30 – CPR Flashcards
1
Q
Anesthesia and drug related CPA survival
A
- Highest: 35-48%
o Already on life support (IV catheter and on O2)
o Witnessed events in controlled circumstances
2
Q
What are 3 categories of CPA?
A
- Anesthesia and drug related
- Underlying disease
- Reversible disease/injury (ex. tennis ball in throat)
3
Q
What is the overall survival rate for patients following Cardio Pulmonary Arrest (CPA)?
A
- 4-9.6%
- POOR
- *human error is a factor in 90% of cases
4
Q
Underlying disease CPA survival
A
- 2% chance of recovery to leave hospital
- GRAVE prognosis
5
Q
Reversible disease/injury CPA survival
A
- 5% will leave hospital
- Quick resolution of underlying disease allows chance of recovery
6
Q
What are the 5 steps/domains to perform effective CPR?
A
- Readiness and preparation
- Basic life support
- Advanced life support
- Monitoring
- Postcardiac arrest care
*need to be good in ALL OF THEM
7
Q
Readiness and preparation
A
- People NEED training and specific jobs during CPR
- ‘ready area’
8
Q
‘ready area’ for CPR
A
- Table: sturdy, adjustable, accessible from all sides
- Equipment: ET tubes, laryngoscopes, catheters
- Oxygen
- Ventilation
- Monitoring equipment
- Crash cart: drugs, dose chart
9
Q
What the 5 roles, 1 for each person when doing CPR?
A
- Compression
- Ventilation
- Administers drugs
- Leader that calls out the shoots
- Documentation
10
Q
What are the clinical signs of CPA?
A
- Unresponsive (loss of consciousness, collapse)
- Lack of spontaneous ventilation (respiratory arrest)
- Lack of heart beat (no pulse=can take to long to ID)
11
Q
Pulse palpation as a technique to confirm CPA
A
- UNRELIABLE
12
Q
Unresponsive patient (5-10s)
A
- STIMULATE!
o No response=call for help! - A: airway
- B: breathing
- C: circulation (pulse)
- *delays in initiation of CPR associated with worse outcome
13
Q
Basic life support
A
- Delays in initiation of CPR=worse outcome
- Benefits of early CPR outweigh RISKS
- Know resuscitation status
- *call for help (need at least 3 people)
- NOTE TIME
- ‘3 minute emergency’
- If under anesthesia: turn off anesthetic
13
Q
‘3 minute emergency’
A
- Brain damage after 3 minutes without O2 and glucose
- Brain exhausts supply of ATP muscles
- Na/K cell pump fails: cell edema
14
Q
Basic life support
A
- Hands-only CPR in humans
- *EARLY VENTILATION is important in dogs and cates
- Single rescuer BLS: 30 compressions:2breaths
15
Q
Goal is to restore blood flow to provide O2 delivery
A
- Compressions should start as SOON as there is a suspicion
- Confirm a heartbeat later
- Patient positioning
o LATERAL RECUMBENCY
o Barrel chested dogs can be in dorsal - *Good EXTERNAL COMPRESSION=25-30% of pre-arresting CO
- Essential to provide highest possible quality of compressions
16
Q
How to be effective at compressions
A
- Rate: 100-120 bpm
- *depth: 25% of depth/width of chest
- LOCK your elbows (gravity vs. muscle strength)
- Duration: rescuer fatigue!: perform uninterrupted cycles of 2 mins
- Relaxation: 1:1 compression to relaxation ratio (allow full recoil of lungs)
17
Q
Rescuer fatigue: length of compressions
A
- Takes 60s to achieve coronary perfusion
- *Minimize interruptions: 2-5 seconds
o Intubation, ECG check, switching people
18
Q
Why is full recoil so important during CPR?
