Anesthesia for the Pregnant and Neonatal Patient

Question 1

What cardiovascular changes occur in the pregnant patient?

Answer 1

Plasma > RBC
“Anemia” (PCV 30-35%)
Related to # of fetuses
Increased CO (SV, HR)
Decreased SVR
No changes in MAP

Question 2

What is important to note about compensatory CV reflexes in the pregnant patient?

Answer 2

Reflexes may be delayed

Question 3

What is uteroplacental perfusion dependent on?

Answer 3

Perfusion
Hypotension = decreased fetus perfusion

Question 4

What respiratory changes occur in the pregnant patient?

Answer 4

Pregnant uterus displaces diaphragm
Decreased total lung capacity
Decreased functional residual capacity
O2 consumption increased 20% (Increased TV, RR)
Increased sensitivity to PaCO2
Increased risk for hypoxemia

Question 5

What CNS changes occur in the pregnant patient?

Answer 5

Anesthetic requirement decreased by 25-40%
Increased sensitivity to anesthetics - overdose risk

Question 6

What GI changes occur in the pregnant patient?

Answer 6

Delayed gastric emptying
Decreased esophageal sphincter tone
Increased risk of regurgitation and aspiration

Question 7

How is drug metabolism altered in the neonate?

Answer 7

If drugs cross the BBB, they cross the placenta
Hepatic enzymes may not be fully developed
Increased duration of drugs if metabolized by the liver

Question 8

Fetal blood supply has _____ PaO2.
Fetal hb has _______ affinity for O2.

Answer 8

Fetal blood supply has low PaO2
Fetal Hb has higher affinity for O2
Left shift

Question 9

How can we prevent defecits in rapid desaturation (hypoxemia) in the pregnant patient?

Answer 9

Preoxygenate

Question 10

How can we reduce risk of regurgitation/aspiration in the pregnant patient?

Answer 10

Rapid induction/secure airway

Question 11

What are the general characteristics of drugs for the pregnant patient?

Answer 11

Reversible or short acting
Minimal CV effects
Local/general anesthesia
Titrate drugs carefully

Question 12

Premedication for the small animal pregnant patient

Answer 12

Opioids
+/- anticholinergics (debatable though because bradycardia in fetus is a sign of distress)

Question 13

Premedication for the large animal pregnant patient

Answer 13

Alpha 2 agonists

Question 14

Premedication for the ruminant/camelid pregnant patient

Answer 14

Benzodiazepines or nothing

Question 15

Induction drugs for the pregnant patient

Answer 15

IV only
Propofol (alfaxalone) preferred +/- etomidate (fentanyl) in small animals
Ketamine +/- propofol (benzo) in large animals

Question 16

How much time should you wait post-induction? Why?

Answer 16

15 minutes
Give time for drug redistribution

Question 17

Why is mask induction no longer recommended in pregnant patients?

Answer 17

Stressful
Prolonged
Risk of regurgitation and aspiration
Severe CV and respiratory depression

Question 18

Inhalant anesthesia for the pregnant patient

Answer 18

Iso, Sevo, or Desflurane
Low dose (minimal neonatal depression)
Local/regional analgesia
IPPV helpful
Avoid nitrous oxide

Question 19

Post-operative pain for the pregnant patient

Answer 19

Incision block
Morphine epidural
Systemic opioids
NSAIDs

Question 20

What are the steps of neonatal resuscitaiton?

Answer 20

Remove placental membranes
Clear oropharynx of secretions
Antagonize drugs
Rub chest vigorously
Supplemental O2 and heat
Intubate if needed

Question 21

Why are neonates susceptible to hypoglycemia? Hypothermia?

Answer 21

Reduced glycogen stores
Maintain >70mg/dl
Greater SA: BW = increased heat loss

Question 22

CV considerations of the neonatal patient

Answer 22

Bradycardia (anticholinergics if necessary)
Hypotension (keep map >55)

Question 23

Respiratory considerations of the neonatal patient

Answer 23

Hypoventilation (IPPV if needed)
Atelectasis