeze
- 5mg salbutamol + 0.5mg ipratropium
discharge advice for anaphylaxis patient
teach adrenaline self-injection and ensure pt has at least 2 epipens
advise wearing medic alert bracelet
advice re recognition and avoidance
arrange outpatient followup: skin prick tests, RAST to identify antigens
what is the definition of a supraventricular tachycardia?
rate > 100 beats/min
QRS width < 120 ms
start from atria/ AV node
types of SVT
Sinus tachycardia
Atrial:
AF, Atrial flutter, atrial tachycardia
AV nodal re-entry tachycardia (AVNRT)
AV re-entry tachycardia (AVRT): e.g. Wolff-Parkinson-White
What is AVRT?
Atrioventricular re-entrant tachycardia
a type of SVT
e.g. WPW
electrical signal passes in the normal manner from the AV node into the ventricles
the electrical impulse pathologically passes back into the atria via the accessory pathway (e.g. bundle of Kent), causing atrial contraction, and returns to the AV node to complete the reentrant circuit
-> may cause heart to beat faster

SVT Mx
if patient is compromised?
sedate + DC cardioversion
otherwise ID rhythm and treat accordingly
pt compromised
ie. MI, syncope, hypotension (shock), heart failure
SVT Mx?
ID rhythm ?
irregular -> treat as AF
regular?
SVT = Start with Vagal Treatment
(e.g. carotid sinus massage, valsalva)
if unsuccessful,
ABCD
adenosine while recording continuous rhythm strip
-> 6mg IV bolus, then 12mg, 12mg
then
choose from:
Beta Blockers: e.g. atenolol
CCB e.g. Verapamil
Digoxin
Amiodarone
SVT mx if all medical treatment fails?
DC cardioversion
SVT mx if adverse signs develop
ie. BP <90, heart failure, decreased consciousness, HR> 200?
Sedation
Synchronised Cardioversion
then
Amiodarone: 300 mg over 20-60 min
then 900mg over next 23 h
what are vagal manoeuvres meant to do in SVT mx?
decreases HR by stimulating vagus nerve
transiently increases AV block and may unmask underlying atrial rhythm
Giving adenosine in SVT mx?
what would it do
transient AV block -> unmasking atrial rhythm
cardioverts AVRT/AVNRT to sinus rhythm
Mode of action of adenosine?
temporary AV node block
Side effects of adenosine?
transient chest tightness, dyspnoea, flushing, headache
relative contraindications of adenosine?
asthma,
2nd/3rd degree heart block
in what type of SVT will you avoid the usual treatment pathway?
ie. Adenosine, CCB, BB
WPW
hx of WPW or AF/flutter with WPW
-> may lead to VF
Use amiodarone or flecainide
mx of AF?
onset <48h consider cardioversion w amiodarone or DC shock
Rate control: BB e.g. metoprolol or digoxin
Anticoagulation with heparin/ warfarin
prophylaxis of SVTs?
BB
AVRT: Flecainide
AVNRT: verapamil
Definition of broad complex tachycardias?
rate > 100bpm
QRS width >120 ms
types of broad complex tachycardias?
VT
Torsades de pointes
SVT w BBB



