CPCR

Question 1

What are the warning signs of cardiopulmonary arrest?(7)

Answer 1

•Changes in the respiratory rate, depth, or pattern

–Especially under anaesthesis

–Marked nystagmus – this can be due to hypoxaemia and actually people then turn them up as they think they are light!!

• Weak or irregular pulse
• Bradycardia
• Hypotension
• Unexplained changes in the depth of anaesthesia

–Can appear lighter especially nystagmus

• Cyanosis
• Hypothermia

Question 2

How can you diagnose cardiopulmonary arrest (4)

Answer 2

1) Absence of ventilation and cyanosis
- respiratory arrest
2) Absence of a palpable pulse
- pulse will disappear when systolic pressure < 60 mm Hg
3) Absence of heart sounds
- heart sounds will disappear when systolic pressure < 50 mm Hg
4) Dilatation of the pupils

Question 3

What are the causes of cardiac arrest in a sick animal? (4)

Answer 3

–Cardiovascular collapse due to hypovolaemia

• GDV
• Colic
• Pancreatitis
• Pyometra

–Severe electrolyte derangements (esp potassium)

• GDV - dogs
• Urethral obstruction
• Ruptured bladder – foals, cats

–Small animals with severe underlying cardiac disease

• DCM, HCM
• Rare in large animals

–Trauma

•Cardiac or respiratory arrest!

Question 4

What can cause arrest in healthy animals? (2)

Answer 4

• Neonates at term
• Anaesthesia

Question 5

Is this cardiac or pulmoanary arrest:

A) Vagal stim?

B) Probs with breathing circuit?

C) Drug overdose?

D) At exubation?

Answer 5

A) Resp

B) Resp

C) Cardiac or resp

D) Cardiac or resp

Question 6

What can help CPCR be successful? (5)

Answer 6

• BUT YOU NEED TO CHOOSE YOUR CASES CAREFULLY – you do not attempt it in every single animal
• Need trained staff
• Need a team
• Need to act swiftly
• Need one person – YOU (veterinary surgeon) – to take charge

Question 7

What is the approach in resp arrest?

Answer 7

• Stick with the traditional A, B, C, D (E,F)
• (airway, breathing, circulation, drugs)
• Or D, A, B, C
• If the animal is intubated – this is easy!
• If not and you don’t have the equipment or are struggling then treat as if cardiac arrested
• Ensure you can intubate in lateral

Question 8

What is the apporach to cardiac arrest? And when to do it?

Answer 8

•In a sick patient have a thought in your mind whether you will resuscitate

–They have arrested for a reason

–Can you sort underlying problem?

–HF – DNR!!

• Adult horses with colic – NO esp if in dorsal recumbency under anaesthesia
• Small animals with severe underlying cardiac disease – NO
• Electrolyte derangements
• Vagally induced

–Absolutely!

•Anaesthesia related

–Absolutely

Question 9

•George

–3 year old Texel cross tup

–Acute onset neurological disease

–Arrested whilst performing AO (alanto-occipital) tap

Why has this happened is it caridac or resp?

Answer 9

–Why?

•Touched the brainstem (too acute angle). Near to or in medulla

–Cardiac or respiratory?

•Respiratory

–Still had a heart beat. Started mouth to nose resus!

Question 10

•3 day old Thoroughbred foal

–Ruptured bladder

–Arrested as closing body wall following surgery

–Prior to arrest ET CO2 had started to fall (see capnograph)

–Had a high K pre surgery – was got down to 6.5mmol

Why has this happened is it caridac or resp? What would you have done differently?

Answer 10

–Why?

• To expire CO2 you need breathing and circulation
• This was likely indicating a reduction in CO before the heart stopped.
• Hyperkalaemia – electrolyte derangement in myocardium

–Cardiac or respiratory?

•Resp

–What would you have done differently?

