This lecture provides an introduction to RECOVER, a campaign to standardize veterinary cardiopulmonary resuscitation (CPR) guidelines. The goals of RECOVER and this lecture are to establish evidence-based best practices for veterinary CPR with the aim of improving survival rates. The lecture covers the basic chain of survival, including preparation, basic life support, advanced life support, monitoring, and post-resuscitation care. Key recommendations include rapid initiation of chest compressions and ventilation, use of epinephrine and vasopressin, biphasic defibrillation when indicated, and monitoring end-tidal carbon dioxide to guide resuscitation efforts.
2. • In the human and animal field, when giving a patient CPR the goal is to have the
patient survive and be neurologically be sound. Cardiopulmonary arrest in our
patients is commonly associated an underlying illness, trauma, or anesthesia.
The Survival to discharge after cardiopulmonary arrest is uncommon in
veterinary medicine ranging from 3% -6% in dogs and 2%- 10 % in cats
• In this lecture there will be an introduction to RECOVER, a recently developed
campaign on Veterinary Resuscitation. It is the goal of this campaign to design a
consensus based clinical CPR guidelines for small animal medicine. We are then
going then delve into a discussion on basic life support, advanced CPR,
monitoring, and post resuscitation care. We will finish the lecture with a
discussion on clinical guidelines for CPR, some which we have instituted in this
hospital and some which will be instituted as we continue forward.
Goals of the lecture
3. • This is an evidence and knowledge gap analysis on
Veterinary CPR.
• The goal of RECOVER was to establish a better way of
providing “CPR” to our patients with the outcome being
survival with intact neurological function following
cardiac arrest
• The goal is standardizing training goals and improved
outcomes for our veterinary patients.
Recover
4. • Preparation and Prevention
• Basic Life support
• Advanced life support
• Monitoring
• Post cardiac arrest care
• Clinical guidelines
5. • Early recognition, Basic Life support, Advanced life
support, Post-resuscitation care
Basic Chain of Survivial
6. • Organized and pre-stocked arrest stations these should
also be close to areas where animals are anesthetized-
check lists, charts, and aids
Anesthetized CPA had a better outcome then CPA
• Post-CPR debriefing is safe, easy, and improves future
performances
Preparation and
prevention
7.
8. • Training increase effectiveness of CPR test standardized
training programs have improved adherence to guidelines
in human medicine and are needed in veterinary
medicine.
• Leadership and team communication training increases
effectiveness of CPR teams
• High fidelity manikins for teaching CPR are highly
effective in human medicine and would be valuable in
veterinary medicine
9. • Rapid recognition of CPA and Rapid initiation of CPR
Identifying the 5 H’s and 5 T’s
• 5 H’s
• Hypovolemia/hemorrhage
• Hypoxia/hypoventilation
• Hydrogen ions/acidosis
• Hyperkalemia - blocked cats or hypokalemia
• Hypoglycemia
Identifying patients at
risk
11. BLS is the immediate response to CPA
•Basic life support (BLS) includes recognition of
cardiopulmonary arrest (CPA), airway management, provision of
ventilation, and chest compressions.
•Early Initiation of high- quality basic life support is essential to
create blood flow to the heart and brain as well as to limit injury
to or preserve organs until spontaneous circulation resumes
•BLS is separate from advanced life support (ALS)
•Minimal monitoring equipment can be initiated immediately at
the onset or arrest
Basic Life support
12. • Immediate initiation of chest compressions with
intubation and ventilation being performed
simultaneously
• In human medicine studies have shown that delayed
initiation of chest compressions due to prolonged
intubation times have a potential negative impact
13. • Chest compressions should aim to compress the chest by 1/3 to half its width in
lateral recumbency, at a rate of at least 100 compressions/min, allow for full
recoil between compressions
• High compression rates could limit the duration of diastolic cornonary perfusion
and impair recoil decompression, thereby compromising venous return.
• Optimal closed chest compressions only produce 25% to 40 % of normal cardiac
output
• Utilization of the 2 minute cycles of uninterrupted chest compressions with
alternation of compressors between cycles. Intercycle interruptions in
compressions should be kept to a minimum; long only enough for rhythm
diagnosis
15. Chest compression techniques for medium, large, and giant breed dogs.
•(A) For most dogs, it is reasonable to do chest compressions over the
widest portion of the chest to maximally employ the thoracic pump
theory.
•Either left or right lateral recumbency are acceptable.
•(B) In keel-chested (ie, deep, narrow chested) dogs like greyhounds, it
is reasonable to do chest compressions with the hands directly over the
heart to employ the
•cardiac pump theory, again in either recumbency.
•(C) For barrel chested dogs like English Bulldogs, sternal
compressions directly over the heart with the patient in dorsal
recumbency may be considered to employ the cardiac pump
mechanism.
