30 anesthesia for cesarean sections, neonates, and geriatrics

1. inc. cardiac output

2. inc. blood and plasma vol

3. inc. minute ventilation

4. inc. O2 consumption

5. inc. intragastric pressure

6. inc. renal plasma flow and GFR

list physiologic changes in pregnancy patients that will increase and can affect anesthesia

1. dec. hemoglobin, PCV, plasma protein

2. dec. PaCo2

3. dec. tidal vol., functional residual capacity and total lung capacity

4. dec. total pulmonary resistance and peripheral vascular resistance

5. dec. GI motility, gastric emptying

6. dec. BUN and creatinine

list physiologic changes in pregnancy patients with will decrease and can affect anesthesia

1. venous return decreased in dorsal recumbency (vena cava compression)

2. relative anemia

3. hypocalcemia (small breed, large litter)

4. inc myocardial work

5. inc alveolar ventilation (lower PaCo2)

6. hypoxemia

7. inc. regurg risk

name some potential complications in the dam undergoing anesthesia:

patient has been in active labor for over an hour but no fetus developed (inc. mortality risk for dam and fetus)

when should you perform an emergency c-section?

feti too large (growing too long) or a large litter.

commonly in small breeds like frenchies or english bulldogs = brachycephalic breeds

name a few common causes of dystocia?

b. 100-150 bpm

which heartrate classifies the puppies as being under "fetal stress"

a. 150-200 bpm

b. 100-150 bpm

cerenia (reduce nausea) and metoclopramide or famotidine

what meds can you give to help prevent esophageal reflux or make it less harmful in dams?

prone to hypoxemia --> fetal hypoxemia and acidosis

why should you preoxygenate dams with 100% oxygen for a minimum of 5 mins before induction?

endotracheal tube (should be noted that flow by or masks only do about 30-40%)

what is the most ideal preoxygenation technique, delivering 100% inspired oxygen?

either 1. avoid premeds to promote viable fetuses (bc babies are part of mom circulation and will struggle once born if you give mom drugs)

or 2. administer opioids for sedation and analgesia so induction and maintenance amounts are decreased

what two things should you keep in mind when premedicating dams?

butorphanol and buprenorphine

you can administer opioids for sedation and analgesia to a pregnant dam so induction and maintenance amounts are decreased for anesthesia. what opioids can you use?

opioid

this premed can be used for sedation and analgesia in pregnant dams but may cause respiratory depression and bradycardia so you should try to avoid it if you want viable feti

atropine

which anticholinergic is controversial to use in pregnant dams because it crosses the placenta and could lead to increased O2 consumption by the fetuses

glycopyrrolate

which anticholinergic may be used in pregnant dams because it does not cross the placenta

benzodiazepines (PREFER MIDAZOLAM)

which premed can be used in pregnant dams, though you must be careful because the fetal livers do not metabolize the drug resulting in prolonged sedation. overall causes mild sedation and skeletal muscle relaxation

phenothiazine (Ace), alpha2 (xylazine especially), inhalant inductions

Name the anesthetic medications NOT RECOMMENDED for C-sections:

cause maternal hypotension --> fetal hypoxemia. long duration + no reversal. dec. neonate thermoregulation

why should you not use phenothiazines like ace on pregnant dams

inc. puppy mortality --> cardiovascular bradycardia, arrhythmia, dec. contractility, oxytocin like effects on uterus

why should you not use alpha2 ESP XYLAZINE on pregnant dams

injectable recommended

for pregnant dams, injectable or inhalant anesthesia is recommended over the other.

FALSE --> will inc. stress and catecholamines and may lead to hypoxemia. may also overdose due to dec. functional reserve during pregnancy

true or false: it is preferred that you mask down pregnant dams for c-section rather than anesthetically inject.

yes

is propofol an acceptable induction injection agent for pregnant dams undergoing c-section?

non cumulative

why is propofol preferred for c-section dams?

propofol

this injectable induction agents is metabolized in the liver and crosses placenta but causes hypotension (vasodilation), resp. depression, no analgesia, but is good because its noncumulative

1. avoid premed for viability of puppy sake

2. induce w/ propofol or alfaxalone

3. local anesthesia if possible

4. minimize time under anesthesia for viability sake

pretty much, what is the overall protocol for putting a pregnant dam under for c-section

Yes

can you use alfaxalone for an injectable induction agent in pregnant dams?

