30. Anesthesia for C-sections, Neonates, and Geriatrics

physiologic changes in pregnancy

what is shown here

decreases in cardiac output which goes on to affect BP

venous return can be decreased in the dam when placed dorsally due to compression of the vena cava by the gravid uterus which results in what effects on the heart

20%

the dam has a risk of relative anima and the maternal BV increases ____, with larger increases in plasma volume....if PCV is normal then she is dehydrated

test of the functional Ca that is available to be used

why is the ionized Ca test preferred in cases of hypocalcemia

potential complications in the Dam

what is shown here

1. patient in active labor for >1hr w/ no fetus delivered

2. may be in a compromised metabolic state

3. viability of puppies a concern

characteristics of emergency C-section

1. gestation length known

2. during "normal" hours of the hospital with plenty of help

3. patient is fasted

characteristics of planned C-section

big heads of puppies are too big for mom to pass

what is the most common cause of dystocia

1. signalment: commonly brachycephalic

2. history: medications and how long shes been in labor

3. PE: abdominal U/s and fetal HR of 150-200bpm

4. bloodwork: PCV, T.S., BUN, calcium, glucose, electrolytes

what is involved in the assessment of patient for C-section

shave abdomen and dirty scrub prior to induction

it is ideal to do what for c-section when prepping so we can induce in the OR

5-10 mins of induction

what is the ideal time frame to have puppies/kittens out of mom

anesthesia, surgery, and puppies based on availability

in a c-section, we should have personnel devoted to....

esophageal reflux

due to increased gastric acid and decreased lower esophageal tone, C-section dogs are prone to what

fetal hypoxemia and acidosis

maternal hypoxemia =

rapid intubation

it is important to preoxygenate C-section dogs for a minimum of 5 mins but to be prepared for....

1. premeds will affect the fetus so need to move quickly

2. opioids like pure mu agonists are useful and are reversible...short acting antagonizing drugs ideal

important considerations for pre-meds in c-sections

do not readily cross placenta

importance of highly protein bound drugs in C-section...something like buprenorphine but needs multimodal approach to make it work

decreased fetal viability and fetal livers do not metabolize due to immature enzyme systems so prolonged sedation

why do we avoid benzodiazepines as premeds in C-section

acepromazine/phenothiazines...no reversal and long acting

what pre med is NOT RECOMMENDED FOR C-SECTIONS

oxytocin like effects on uterus...consider after puppies removed

what is the effect of an alpha-2 like xylazine in a c-section

swiftly securing airway reduces risk of aspiration, have suction available, keep patient sternal with head above stomach

what is important about C-section induction

mask anything down

we should not ______ to induce a patient, use injectable technique instead

propofol and alfaxalone

what is considered a great induction agents for C-sections

ketamine causes depressant effects in breathing of neonates

why do we not use ketamine + midazolam in c-sections

lipid solubility and low molecular weight

how are inhalants able to cross placenta to cause CV and respiratory depression

16-40%

MAC for isoflurane is decreased in pregnancy to _____

needed due to pressure on diaphragm from uterus...hyperventilation can decrease uterine blood flow leading to fetal hypoxemia

why might we need to utilize manual or mechanical ventilation during C-section

propofol, alfaxalone, and isoflurane

which anesthetic protocol is associated lower puppy morality rate

xylazine, benzos like diazepam

what anesthetic protocols are associated with increased puppy mortality rate

prior to sx. and after and ensure you block the layers as you close

when should lidocaine or bupivacaine line blocks be provided during C-section

liposome encapsulated bupivacaine as a pre and post line block for extended analgesia

function of nocita in c-sections

1. helpful for analgesia so do it if you can but dont take too much time trying to accomplish this

2. lidocaine is his preferred drug

considerations for epidurals

1. ephedrine

2. dobutamine and dopamine

3. ENSURE THERE ARE AGGRESSIVE FLUIDS IF ABLE

what are some of the positive inotropes we can use to support hypotension in mom

1. suction bulbs to clear airway

2. oxygen if bradycardic (want HR >180bpm)

what are the important supplies for managing newborns

1. rub newborn vigorously to stim breathing

2. DO NOT SWING

3. Epi under tongue

4. acupuncture at GV-26

what is important when stimulating puppies

risk of cerebral contusion and hemorrhage

why do we NOT swing puppies

1. local anesthesia

2. minimize time under general anesthesia

review the summary for C-section, what are the two most important things

1. HR dependent so avoid bradycardia and avoid ACE

2. tissue O2 demand is 2-3x greater so predisposed to hypoxemia

3. hypoglycemia can occur due to higher metabolic rate

4. poor thermoregulatory ability so have warming devices ready

important anesthetic points for neonates and pediatric patients

1. avoid ACE and alpha 2 agonists to avoid bradycardia

2. opioids can cause bradycardia so consider anticholinergic...naloxone needed for reversal

considerations for premeds of neonates

1. AGE IS NOT A DISEASE

2. history, PE, BP, stress test and other tests indicated

3. lower doses and short-acting drugs can be used just important to balance anesthesia plan

4. careful titration of IVF

5. decreasing mental status can mean prolonged recoveries in some

important points for anesthesia of geriatric patients