Felipe M.

Hi there Samantha

I am glad you are finding the information useful, thank you so much!

Great question, and a valid concern.

Indeed, (sidestream, the most common) capnography monitors can get damaged if water is suctioned in the line by the pump and it goes into the infrared spectrometer. However, in order to stop this, there is most often a water trap (where the line connects to the monitor, a plastic receptacle with a clear cup), that prevents this. Condensation suctioned in the line is collected there. It is good practice to always make sure at the end of an anaesthetic or a workday that the water trap is emptied (in most monitors the water trap can be taken off and clear cup comes apart for this reason). This water trap is usually changed every so often (as per manufacturer’s recommendations).

During a dental there is indeed a lot of lavage fluid in the mouth, however this should never be going inside the airway. Use of appropriate size cuffed et tubes, with cuff inflated appropriately and having a leak free airway, together with effective throat packing and head positioning should mean no lavage enters the airway. Should all connections be appropriately tight, the only way of this water to go in the capnograph would be if said water has entered the airway, which would certainly cause major problems in our patients.

Some additional precautions can be taken anyway, which are good practice. Keeping the insert of the capnograph to the breathing system uppermost (by rotating the attachment, never the ET tube inside the trachea!) avoids condensation pick up and prevents the line insert being in a pool of lavage. Covering said insert with swabs can also help. Lastly, something we use for every and any patient is a HME. These filters prevent bacteria and condensation from going into the breathing system, and since the capnograph insert is beyond the filter, no condensation ever makes it to the capnograph. Ensuring the capnograph line is not split (especially where it joins the luer connector) is necessary to avoid isoflurane leaking, artifactual capnography readings and fluids potentially entering the line too.

In any case, lavage should never make it inside the airway, which is the most likely place where it would be picked up by the capnograph.

We use and have always used capnographs for any and every procedure, including those with copious lavage or bleeding around the area and I cannot remember a time fluid has gone in the capnograph.

So in summary, look after your capnographs but look after your airways even more! By all means use your capnograph for all your dentals, just be mindful of connections being tight, airway being secure, and equipment being in good working order and you should always be fine. And in any case, the water trap should be there in case.

Hope this helps!

Felipe

Replying to Emma S. 17/05/2023 - 17:13

Hi Emma!

That is fantastic to hear, thank you very much! 🙂

Felipe

Replying to Okba Takieddine C. 16/05/2023 - 10:46

Hello everyone!

Be very welcome to this course.

I am so happy you have chosen us to learn a bit more about anaesthesia! I really hope you enjoy this course as much as I have enjoyed creating every lesson.

Anaesthesia, like any other discipline, is a very wide field that can be very challenging to condense to a course format. For this reason I took what I have found over the years that is the basic foundations that have the biggest impact on patient safety and care, put it together with those things I am asked most frequently by colleagues, and made this course in the most practical manner possible.

However, you may find that there are things you wanted to know about that haven’t been touched in the depth you wanted during the course. No problem at all! This forum is here for everyone to ask those questions they would like more information on or clarifying further. Do not be afraid to ask away, even if you think it is a very basic question. There are certainly no silly questions, especially when even the most basic principles in anaesthesia are fundamental to maximising patient safety.

You will hear me repeat “patient safety” endless times during the course. And it is for a reason. In my opinion, anaesthesia has several aims, but one is the most important. Obviously we want to provide analgesia, amnesia, muscle relaxation and overall anaesthesia to the animal undergoing a procedure, but for me the most important is patient safety. When an animal is under the anaesthetist care, the paramount duty of the anaesthetist is to ensure the animal is safe while the needed procedures are performed, so the patient can go back to their normal lives without any impediments. I am convinced little changes and tweaks to our everyday practice can have a massive impact in patient safety, and this then became the priority in the course! I hope you find it very useful.

I will post a question every now and then for everyone to have a think and fire your most wild guesses. Please do not be afraid to answer!

