PBL extra LOs Flashcards
what is cardiac arrest
Sudden & complete loss of CO due to asystole, VT or VF, or loss of mechanical
cardiac contraction - breathing may take some time to stop
what are the 2 non-shockable rhythms
asystole; pulseless electrical activity (PEA)
most common cause of cardiac arrest
CAD leading to catastrophic arrhythmia
what causes fatalities in MI
pts susceptible to VT/VF in first few hours of an MI leading to death; previous MI leads to scarring which increases risk of sudden fatal arrhythmias (esp if LV scarring)
Defib steps (10)
- CPR and air to be given (30:2) ratio, defib pads placed on;
- CPR stopped, rhythm assessed, VF or pulseless VT should be treated w immediate defibrillation;
- CPR restarted, everyone else clear
- pads charged;
- CPR move away, make sure everyone else is clear;
- administer shock;
- CPR immediately restarted
- After 2 mins, pulse not restored, further biphasic shock of 150-200joules should
be given; - Thereafter, additional biphasic shocks of 150-200 joules are given every 2
minutes after each cycle of CPR; - adrenaline should be given evert 3-5 mins and IV amiodarone considered after successful defib
how should PEA be treated
by continuing CPR & adrenaline
administration while seeking causes.
reversible causes of cardiac arrest (5hs, 4Ts)
Hypoxia, Hypovolaemia, Hypo/hyperkalaemia, Hypothermia, (Hydrogen ions → acidosis);
Toxins, Tamponade, Tension pneumothorax, Thrombosis (MI), (Thromboembolism (PE))
most common cause of PEA
hypovolaemia (fluid loss e.g. blood)
what is syncope
A transient loss of consciousness due to cerebral hypoperfusion
(inadequate blood flow to brain) characterised by a rapid onset,
short duration and spontaneous complete recovery
how does syncope occur
rapid drop in systemic BP/bradycardia -> decreased blood flow to brain -> decreased O2 perfusion -> LOC
types of syncope (3)
reflex/natural; orthostatic hypotension; cardiac causes
what is natural syncope + examples
Reflexes that control blood pressure and heart rate suddenly and spontaneously malfunction, rapid recovery;
Vasovagal syncope - Orthostatic vasovagal (standing up too quickly), Emotional Vasovagal (fear/phobia); Situational Syncope; Syncope after defecation/swallowing and
coughing; Carotid Sinus Syndrome (Excessive
pressure on carotid artieries)
what is orthostatic hypotension syncope + examples
postural hypotension, low blood pressure that happens when standing after sitting or lying down;
Volume Depletion (due to haemorrhage, vomiting and diarrhoea); Autonomic Failure - Primary (Old age, Parkinson’s), Secondary (diabetes, amyloidosis, post exercise); Drug Induced (Vasodilators, diuretics, anti depressants); Neurological (epilepsy, TIA, Stroke)
what is cardiac caused syncope + examples
syncope caused by cardiac conditions;
Arrhythmia (Bradyarrhythmia, Tachyarrhythmia); Structural Defect (Aortic Stenosis, Prosthetic valve, dysfunction, Myocardial infarction); Great Vessel Defect (pulmonary embolus, Acute Aortic dissection)
signs of syncope
Light headed; Pallor; Sweating; Nausea; tunnel vision; cold clammy sweat
