CARDIOPULMONARY RESUSCITATION Flashcards
Common precipitants of cardiorespiratory arrest?
75% are cardiac:
Arrhythmia e.g. VF, PEA and asystole
Coronary artery abnormalities
MI
Myocardial hypertrophy e.g. HOCM
Valvular heart disease
Inflammatory heart diseases
Dilated cardiomyopathy
Inherited disorders e.g. brugada syndrome
HF
Congenital heart disease
25% respiratory
Airway obstruction e.g. Bronchospasm or severe asthma/COPD
PE
Respiratory muscle weakness e.g. due to spinal cord injury
Shockable and non-shockable rhythms
Shockable: pulseless VT, VF
Non-shockable: asystole, PEA
What is ROSC/
Return of Spontaneous circulation
How can cardiac arrests be prevented?
Healthy diet
Not smoking
Keeping bp healthy
Low alcohol
Healthy weight
Exercise
Optimisation of medical conditions
What is the chain of survival?
A series of action that, when properly executed, reduce the mortality associated with cardiac arrest
What are the 4 links in the chain of survival?
Early recognition and call for help
Early CPR
Early defibrillation
Early advanced cardiac life support
Where should a pt who has had a cardiac arrest be looked after in the hospital?
ICU or coronary care unit
Outline ALS first few steps before shock/meds?
Check its safe to approach
Check carotid pulse and look for breathing.if not…
CPR 30:2 attach defibrillator
Call resuscitation team!
Assess rhythm
What 3 factors in ALS are said to improve survival rates?
Performing high quality CPR, defibrillation asap and reducing hands off time to <5 seconds per cycle
What should you do in thr ALS scenario when you identify a pt with a shockable rhythm e.g. VF or pulseless VT?
Give 1 shock with minimum interruption
Immediately resume CPR for 2 minutes
Then assess rhythm again
Continue this until you have return of spontaneous circulation or you have given 3 shocks
Why is it important to have minimal time off the chest before giving a shock?
You want to keep the heart from dilating and this will make it mnore responsive to the shock
If the arrest team deliver 3 shocks to the pt and the pt is still in a shockable rhythm what drugs should be administered?
Adrenaline 1mg 1 in 10,000 ever 3-5 minutes
Amiodarone 300mg single dose
What drugs do you give in a non-shockable rhythm?
Adrenaline 1mg 1 in 10,000
What is adrenaline?
An endogenous catecholamine hormone and neurotransmitter in the sympathetic nervous system
Usually synthesised in the adrenal medulla .
Moa of adrenaline?
An alpha and beta adrenoreceptor agonist
In cardiac arrest…
Alpha 1 and 2 - vasoconstriction
Beta 1 - positive chronotropic and inotropic effects
Cautions for adrenaline?
IHD
cerebrovascular disease
Diabetes
Hypertension
Hyperthyroidism
Hypokalaemia
Hypertension
Palpitations
Tissue necrosis
Metabolic acidosis
Note: not applicable to emergencies as pt is already dead!
Interactions with adrenaline?
Amitrypriline - Increased effects of adrenaline
Beta blockers - causes severe hypertension
MAOI - hypertensive crisis
How do you give adrenaline?
1mg IV using 1 in 10,000 solution followed by 20ml flush of 0.9% NaCl
Why is there a risk of severe hypertension when beta blockers and adrenaline interact?
Beta blockers prevent adrenaline from acting on beta receptors in the heart but don’t prevent it from acting on alpha receptors in the body so the vasoconstrictive effects of adrenaline on alpha receptors can predominate
This causes severe narrowing of blood vessels without the compensatory vasodilatory effects normally produced by beta receptor activation = hypertension
What drug class is amiodarone?
Class 3 anti-arrhythmia
MOA of amiodarone?
Inhibits K+ channels involved in repolarisation which prolongs the cardiac action potential and delayed the refractory period
Why is amiodarone used instead of lidocaine now in ALS/
As amiodarone does not drop the bp like lidocaine did!
What are the challenges of amiodarone?
In complete oral absorption
Large volume of distribution
Extremely long Half-life
This means it needs a large loading dose of up to 3-6 weeks to load!
