Preoperative warming

RE: Preoperative warming

James Colver Cert. Ed, RVN — Fri, 05 Oct 2018 23:21:08 GMT

Hi again this one just cropped up on my newsfeed, maybe it's something else that will help with your info gathering! https://www.vettimes.co.uk/article/animal-anaesthesia-what-vet-nurses-need-to-know/

RE: Preoperative warming

Annalise Gray — Tue, 02 Oct 2018 22:41:29 GMT

Thank you Tara. I have private messaged you :)

RE: Preoperative warming

tara sutton — Tue, 02 Oct 2018 14:10:59 GMT

Don't know whether you would find this helpful but I did a mini study on hypothermia in surgical patients 3/4 years ago as it was something I felt my practice needed to improve. If you give me your email address I can send it on to you.

RE: Preoperative warming

Susanna Taylor — Mon, 01 Oct 2018 04:43:06 GMT

Hi. I just want to clarify the concept/theory of ‘prewarming’ that I think the OP is referring to, just to avoid confusion of any readers that may not have come across it before. Prewarming is NOT about raising the patients CORE temp, as this would be detrimental. It is based on the theory of heat being moved from the core to the periphery in the first stage of hypothermia (distributive phase). This occurs because there is a natural gradient between the warm core, and the cooler periphery, and the bodies thermoregulation centres maintain this in balance. Anaesthesia suppresses thermoregulation and the balance is reduced, with warmth from the core travelling to the periphery, it is exacerbated by vasodilation from drugs. The idea of prewarming is to heat the PERIPHERY (only) so there is less of a gradient between it and the core, meaning that under anaesthesia, less heat is lost from the core. I haven’t had time to do an up to date literature search, but I know it was shown to be beneficial in paediatrics and it was regularly used (ie bair hugger applied for 20min before induction). It is important to be able measure skin temp and core temp when using/studying this.

RE: Preoperative warming

James Colver Cert. Ed, RVN — Sun, 30 Sep 2018 23:24:52 GMT

preoperative warming --> only if the patient is hypothermic :) Otherwise, preoperative insulation!

https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=8&ved=2ahUKEwjZg7bN4OPdAhWSTsAKHYBUARYQFjAHegQIAhAC&url=https%3A%2F%2Fwww.vettimes.co.uk%2Farticle%2Fperioperative-hypothermia-prevention-is-better-than-cure%2F%3Fformat%3Dpdf&usg=AOvVaw3igDfyv1QxgIARUtbXVwPo

RE: Preoperative warming

Annalise Gray — Sun, 30 Sep 2018 22:38:48 GMT

Hi, no I haven’t got a bair hugger but I have seen them used before. Thank you for all the information, it’s a great help! It’s really interesting to get other people’s views on preoperative warming and how and when it is used and various techniques that can be used :)

RE: Preoperative warming

James Colver Cert. Ed, RVN — Sun, 30 Sep 2018 21:57:02 GMT

Hi again! At the time of premed, insulating the patient to try to prevent heat loss is the goal, rather than seeking to warm them up. We would use bubble wrap, foil blankets, newspaper (a great insulator) or just towels / blankets.

I would only try to warm a patient up if it had a subnormal temp (as said before, no point in pre-emptive warming). In this instance, I would always try to warm the patient from the inside i.e. warm iv fluids or one of the heaters that go onto the giving set.

It's important to be careful with applying external heat - apart from the obvious risks of burning or scalding an unconscious / recumbent patient, applying heat to the skin will cause peripheral vasodilation, which will for a time take the heat away from the core, where it's needed most of all.

Have you got a bair hugger? They are a brilliant, safe way of providing warmth.

RE: Preoperative warming

James Colver Cert. Ed, RVN — Fri, 28 Sep 2018 17:10:56 GMT

No point in warming a normothermic patient prior to him or her having any drugs - same as no point in volume loading a euvolaemic / normotensive patient with IVFT - as said above, it's likely to be detrimental

RE: Preoperative warming

Annalise Gray — Fri, 28 Sep 2018 10:02:43 GMT

Hi, thank you for your reply and the article it’s really interesting! What method of warming do you use after premed and do you do this for all of your patients? Also, how long are your patients usually warmed for before an anaesthetic?

RE: Preoperative warming

Courtney Scales — Thu, 27 Sep 2018 20:48:09 GMT

Hey! We only heat from premed. I think there are some studies already that don't show much of an advantage as it exacerbates the Phase 1 of hypothermia. Check out this study: