15. Geriatric Anesthesia

Question 1

What defines a geriatric patient?

Answer 1

When a patient has reached 80% of their anticipated life span
Dogs >8yrs
Cats >12yrs
age is NOT a dz

Question 2

What makes geriatric patients different

Answer 2

with age there is a dec in organ func and reserves
age-related concurrent diseases increase the anesthetic risk
geriatrics tend to have chronic systemic diseases that affect how anesthesia should be managed

Question 3

What are the ASA scores for geriatric patients

Answer 3

ASA 2: healthy geriatric, only minor organ dysfunction
ASA 3: subclinical organ dysfunction - bloodwork or PE findings
ASA 4-5: severe clinical organ dysfunction - exercise intolerance heart dz

Question 4

What are some physiologic changes in geriatrics regarding cardiac diseases

Answer 4

• Most common non-congenital heart disease in dogs is Mitral
  Valve dysfunction (Endocardiosis)
• Most common non-congenital heart disease in cats is
  Hypertrophic Cardiomyopathy (HCM)
• Reduced cardiac reserves, patients are unable to compensate for
  anesthetic induced hypotension
• Hypotension treatment can be very different depending on the
  type of heart disease present

Question 5

What are some cardiac disease considerations?

Answer 5

• Thorough heart work-up will help to adjust anesthetic
  medication according to type of disease present
• It is not always what you think
• Pre-oxygenate and provide oxygen in recovery
• Avoid fluid overload
• Avoid stress, excitement, pain (catecholamine release)

Question 6

What are some physiologic changes in geriatrics that might affect respiratory?

Answer 6

weakened respiratory muscles, inc fibrosis of the lungs,
dec ability to compensate when stressed - hypoxemia during induction and recovery
pre-ox and supply O2 in the recovery period
manual or mechanical ventilation should be anticipated

Question 7

What are some physiologic changes in geriatrics in regards to orga function?

Answer 7

dec renal and hepatic function(dec metabolism = slower recovery), variable patient to patient
pre-anes bloodwork essential for organ screening
liver and kidneys vital to drug metabolism and elimination - dec func = dec drug metabolism

Question 8

What are some physiologic changes in geriatrics of the GIT?

Answer 8

dec laryngeal/pharyngeal reflexes, dec lower esophageal sphincter tone, lower gastric pH, more prone to esophagitis and regurgitation with anesthetic

Question 9

What are some physiologic changes of the CNS in geriatric patients

Answer 9

loss of senses (blind, deaf)
Dec cognitive function
senility
the results of age relate degradation -> inc anxiety, inc risk of emergence delirium and dysphoria due to anesthetic drugs

Question 10

What are some generalized anesthetic considerations for geriatrics?

Answer 10

gentle handling, minimize patient stress
pre-ox and supply O2 post-op
IV fluids adjusted accorded to concurrent dz
may need to provide manual or mechanical ventilation
monitor closely for hypothermia
take care when positioning geriatrics bc of arthritis
Manage BP aggressively (MAP >80mmHg), anticipate a long and dysphoric recovery
Any current meds that will compound effects of sedatives
Use short-active, easily eliminated drugs
when using sedatives, use the low end of the dose range
use co-induction agents when possible, to minimize hypotension during induction (ex. midazolam/alfaxalone)

Question 11

midazolam is a good ppetite stimulant for geriatrics