Age Conciderations Flashcards
Neonatal are animals younger than ??
Dog and cat < 6weeks
Foals and calves < 2weeks
Pediatric animals are less than ??
12weeks old
How does the cardiovascular system of neonates differ from adults?
Dependent on heart rate for CO —> minimal ability to increase contractility
Immature sympathetic NS
Increased extracellular fluid volume
Higher metabolic rate
Persistent fetal circulation (esp in foals)
How does the respiratory system of neonates differ from adults?
High resting respiratory rate/minute ventilation
- d/t increased O2 demand
Greater work of breathing
Minimal pulmonary reserve
What hematologic differences are present in neonates compared to adults?
PCV decreases 1/3 in fist 28days in small animals
-Blood loss -> significant decreased in O2 delivery to tissues
Hypoalbuminemia
-highly protein-bound drugs will have greater activity
Why are drug effects prolonged in neonates?
Deficient hepatic microsomal enzymes
Decreased GFR
Why are neonates susceptible to hypoglycemia?
High metabolism and minimal hepatic glycogen
T/F: pain experienced as a neonate may cause altered pain processing/perception for life ?
True
—> analgesia important in all ages
How long do you fast nursing animals? What about weaned animals?
You don’t fast nursing animals —> susceptible to hypoglycemia
Weaned - 3-4hrs
Where do you get IV catheter access in neonates?
IV catheter difficult or impossible
Intraosseous —> anything given IV can be given IO
Fluid, blood product, drugs
Why are phenothiazines and A2 agonsits not recommended ?
Acepromazine —> hypotension
A2 agonsit—> bradycardia
CV depression cannot be handled well in neonate
What are generally safe sedatives in young animals? Which of this family of drugs is usually preferred?
Benzodiazepines
Midazolam because it requires less liver metabolism
What is a good choice drug for analgesia +/- sedation in young and geriatric animals?
Opioids
- minimal CV/resp effects
- reversible
Pure mu > partial
Buprenorphine has long duration of action and is poorly reversible
What do we often give young animals with premed to maintain heart rate for CO?
Anticholinergic
—young animals are solely reliable on HR for cardiac output because they cannot change contractility
Can NSAIDS be used in neonates?
Nope
Immature hepatic and renal function
NSAIDS 4-6months minimum
What is used for induction in young animals?
Propofol -rapid onset and recover but can cause hypotension and respiratory depression
Alfaxalone -rapid onset, CV stability, but respiratory depression (use in sick or if there are CV problems )
Etomidate- rapid onset, CVstability, but respiratory depression
Ketamine - longer induction and recover, hepatically meatbolized (longer duration than in adult)
T/F: foals can be induced with iso/sevoflurane
True
- via nasotracheal tube
—> smooth induction
What is used for maintenance in young?
Sevoflurane / iso
Minimal metabolism
Can cause hypotension and hypoventilation
What is the BP in neonates?
50mmHg
Why do you need to be careful when administering fluids to young?
Higher daily fluid requirements, BUT less tolerant of fluid overload
How does the cardiovascular system change in geriatric patients?
Dependent on atrial kick and normal sinus rhythm for cardiac output
-adequate preload is important
Limited ability to increase HR
-LEss responsive baroreceptors
Rely on increased SV to increase Cardiac output
Decreased
-arterial and myocardial compliance
May have valvular incompetence
How does respiratory function change in geriatric patients?
Overall decreased in function and efficiency
-decreased—> gas exchange, viral capacity, thoracic compliance, and lung elasticity
-decreased PaO2
Increased work of breathing
Why is there usually prolonged DOA of drugs in geriatrics?
Decreased liver mass- decrease drug clearance
Decreased kidney mass and fontina nephrons
-> decreased GFR, decreased concentration of urine, decreased volume correction
Is MAC increased/decreased in geriatrics?
Decreased
Do geriatrics have more or less body water?
Decreased —> increased plasma drug concentration
What sedatives can be used in a HEALTY older patient?
Phenothiazines and A2 agonists
- cause CV side effects
- conservative dosing
What would you use as a sedative in a sick geriatric patient?
Benzodiazepines
-maintains resp and CV runtion
How would you sedate an ancient crabby cat??
Heavy IM sedation may be needed for diagnostics of IVC placement
May have murmur, hyperthyroid, or renal disease
Alfaxalone is probably the most appropriate with opioid and benzo
Dexmedetomidine and ketamine can have significant CV effects, avoid if possible
Would you use anticholinergic as part of your premed in geriatric animals?
No
- only use as needed for bradycardia or procedures causing vagal stimulation
What are benefits of local anesthetics in geriatrics ?
Provide good analgesia
Decrease MAC
*remember to adjust dose if there is hepatic dysfunction
Can NSAIDS be used in geriatrics?
In healthy, yes
Requires normal liver and kidney function
What induction agent should you avoid in cats with chronic renal fialure?
Ketamine
Excreted renally
Also avoid in cats with confirmed/suspect heart disease —» can precipitate CHF
If your geriatric patient has renal disease, you want to maintain your MAP ______mmHg
> 70
