16.8.2: Therapeutics/anaesthesia of dam and neonates

Question 1

How does the position of the diaphragm change in pregnancy?

Answer 1

The increased size of the uterus causes cranial displacement of the stomach -> leads to cranial displacement of the diaphragm

Question 2

Describe the changes to the stomach during pregnancy

Answer 2

• Increased gastrin production -> increased HCl secretion -> decreased stomach pH
• Decreased gastric motility
• Reduced oesophageal sphincter tone
• Increased risk of regurgitation + aspiration pneumonia

Question 3

Describe the effect of pregnancy on FRC and the significance of this

Answer 3

• In pregnancy there is reduced functional residual capacity -> these animals can decompensate quickly

Question 4

Describe the effect of pregnancy on the respiratory system

Answer 4

• Increased oxygen consumption and basal metabolic rate due to increased cardiac workload to meet the needs of the foetuses
• Circulating progesterone causes sensitisation of the respiratory system -> deeper, bigger breaths
• Minute volume is increased due to increased tidal volume
• Increased ventilation causes respiratory alkalosis, however blood pH remains normal due to renal compensation (by excreting bicarbonate)