Side effects of amiodarone?
Hypo/hyperthyroidism
Hepatitis
Interstitial lung disease and pulmonary fibrosis
Corneal micro deposits
N&V
Taste disturbance
Light-sensitive blue-grey discolouration
Bradycardia, heart blocks, dysrhythmias, prolonged QT interval
Epididymitis
Monitoring for a pt on amiodarone?
TFTs
LFTs
If IV then ECG
Contraindications for admiodarone?
Severe cardiac conduction disturbances (unless they have a pacemaker fitted)
Thyroid dysfunction
Iodine sensitivity
Severe respiratory failure
Circulatory collapse
Interactions with amiodarone? And what are the effects?
BB, CCB, digoxin - bradycardia
Lithium, ondansetron - prolonged QT
Steroids, thiazide diuretics, loop diuretics - hypokalaemia
Statins - rhabdomyolysis
Phenytoin - peripheral neuropathy
Warfarin - increased bleeding
How do you manage a stable SVT?
Vagal manouvres
Adenosine 6mg rapid IV bolus. If no effect give 12mg. If no effect give a further 12 mg.
Monitor ECG continuously
If sinus rhythm is achieves then probable re-entry paroxysmal SVT.
If not achieved then seek expert help and consider possible atrial flutter
MOA of adenosine?
Conduction time is decreased by inducing potassium efflux and inhibiting calcium influx through channels in nerve cells, leading to hyperpolarization and and increased threshold for calcium dependent action potentials. Decreased conduction time leads to an antiarrhythmic effect.
Contraindications of adenosine?
Asthma/COPD
Decompensated HR
Long WT/AV block/sick sinus syndrome
?wolf parkinsons white
Severe hypotension
Interactions with adenosine?
Dipyridamole can increase adenosine exposure
Aminophyline/theophylline can decrease adenosine efficacy
Some local anaesthetic agents - can cause cardio depression
SE of amiodarone?
Headaches
Dizziness/syncope
Apprehension / sensation of impending doom
Sweating and flushing
Blurred vision
Metallic taste
Angina, arrhythmias, AV block
Hypotension
N&V
Bronchospasm, dyspnoea, resp failire
Tx for sinus bradycardia if haemodynamically stable?
If no risk of asystole e.g. recent asystole, mobitz II etc then continue obersvation
If any risk of asystole then give atropine 500mcg IV and repeat to a maximum of 3mg
Tx for sinus bradycardia if haemodynamically unstable?
Atropine 500mcg IV
If no satisfactory response repeat to a maximum of 3mg OR transcutaneous pacing OR isoprenaline/adrenaline/alternative
MOA of atropine?
Muscarinic antagonist which increases firing of the SAN by blocking the actions of the vagus nerve on the heart
Side effects of atropine?
Dry eye/blurry vision
Dizziness or drowsiness
Dry mouth
Flushing
Headache
N&V
Tachycardia
Constipation
Skin reactions
Urinary retention
Contraindications of atropine?
Any GI obstruction, urinary retention and myasthenia gravis
Interactions with atropine?
Anything with antimuscarinics moa e.g. TCA, muscarinic antagonists, antihistamines, antipsychotics,
Phenylephrine - can cause severe hypertension
Levodopa - can decrease levodopa’s absorption
Tx of anaphylaxis?
Remove allergen if possible
IM adrenaline 0.5ml 1 in 1000 - can be repeated every 5 minutes
After stabilisation: may give non-sedation oral antihistamine
Advice to pt on using an epipen?
Any symptoms -> use epipen
“Blue to sky orange to thigh” - use dominant hand, take blue cap off, can go through clothing, go into outside of thigh and count to 10
Remove and rub the thigh for 10 seconds
Go to A&E after using epipen
Lie on floor with legs in the air if you can tolerate it
Advise them not to get up too fast as bp will drop
Give epipen to ambulance drivers. Get new one at A&E
If Sx dont get better after 5-10 minutes then use second epipen - can be done in either leg
Investigations post cardiac arrest?
CXR
Frequent 12 lead ECGs
Potassium and lactate on VBG/ABG
CTPA or echocardiogram
USS chest