A
- *represents diastole
- NO LEANING ON CHEST
o Increased intrapleural pressure
o Reduced venous return
o Suboptimal ventricular filling
19
Q
Systole (alive) or compressions (CPA)
A
- Coronary blood flow negligible OR even retrograde
20
Q
Diastole (alive) or decompression (CPA)
A
- Majority of coronary blood flow
21
Q
For animals <10kg or dogs with narrow, keel-chest conformation (CARDIAC PUMP)
A
- DIRECT compressions of heart (3rd to 6th IC space)
o Pushes blood out into circulation - Cup hand around sternum to squeeze with one hand
- Avoid using fingertips (no pinching)
22
Q
3 techniques for CPR in small animals
A
- One-handed thumb-to-fingers
- Circumferential
- One-handed palm
23
Q
For animals >10kg (THOARACIC PUMP)
A
- Compression over WIDEST PART OF THORAX
- Increases overall intra-thoracic pressure
o Secondarily compress aorta
o Leading blood flow out of thorax - During elastic recoil
o Sub-atmospheric intra-thoracic pressure favours blood flow from the periphery back to thorax
24
Q
Flat chested dogs: position
A
- Between front legs
- *when you put them in dorsal and they stay
o If do not stay=do thoracic pump
25
Q
Ventilation with CPR
A
- *INTUBATION is best
- 100% O2
- Use anesthesia machine or Ambu bag
- *turn OFF vaporizer
- Room air 21% O2
- Own breath: 14% O2
26
Q
Securing airway for provision of ventilation is critical (‘next choices’)
A
- Check for obstruction (blood, fluid): have suction ready
- MASK
- MOUTH-to-SNOUT
27
Q
Mask for ventilation
A
- Not ideal, only if intubation is not available
- Provides O2, extend head and neck to avoid aerophagia
- Must STOP compressions to ventilate
- Compression-to-ventilation ratio 30:2 recommended
28
Q
Mouth-to-snout for ventilation
A
- Hold mouth tightly closed
- Put own mouth over patients nares
- Low fraction of inspired O2
- *not ideal
29
Q
Intubate patients as soon as possible during CPR
A
- LATERAL recumbency, neck extended
- Use laryngoscope (no room for error)
o Visualize what you are doing
o Check proper placement
o Avoid vagal stimulation - Inflate cuff
- Secure/tie in place
- Replace if necessary
- *provide 100% O2
- *can be performed SIMULTANEOUSLY WITH CHEST COMPRESSIONS
30
Q
Ventilation respiratory rate
A
- 10 breaths per minute
- Do NOT go too fast
- Tidal volume: 10ml/kg
- Inspiratory time: 1s
- Airway pressure: sufficient to result in a visible chest rise
- *airway pressure (IPPV): 30-40 cmH2O during chest compression
o In between compressions, less than 20cmH20
31
Q
Advanced life support
A
- Initiate monitoring:
o ECG
o Capnography
o Femoral pulse - IV access
- Reversals
32
Q
Monitoring with ECG
A
- Diagnosis of arrest rhythm
- Determine advanced life support
- *do not interrupt 2 min cycle of compression
o Inter-cycle pause; minimize time <10s
o Check ECG and palpate pulse at same time
o Do NOT delay resumption of chest compressions - *leader should call out arrest rhythm and ask if everyone agrees
33
Q
What are the most common arrest rhythms?
A
- Non-shockable
o Asystole
o Pulseless electrical activity (PEA) - Shockable
o Pulseless ventricular tachycardia
o Ventricular fibrillation - Initial rhythm can change! (continue to check!)
34
Q
Asystole
A
- Most common arrest rhythm in dogs and cats
- Non-shockable
- ‘flat-line’ (no electrical activity in heart)
35
Q
How do you treat asystole?
A
- Continue basic life support: supplements heart action
- Drugs
o Epinephrine +/- vasopressin (every other cycle)
o Atropine: ONLY once and early on
36
Q
Pulse electrical activity
A
- See in overdose GA (barbiturates)
- Non-shockable
- Normal HR and rhythm, but NO myocardial contractility
- Heart rate less than 200bpm
o Continue basic life support - Drugs:
o Epinephrine +/- vasopression (every other cycle)
o Atropine: only once, early on
37
Q
Ventricular fibrillation (fine or coarse)
A
- Unorganized electrical activity in heart
o Poor myocardial contractions: loss of CO - Most common initial arrest rhythm in people
- *uncommon in cats and dogs
- May develop during course of resusication
o Need to monitor ECG during compression pauses
38
Q
What is the treatment of ventricular fibrillation?
A
- Electrical defibrillation
- Precordial (‘hit chest’)
39
Q
What is the concept of electrical defibrillation
A
- Electrical impulses depolarizes myocardial cells ‘reset button’
- Electrical and uncoordinated mechanical activity stops
- Allows regular pacemaker cells to regain control
o Sinus rhythm
o Asystole: if SA node doesn’t refire - *start basic life support at same time you charge the defibrillator
40
Q
Electrical defibrillation ‘steps’ or guidelines
A
- Lubricate paddles with conductive gel
- Do NOT use alcohol: combustible
- DORSAL recumbency
- Place paddles on opposite sides of thorax
o Over heart at costo-chondral junction - *check that NO one is in contact with patient or table
o Shout ‘clear’ when ready
41
Q
What do you do after defibrillation?
