Pregnancy And Cesarean Section Flashcards
How does pregnancy affect cardiovascular function?
Cardiac output increases 30-50%
-increase HR and SV
Plasma volume increase >RBC increased
BP remains the same
How is respiration affected during pregnancy?
Increased O2 consumption
Decreased PaCO2 (hyperventilation)
- > caused by progesterone
- > respiratory acidosis is compensated metabolically
Decreased functional residual capacity
Decreased pulmonary resistance
Why is there a decreased functional residual capacity in pregnant animals?
Increased abdominal volume
Why is there decreased pulmonary resistance in pregnant animals?
Progesterone causes relaxation of bronchial smooth mm
How does pregnancy affect GI function?
Delayed gastric emptiness
Increased gastric acidity
Decreased lower esophageal sphincter tone —> increased risk of regurgitation/aspiration
Why is gastric emptying delayed in pregnant animals?
Pressure from uterus
Progesterone—>Decrease gastric motility
How does renal function change with pregnancy?
Glomerular filtrate rate increases (parallel with CO)
Decreased BUM and creat
No change in electrolytes
Does pregnancy increase or decreased MAC in the dam?
Decreased
How does pregnancy affect sensitivity to local anesthetics?
Increased sensitivity
T/F: fetal drug metabolism is fast
False
Slow —> immature hepatic microsomal enzyme system
How can we maximize O2 delivery to the fetus?
Maintain dam CO and oxygenation
Avoid uterine contraction or uterine vasoconstriction
What sedatives are NOT recommended in pregnant small animals??
Acepromazine —> long acting, not reversible, fetal depression
Benzodiazepines —> fetal depression
A2 agonstis—> decrease CO
T/F: like in small animals, A2 agonists and Benzodiazepines are not used in pregnant large animals
False
A2 are routinely used in pregnant mares
- > increased uterine pressure and decreased O2 to fetus
- > detomidine may cause less uterine tone compared to Xylazine
Benzodiazepines are commonly used with ketamine
Can opioids cross the placenta? Do we give to pregnant dams?
Yes they cross the placenta
May take 2-6days for fetal elimination
—Reversible, can give naloxone
—administer to mom after neonates are delivered
What induction agents are acceptable in pregnant small animals, what one is not recommended?
Propofol, alfaxalone, and etomidate are all acceptable
Propofol is rapidly metabolized in neonate
Etomidate may have less smooth induction and recovery
Ketamine is not recommended —> increase mortality in neonates
T/F: ketamine is used for induction of pregnant mares
True
—can be used safely in large animals, unlike small animals
What are the side effects of inhalation agent??
Unchanged during pregnancy
- hypotension
- hypoventilation
How would you change your dose of local anesthetics in pregnant animals
Do not give max dose, scale back 25%
Are esters or amides more likely to accumulate?
Amides —> metabolized by hepatic microsomal enzymes
T/F: NSAIDS are not recommended for use during pregnancy
True
What would you include in your premeds to reduce uterine contraction??
Anticholinergic —> glycopyrrolate» atropine
Can be used intra-op for bradycardia
In an emergency C-section, the patient is likely comprised. What underlying problems should you correct FIRST prior to anesthesia?
Hypovolemia
Hypoglycemia
Hypocalcemia
T/F: Horse dystocia is a emergency
True
Foals normally delivered <30mins from membrane rupture
Almost none survive at > 90mins
What are the two approaches in a horse dystocia that anesthesia is required for?
Controlled vaginal delivery (attempted first)
C-section
T/F: in a non-emergent C-section, dogs are fasted
True
What is the technique used for small animal C-section?
Pre-oxygenate 5mins
+/- short acting opioid
Propofol or alfaxalone induction
Rapid control of airway
ISO/Sevoflurane in O2 maintence
Local anesthesia (?)
- > lumbosacral epidural (add morphine for prolonged action) and line block
- > lidocaine or bupivacaine
What are potential complications to epidurals?
Pregnant
—> increased vol of epidural blood vessels
—> increased epidural fat
=> decreased epidural space and increased cranial spread of drug which can lead to hypotension
How should you change your epidural drug volume in pregnant patients
Decrease by 1/3
How should you position your small animal during C-section surgery?
In dorsal recumbency, tilted off of midline to avoid aortocaval compression
What do you do for neonatal care after C-section?
Clear oropharynx Clamp and cut umbilical Towel dry Reverse opioid (1-2drops naloxone sublingually) Heat \+/ - O2
How can your provide analgesia during C-section and during recovery?
Epidural with morphine (up to 24hrs) -> reverse in neonates once delivered
Tramadol or buprenorphine(cat) to go home
Acetaminophen for dog (careful dosing)
-> ABSOLUTELY NOT FOR CAT
What is given for large animal general anesthesia during C-section?
Xylazine/detomidine for sedation
Ketamine + diazepam/midazolam for induction
Rapid control of airway, supply 100% O2 via demand valve ASAP
ISO/sevoflurane for maintence
Mechanically ventilate (hypoxemia and hypercapnia likely)
Why is recovery difficult in lg animals?
Extra weight
Exhausted from labor
Ligament laxity
What locoregional analgesia techniques can be used in small ruminants?
Small ruminants: Line block for lubosacral epidural (morphine)
Lg ruminants: paravertebral block or inverted L block
What drugs are used for analgesia in pregnant horse?
Butorphanol (can reverse in foal) given as caudal epidural
NSAIDS are not recommended during pregnancy or lactation