•Wait until K normal

Question 11

•Spike

–15 year old Cob gelding

–Presented with a history of up to 18 hours of signs of severe abdominal pain. Colicking

–In addition the horse had two septic tarsocrural joints

–6 hours of surgery

–Horse was hypoxic and severely hypotensive for much of surgery (not too uncommon in colic)

–Horse observed to stop breathing in the recovery box

Why has this happened? Is it cardiac or resp? What to do next? What may we do next time?

Answer 11

•Why?

–Sick horse with dead intenstine

–SIRS and sepsis

–Could be anaesthesia – less likely

•Cardiac or respiratory?

–Cardiac

•What next?

–CPR

•What might you do differently next time?

–Realised it was a sick horse and then chances of getting it back were minimal

–Shouldn’t have done both surgeries at the same time! Done the colic surgery and then flushed standing or brought back in a few days later

Question 12

• Taloolah
• 12 year old pony mare presented for with a septic fetlock joint
• Called by intern to say pony not breathing
• On arrival pony is profoundly hypotensive, hypoxic and has atrial fibrillation and occasional VPD’s (ventricular ectopic)
• Pony has nystagmus (so they thought to turn up iso)
• What are you going to do next?

Answer 12

–Turn off iso – have injectable ready to keep asleep

–Check the ET tube was in. The cuff was let down and the pony was then cuffed. So the tube was too small and the cuff had then come across the eye of tube.

–Wake the pony up – severely hypoxic and cardiac rhythm. Can do surgery tomorrow

Question 13

How do we do compressions?

What is the rate? Depth? Time?

Answer 13

•High-quality chest compressions should be delivered in uninterrupted cycles of 2 minutes with (most) patients in lateral recumbency

–compression rate of 100–120/min

•Current recommendations – may be increased to recommend 150/min

–compression depth of 1/3–1/2 the width of the chest

•allowing for full elastic recoil of the chest between individual compressions

–SWAP person after a couple of minutes if there is the option

Question 14

What does this show?

Answer 14

>10Kg – Thoracic pump – dogs and foals

High up behind heart – thoracic recoil to push blood out of thoracic cavity around the body

Question 15

What does this show?

Answer 15

<10Kg – Cardiac pump – small dogs and cats. Grab round the heart – get the blood to flow round

Question 16

How do we approach CPCR in an adult horse?

Answer 16

• Need LOTS of people
• EXHAUSTING
• Need to swop in every 2 minutes
• AIM highest compression rate you can
• Throw whole body onto caudo-dorsal lung field
• Horse needs to be in lateral recumbency on solid surface
• Success reported in the literature limited

Question 17

How do we approach the ventillation and breathing?

Answer 17

•Likely that early intubation and ventilation in veterinary CPR highly valuable

–ventilation rate of approximately 10 breaths/min

–tidal volume of 10 mL/kg

–inspiratory time of 1 second delivered simultaneously with compressions

•Mouth-to-snout ventilation or ambu bag is an acceptable alternative to ETT – neither appropriate for adult horse

–Easy to intubate the adult horse

• Repeated rounds of 30 chest compressions followed by 2 rapid breaths in cycles of 2 minutes
• After each 2-minute cycle compressor should be rotated to prevent fatigue

–decreases quality of chest compressions

•Minimise duration of chest compression interruptions between cycles

Question 18

How do you do mouth to snout resuscitation in a dog?

Answer 18

make a seal and go round both nostrils

Question 19

How can you mouth to snout in farm animal?

Answer 19

Cover one nostril

Question 20

What can you do for an animal in ventricular fibrillation?

