Age-Related Considerations for Anesthesia & Analgesia Flashcards
What are neonatal, pediatric, and geriatric patients?
NEONATAL = up to 4 weeks
PEDIATRIC = up to 12 weeks
GERIATRIC = greater than 75-85% of breed/species life expectancy
How does age and size contribute to anesthesia risk?
- cats under 6 months have a lower risk of mortality
- smaller dogs (<5 kg) and cats (<2 kg) have a higher risk of mortality
Why are smaller patients at a higher risk for mortality?
- shivering and increased oxygen consumption
- monitoring challenges
- IV access
- airway management challenges
How does the cardiovascular system develop upon birth? How can this affect anesthesia?
BIRTH = increased SVR and decreased PVR, which causes a reversal of blood flow through PDA and closure of foramen ovale
changes are not anatomical for several weeks and hypoxemia or acid base imbalances from anesthesia can cause re-opening of fetal circulation due to an altered PVR
What determines MAP? CO? SV?
MAP = CO x SVR
CO = SV x HR
SV = inotropy x afterload x preload
What is especially poorly tolerated in the neonatal cardiovascular system? What does this result in?
bradycardia —> CO is rate dependent
- low pressure and SVR
- poor ability to vasoconstric
How does the pediatric SNS affect reaction to anesthetic drugs?
underdevelpment = poor response to inotropes and vasopressors
Other than bradycardia, what else is poorly tolerated in pediatric patients?
blood loss greater than 5 mL/kg —> hematopoiesis poor until 2-3 months
What are 4 differences in the pediatric respiratory system? How are they addressed for anesthetic procedures?
- large tongue + narrow airway = higher airway resistance
- FRC closer to or lower than CC = atelectasis
- high lung and chest wall compliance
- higher RR = tissue oxygenation demand higher
respiratory depressants have a profound negative effect —> supplemental oxygen and ventilatory assistance helpful
What is the pediatric hepatic system like? How does this affect anesthesia?
- immature microsomal enzyme system = drug metabolism and transformation not fully functional until 8 weeks
- minimal glycogen storage = supplemental glucose needed for longer procedures
- low plasma albumin = increased impact of protein-bound drugs
What is the pediatric renal system like?
reduced function until 6-8 weeks = cannot tolerate large volumes given rapidly and not as able to concentrate urine
What is hydration, temperature regulation, and BBB like in pediatric patients?
higher TBW and ECF volume = dehydration happens rapidly at smaller volume losses
low SQ body fat and high SA:body mass = hypothermia
increased permeability = lower anesthetic drug dose needed
What fasting is required in neonatal/pediatric anesthesia? What is necessary before performing anesthesia?
<2 hr or none at all - low glucose stores! (6 hr at most)
accurate BW day of procedure
What are important aspects of neonatal/pediatric anesthesia?
- dilute drugs for accuracy
- use reversible drugs
- pre-emptive analgesia including local blocks
- monitor HR and aggressively treat bradycardia
- avoid blood loss, be careful with fluid administration (immature renal function)
- monitor pulse ox and supplement oxygen
- prevent, avoid, and treat hypothermia
- keep anesthesia time to the shortest possible duration
What are the main 8 things that make anesthetic events difficult for puppies and kittens?
- handling can cause excitement at induction
- easy to traumatize soft tissue with intubation
- challenging IV access
- HYPOTHERMIA
- hypoglycemia
- bradycardia
- monitors do not work well due to size
- jaw tone and palpebral reflex not goof indicators of depth at this age —> rely on monitors and physiologic values
