CPR Flashcards
Discuss the logistical and ethical considerations of cardiopulmonary resuscitation in dogs and cats
Consider survival to discharge, often very low
Consider the cause of arrest, can we quickly correct the cause? If not, likely to rearrest
Causes trauma during resuscitation the longer it goes on
Is there any end-stage disease going on? Not good canditate
Prior health and reason for arrest (ie. anaesthesia vs. multi-organ failure)
Define respiratory arrest and cardiopulmonary arrest and explain how each can be diagnosed in a clinical situation
Respiratory arrest = not breathing, but does have cardiac function
Cardiorespiratory arrest = sudden cessation of spontaneous and effective respiration and heart beat
Three most common types of cardiac arrest in animals are asystole, pulseless electrical activity and ventricular fibrillation
Discuss the factors affecting survival rates following treatment of true cardiopulmonary arrest
The cause of the arrest, if anaesthetic arrest then high chance of recovery, same with hypovolaemia and hypothermia if can correct the initial cause. If cause due to SIRS or other, not as good an outcome.
Asystole is the most common cause of cardiac arrest in animals
List the factors that predispose to cardiopulmonary arrest and explain how each contributes to its development
Heart becomes unable to pump effectively
Hypoxaemia of tissues
List the clinical signs of cardiopulmonary arrest
Not breathing
No heartbeat
Describe the approach to management of an arrest situation and explain what each step is designed to achieve
Airway - assess the airway, intubate and inflate cuff, designed to provide high concentration of oxygen to the patient but also reduce risk of aspiration, and can also use for admin of intratracheal drugs if cannot gain iv access
Breathing - breathe for the patient at rate of 8-12 per minute , tidal volume of 10-15ml/kg, cautious not to overinflate during CPR ,
Circulation - generate adequate blood flow to reach the main target organs (myocardium via coronary arteries and brain via cerebral) 100bpm
List common drugs used for the management of cardiopulmonary cerebral resuscitation
Adrenaline (epinephrine) first line drug
Vasopressin / ADH
Atropine
Lidocaine
Naloxone
Adrenaline
indications, contraindications, interactions and how they can be administered.
Indicated in bradyarrhythmias, asystole, Vfib or hypotension during CPA
Low dose indicated, high dose not recommended for routine use due to increased incidence of post-rescus complications (hyperglycaemia, hyperkalaemia, cardiac dysrhythmias and myocardial necrosis)
Alpha and beta adrenergic effects (fairly equal, vs. noradrenaline which is stronger alpha than beta, so not as much effect on cardiac contractility),
alpha is most useful - an intense peripheral vasoconstriction -> increase mean arterial BP , increased aortic diastolic BP and therefore increased coronary perfusion pressure
Beta effect include increase HR and myocardial contractility and improves cerebral perfusion by vasodilating cerebral vasculature
Can be given IT (give 5-10x the dose and mix with 10ml water or saline)
Vasopressin
indications, contraindications, interactions and how they can be administered.
Non-adrenergic hormone
Decreases renal blood flow and urine output
In slightly higher doses it causes vasoconstriction in peripheral tissue beds
Increases myocardial and cerebral blood flow without the positive inotropic and chronotropic effects of adrenaline
Longer onset of action than adrenaline
Long half life in circulation (17-35 mins)
May be more useful than adrenaline in asystolic arrest
Can be given IT (5-10X THE DOSE)
Atropine
indications, contraindications, interactions and how they can be administered.
Parasympatholytic
Atropine is a prototype antimuscarinic drug, meaning that it blocks muscarinic receptors, which are acetylcholine receptors in all effector cells of the parasympathetic nervous system (i.e., cells of muscles, glands, or organs that can respond to a nerve impulse). The heart is supplied with parasympathetic and sympathetic nerves. The parasympathetic nerves (also known as vagi) are mainly attached to the sinus and atrioventricular nodes of the heart.14 When stimulated, vagi release acetylcholine at their vagal ending. Acetylcholine decreases the (1) rate of the sinus node and (2) excitability of the atrioventricular junctional fibers, thus decreasing the cardiac impulse to the ventricles.14 This is also known as a vagal response. Vagal stimulation slows the heartbeat, and excessive stimulation can stop it entirely. Atropine inhibits acetylcholine at postganglionic parasympathetic neuroeffector sites, which helps to stop the vagal response.
Tx of sinus bradycardia or to counteract increased vagal tone
Recommended for use in combo with adrenaline in patients that have been treated with opiates or anaesthetic agents prior to arrest
Can be given IT
Lidocaine
indications, contraindications, interactions and how they can be administered.
Not indicated in Vfib as may increase the defibrillation threshold and make electrical defib more difficult
May be indicated for post-arrest ventricular tachycardia although amiodarone or procainamide are first line treatments
Naloxone
indications, contraindications, interactions and how they can be administered.
Opiate antagonist
Will counter the myocardial effects of endogenous opiates
Endogenous opiates are thought to play a role in depressing myocardial contractility which may lead to the generation of pulseless electrical activity
May also have mild direct vasoconstrictive , anti-arrythmic and positive inotropic effects.
Can be given IT
Drugs that can be given intra-tracheal during CPR
Naloxone
Atropine
Vasopressin
Epinephrine
Lidocaine
Explain the importance of defibrillation in successful resuscitation and the limitations of performing cardiopulmonary cerebral resuscitation without a defibrillator
Electrical defibrillation is indicated in patients suffering from ventricular fibrillation (VF) (Figure 5) or pulseless ventricular tachycardia (VT), and has been shown to significantly improve ROSC in these patients.6
If you dont have a defibrillator then try a precordial thump
Describe the pathophysiological consequences of cardiopulmonary arrest on the function of various organs
Hypoxaemia, significant effect on the brain and heart, and kidneys, blood pressure effect on the kidneys, below 60?
Lactic acid buildup from hypoxaemic cells
Trauma from chest compressions, and cardiac myocardial damage
Some degree of hemodynamic instability related to vasopressor therapy during CPR or the underlying cause of CPA
Cardiac ischemia
Systemic inflammatory response syndrome (hallmarked by inflammatory system activation and excess circulating cytokines)
Anoxic brain injury.
