No one died… Anaesthesia into the future

Anaesthesia monitoring into the future

When I first started learning about anaesthesia I was worried about if the patient would wake up or even survive the surgery. I was thinking about this today and realised that my thinking about anaesthesia has evolved since then. It used to be that I was grateful no one died when I was doing anaesthesia as that would be bad, I would have failed, and it would have taken a life because of my failure.

Today however I realised that it is not just enough that my patient survives any longer; it is how they survive that is more important. It is the quality of the anaesthesia, the maintenance of the depth of anaesthesia and the quality of the recovery from anaesthesia. All of these can be managed with an understanding of physiology, the effects of drugs, and with the correct monitoring. There are specialists in anaesthesia and whilst previously they mainly resided within universities there are many that are moving to private practices and referral hospitals. This means that the quality of anaesthesia is increasing – and in some places is done by specialists that only do anaesthesia which allows a higher standard to be provided.

Something that has always been a big problem here in Slovakia is maintaining temperature as the heating in the hospital is not great, the weather regularly drops below freezing in winter and we do not have warming blankets or systems apart from microwave heat pads which tend to go cold on a long surgery. In addition our monitor does not include an esophageal thermometer so we do not have any continuous monitoring of the body temperature once the patient is under drapes.

Once surgery finished instead of the recovery being as fast as it should the decreased body temperature and hypothermia increased the time that patients took to wake up. This was not so great for the patient however in terms for learning it was something that increased my experience and understanding of the physiology of the body system. It gave me experience in how quickly the temperature of an animal can change and the importance of body surface to volume ratio. Hopefully in the new surgical hospital now it will hopefully be less of a problem with new heating systems.

This is not the only factor that is important when it comes to anaesthesia, one of the things that I find important and I do not like to be without is a cannula which is an injection port into a vein. Normally I would also include fluids here at a low maintenance rate so that if I get problems I can then increase the fluid within the vascular system quickly in response.

It seems that things always come in bunches and so last week we had a few patients that had unwanted heart rhythms during their surgeries. Emergencies can and do occur and in this case from seeing the rhythm on the monitor it took just a minute to prepare the medications needed and get them into the patients because there was an IV cannula in place giving us access.

Thinking forwards I see anaesthesia becoming more about the big picture of pain management to ensure a smoother anaesthesia and recovery without the patient experiencing pain. And that is the entire point of anaesthesia – to allow operations without pain.

A hole in the foot (Day -275)

Cow in crush after amputation

When you put your finger into a hole in the foot of a cow and can feel bone you know it is going be interesting for you and very painful for the cow.

Now to understand what happens here you need to understand that cows have two toes (or claws) that contact the floor on each foot. With such a severe problem involving the bones and tendons of a toe the normal treatment would be amputation of that toe. Cows can generally survive on a single toe pretty well just so long as regular foot trimming and management is carried out.

However in the case of this cow the second toe of the same foot was affected though it was only a mild case at this stage. So if we had done amputation here of the really bad toe, the second toe would deteriorate further to the point where it would not be able to support the cows weight, and so the amputation would be pointless.

Economics unfortunately come into play as each cow in the herd has a value, both as meat and as a milking cow. This can justify the cost of the amputation surgery or whether the cow goes to slaughter – however if she is a good milker it is often the farmers wish to avoid this. Now the economics of amputation followed by slaughter in a week or two do not balance and so a clinical gamble based on years of experience was taken by the doctor here.

Amputation is necessary however this amputation would only be done if the other toe recovered. However as with any infection the key is to remove the source and so it was decided that the necrotic bone, tissue and some of the toe would be removed from the toe that would potentially be later amputated.

This level of injury is painful, and so requires good anaesthesia. In cows anaesthesia is usually local – so it only affects the area of the body where the surgery takes place much like if you yourself go to the dentist.

For the legs we apply a tourniquet to separate the foot from the rest of the body, and then make an injection into the veins of a local anaesthetic drug. This time the anaesthetic drug we used was procain – it is another topic however just quickly when using drugs in cows we have to really careful to use drugs that will not get into meat or milk to protect humans.

I was offered the chance to try to make the anaesthesia, and after my dismal first attempt at blood collection on Monday made amends by putting the needle, and then the anaesthetic drug directly into the vein on my first attempt (yay!). Still really believe it was complete beginners luck as me and cows have not really ever got acquainted.

The doctor removed the sesamoid bone and the tendon around this before then debriding the open bone surfaces of the digit. In this process the bottom of the joint capsule was lost and so in an attempt to help preserve the toe for another two weeks for the second toe to heal we also placed antibiotic drugs into the joint space.

Just to show how well an amputation heals (and to avoid gross photos) I’ve chosen today’s photo to be a cow that had an amputation around 6 weeks before.

Wrestling cows and a popping eye…

Vet Student Ruminants practical on the farm

Waking up this morning it was white out with thick fog, however I had a coach to catch to the farm at 8am for a practical class in ruminants. Making it to the bus on time we were told that the heaters were not working. Basically it was warmer outside than in.

Practical class today was scheduled to be on hoof correction as part of our training in cow orthopaedics, however after the first 2 patients this was interrupted with a request for us to go to a downed cow. Now a downed cow just means that the cow cannot stand up – whether it is because of broken bones, nerve damage, neurological problems or electrolyte problems within the body.

The first step therefore was for diagnosis of the problem, the cow had given birth the day before and apparently had been down around 18 hours before we were called. Because of the length of time spent laying there is the potential for major nerve damage and muscle problems. These then compound what could have been a simple problem. As a group we managed to turn the cow to the other side to examine both sides and the neurological responses.

The problem with cows is that they are very big, messy and heavy. I struggled to restrain the head whilst we tried to give the fluids, a man vs a 500Kg animal generally indicates that the animal will win unless specific techniques are used. So to nurse a cow that is down it needs to be turned every 3-4 hours, and requires special equipment for lifting and also for milking. This is something that just doesn’t exist on most farms – and then the manpower doesn’t exist either.

Unfortunately this cow had a very bad prognosis however we tried to give intravenous fluids with glucose and then some calcium. After this the cow managed to stand on her own for a few minutes before collapsing again. We gave it more fluids, and left instructions with the farm workers to watch her for the next few hours before if necessary going for emergency slaughter.

Coming back to the university around lunchtime I somehow ended up getting called to surgery to run anaesthesia on a dog that had prolapsed its eye. This was a high risk patient as it was a brachycephalic breed where the face is squashed flat like with pugs and was also a small dog with a low bodyweight. This causes compromise in the respiratory system so I wanted to run this anaesthesia using a ventilator in case there was problems with the breathing.

This was a very interesting patient as the globe part of the eye was outside of the socket with all the muscles that normally hold it in place torn from it. The eye was so far forward that we also suspected that the optic nerve had been torn as well. The only treatment in this case as the eye is dead is for enucleation. This is where the eye globe is removed from the socket and then the skin closed over the socket.

The patient here recovered from the anaesthesia well, and I was very happy with how it went.