An Update on CPR

Presenter: Louise Clark BVMS, CertVA, Dip.ECVAA, MRCVS, Davies Vet Specialists
A hearty thank you to Louise Clark for this week’s webinar, a stimulating whirlwind tour on approaching cardiopulmonary resuscitation (CPR) in general practice.

Louise opened with an honest review of the statistics for success in CPR, which make rather grim reading. Whilst the immediate outcome following CPR may be favourable, the survival to discharge rates are very low indeed – only 30-40% of humans and 2-10% of dogs and cats make it home following cardiac arrest, mainly due to post-cardiac arrest syndrome.

Therefore it must be understood that CPR does not stop at return of spontaneous circulation, but must be continued with close monitoring in the following 24-48hours.

Anaesthesia-associated cardiac arrest generally has a better outcome, as do events secondary to drug reactions, anaphylaxis, acute hypoxia e.g. airway obstruction, acute haemorrhage and acute stress.

We are fortunate in that our patients are often suffering an airway obstruction as the primary cause and not the very human disease of clogged coronary arteries.

So what is CPR?
Broadly split into 3 parts, the first and most critical is Basic Life Support, i.e. maintaining Airway, Breathing, Circulation (ABC). This must continue throughout the CPR cycle, even if more advanced techniques are also available.

Advanced Life Support describes the use of drugs and ECG plus electrical stimulation.
Prolonged Life Support is the post-recovery period in intensive care, including close monitoring and intensive nursing, and of course here the costs will soar over a 24 hour period.

Recipe for success
Delay worsens outcomes, so be prepared with crash trolley, in-date medication and preferably dosage charts. Record everything you do and give! Ensure all staff receive regular refreshers and ideally training exercises, with a designated “crash team” where feasible.

Typically at least 2 or 3 people will be needed, one in control of ventilation and another performing chest compressions, with perhaps a third to prepare medication, fluids and all the other urgent demands at this time. Ventilation without compression will not work.

When intubating, make sure that close to hand are a mouth gag and dry swab to grip the tongue and clear foreign bodies, and a guide wire to aid passage of the ET tube.

Louise was most scathing of red rubber ET tubes – use transparent tubes to see what’s going on inside, e.g. any blood. Also red tubes kink very easily and have an unreliable cuff. Trans-tracheal intubation is also an option if required. Aim for 10 breaths per minute, 1 sec per breath, but do not hyperventilate! To maintain circulation ensure good chest compression, which is hard work, especially at the required rate of 100-120 compressions per minute, compressing the chest by 25-30% each time. Internal cardiac massage is generally reserved for heroic surgeons, and is rarely popular with clients.  In terms of monitoring, only end tidal Co2 is useful, plus an ECG to identify fibrillation and other abnormalities.

Finally, Louise quickly reviewed the various drugs at our disposal. Firstly, it is important to have an ECG! Lidocaine is used for ventricular fibrillation if identified. Atropine has no benefit once the animal is in cardiac arrest, and must be used at a much earlier stage. Adrenaline (epinephrine) is most effectively used in repeated doses at the lower end of the dose range. Fluids should not be given at high rates and avoid glucose at all costs as it causes brain damage

Maintain a mild hypothermia and allow the patient to warm slowly, without additional heat.
Finally, remember that despite all your best efforts, CPA will often recur and the whole process will have to be repeated, so remember that euthanasia is also an option for these patients.
Do not give – corticosteroids, glucose, seizure prophylaxis or osmotic diuretics such as mannitol (use hypertonic saline).

Dose rates and a full list of medications are available from the webinar.

The Stethoscope’s holiday stand-in (MRCVS)

If you missed the webinar and would like to view the recording please visit:

http://thewebinarvet.com/webinar-archive/


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