How to reduce anaesthetic risk in geriatric patients

As animals age, changes to multiple organ systems occur that require knowledge from the veterinary team to facilitate adjustments. The changes to these important systems are often not evident to pet owners; studies have shown that clinically significant changes have occurred in up to 30–80% of ‘healthy’ geriatric dogs (Willems et al, 2017). Pet owners often miss common changes and on veterinary examination and laboratory test, changes such as polyuria/polydipsia, changes in urination habits (like stranguria or pollakiuria), weight changes, orthopaedic changes, dental disease, and liver and kidney enzyme elevations are discovered (Willems et al, 2017).

Veterinary teams need to ensure that pet owners are educated on the importance of regular physical examinations and closely observing their pets, watching for changes to appetite and behaviour at home. Prior to coming to the hospital for any anaesthetic event, geriatric pet owners should receive directions tailored to their pet's specific needs. Any fasting for these animals should be reduced to only 4–6 hours (Grubb et al, 2020). A small meal can be offered in the morning to help reduce gastro-esophageal reflux. All chronic medications such as thyroid, behaviour modification, steroids, antibiotics, and analgesics should be given as normal. Cardiac patients should not receive their angiotensin-converting enzyme (ACE) inhibitors the morning of anaesthesia and insulin should be discussed with the veterinary surgeon (Grubb et al, 2020). Stress and anxiety should be avoided as much as possible and can be reduced by administering gabapentin (30–60 mg/kg in dogs; 10 mg/kg up to 100 mg/cat in cats) 1–3 hours prior to arrival at the hospital. It is important for the team to ask about and then record the use of gabapentin, as morphine and hydromorphone have been shown to increase gabapentin activity, and gabapentin can decrease the activity of morphine and hydromorphone (Cirribassi and Ballantyne, 2019).