Lecture 19 11/19/24 Flashcards
What are the rates of perioperative fatality in different species?
dogs: 0.17%
cats: 0.24%
horses: 0.9%
What are the stats on patients that are revived with CPR outside of anesthetic events?
less than 6% survive to discharge
What are the stats on patients that are revived with CPR during an anesthetic event?
50% of dogs survive to discharge
What is the easiest way to be prepared for cardiopulmonary arrest?
well stocked, well organized crash cart
What can lead to a delay in CPR?
-missing equipment
-failure to do preventative maintenance
-equipment failure
How long of a delay in starting CPR can lead to a huge decrease in survival?
10 to 20 seconds
In addition to a good crash cart, how else can veterinary professionals prepare for CPR?
-learn on manikins
-undergo standardized training
-have one confident leader during CPR
-have one individual per job during CPR
-debrief following CPR about what did and did not go well
What are the characteristics of CPA recognition?
-early diagnosis is crucial
-eval. should only take 5-10 seconds
-start CPR immediately in unresponsive, apneic patients
-risk of CPR in animals not in CPA is minimal; better to start CPR than do a lengthy assessment
How can CPA be recognized on monitoring tools?
-loss of pulse on doppler
-stair-step waveform on EtCO2
What are the characteristics of chest compression set up?
-airway management and ventilation should not delay start
-place most patients in lateral, barrel-chested dogs in dorsal
-cardiac pump in cats and pointed chest dogs
-thoracic pump in other dog breeds
What percent of cardiac output is achieved with chest compressions?
20%
What is the purpose of the cardiac pump mechanism?
directly compress heart
What is the purpose of the thoracic pump mechanism?
rely on elastic recoil of chest to move blood
How should chest compressions be carried out?
-100 to 120 compressions/minute
-1/3 to 1/2 of thorax compressed with each compression
-2 minutes uninterrupted
-no leaning on patient; reduced coronary and cranial partial pressures
What are the characteristics of open chest CPR?
-better than closed chest CPR in patients with pulmonary or cardiac disease
-must make decision to do open chest CPR promptly
-intra-abdominal procedures can cut through diaphragm to perform open chest CPR
-must be prepared to manage open chest
What are the characteristics of airway management and ventilation during CPR?
-does not take priority over starting chest compressions
-must intubate in lateral
-want 10 breaths/minute with a tidal vol. of 10 ml/kg
-inspiratory time should last for 1 second
What are the characteristics of compressions and ventilation when there is a single rescuer?
-neck is extended
-30 compressions to 2 breaths
-no evidence for use, but no harm
Which monitoring steps are preferred in CPR if available?
-EtCO2
-ECG
-doppler
-electrolytes
What are the characteristics of EtCO2 during CPR?
-verification of tracheal intubation
-effectiveness of compressions
-sudden rise in EtCO2 correlates with return of spontaneous circulation
-want measurement of 18mmHg or higher for dogs and cats
What are the characteristics of ECG during CPR?
-susceptible to artifact
-used to guide advanced therapy/defibrillation
-brief interruption during CPR changes to evaluate ECG
What are the ECG rhythms of death and their shockability?
-asystole: not shockable
-pulseless electrical activity: not shockable
-pulseless ventricular tachycardia: shockable
-ventricular fibrillation: shockable
What are the characteristics of defibrillation?
-prompt shocking of shockable rhythms has greater chance of ROSC
-will always do 2 minutes of compressions before a shock
-CPA greater than 4 minutes requires compressions/basic life support first
What are the three phases of myocardial ischemia?
-electrical: 4 minutes
-circulatory: 6 minutes
-metabolic
How does a biphasic defibrillator differ from a monophasic?
-monophasic sends electricity through chest once; biphasic sends electricity twice
-biphasic requires less energy
-biphasic causes less myocardial damage
How does defibrillator energy dose differ with each shock?
increase dose by 50% with each subsequent shock
Which drugs are used in advanced life support?
-vasopressors
-parasympatholytics
-IV fluid therapy
-anti-arrhythmics
-reversal agents
How can emergency drugs be administered?
-IV if access is obtained
-intra-osseus
-intra-tracheal
Which emergency drugs can be delivered via the trachea?
-naloxone
-atropine
-vasopressin
-epinephrine
-lidocaine
What are the characteristics of vasopressors?
-cause high peripheral vascular resistance
-divert blood from the limbs to the viscera
-include epinephrine and vasopressin
What are the characteristics of epinephrine?
-vasopressor acting at alpha1
-inotropic/chronotropic acting at beta1
-inotropic/chronotropic function harmful; increases heart rate and heart O2 requirements
-only recommended in low doses
What are the characteristics of vasopressin?
-vasopressor acting at V1
-no chronotropic or inotropic effects
-works better than epinephrine in an acidic environment
-used in place of or in combo with epinephrine
What are the characteristics of atropine?
-no evidence for benefit or detriment
-higher dose associated with worse outcome
-drug of choice for CPA with high vagal tone
What are the characteristics of fluid therapy during CPR?
-indicated in cases with hypovolemia
-not recommended in euvolemic/hypervolemic cases
-improper admin. can oppose blood delivery to brain and heart
What are the characteristics of amiodarone?
-non-selective class III anti-arrhythmic
-used for resistant pulseless v-tach and v-fib
What are the characteristics of lidocaine?
-class 1B anti-arrhythmic
-consider in pulseless v-tach or v-fib resistant to shock and amiodarone
What are the characteristics of magnesium?
-currently not part of RECOVER guidelines
-increasing number of case reports indicating magnesium helps in CPR cases
Which reversal agents are considered in CPR?
-naloxone
-flumazenil
-atipamazole
-turn off vaporizer, disconnect patient, and flush to remove inhalants
What are the characteristics of hypocalcemia?
-calcium is necessary for muscle contraction and cell communication
-not routinely administered
-replace calcium in moderate to severe hypocalcemia cases
What are the characteristics of hyperkalemia?
-common in prolonged CPA
-improved outcome when treated with hemodialysis
-recommended to treat
What are the characteristics of corticosteroid use in CPR?
-lack of evidence
-not recommended for routine use
-adverse effects outweigh benefits
-should be used in patients arresting due to Addison’s disease
-can delay ROSC and alter vascular tone
What are the characteristics of sodium bicarb?
-thought to promote alkalosis in acidotic patients
-can make patient more acidotic if not ventilating well
-evidence of worse outcome in early CPR
-used in CPR that goes longer than 10-15 minutes
What are the characteristics of oxygen therapy?
-want FiO2 of 100%
-maximize PaO2 in face of decreased CO
-hypoxemia and reactive oxygen species can prevent ROSC
-target PaO2 of 85-100mmHg