16. • Cardiac pump –directly exert force on the heart and
generate force on the heart and generate blood by
changing the dimension of the individuals cardiac
chambers
• Thoracic pump – increased intrathoracic pressure during
chest compressions , secondarily compressing the aorta
and collapsing the vena cava leading to blood flow out of
the thorax
• Sternal compression – dislocates the costalchondral
junctions –cardiac pump mechanism established
18. Chest compression techniques for small dogs and cats.
•A) For most cats and small dogs (<10 kg) with compliant chest.
The use of a 1-handed technique to accomplish circumferential
chest compressions with the hand wrapped around the sternum
directly over the heart may be considered.
•(B)An alternative chest compression method for cats and small
dogs is the 2-handed technique directly over the heart to employ
the cardiac pump mechanism. This method may be considered in
larger cats and small dogs with lower thoracic compliance, or in
situations in which the compressor is becoming fatigued while
doing 1-handed compressions.
19. • Controlled airway, usually via ET intubation
• ventilation rate of 10 breaths/min without interruption of
chest compressions
• Acceptable tidal volume per breath is 10ml/kg with a 1
second inspiratory time
• Why not give more?
• What is the driving force for a breath?
( what we are targeting is normocapnia will avoiding
arterial hypoxemia )
20. The ratio of chest compressions to Breath is
30:2
If you are by yourself –
BLS
21. • The RECOVER ALS program was designed to evaluate
the vasopressors, positive inotropes, anticholinergics,
correction of electrolyte disturbances, volume deficits,
severe anemia, and prompt defibrillation.
• If BLS and ALS are performed promptly, initial return of
spontaneous circulation rate may be as high as 50% in
dogs and cats
Advanced Life Support
(ALS)
22. • Standard dose epinephrine (0.01 mg/kg IV ) is the preferred dose for
CPR – easy way to do the math = a dog weighs 5.0 kgs move the
decimal point over to the left twice and you will get the ml’s of
epinephrine that need to be given to a patient.
• ( epi is 1 mg /ml )
• Rapid defibrillation is warranted in animals with observed
progression to pulses of VT or VF, preferentially using a biphasic
(BP) defibrillator
• Biphasic – current flows in one direction in the first phase of the
shock and then reverses for the 2nd phase. – Gold standard device.
They pose less risk of injury to the heart.
• Defibrillation should follow a cycle of CPR in unwitnessed pulses
VT or VF
ALS key
recommendations
23. • Reversal of anesthetic agents can correction of acid –base
electrolyte disturbances is advisable
Turn off the inhalant
• Open chest CPR might be considered in select cases with
access to postcardiac arrest support
24. • A crucial aspect of restoring myocardial function is
improving coronary perfusion pressure
• Vasopressors increase aortic pressures by increasing
peripheral vascular resistance directing more of the
intravascular volume to the central circulation.
• Vagolytic therapy, specifically atropine, should be used
to counteract high vagal tone.
Vasopressors and vagolytic therapy
25. • Epinephrine
• Standard recommendations ( 0.01 mg/kg/IV ) q. 3-5 minutes
• Vasopressin
• 0.8 U/kg IV
• with or without epinephrine is an appropriate intervention in
CPR
• Vasopressin my benefit in patients with prolonged CPA, asystole,
or CPA with associated hypovolemia
• Atropine
• Data supports that the use of atropine during CPR is limited. Most
studies use it as an additional drug, rather than a sole drug
• For animals with high vagal tone ( vomiting, ileus) subsequent
bradycardia/asystole
26. • Evidence suggests that low- dose epinephrine and
vasopressin are first line pharmacologic agents in CPR,
providing peripheral vasoconstriction to improve blood
flow to heart, brain, and enhanced the change for
recovery
27. • Antiarrhythmic drugs
In cases of asystole, PEA, pulseless VT and VF
There is no compelling evidence that supports the routine use
of antiarrhythmic drugs improve outcome of dogs and cats
with cardiac arrest.
Other medication
28. • Steroid
• There is no evidence that corticosteroid administration is
beneficial or harmful in the ALS phase of CPR.
• Studies suggest that in other diseases it has a harmful effect
• At this time it is not recommended to use steroids in
patients that you are providing CPR to
29. • Naloxone
• In dogs and cats with cardiac arrest and suspected narcotic
depression secondary to opioids naloxone may be beneficial
• There are 2 perspectives for the use of naloxone
1. use in opioid overdoses
2. positive inotrope and antiarrhythmic mediated by
reversal of endogenous endorphins.
30. • Electrolyte disturbances associated with CPA may exist
prior to the arrest or may develop during CPR subsequent
to metabolic acidosis, drug therapy, or other metabolic
derangements.
• There is no evidence that suggests treatment to mild
electrolyte disturbances.
