Hypoxemia and General Anesthesia in Horses

Research on restoration of arterial oxygen tension in horses recovering from general anesthesia

Controlled mandatory ventilation during general anesthesia may result in better pulmonary function in horses. Amy Dragoo

This prospective study investigated changes in arterial oxygen tension (PaO) in horses during recovery from general anesthesia. This article was authored by Bardell, D., Mosing, M., Cripps, P.J. of the University of Liverpool in the United Kingdom.

In total, 102 systemically healthy horses undergoing general anesthesia for elective surgery were included in the study. Arterial blood samples were obtained prior to administration of pre‐anesthetic medication (baseline), at the end of anesthesia, when placed in recovery, at 10 minute intervals while in lateral recumbency, immediately upon achieving sternal recumbency, at 10 minute intervals until standing and 1 hour after standing (STAND+1).

Pre‐anesthetic medication consisted of acepromazine, an alpha-2 adrenoreceptor agonist and a µ‐receptor agonist opioid. Induction was achieved with thiopental or ketamine plus a benzodiazepine, and anesthesia was maintained with isoflurane or sevoflurane. Forty horses received controlled mandatory ventilation (CMV) throughout anesthesia, 47 breathed spontaneously (SV) and 15 breathed spontaneously before CMV was commenced (S‐CMV).

Overall, PaO alveolar‐to‐arterial oxygen tension difference (P(A‐a)O) and arterial carbon dioxide tension (PaCO) remained significantly lower than baseline at the STAND+1 time point. The only group in which these values had returned to baseline values at STAND+1 was S‐CMV. CMV resulted in higher PaO at the end of anesthesia and during early recovery than SV. Highest PaO values associated with CMV were also associated with early recovery apnea. Oxygen supplementation in recovery resulted in higher mean PaO than in horses receiving no additional oxygen. High PaO values did not appear to adversely affect outcome.

Bottom line: Controlled mandatory ventilation during general anesthesia may result in better pulmonary function in horses.

For access to this article from Wiley online library click here.

categories
tags
Trending Articles
Yearling filly on pasture
Disease Du Jour: OCD in Horses 
Farrier at the hoof care on the horse
AAEP Health Coverage: Barefoot Methodology
Confident female vet standing by horse in stable
How Equine Veterinarians Can Avoid Mental Traps 
Female Vet With Digital Tablet Examining Horse In Stable
AAEP Business Coverage: Equine Financial Statement Benchmarks 
Newsletter
Get the best from EquiManagement delivered straight to your inbox once a week! Topics include horse care, disease alerts, and vet practitioner updates.

"*" indicates required fields

Name*
Country*

Additional Offers

Untitled
This field is for validation purposes and should be left unchanged.