Anaesthesia: Challenging and hands-on EMS experience

Dog under anaesthetic
Veterinary students always want to be able to get hands-on experience during EMS. Anaesthesia is one area where we can challenge ourselves.

Calculating drug dosages

Ask the supervising vet if you can calculate and draw up the sedative or anaesthetic drugs for an animal. Committing dose rates of particular drugs to memory isn't necessary as they will come with experience, and, if in doubt, you can always consult the formulary. What's important is getting good at actually calculating doses (sometimes quickly and without a calculator; for example, in an emergency) and then drawing them up accurately with an appropriate needle and syringe.

Remember to double-check all drugs and dosages with the vet in charge of the case.

Familiarity with sedatives, anaesthetics and analgesics

Many practices have a ‘standard’ sedation or anaesthetic protocol for dogs and cats. This is common in busy practices where there may be several operations taking place each day and there simply isn't the time or resources to create a tailored anaesthetic plan for each patient. This can also be useful for vet students as it helps us to become familiar with particular drugs and drug combinations. It is often said that the safest anaesthetic is the one you know.

It is important that you also actively think about individual cases yourself. If you were the vet in charge, would you do anything differently? The one-size-fits-all approach may not always be the best choice. Perhaps you have seen a particular drug or drug combination used that you weren't keen on; equally, you may find a technique that you feel comfortable with. What interests me about anaesthesia is that there is rarely one approach or one solution to a problem.


"It is important that you also actively think about individual cases yourself. If you were the vet in charge, would you do anything differently?" 


If the opportunity arises, ask the vet to let you design your own anaesthetic plan for an animal, and effectively ‘manage’ the anaesthesia under their guidance.

Placing intravenous catheters

EMS provides an excellent chance to practise cannulation. Practising this technique simply can't be recreated on anything other than a real animal, regardless of how good the dummy leg is in your vet school's clinical skills lab. I have found that most vets and nurses are more than willing to let you place catheters unless the animal is particularly fractious or has veins that are almost impossible to access.

Know your way around breathing circuits and anaesthetic machines

EMS is the perfect opportunity to familiarise yourself with the workings of the anaesthetic machine. Practice choosing a suitable breathing system and endotracheal tube for a variety of sizes of patient to really appreciate the differences.

Once it is set up, you could offer to leak test the system, check the level of inhalational agent in the vaporiser and the level of oxygen in the cylinder – make yourself popular with the nurses!

Become a vigilant monitor of anaesthesia, including during the recovery period

As a vet student, this is definitely an area you can help the nurses with. It allows you to get used to filling in an anaesthetic record, which should ideally be done every five minutes. You can practice taking the heart rate, respiratory rate and rectal temperature, feeling pulses and assessing depth of anaesthesia. Learn to recognise variations in these and what can be done to correct problems if they arise. Also get used to setting up and interpreting monitoring equipment such as ECG leads, pulse oximetry and capnography – different practices use different pieces of monitoring equipment.


"EMS is the perfect opportunity to familiarise yourself with the workings of the anaesthetic machine"


It is crucial to realise that anaesthesia does not end when the vaporiser is turned off and the vet goes to write up their notes and get a cup of coffee. In a study into perioperative death in small animals, postoperative deaths accounted for 47 per cent of deaths in dogs, 61 per cent in cats and 64 per cent in rabbits (Brodbelt and others 2008). Good postoperative care involves ensuring the animal is pain-free, warm, comfortable and adequately hydrated.

On placement, it is good practice to keep an eye on a recently anaesthetised animal after surgery, and it shows you have thought about that animal's welfare.


Anaesthesia and analgesia go hand in hand. On EMS, you could think about creating an analgesic plan as well as an anaesthetic plan – consider the likely degree of pain, which drug(s) you would use and their route of administration. There are several postoperative pain scoring systems available for use in dogs and cats; one of the most widely used is the Glasgow Composite Pain Scale, and it might be useful to familiarise yourself with some of the criteria used to assess pain in companion animals ahead of an EMS placement.


BRODBELT D. C., BLISSITT K. J., HAMMOND R. A., NEATH P. J., YOUNG L. E., PFEIFFER D. U., WOOD J. L. (2008) The risk of death: the confidential enquiry into perioperative small animal fatalities. Veterinary Anaesthesia and Analgesia 35, 365–373


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