Acute Care - Arrest, Brady and Tachy

Question 1

where are pacemaker cells found?

Answer 1

SA node

Question 2

what happens in pacemaker cells?

Answer 2

decreased K efflux + increased Na influx

then Ca influx causes the spike

once at the top, K efflux increases and Ca influx decreases

Question 3

what happens in ventricular muscle cells?

Answer 3

increased Na and Ca influx

plateau occurs, Na channels close

after this, Ca influx increases and K efflux occurs

Ca channels close and K efflux continues

Question 4

what can cause bradycardia?

Answer 4

hyperkalaemia
BBB
heart block
physiological

Question 5

Tx for bradycardia?

Answer 5

observe if no adverse features

500mcg IV atropine (repeat up to 6 times)

can give adrenaline IV

transcutaneous pacing

Question 6

how does atropine work?

Answer 6

inhibits muscarinic actions (parasympathetic)

Question 7

what are causes of tachy - broad vs narrow?

Answer 7

narrow =
atrial flutter
AF
re entrant SVT

broad =
AF + BBB
VT
SVT +BBB

Question 8

what is the Tx for narrow QRS, regular rhythm tachycardia?

Answer 8

vagal manouvres

adenosine 6mg IV

Question 9

how does adenosine work?

Answer 9

activates K channels to hyperpolarise and cause delay between AV node

Question 10

what is the Tx for narrow QRS, irregular rhythm tachycardia?

Answer 10

probably AF

Bblocker/CCb
or
digoxin/amiodarone if HF

Question 11

what is the Tx for broad QRS, regular rhythm tachycardia?

Answer 11

probably VT

amiodarone 300mg IV

Question 12

what is the Tx for broad QRS, irregular rhythm tachycardia?

Answer 12

AF with BBB - treat alike narrow complex

polymorphic VT - magnesium 2mg

Question 13

4H’s of cardiac arrest?

Answer 13

Hypovolaemia
Hypothermia
Hypo/hyperkalaemia
Hypoxia

Question 14

4T’s of cardiac arrest?

Answer 14

Tension pneumothorax
Thrombus
Tamponade
Toxins

Question 15

what is the specifications of good chest compressions?

Answer 15

30:2
100-120 a min
5-6cm depth

Question 16

what are the shockable rhythms?

Answer 16

VF

pulseless VT

Question 17

when and what drugs are given during CPR?

Answer 17

adrenaline 1mg IV every 3-5 mins (alternate shocks)

30mg amiodarone after 3 shocks

Question 18

how long should CPR be done for between shocks?

Answer 18

2 mins

Question 19

how is paediatric CPR done?

Answer 19

head tilt after 1yr

5 rescue breaths: 15 compressions

Question 20

when is adrenaline given if it is confirmed to be a non shockable rhythm?

Answer 20

as soon as

Question 21

if a non shockable rhythm, what is the CPR pathway?

Answer 21

recheck every 2 mins

regive adrenaline every 3-5mins