Exam 1 - CPCR 2.0

Question 1

T/F: currently, survival to discharge following cardiopulmonary arrest (CPA) in veterinary species is <6% if not associated with anesthesia; survival for anesthetic-related CPA approaches 50%

Answer 1

true

Question 2

what is the most common underlying cause in veterinary medicine leading to CPA?

Answer 2

multi-organ dysfunction causing high vagal tone - leads to arrest

Question 3

what is the most common etiology resulting in arrest? what are some other etiologies?

Answer 3

hypoxemia

anemia, arrhythmias, cerebral trauma, & anaphylaxis

Question 4

what common signs are associated with arrest?

Answer 4

agonal breathing & apnea followed by collapse

Question 5

why does respiratory arrest carry a better prognosis than cardiopulmonary arrest? which is more commonly encountered?

Answer 5

the heart continues beating for a short period of time following to the development of apnea

cardiopulmonary arrest is more common

Question 6

what is the mechanism of cardiopulmonary arrest?

Answer 6

cessation of cardiac contractions

Question 7

what is the most commonly encountered rhythm in patients with CPA?

Answer 7

asystole

Question 8

what is asystole?

Answer 8

no electrical or mechanical activity of the heart

Question 9

what is pulseless electrical activity?

Answer 9

occurs when there is still electrical activity in the heart but these impulses don’t stimulate contractions - complexes generated can appear as sinus beats or escape rhythms

Question 10

when is ventricular fibrillation seen in veterinary patients?

Answer 10

rare - association with CPR, cardiac disease, or anesthesia

Question 11

how can you differentiate between ventricular tachycardia & pulseless electrical activity?

Answer 11

if the heart rate is greater than 180 bpm - v tach

if the heart rate is less than 180 - PEA

Question 12

what is the pathogenesis of CPA at 20 seconds, 5 minutes, & 30 minutes?

Answer 12

20 seconds - electrical activity within the brain is compromised due to lack of oxygen for high energy metabolism

5 minutes - complete depletion of ATP stores within the body

30 minutes - irreversible histological changes within cells are identified

Question 13

what is phase I of ventricular fibrillation?

Answer 13

first 4 minutes - little to no ischemic damage to myocardial cells

Question 14

why is phase I (electrical phase) of ventricular fibrillation most successful for defibrillation?

Answer 14

little to no ischemic damage to myocardial cells

Question 15

what is phase II of ventricular fibrillation?

Answer 15

circulatory phase - next 6 minutes, reversible damage occurs within the cardiac myocytes

Question 16

why is CPR recommended during phase II of ventricular fibrillation?

Answer 16

provide oxygen to the patient prior to defibrillation - if no CPR, patients suffer increased damage & are likely to fibrillate again even if successful the first time

Question 17

what is phase III of ventricular fibrillation?

Answer 17

metabolic phase - fibrillation that has occurred greater than 10 minutes

irreversible ischemic damage to the myocardium & defibrillation is typically unsuccessful

Question 18

the fundamentals of CPR focus on what 2 things?

Answer 18

improving perfusion to the heart & brain

identifying/addressing the underlying cause of the arrest

Question 19

what is needed on a CPR team?

Answer 19

leader, compressors, ventilator, drug administrator, recorder/timer, & someone to obtain a history

Question 20

what are the 2 most important pieces of equipment that should be immediately attached to a coding patient?

Answer 20

ECG & ETCO2

Question 21

why is an ECG important for a coding patient?

Answer 21

essential for rhythm diagnosis between compressors & helps determine next therapeutic course of action

Question 22

what therapy is indicated for non-shockable rhythms? what about shockable rhythms?

Answer 22

non-shockable: epinephrine & compressions

shockable: defibrillation & compressions

Question 23

what are the non-shockable rhythms?

Answer 23

asystole & PEA

Question 24

what ETCO2 measurement is considered to correlate with effective compressions? what if this isn’t achieved?

Answer 24

15 mmHg

efficiency of compressions should be evaluated for proper rate, depth, compression point, & posture

Question 25

T/F: while not all patients will achieve an EtCO2 of >15 mmHg during CPR (which conveys a poor prognosis for recovery), every attempt should be made to ensure that this low value is not from inadequate compressions

Answer 25

true

Question 26

how should compression be performed?

Answer 26

rate of 100-120 bpm, compressing the chest 1/3 to 1/2 of the total width allowing for complete recoil

Question 27

what do incomplete or rapid compressions cause?

Answer 27

decreased ventricular filling & decreased cardiac output

Question 28

T/F: efficacy of compressions decrease after 2 minutes regardless of perceived fatigue

Answer 28

true - switch every 2 minutes

Question 29

optimal compressions generate approximately ___% of normal cardiac output when performed appropriately?