A
- Restart chest compression immediately (full 2-min cycle)
- Desired outcome
o Normal ECG rhythm
o Asystole: all electrical activity is stopped and hopefully starts again
*Compressions should be performed for 2mins prior to next shock
42
Q
If a shockable rhythm persists after first defibrillation attempt, what do you do?
A
- Double energy dose for next shock
- Stay at dose for subsequent doses
- LOW DOSE epinephrine
43
Q
Monitoring end tidal CO2
A
- Info about CO and pulmonary perfusion
- Measure efficacy of chest compressions
o EtCO2 <18mmHg=POOR perfusion
o Normal: 35-45 mmHg - *MOST predictive prognostic indicator
44
Q
End tidal CO2 most predicative prognostic indicator
A
- Higher EtCO2 values (>15mmHg) during CPR associated with increased rate of return of spontaneous circulation
- *Fast indicator of return of spontaneous circulation: sudden increase in EtCO2
45
Q
What are the 2 types of CV drugs?
A
- Vasopressive agents
- Vagolytic drugs
- Anti-arrythmic drugs
46
Q
What are some reversal drugs of anesthetic agents?
A
- Opioids
- Alpha-2 agonists
- Benzodiazepines
47
Q
Routes of drug administration
A
- IV
- Intraosseous (IO)
- Intratracheal
- Intracardiac=NOT recommended
48
Q
IV drug administration
A
- *preferred route of drug administration
- Cutdown in necessary
- Flush with large volumes after drug administration
- Decreased CO means poor distribution in dogs
49
Q
Intraosseous (IO) drug administration
A
- If can’t achieve IV within 2 mins
- Handheld electrical IO drills
- Circulating time do drugs comparable to IV
50
Q
Intratracheal drug administration
A
- Simple, rapid but NOT recommended as primary route
- ONLY if IV or IO not possible
- Lower airways have large absorptive capacity
- Drugs absorbed into pulmonary circulation
- Ex. atropine, epinephrine, vasopressin, lidocaine, naloxe
51
Q
Technique for intratracheal drug administration
A
- Pass feeding tube down ET tube to level of carina
- Flush catheter with air and give a few good breaths
- *Drug dose is DOUBLED
- Epinephrine uses ‘high dose’
- Drugs diluted in 0.9% NaCl
52
Q
Epinephrine
A
- Catecholamine with NONSPECIFIC alpha and beta adrenergic effects
- *alpha mediated vasoconstriction: key for CPR
- Blood volume: central circulation
- Beta effects may be harmful
- *do NOT work well in hypoxemic, hypothermic and academic environment
53
Q
Epinephrine doses
A
- *LOW dose IV
- High dose=NO longer recommended
- Repeat every 3-5mins of arrest (every other 2 min cycle)
54
Q
Vasopressin
A
- Non-catecholamine vasopressor
- Acts on V1 receptors of vascular smooth muscle
- Profound peripheral vasoconstriction
o Not in coronary or renal arteries
o Mild cerebral vasodilation - More effective in hypoxemic, hypothermic, academic environment
- Double does for intratracheal
- *as a substitute or in combo with E every 3-5 mins
o Usually more expensive
55
Q
Atropine
A
- Patients arrested due to HIGH VAGAL TONE
- Vagolytic drugs inhibit PS tone
o Increases HR
o Increases AV nodal conduction - *as early as possible and ONLY ONCE
- Lack of sufficient evidence for effectiveness duing CPR in people
56
Q
Monitoring effectiveness of CPR
A
- After 30-60s
o Palpable femoral pulse
o Capnogram (EtCO2>15mmHg) - if ineffective, change technique
o person, position, augmentation
o (consider open chest: lots of after care)
57
Q
What is the initial return of spontaneous circulation and how many survive hospital discharge?
A
- Initial ROSC: 35-40% of animals
- 2-10% survive hospital discharge
- *optimizing post cardiac arrest care is ESSENTIAL for successful CPR
58
Q
What makes being back from the dead tricky?
A
- Ischemia-reperfusion injury
- Brain injury
- Myocardial dysfunction
- Something killed you originally
o Persistent precipitating pathology
59
Q
Ischemia-reperfusion injury
A
- Sepsis likes syndrome
- Hemodynamic optimization, glycemic control, adrenal function
60
Q
Brain injury
A
- Injury occurs during reperfusion
- Mannitol, hypothermia, seizure prophylaxis
