Therapeutics and anaesthesia of the dam and neonates

Question 1

what happens to the diaphragm during pregnancy

Answer 1

increased size of uterus
Cranial displacement of the stomach or altered position
Diaphragm pushed cranially

Question 2

List 3 things that happen to GI system during pregnancy

Answer 2

Increased gastrin production –> increased HCl secretion –>decreased stomach pH
Decreased gastric motility
Reduced oesophageal sphincter tone

Question 3

what is a dog at increased risk of towards the end of gestation

Answer 3

regurgitation
aspirational pneumonia

Question 4

why is oxygen demand increased in pregnant aniamls

Answer 4

Pregnant animals have an increased basal metabolic rate and an increased cardiac workload to meet the demands of the growing fetuses.

Question 5

what happend to lung capacity during pregnancy

Answer 5

it decreases

Question 6

define atelectasis

Answer 6

early closure of the small airways

Question 7

why does atelectasis occur in pregnant patients

Answer 7

there is an increased pleural pressure due to the cranial displacement of the diaphragm

there is also a reduced functional residual capacity

Question 8

why does a V/Q mismatch occur in pregnant patients

Answer 8

due to the early collapse of some alveoli, blood will have to be shunted elsewhere

Question 9

what can be compressed if you place a pregnant animal in dorsal recumbency

Answer 9

the inferior vena cava

Question 10

why does cardiac output increase in pregnant animals

Answer 10

to meet the demands of the fetus

Question 11

what does uterine blood flow depend on

Answer 11

maternal cardiac output and uterine perfusion pressure

Question 12

why does a respiratory alkalosis occur in pregnant patients

Answer 12

due to the increased ventilation

Question 13

do pregnant patients get metabolic alkalosis with their respiratory alkalosis

Answer 13

no, renal compensation keeps their blood pH normal

Question 14

what molecule causes a right shift in haemoglobin affinity in pregnant animals

Answer 14

maternal 2,3-DPG

Question 15

Describe the effects of increased maternal 2,3-DPG

Answer 15

reduced affinity of haemoglobin for oxygen, right shift
facilitates movement of oxygen across the placenta

Question 16

why do we need to consider that pregnant animals have increased progesterone and neuroinhibitors

Answer 16

it reduces the amount of drugs we need to use due to the sedative and antinociceptive effects

Question 17

Define pharmacokinetics

Answer 17

movement of drugs through the body
absorption, distribution, metablism and excretion
what the body does to the drug

Question 18

Define Pharmacodynamics

Answer 18

the body’s biological response to drugs
what the drug does to the body

Question 19

Describe the ASA grades

Answer 19

1. Normal healthy patient
2. Mild systemic disease
3. Severe systemic disease
4. Severe systemic disease that is a constant threat to life
5. morbbibund patient

Question 20

what premed should we give before a c section

Answer 20

opiods at low doses e.g. methadone

Question 21

why do we use pre-meds off licence in pregnant animals

Answer 21

There are currently no drugs licensed for the premedication of pregnant animals, so drug we use are off license and used following the cascade

Question 22

why do we use low dose of pre-med in c-sections

Answer 22

Drugs that cross the blood-brain barrier (and therefore sedative and anaesthetic drugs) will also cross the placental barrier. Therefore, these drugs will affect the neonate as well as the dam.

Question 23

why do we avoid alpha-2’s in pregnant patients

Answer 23

due to their vasoconstriction and reduced CO effects

Question 24

why is acepromazine avoided in pregnant patients

Answer 24

it is long-acting and irreversible

Question 25

why is midazolam/ketamine combination avoided in pregnant patients

Answer 25

neurological depression has been seen in puppies following this combo

Question 26

why are benzodiazepines avoided in pregnant patients

Answer 26

they cross the placenta and are associated with a reduction in neonates

Question 27

Describe how we can prevent hypoxia in pregnant patients

Answer 27

pre-oxygenate for at least 5 mins before induction supplement O2 during surgery

Question 28

Why are pregnant patients at increased risk of regurgitation and aspiration

Answer 28

The cranial stomach position increase intrabdominal pressure reduced oesophgeal sphinchter tone reduced stomach pH

Question 29

Describe how we can reduce the risk of regurgitation and aspiration in pregnant patients

Answer 29

give omeprazole or maropitant prior to intubation prompt induction raise the head and intubate swiftly cuff the tube

Question 30

Describe when to extubate pregnant animals

Answer 30

only once laryngeal reflexes have returned

Question 31

which induction agent should not be used in pregnant animals

Answer 31

Ketamine because associated with decreased likelihood of puppies breathing

Question 32

why do we tilt the table slightly when performing c sections

Answer 32

avoids exacerbating reduced FRC reduces aortovenous compression reduces regurgitation risk

Question 33

why are MAC levels lower in pregnant patients

Answer 33

potentially due to the increased progesterone levels

Question 34

why do we want to use a balance of different anaesthetics in c sections

Answer 34

in order to reduce the level of inhalation agent required

Question 35

if we have hypotension in a pregnant patient, what do we need to do

Answer 35

IVFT to increase BP asap

Question 36

what do inhalation agents cause in pregnant aniamls

Answer 36

Inhalation anaesthetics cause significant cardiovascular depression in both dam and the neonates

Question 37

what is placental blood flow dependent on

Answer 37

maternal blood pressure

Question 38

Why do we need to be careful of hypocapnia in pregnant patients

Answer 38

this can cause placental vasoconstriction

Question 39

what does the alveolar recruitment manoeuvre do

Answer 39

inflate the lungs in order to open up the alveoli

Question 40

why do we give NSAIDs post c section

Answer 40

they provide adequate analgesia and are not excreted in milk

Question 41

List 4 ways that we can assist neonatal ventilation

Answer 41

mouth-to-mouth intubation IPPV flow by oxygen

Question 42

List 3 things we should do after puppies are born via c-section

Answer 42

prepare a warm box/cage or incubator Clear away any membranes and fluid from the mouth and nose Rub vigorously (avoid swinging)

Question 43

if we gave opiods to the dam and we have lethargic puppies, what can we consider

Answer 43

naloxone to reverse the opiods

Question 44

why do we no longer recommend swinging puppies after they are born

Answer 44

it can cause head/neck trauma and haemorrhage

Question 45

why do we want to avoid giving new born puppies doxapram

Answer 45

it increases cerebral oxygen demand

Question 46

What is normal neonatal canine heart rate

Answer 46

over 220bpm

Question 47

what is a suitable choice of induction agent for a dog undergoing a C-section

Answer 47

either propofol or alfaxalone

Question 48

in a pregnant animal, how might the reduction in FRC (functional residual capacity) affect tissue oxygen delivery

Answer 48

reduces oxygen delivery by causing ventilation/perfusion mismatch