Answer 29

20%

Question 30

where are compressions performed in small dogs & cats?

Answer 30

directly over the heart in line with the cardiac pump theory

Question 31

what is the cardiac pump theory?

Answer 31

ventricles of the heart are compressed mimicking a contraction - compressions directly over the heart for small dogs/cats

Question 32

where are compressions performed in large breed dogs?

Answer 32

compressions are performed at the highest point of the chest to increase intrathoracic pressure & causes the great vessels (vena cava & aorta) to collapse - thoracic pump theory

Question 33

what is the thoracic pump theory?

Answer 33

compressions are performed at the highest point of the chest to increase intrathoracic pressure which causes the great vessels (vena cava & aorta) to collapse recoil causes the vessels to expand again & triggers the movement of blood with the heart acting as a conduit for blood instead of the mechanism of movement

Question 34

where are compressions performed in barrel-chested dogs (bulldogs)?

Answer 34

dorsal recumbency

Question 35

what is the respiration rate used for CPR?

Answer 35

one breath every 10 seconds with an inspiratory time of 1 second & pressure of 10-15 cmH2O

Question 36

how does hyperventilation negatively affect the coding patient?

Answer 36

it maintains positive intrathoracic pressures which compresses the major vessels impeding venous return

Question 37

how does hypoventilation negatively affect the coding patient?

Answer 37

allows for the accumulation of carbon dioxide which results in cerebral vasodilation, increased intracranial pressure, and decreased cerebral perfusion

Question 38

what kind of drug is epinephrine?

Answer 38

non-selective sympathomimetic - alpha & beta adrenergic stimulation

Question 39

giving epinephrine results in what?

Answer 39

increased systemic vascular resistance, heart rate, & force of contraction

Question 40

what is the primary purpose of giving epinephrine to a coding patient?

Answer 40

increase systemic vascular resistance to shunt blood back to the core organs

Question 41

what is the recommended dose of epi given for the first two administrations given every other cycle?

Answer 41

0.01mg/kg

Question 42

when is high dose epi used? why is it not the first choice?

Answer 42

when low dose epi has failed it will achieve a higher ROSC, but is also associated with higher rates of neurologic impairment & mortality

Question 43

what are your shockable rhythms?

Answer 43

pulseless ventricular tachycardia & ventricular fibrillation

Question 44

what is the mechanism of vasopressin?

Answer 44

acts on V1 receptors in peripheral vasculature to increase systemic vascular resistance without increasing myocardial oxygen demand

Question 45

what is the mechanism of action of atropine?

Answer 45

parasympatholytic - decreases vagal tone

Question 46

what is the dose used for atropine for a coding patient?

Answer 46

0.04 mg/kg administered every other cycle opposite of epi - low dose epi -> 2 minutes later -> 1 dose atropine -> 2 minutes later -> low dose epi

Question 47

what drugs can a patient receive through an ET tube? how does the dosing change?

Answer 47

epinephrine, atropine, vasopressin, lidocaine, & naloxone double the doses - give through a red rubber as close to the carina as possible to improve absorption

Question 48

T/F: asystole & PEA respond well to defibrillation

Answer 48

false

Question 49

how is a defibrillator used?

Answer 49

patient in dorsal recumbency, paddles covered in electrode transducer gel, placed on lateral adjacent thoracic walls directly over the heart no one in direct contact with table & patient after the paddles are in place, operator yells clear, everyone says clear back, patient is shocked

Question 50

what is assessed after defibrillating your patient?

Answer 50

another round of compressions is performed & rhythm analysis performed at the next compressor change

Question 51

T/F: in cases of shockable rhythms, epinephrine is typically not administered; instead defibrillation is performed every cycle that a shockable rhythm is diagnosed until the patient converts to a perfusing or non-shockable rhythm.

Answer 51

true

Question 52

why should iv fluids only be given to hypovolemic patients as a part of CPR?

Answer 52

giving fluids to normovolemic/hypervolemic patients will increase right atrial pressure & decrease venous return

Question 53

when is open chest CPR indicated?

Answer 53

pleural space/pericardial disease, thoracic trauma, giant breed dogs, concurrent surgery, & prolonged CPR (> 10 minutes)

Question 54

why is open chest CPR not commonly performed?

Answer 54

significant morbidity and cost following this procedure with no change in survival to discharge

Question 55

how is open chest CPR performed?

Answer 55

patient placed in lateral recumbency (left preferred) & 6th ICS is clipped/prepped while external compressions continue - sterile gloves are worn & chest cavity is entered & internal massage starts

Question 56

in cases of open chest CPR for pericardial effusion, what should be done?

Answer 56

pericardium should be torn to allow the fluid to evacuate

Question 57

how often should compressors switch in internal CPR?

Answer 57

every 2 minutes