Cardiopulmonary Resuscitation - Lecture Notes

Cardiopulmonary Resuscitation CPR • The aim is the return of spontaneous circulation • This restores oxygen delivery to the tissue e.g heart, lungs and brain • This ensures that the brain receives adequate levels of oxygen to function • Dogs have < 5% chance of survival • Cats have < 10% chance of survival this us because they are smaller so efforts are more successful • However 47% survival in animals under sedation as they have adequate monitoring and oxygen levels being delivered • RECOVER initiative: REassessment Campaign On VEterinary Resuscitation Context of CPR • What leads to cardiac arrest • H’s = Hypoxia, Hypovolaemia, Hydrogen ions, Hyper/HypoK+, Hypothermia and Hypoglycaemia • T’s = Toxins, Tamponade, Tension pneumothorax, Thromboembolism, Trauma and Tachycardia • Consequences of cardiac arrest: 1. No oxygen delivery 2. Reserves exhaustion 3. Vital organs begin to fail 4. Non reversible if cells die • Recognising cardiopulmonary arrest: 1. Loss of consciousness in an awake patient 2. Apnea 3. No palpable pulse 4. Loss of instrumental monitoring and abnormalities • Crash box needs to be prepared: 1. Intubation = ET tubes, laryngoscope and tube tie 2. Injections = Pre filled saline flush syringes, Adrenaline and Atropine • Staff should undergo regular training • In a crash box you can add algorithms and drug charts • One person should take the lead and be open to suggestions from the team CPR steps 1. Identify and initiate: • Check for pulse and heart rate • HELP • Take note of the time when starting CPR • Turn off the vaporiser • Antagonise any drugs that can be • Start basic life support 2. Basic life support: • C = Blood CIRCULATING? Begin chest compressions • A = Is the AIRWAY patent? Clear airway and intubate • B = Is the patient BREATHING? Begin ventilating 3. Advanced life support: • D = DRUGS • E = ECG • F = FLUIDS 4. After care: • Reflect on mistakes and discuss why the animal arrested and what you did • Stabilise the patient with respect to cardiovascular and respiratory systems and look at any electrolyte imbalances • Treat consequences with respect to neurological and traumatic Chest compressions • Position = Lateral or dorsal recumbency • Technique = Can use one or two hands to compress making sure elbows are locked. 100 compressions per minute is a guideline and must allow the chest to recoil in between compressions Airways • If the patient is not intubated clear the airways and secure an ET tube • If they are intubated then check the position of the tube to see if it has been dislodged and check the tube is patent Ventilation • Equipment = Ambubag, anaesthesia machine and fresh supply of oxygen • Guideline of 4-10 breaths per minute and allow for a recoil so there is no risk for hyperventilation Assessment of basic life support • Continue for at least 2 minutes as stopping increases chance of death and it takes about 2 minutes to get the blood moving again after it has stopped • After 2 minutes assess: 1. Check for pulse 2. No pulse → restart compressions 3. Pause for as short as possible Drugs • First stop any undesired drugs by antagonising them if possible • Aims: 1. Pool the blood towards the vital organs 2. Correction of arrhythmias 3. Increase rate and contractility of the heart • Intravenous = Flush after with 20mls of saline • Intratracheal = Give up to 10x the normal dose and dilute with 5-10ml saline • Intraosseus = Good choice in collapsed animals • Never directly administer drugs into the heart • Adrenaline = Adrenergic 𝛼 and β agonist causes vasoconstriction and increases rate and contractility. usually uses a dose of 0.01 mg/kg • Atropine = Anticholinergic antagonises the vagal nerve and increased heart rate. Dose is usually 20-40 𝜇g/kg • Lidocaine = Sodium channel blocker that decreases the heart rate and dose rate us usually 0.1ml/kg ECG • Interpretation of cardiac rhythm • Identification of ventricular tachycardia • Rhythm is not cardiac output • Asystole = Use adrenaline • Pulseless electrical activity = Use adrenaline • Ventricular tachycardia = Use Lidocaine • Bradycardia = Use atropine • Can use capnography which confirms if the ET tube placement is correct and provides effectiveness of CPR • Precordial thump = hard slap over the hear and then immediately followed by compressions Fluids • 10ml/kg colloid • 20ml/kg crystalloid