Anaesthesia for Caesarean section Flashcards
What ASA category is a Caesarean section
Often an emergency procedure in SA practice
Present in all different states
* Range of ASA categories
Unlikely to be ASA1/2
Physiological alterations in gestation and parturition
Gastric emptying is delayed
More likely to have food in stomach
More instances of regurgitation
pH of gastric fluid is low because of reduced gastrin
Considerations to reduce regurgitation
Keep head elevated
Inflate ET cuff
Position with head up
How can we make anaesthesia safer for Caesarean sections
- Choose drugs with a short duration of action
- Use the lowest possible dose (parturients need less 30-60%)
- Provide oxygen and intubate, cuff tube with head elevated
- Provide opioids to the dam
○ Benefit to dam outweighs risk to neonates - Use local anaesthetics if possible to reduce MAC & provide analgesia
- Position dam carefully to reduce regurg & CVC compression
○ Slightly off midline - Monitor ABP, administer fluids
○ Increases perfusion of placenta
What kind of pre-med should you use?
Pure Mu opioid (methadone)
* Minimal placental transfer
* Profound analgesia
* Degree of sedation
Antiemetic (maropitant)
* Visceral analgesia
* May reduce amount of anaesthetic required
Anaesthetic equipment checks
○ Machine
○ Breathing circuit
○ Vaporiser topped up
○ Adequate oxygen supply
○ Draw up drugs
○ ET tubes - check cuffs
○ Laryngoscope
○ Resus of neonate equipment
Why should you pre oxygenate?
○ 3-5 minutes prevents desaturation during intubation
How should you induce anaesthesia
Slowly over 60s to effect
Propofol or alfaxalone
What local blocks can you do?
Line block
Perioperative analgesia
Degree of peripheral analgesia when nursing
What should you monitor during anaesthesia
○ Blood pressure
○ EtCO2
○ SPO2
○ ECG
○ Reflexes
○ Muscle tone
○ Eye position
○ Temperature
Should you give fluids?
Yes - can go hypovolameic due to blood loss
IV HArtmann’s
○ 10-20mls/kg/hr in dog
○ 5mls/kg/hr in cat
Be prepared to turn down volatile agent in hypovolaemic
When should you give NSAIDs?
When animal is NOT hypovolaemic
Considerations for neonates
- Warm dry box/cage prepared
- Clear away membranes and fluid away from mouth and nose
○ Suction, cotton buds, bulb syringe
○ Vigorous rubbing, swinging - Prepare to intubate if necessary and provide oxygen
○ Oxygen vs room air, ‘flow by’ rarely reaches 100%
○ Slow HR in pups or kittens - likely due to hypoxaemia? - Naloxone - if suspect not responding due to opioid given to dam
○ Im, po, or iv into neonatal umbilical vein - Avoid doxapram
○ Causes increased oxygen consumption - Apgar scoring puppies & kittens
Why would you give naloxone to neonates?
Reverses effects of opioid
Local anaesthesia methods in Ruminants
Inverted L block
Proximal Paravertebral block
Distal paravertebral block
