1 May 2025
A new study has suggested clinicians should adapt their procedures after their analysis suggested pre-anaesthetic medication could offer substantial benefits.
Allister Webb
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Image: daylight917 / Adobe Stock
A pre-anaesthetic medication could be used to identify intracranial space occupying lesions (iSOLs) and intracranial hypertension (ICH) in dogs, according to a new study.
Researchers have also suggested vets should adapt their anaesthetic protocols to the presence of ICH if dogs meet certain conditions after having intravenous butorphanol administered.
The study, published in the Journal of Veterinary Anaesthesia and Analgesia, observed 53 dogs requiring brain MRI presented to the CVS Group’s Lumbry Park Veterinary Specialists in Hampshire between December 2022 and September 2023.
It found dogs with iSOLs had “significantly higher” median sedation scores within 15 minutes of receiving the opioid than those without, while dogs with ICH achieved recumbency in the same time frame almost twice as frequently as those without.
A median sedation score of 12 was recorded in animals with intracranial disease after 15 minutes, whereas those without had a median score of 5, described as a “distinguishable difference in the sedation level of the dog.”
Recumbency, recorded when a dog lays down without the ability to stand, was achieved by nine out of 10 (90%) of dogs with ICH, compared with 20 out of 43 (46.5%) of dogs without.
The paper suggested a non-invasive method of detecting ICH would be “beneficial” due to the intrusive, expensive, and occasionally challenging nature of directly monitoring intercranial pressure.
Lead researcher Emma Sansby, resident in anaesthesia and analgesia at Lumbry Park, said: “When intracranial disease is suspected, the administration of butorphanol as a premedicant for anaesthesia could be used to predict the presence of MRI-iSOL and MRI-ICH.
“If a dog becomes recumbent or has a sedation score of more than 10 within 15 minutes of butorphanol administration, the animal should be treated with an anaesthesia protocol adapted to the presence of ICH – so as not to increase intracranial pressure.
“These adaptations include, but are not limited to; adequate preoxygenation – to prevent hypoxaemia and elevation of the head to no more than 30 degrees; preventing increases in central venous pressure – by avoiding jugular compression and avoiding excessive intraabdominal and intrathoracic pressure; and a smooth anaesthetic induction – ensuring an adequate depth of anaesthesia prior to tracheal intubation to prevent the cough reflex and judicious mechanical ventilation to enable a low-normal end-tidal carbon dioxide.”
The study was funded through a residency research grant as part of the group’s Clinical Research Awards programme which was launched three years ago.