Answer 20

Defib - unlikely youll have this

Precordial thump with palm of thumb and hit heart as hard as you can

Doesn’t do much in a horse

Question 21

What drugs can you give for ventricular tachycardia? (2)

Answer 21

lidocaine and if that doesn’t work – adrenaline

Question 22

What can you give for asystole? (2)

Answer 22

adrenaline

Atropine only useful if you suspect vaso-stimulation

Question 23

What are the best routes for administration of drugs for CPR? (4)

Answer 23

1) Intravenous (IV)-Preferred route. When giving IV drugs during CPR follow each drug with a bolus of saline or water for injection to encourage transport towards the heart

–cardiopulmonary arrest usually results in hypotension, vasoconstriction, and hypovolaemia

2) Intratracheal (IT)-Advantages are accessibility, close proximity to the left heart via PVs, and large surface area for drug absorption Disadvantages are increased dose required for many drugs (10 times that given IV!), decreased efficacy in the presence of pulmonary disease, and some drugs cannot be given IT as irritant (ie, sodium bicarbonate).
3) Intraosseous (IO) or Intramedullary – BM large venous access to CVS. Access through the trochanteric fossa of the femur or the distal cranial femur during CPR.

Medial aspect of proximal tibia – good

• 4) Intracardiac (IC)-Drugs delivered directly to the heart. When using the IC route, the difficulty comes with the inability of personnel to inject the drugs into the heart. Without the apex beat very difficult!! Problems with delivery of drugs into the myocardium instead of the ventricular chambers. Can result in dysrhythmias, laceration of coronary arteries, and will require you to discontinue basic life support while attempting the IC injections.
• Irritate myocardium – bad
• Move – instead of injecting ventricle; makes a hole and the animal bleeds out

Question 24

What drugs can we use for CPCR? (3)

Answer 24

• Adrenaline
• Vasopression
• Atropine

Question 25

When would we give adrenaline?

Answer 25

–Administer during every other cycle of BLS

Question 26

How does vasopressin work?

Answer 26

–Works on V1 receptor causing vasoconstriction –May work better than Adr in acidic environments –Not shown in people any benefit or contra-indications

Question 27

How does doxapram?

Answer 27

•Its primary use is for the treatment of PRIMARY APNOEA –Ie for a neonate that has NEVER BREATHED –IE that is born via caesarean section and then animal has not engaged in the pelvic canal * Most neonates that have become hypoxic in birth canal have breathed and then stopped * SECONDARY APNOEA * IE they have respiratory arrested and require A,B,C, (D) * Does it matter? –YES –Wasted time with inappropriate, ineffective treatment –Increases cerebral oxygen demand in the face of hypoxia •Increases likelihood of failure and neurological problems –PAS – foals and calves

Question 28

How does electrical defibrillation work?

Answer 28

* Convert chaotic electrical activity of the fibrillating heart to sinus rhythm * Discharge of an electrical current through the myocardium aims to allow SA node to resume its normal rhythm * Perform as soon as ventricular fibrillation diagnosed –success is inversely related to the elapsed time since fibrillation.

Question 29

How do you do external defib?

Answer 29

–Gel applied to the defibrillator paddles –Placed firmly over the heart on each side of the chest –No personnel should be in contact with the patient at the time of discharge, therefore the operator should inform staff to ‘clear’. Energy level = 1-5J/kg.

Question 30

How do you do internal defib?

Answer 30

–Covered in saline soaked swabs to ensure good contact –The paddles cradle the heart opposite each other –Procedure as above –Energy level = 0.1-0.5 J/kg.

Question 31

What can we do with no defib?

Answer 31

Precordial thump

Question 32

What do we do to follow up post CPCR?

Answer 32

•Continue IPPV until patient breathing spontaneously –provide a method of supplementing oxygen in the recovery period * Correct Acidosis: Establish normal renal function or administer sodium bicarbonate if blood gas analysis is available and pH\<7.1 * Cardiac Support: Inotropes may be required to maintain cardiac output and improve renal blood flow. * Fluid Therapy: Fluids should be administered to maintain blood pressure and urine output * Minimise cerebral oedema: Position patient with head inclined upwards, keep PaCO2 in normal range * Assess neurological function * Monitor and maintain urinary output at 1-2ml/kg/hr. * Maintain body temperature