So all in all, thank you once more for being here, and be very very welcome!

Excellent!

Felipe

Dear Emma

Lovely to read you again!

Great question indeed.

To begin with, I’d say, in additive order my protocols would be:

– OA: Frunevetmab injections (solensia) +\- NSAIDs +\- gabapentin +\- amantadine

– Dental pain: NSAIDs +\- gabapentin +\- amantadine

In terms of NSAIDs in IRIS stage 2 and 3 CKD, there are a couple of studies looking at this:

Meloxicam: it has been tested up to 6 months, with a lower daily dose (0.02mg/kg), in cats with IRIS stage 2 and 3 CKD. No deleterious effects were found. (Reference: 10.1177/1098612X20935750.)

Robenacoxib: it has been tested for up to a month, with a daily dose ranging between 1 to 2.4mg/kg, in a population that included a good number of IRIS stage 3 CKD. No deleterious effects were found (Reference: 10.1177/1098612X15590870)

So in terms of NSAIDs and CKD I would say the current consensus is that its use in this population should still be judicious and on a risk-benefit basis, always aiming to use the lowest dose that gives a clinical effect. On the other hand it is accepted these two drugs seem to be well tolerated chronically, provided the animals are well hydrated (I.e. encouraging extra water intake, etc.). I would still recommend monitoring the renal parameters once or twice a year (at the end of the day no studies have monitored beyond 6 months).

I hope this helps!

Thank you

Felipe

Hi there Gosia

Thanks a lot for this question, I am very happy to hear you are finding the course helpful!

Excellent question indeed, and a very common topic.

As I elaborated on in the course, the dose of medetomidine used and even recommended by some charts can be astonishingly high. In addition, and in my opinion, the induction of general anaesthesia via a single intramuscular injection is only justified in exceptional circumstances. In the vast majority of cases and standard clinical environments, I cannot find a justification for not using an IM pre-anaesthetic medication, IV access, pre-oxygenation, and IV induction with the agent titrated to effect. This is indeed how I manage all my feline patients, and how I have done it for years now with the main reason being sheer patient safety.

In first place, very well done for pursuing change!

Secondly, I completely agree on the concern of using high doses (if any) medetomidine in animals younger than 3 months. The direct evidence might not be overly available but we can make a very reasonable inference and recommendations are made in some books. We know paediatric patients (up to 3 months old, approximately) have a limited myocardial contractility and therefore the cardiac output is largely heart rate dependent (this is detailed in Lumb & Jones Veterinary Anaesthesia, in chapter 53, Neonatal and Paediatric patients). We know as well alpha-2 agonists produce a marked decrease in cardiac output, and especially heart rate (plenty of evidence, but one of the main research papers would be Pypendop et al 2011, in Vet Anaesth Analg, DOI: 10.1111/j.1467-2995.2011.00663.x). With this two things in hand, alpha-2 agonists should be used, if at all, “judiciously at low doses, in selected young patients with no cardiovascular disease” (this is again from Lumb & Jones, same chapter). They go on afterwards to elaborate on the potentially detrimental effects they may have anyway on very young animals, which should be taken into account.

With all this in hand, my personal recommendation and my clinical praxis, is to avoid alpha-2 agonists in animals younger than 3 months, and use low doses in animals older than 3-months but not far from this age. Other combinations like opioid+midazolam+ketamine or opioid+midazolam+alfaxalone, administered IM to achieve sedation (not at anaesthetic doses) can be used instead to a satisfactory result. This is then followed by IV placement and pre-oxygenation and induction with IV alfaxalone given to effect, plus maintenance with isoflurane.

As a general thought, paediatric animals are not “stronger” and therefore can cope/need higher doses, but quite the opposite in some respects.

I hope this helps, but by all means let me know if you’d like me to elaborate on any of the above or if you need additional help!

Once again thank you so much, and great to hear you are working towards tweaking you anaesthetic protocols!

Felipe