Yes, but not typically reached for first because there are significant depressant effects on neonates

can you use ketamine + diazepam for C-section induction?

etomidate is a good induction agent of choice for dams with pre-existing cardiac conditions

why would you use etomidate over propofol or alfaxalone as an induction agent in pregnant dams?

etomidate

which injectable induction agent is acceptable for pregnant dams undergoing c-section, with a rapid induction, short duration, minimal cardiovasc. and resp. depression, though should be administered with benzos to reduce excitation. good for cardiac dz. patients.

thicker

etomidate is a thinner/thicker solution

AVOID

you should use/avoid inhalant anesthesia for pregnant dams undergoing c-sections

1. cardiovasc. and resp. depression

2. MAC is decreased during pregnancy (easy to run them too deep)

3. all cross placenta

name the issues with inhalant anesthetics for pregnant dams undergoing c-sections

maternal hypocapnia --> dec. uterine flow and inc. maternal affinity for hemoglobin --> fetal hypoxemia

why should you avoid hyperventilating pregnant dams when possible?

thiopental, ketamine, inhalant anesthetics

use of which drugs are associated with decreased puppy vigor but not necessarily increase mortality

xylazine NEVER USE

use of which drugs are associated with increased puppy mortality rate

propofol, alfaxalone, isoflurane (but pretty sure you still avoid if you can)

use of which drugs are associated with a lower puppy mortality rate

lidocaine: lasts 60-90 mins

bupivacaine: lasts 4-6 hours

what is the difference in how long lidocaine and bupivacaine last?

FALSE: local anesthetics are good to use and should often be considered

true or false: avoid local anesthetics at all cost in pregnant dams for c-section

epidural, line block, TAP block

in what ways can you administer local anesthetics for c-section patients:

use lidocaine: because it doesn't last on long and has a shorter onset which will be good to allow for dam to leave hospital walking on her own

for epidurals on pregnant dams, you should use lidocaine/bupivacaine

morphine

local blocks do not do analgesia. what can you combine with it for analgesia?

hypotension (due to hemorrhage or inc. intra-abdominal pressure)

name a very common complication during anesthesia for pregnant dams undergoing c-section

MAP below 60 mmHg or Systolic under 80 mmHg

when do you treat hypotension in pregnant dams undergoing c-section

dec. depth, crystalloids, opioid bolus (only if puppies are out), atropine, vasopressor and chronotropic drugs (ephedrine, dobutamine, dopamine)

name the things you can do to correct hypotension in pregnant dams under anesthesia

Ephedrine: improve BP withOUT decreasing uterine blood flow

Dobutamine/Dopamine: improve BP and decreases uterine blood flow

what is the difference between ephedrine and dobutamine/dopamine positive inotropes (all used to improve hypotension)

dopamine

which is often considered better to use in pregnant dams undergoing c-section: dopamine or dobutamine

fetal oropharyngeal cavities

what must you clean in newborns to avoid upper airway obstruction?

if bradycardic aka heartrate over 180 bpm

when should you supplement newborn puppies with oxygen?

causes hypoxia

you CAN use atropine in newborn puppies, but why should you probably NOT?

rub

you should rub/swing newborn puppies to stimulate breathing and movement

doxapram (acupuncture also works)

if rubbing a newborn doesn't work to stimulate breathing, what can you give them sublingually?

neonate

a neonate/pediatric is 4-6 weeks old.

pediatric

a neonate/pediatric is 6-12 weeks old.

2-3x greater

what is tissue oxygen demand like in neonate and pediatric puppies?

fully functional at 8 weeks: avoid drugs with extensive metabolism

when do hepatic and renal systems become fully functional in puppies. why do we care?

dextrose

what do you add to neonatal fluids to prevent hypoglycemia?

Ace and alpha2 (don't use until at LEAST 6-8 mo. of age)

which drugs should you AVOID is pediatric patients?

midazolam

which has shorter duration in neonatal puppies, midazolam or diazepam

provide IPPV and anticholinergic (glycopyrrolate bc it lasts longer)

you can use opioids in neonate puppies, but it may cause respiratory depression and bradycardia. how do you combat this?

lower (also use ones that can be antagonized)

use higher/lower doses of drugs when sedating geriatric patients.

fatigue easily

why do you need oxygen supplementation and IPPV for geriatric patients undergoing anesthesia?

hypothermia and hypotension

what is one of the most common complications of geriatrics undergoing anesthesia?