Cardiac Arrest Flashcards
what is cardiac arrest
effective cessation of heart, no circulation and oxygen delivery
how do you recognise cardiac arrest
unresponsive patient, not breathing normally, no pulse
what is SaO2 or its indirect measurement SpO2
concentration of oxygen bound to haemoglobin in arterial blood
what is the formula for oxygen delivery
DO2= SaO2 x [Hb] x O2cc (carrying capacity of Hb) x Co (HR x SV)
what rhythms are shock able
ventricular fibrillation and pulse-less ventricular tachycardia
what does cardiac arrest often preceed
hypoxia and hypotension
what are the core standards for cardiac arrest
- recognise deterioration EARLY and prevent if possible
- arrest recognised early and CPR started immediately
- help summon as soon as arrest recognised
- defibrillation if appropriate, within 3 mins
- appropriate post arrest care
how do you increase SaO2 (SpO2)
increase FiO2, clear airway, maintain adequate breathing
how do you increase [Hb]
transfusion trigger, treat anaemia
how do you treat low HR
atropine or B-stimulant (ephedrine)
how do you treat decreased pre load
IV fluid, raise lags
how do you treat low contractility
treat cause e.g. PCI for MI
how do you treat excess afterload
vasodilators (get this in e.g. high BP)
how do you treat reduced after load
vasoconstrictors (get this in e.g. septic shock)
how do you asses SaO2
pulse oximetry, ABG
how do you assess [Hb]
FBC
how do you assess HR
pulse, pulse oximeter, ECG monitor, arterial BP monitor
what are the two main component affecting BP
cardiac output and total peripheral resistance
what can cause airway obstruction
CNS depression- tongue
lumen blocked- blood, vomit, forgein body
swelling- trauma, infection, inflammation
muscle- laryngospasm, bronchospasm
how can you recognise airway obstruction
talking, difficulty breathing, distressed, choking, shortness of breath, stridor, wheeze, gurgling, see-saw respiratory pattern, accessory muscles
how is an airway obstruction treated
airway opening (head tilt chin lift, jaw thrust, suction)
simple adjuncts/ advanced techniques (tracheal tube)
oxygen
what can cause breathing problems
airway problems,
decreased resp drive (CNS depression),
decreased resp effort (muscle weakness, nerve damage, restrictive chest defect, pain from fractured ribs)
lung disorders (pneumothorax, haemothorax, infection, COPD exacerbation, asthma, PE, ARDS)
what are the clinical signs of breathing problems
resp distress, accessory muscles, cyanosis, resp rate, chest deformity, conscious level, noisy breathing, expansion, percussion, tracheal position
what are the primary causes of circulation problems
Acute coronary syndromes Dysrhythmias Hypertensive heart disease Valve disease Drugs Hereditary cardiac diseases Electrolyte / acid base abnormalities Electrocution
what are the secondary causes of circulation problems
Asphyxia Hypoxaemia Blood loss Hypothermia Septic shock
what are the clinical signs of circulatory problems
distress, pallor, organ perfusion (chest pain, mental state, urine output), BP, HR, cap refill, bleeding, fluid losses, JVP, CVP
how is disability in ABCDE treated
ABC then treat underlying cause
-e.g. blood glucose
consider recovery position
check drug chart
what happens in exposure in ABCDE
Remove clothes to enable thorough examination (to avoid missing causes of problems)
avoid heat loss and maintain dignity
whats haematoma
solid swelling of clotted blood within the tissues
what is respiratory arrest
unresponsive, not breathing but have pulse
how is a-systole and PEA treated
adrenaline 1mg IV ASAP, every 3-5 mins after and CPR
what heart rhythms are not shockable
a systole, pulseless electrical activity
describe VF on an ECG
irregular, no recognisable QRS complex, random frequency and amplitude
is ventricular fibrillation shockable
yes
describe ventricular tachycardia on an ECG
two types
monomorphic VT- broad complex rhythm, rapid rate, constant QRS morphology
Polymorphic VT- torsade de pointes
when is VT shockable
when it is pulseless
what is a precordial thump
rarely effective, used only if defibrillator not immediately available and in witnessed and monitored VF/VT cardiac arrest
what is defibrillation
use of electrical current to reset heart electrical rhythm with hope that regular rhythm will recur
when should amidarone be given and what does it do
during CPR after 3 shocks- anti arrhythmic drug
what effect does adrenaline have
alpha vasoconstriction
beta inotropic
what are the potentially reversible causes of cardiac arrest
four H’s and four T’s
- hypoxia
- hypovolaemia
- hypo/hyper-kalaemia/ metabolic
- thrombosis- coronary or pulmonary
- tension pneumothorax
- tamponade
- toxins
what is avoiding hyperventillation
ensuring that large volumes and high rates are not used as these will increase intrathoracic pressure, decreasing venous return and coronary perfusion
how can an airway be secured
tracheal tube, supraglottic airway device
what is a risk of mask to mouth and self inflating bag ventilation
gastric inflation, risk of inadequate ventilation
what extra advantage does a self inflating bag have
allows oxygen supplementation (up to 85%)
what is ROSC
return of spontaneous circulation
what is post cardiac arrest syndrome
brain injury, myocardial dysfunction, systemic ischaemia/ re-perfusion response, persistent precipitating pathology
when can therapeutic hypothermia be used
unconscious adults with ROSC should be cooled to 32-37 degrees
