CPR

Question 1

When is the safest time for an animal to arrest?

Answer 1

Under anaesthesia

Question 2

Is it likely that you will be able to revive a animal dead on arrival?

Answer 2

no but always try and help even if just taking them out the back

Question 3

What is CPR?

Answer 3

• patient stops breathing OR its heart stops beating
  (minute after respiratory arrest before cardiac arrest follows, if under GA oxygen levels ^ so 5 minutes)
• means to support circulation and oxygenation

Question 4

define rsp/cardiorespiratory arrest

Answer 4

• cessation of effective breathing

- cessation of effective cardiac activity (CO) and respiration

Question 5

Define return of spontaneous circulation (ROSC)

Answer 5

• re-establishmenet of sustained CO without assistance (not just electrical activity - pulseless electrical activity)

Question 6

Define basic life support

Answer 6

• chest compressions and assisted ventilation

Question 7

Define advanced life support

Answer 7

• BLS + medical and electrical intervention

Question 8

What is CPCR?

Answer 8

• cardiopulmonary CEREBRAL resuscitation
• rescusitative efforts required to elicit ROC and emphasising the importance of neuroplogical outcome
• mainly in humans (dropping core temperature etc.)
• dogs and cats more tolerant of periods of hypoxia

Question 9

How can impending cardiopulmonary arrest be recognised?

Answer 9

• not easy in critically ill patients
• hypoventilation and bradycardia esp if sudden
  > pre-arrest rhythms
• ventricular tachycardia with R on T phenomenon (no return to baseline, no repolarisation)
• ventricular flutter/fibrillation (needs defib within mins)
• third degree AV block (dissociated of atria and ventricles, ventricles will beat d/t escape complexes @ 40bpm, needs pacemaker)

Question 10

How can an arrested patient be identified?

Answer 10

• spontaneous breathing efforts
• auscult heart
• feel for apex beat
• palpate pulses

Question 11

Most common cause of CPA in animals cf. people?

Answer 11

• airway obstruction (always intubate)

- humans more likely myocardial infarction

Question 12

How many people are needed for effective CPR?

Answer 12

3-4 people min
- ventilation
- compressions
- IV access
- ECG
- runner
- scribe
- pulse taker (spontaneous or compressions) 
- abdominal counterpressure to divert blood to cranial vena cava and brain 
> one person should take charge

Question 13

What is vasovagal syncope and vagal arrest?

Answer 13

• stimulation of vagus nervie -> life threatening bradycardia
  > causes of vagal stimulation
• V+
• defeacation/urination
• respiratory arreat
• ocular or neck surgery
• patients with pre-existing high vagal tone pdf

Question 14

Tx high vagal tone?

Answer 14

Atropine (parasympatholytic)

• intubate
• oxygenate
• can anaesthesise

Question 15

Causes and tx of anaesthetic related arrest?

Answer 15

• OD anaesthetic (stop giving anaesthetic, reverse)

- hypoventilation/hypxia/hypercarbia

Question 16

Complications of anesthetic CPA?

Answer 16

hypoxia leads to... 
- blindness
- dysphoria
- neuro dysfunction
> most go away with time and good nursing care

Question 17

How can positive pressure respiration be given?

Answer 17

• positive pressure on anaesthetic machine
• Ambu bag (regulates pressure so you cant overdo it)
• 10-12 breaths per minute (don’t hyperventilate!! CO2 taken off too much -> vasoconstriction)
• 100% oxygen
• deliver breaths simultaneous with compressions
• max pressure 15cmH20 cat, 20cm H2O dog)
• inspiratory time

Question 18

What does too much ventilation do

Answer 18

• ^ intrathoracic pressure
• v CO
• v cerebral and coronary perfusion

Question 19

Aim of circulatory support?

Answer 19

• maximise myocardial/cerebral perfusion
• myocardial perfusion depends on DIASTOLIC pressure
• cerebral perfusion depends on MAP
• minimise interruption of compressions

Question 20

How is CPR physically carried out?

Answer 20

7kg
- compress thorax (thoracic pump mechanism)
~ 100bpm
~ 50:50 duty cycle (let chest expand between compressions)

Question 21

How often should you switch people compressing?

Answer 21

2 minutes

Question 22

Indications ofr open chest CPR?

Answer 22

• large dogs
• significant pleural space disease
• chest wall disease
• pericardial effusion
• penetrating chest wounds
• intra-operative arrests (esp abdo, cut through diaphragm)
• haemoabdomen
• unwitnessed arrests
• unsuccessful closed chest CPR (after 5-10mins? no proof for this)

Question 23

Advantages of open chest CPR

Answer 23

• diastolic filling assessment
• pericardial tamponade avoided
• aorta cross clamped
• ventricular fibrillation visually diagnosed
• myocardial flaccidity assessed directly

Question 24

Disadvantages of open chest CPR?

Answer 24

• need experienced personel
• need more personnel
• significant procedure
• financial and surgical backup
• infection (non-sterile)

Question 25

What is involved in advanced life support?

Answer 25

- determin arrest rhythem - defib - cardiac pacing - vascular access > drugs - vasopressor (adrenaline) - vagolytic (atropine) - antiarrythmic (lidocaine) - buffer (acidosis eetc.) - electrolyte - IVFT

Question 26

Is VF common in small animals? Wht is the only tx method?

Answer 26

No (cf. humans) - need defib to convert - can try pre-cordial thump

Question 27

Which drugs can be given ET if no venous accccess present?

Answer 27

``` Lipid soluble: N- naloxone A - atropine V - vasopressin E - Epinephrine L - Lidocaine > NOT ca or bicarb ```

Question 28

Has any drug tx been shown to ^ survival?

Answer 28

NO

Question 29

What does atropine do? Indications?

Answer 29

> vagally mediated arrests - parasympatholytic - accelerates pacemakers - ^ AV conduction

Question 30

What does epinephrine do? Indications?

Answer 30

> standard vasopressor for cardiac arrest | - a-- mediatedvasoconstriction, ^ aortic pressure, ^ myocardial perfusion

Question 31

What does calcium do? Indications?

Answer 31

> previous hx of hyperkalaemia, hypoclcaemia | - specific indications only

Question 32

What does glucose do? Indications?

Answer 32

> Tx hypoglycaemia pre/during arrest | - check glucose during CPA, tx hypoglycaemia as required

Question 33

What does lidocaine do? Indications?

Answer 33

> ventricular tachycardia | - v automacity an suppresses ventricular arrhythmias, less effective than amiodarone

Question 34

What is sodium bicarbonate? Indications?

Answer 34

> hyperkalaemia/metabolic acidosis | - routine administration does not improve outcome

Question 35

What is vasopressin? Indications?

Answer 35

> Vasopressor - some theoretical advantages over epi - inconsistent results - only neeed to give once

Question 36

What is always indicated for severe bradycardia?

Answer 36

Atropine

Question 37

Side effects of atropine?

Answer 37

- may contribute to development and maintainence of PEA/asystole - may potentiate sinus tachycardia - may encourage VF when given in the vicinity of epinephrine > give one dose in early CPR

Question 38

When are IV fluids indicated?

Answer 38

``` > NOT AS STANDARD - following drug administration - pre-existing severe hypovolaemia - bleeding out > overhydrating decreases coronary perfusion (^ right sided heart pressure) ```

Question 39

When is the majority of ROSC successful? When can you ggive up?

Answer 39

8-10 minutes - check end tidal CO2, if zero give up - after 30 mins probably ok to give up if no signs of life