• Moderate to severe hyperkalemia influences myocardial
function and should be treated. *Blocked cats*
• Severe ionized hypocalcemia may be treated and calcium
therapy is warranted in symptomatic calcium channel
blocker overdosage
Electrolyte Disturbances
31. • Calcium is vital in cellular communication ( signaling )
as well as muscle contraction in skeletal, cardiac, and
smooth muscles. Adequate calcium concentrations are
required or cardiac contractility
• There is a clear relationship between low ionized calcium
levels and poor outcome in CPR.
Calcium
32. • In dogs and cats with cardiac arrest due to VF or pulseless VT
the use of prompt defibrillation is associated with a markedly
higher rate of chance for survival.
• BP defibrillation is preferable to monophasic defibrillation.
• Selection of the appropriate energy level for an animal size
device
• Monophasic 5+/- 1 J/kg
• Biphasic 3 +/- J/Kg
• Minimize of impedance by creating optimal contact between the
paddles and the chest
Defibrillation
33.
34. • There is less evidence that stacking shocks is beneficial
and rather one shock followed by compressions for 2
minutes etc. Has a better outcome – this minimizes the
time without blood flow and reduces myocardial
hypoxemia
• Any Subsequent shocks should be increased by 50% once
should be considered.
35. • Evolving Concepts in CPR support the 3 –phase model of
CPR
• 1st pahse lasting approximately 4 minutes and termed the
electrical phase
• 2nd phase, the circulatory occurs between 4-10 minutes after
CPA and is associated with energy depletion and potentially
reversible cellular damage
• 3rd After 10 minutes of no circulation, the metabolic phase
begins, and is characterized by ischemia injury that require
more advanced strategies then BLS and ALS
Timing of defibrillation
36. • Immediate defibrillation is warranted if the duration of
VF is 4 minutes or less
• In arrests that have lasted longer then 4 minutes, one
cycle of CPR before defibrillation may help replenish
energy substrates and increase the likelihood of
successful defibrillation
37. • Open chest CPR
• Open chest compression is more effective than closed chest
CPR
• In open- chest CPR requires a skillful team and demands
advanced postcardiac arrest support
• In cases of significant intrathoracic disease, such as tension
pneumothorax or pericardial effusion, it may be advisable to
promptly perform open –chest CPR.
• Defibrillation should be readily available.
Other ALS topics
38. • Faced with the lack of venous or IO access, intratracheal
administration of epinephrine, atropine, and vasopressin
may be considered.
• If it is chosen, a 10 fold increase in the dose of Epi. ( 0.1
mg/kg) should be given
• It should be delivered via a catheter to the level of the
carina or ideally farther distal into the bronchial tree.
• The drug should be diluted in sterile water ( saline cane
by used )
Intravenous vs.
intratracheal drug
administration
39. • Animals under anesthesia should be resuscitated
aggressively
• Careful monitoring during anesthesia may permit more
rapid recognition and potentially improve outcome.
• Lipid rescue may be considered in animals with CPA due
to local anesthetic drugs or in association with other
lipophilic drugs.
Anesthetic –related
arrest
40. • Monitoring is divided into 3 important aspects of CPR
• Confirm CPA and endotracheal intubation
• Monitoring options during CPR
• Monitoring options following return to spontaneous
circulation
Monitoring
41. • Time spent verifying an absent pulse may delay onset of CPR; chest
compression should be initiated immediately for apneic,
unresponsive patients
• Palpation of FP versus assessment for other signs of life pupil size,
agonal breathing, thoracic auscultation
• Loss of FP and radial artery doppler signal may occur before
complete cardiac arrest. Doppler pulse sounds are not a reliable tool
for the dx of cardiac arrest.
• ECG analysis of unresponsive patient may help to rule out CPA, or
be used to evaluate for rhythms requiring specific therapeutic
approaches. Pauses in chest compressions to evaluate the ECG
rhythm should be minimized
• Enables identification of rhythms that can be treated with
defibrillation
42. • End- tidal CO2 may be used to identify Et placement. And to
evaluate efficacy of CPR. Under physiologic conditions,
PETCO2, severs as a close est. of the alveolar partial pressure
of CO2. PETCO2 is very responsive and sensitive indicator
that almost immediately increases upon ROSC .
• EtCO2 monitoring is useful to identify ROSC and may be
prognostic for the likelihood for ROSC
• When a PETCO2 remains < or equal to 10 mmHg despite
maximal effort and the ECG is not showing electrical activity
discontinuation of the resuscitation attempt can be considered.
• Patient monitoring following ROSC should be directed at
identifying abnormalities that may portend another CPA, and
should be tailored to each patient
43. • Blood pressure monitoring – noninvasive monitoring such as
the doppler sphygmomanometry or oscillometric methods are
not useful to evalute CPR but have a role in postresuscitation
care. Arterial catheters are impractical to place during CPR,
however be useful during postresuscitation care.
• Venous blood gas may have a better predictor value for for
ROSC than arterial blood gas values are directly related to
cardiac output and tissue perfusion (there is evidence that
venous mixed blood gas values changed to a greater degree
during the resuscitation period than did the arterial samples.
44. • In cases where there is cardiac arrest due to electrolyte
abnormalities, the measurement of serum electrolytes
may allow for direct therapy in addition to standard CPR.
45. • Hemodynamic optimization protocols during the CPA
phase are clinically feasible and potentially useful in
unstable animals- CO instability after CPA can be
attributed to the disease. To maintain adequate organ
perfusion following ROSC.
• There is good evidence to advocate normoxemia versus
hyperoxemia or hypoxemia in the early PCA period
• Evidence suggests neurological benefit of mild
hypothermia (33+/- 1’C) in the early postresuscitation
period, and that fast rewarming after induced or
uninduced hypothermia may be harmful
Post cardiac arrest
46. • There is no evidence to support routine administration of
corticosteroids, anti-seizure medication, mannitol, or
metabolic protectants after cardiac arrest
• Low –dose corticosteroid tx in patients with persistent
hypotension requiring sympathomimetic support may be
considered – addisons disease
• Hypertonic saline may be considered in animals that are
suspected in having cerebral edema as evidenced by
coma or obtundation after cardiac arrest
47. • More PCA care in a specialty center with advanced
monitoring may have outcome benefits
48. • The goal in PCA is hemodynamic optimization
• Fluid
• Pressors
• Central venous blood oxygen saturation
• Blood lactate
• CVP/Arterial pressures
49. • Fluid therapy there is no evidence currently that supports
or does not support fluid support post ROSC
• There is not evidence the particular pressor usage
compared to standard care results in better outcome.
50. • Support of ventilation and oxygenation
Rapid normalization of blood oxygen, carbon dioxide, pH,
and reoxygenation of ischemic tissue is the primary
objective in PCA period.
51. • Oxygen supplementation
There is good evidence to advocate for
normoxia/normoxemia vs hyperoxemia in early PCA
• Hypothermia after Cardiac Arrest
Lowering the patients’s core temperature to 32-34’C is
widely used in human patients that are in a coma.
There is a beneficial effect on neurologic intact survival of
mild hypothermia ( core temperature of 33+/- 1’C )
institutes as soon as possible and maintained for >12
hours.
52. • Rewarming rate after cardiac arrest
• Slower rewarming rates of rewarming after accidental or
therapeutic hypothermia, slower rewarming rates appear
preferred over a faster rate.
53. • Neuroprotective, metabolic, and supportive strategies
There is no evidence to support routine administration of
corticosteroids, anti-seizure medication, mannitol, or metabolic
protectants after cardiac arrest
Low –dose corticosteroid tx in patients with persistent
hypotension requiring sympathomimetic support may be
considered – addisons disease
Hypertonic saline may be considered in animals that are
suspected in having cerebral edema as evidenced by coma or
obtundation after cardiac arrest
54. • CPR algorithm chart. This chart summarizes the clinical guidelines most relevant to
the patient presenting acutely in CPA. The box surrounded by the grey dashed line
contains, in order, the initial BLS and ALS actions to be taken when a patient is
• diagnosed with CPA:
• (1) administration of chest compressions,
• (2) ventilation support,
• (3) initiation of ECG and EtCO2 monitoring,
• (4) obtaining vascular access for drug administration, and
• (5) administration of reversal agents if any anesthetic/sedative agents have
• been administered.
• The algorithm then enters a loop of 2-minute cycles of CPR with brief pauses between
to rotate compressors, to evaluate the patient for signs of ROSC, and to evaluate the
ECG for a rhythm diagnosis.
Cardiac algorithm
55. • Patients in PEA or asystole should be treated with
vasopressors and, potentially, anticholinergic drugs.
These drugs should be administered no more often than
every other cycle of CPR.
• Patients in VF or pulseless VT should be electrically
defibrillated if a defibrillator is available, or mechanically
defibrillated with a precordial thump if an electrical
defibrillator is not available.
• Immediately after defibrillation, another 2-minute cycle
of BLS should be started immediately.
56.
57. • Figure 2: Post-cardiac arrest (PCA) care algorithm. This chart
summarizes a comprehensive treatment protocol for PCA care that
• includes components of controlled ventilation and oxygenation, goal-
directed hemodynamic optimization, and neuroprotective strategies.
• The sequence shown reflects the order in which each component
should be assessed and treatment initiated. Assessment and
• initiation of treatment for the subsequent component will likely
commence before the endpoints of the previous component have
been completely met. Thus respiratory, hemodynamic, and
neuroprotective treatment strategies will be initiated in parallel in
most cases.
Post Cardiac Arrest Care
