C section anaesthesia Flashcards
What is the ASA level of animals needing C sections?
Can be anything from elective (1) to big emergency (5)
List changes associated with pregnancy that may affect safe effective anaesthesia
Respiratory:
- ↓ capacity & TLV
- ↑ O₂ demand
- Faster inhalant uptake
= Risk of hypoxaemia & overdose
Cardiovascular:
- ↑ Cardiac output & blood volume
- Delayed reflexes to blood loss
= Risk of hypotension & fetal hypoxia
Neurological:
- ↑ Sensitivity to anaesthetics
= Lower drug requirement, overdose risk
Gastrointestinal:
- Delayed gastric emptying
- ↓ oesophageal sphincter tone
- ↑ gastrin
= Risk of regurgitation & aspiration
Mechanical:
- Enlarged abdomen
- Diaphragm pushed cranially
= Risk of hypoventilation & hypotension
How can anaesthetic risk be minimised for Caesarean sections in cats and dogs?
Choose drugs with short duration of action
Use lowest effective dose
Provide oxygen & intubate with cuffed tube, head elevated
- Small stomach +- recent food –> risk of regurgitation
Use local anaesthetics if possible to reduce MAC & provide analgesia
Position dam carefully to reduce regurgitation & CVC compression
Monitor ABP & administer IV fluids
How should puppies and kittens be cared for immediately after delivery?
Place in warm, dry environment
Clear membranes & fluid from mouth & nose
- Suction, cotton buds, bulb syringe
- Perform vigorous rubbing
Consider oxygen therapy
Check for hypoxaemia & consider naloxone (IM, PO, or IV via umbilical vein)
Avoid doxapram (increases oxygen demand)
Use GV26 acupuncture point
- Respiratory stimulant
Perform APGAR scoring
What are the key steps in C-section anaesthesia for dogs?
- Premedication
- Opioid (Buprenorphine/Methadone)
- Antiemetic (Maropitant, Ondansetron) - Equipment Check
- Anaesthesia & neonatal resuscitation setup - IV Cannula Placement & start fluids
- Preoxygenation & Induction – Alfaxalone/Propofol, head elevated
- Anaesthesia Maintenance & Monitoring
- Surgery & Local Anaesthetic – Line block, table tilt, IVFT 10-20 ml/kg/hr
- Postoperative Recovery – Warming, analgesia, NSAIDs
- Discharge – Pain assessment, continued NSAIDs
How should IV fluid therapy be managed in a pregnant dam?
Higher IVFT rates due to increased blood volume
Monitor BP closely; be ready for boluses if pressure drops
Use Hartmann’s (10-20 ml/kg/hr) or consider colloids
When should NSAIDs be given in a C-section?
At end of procedure, after confirming urine production to ensure renal function
Why is post-op analgesia crucial in a C-section?
Allows proper nursing & bonding
Reduces stress & improves recovery
Use opioids (Buprenorphine/Methadone) & NSAIDs
How can vomiting and aspiration be prevented during C-section anaesthesia?
Use antiemetics (Maropitant, Ondansetron)
Protect airway: Rapid induction & secure intubation
Monitor for regurgitation during recovery
What are key considerations for premedication for dog C-sections?
Drugs cross placenta, affecting neonates
Avoid xylazine (↑ neonatal mortality)
Use alpha-2s cautiously (↓ cardiac output, reversible)
Acepromazine – Use with caution (long-acting, irreversible, hypotension risk)
Opioids preferred for pain control with minimal neonatal effects
Why is careful monitoring of anaesthetic depth important in pregnant dogs?
Pregnancy reduces anaesthetic requirements due to hormonal/neuroinhibitory changes
Monitor closely to avoid overdose due to reduced inhalant requirements (MAC)
What are the main local anaesthesia options for C-sections in cows?
Inverted L Block
Paravertebral Block – Less used due to risk of cow collapsing (L3 block)
How does the inverted L block provide anaesthesia for a C-section?
Blocks tissue along caudal 13th rib & ventral lumbar transverse processes
Creates field of anaesthesia over incision site
Why is the inverted L block commonly used for C-sections?
Simple & easy to perform
Doesn’t affect cow’s ability to stand/walk
Minimises incisional swelling & haematoma formation
What are the limitations of the inverted L block in a C-section?
Incomplete analgesia & muscle relaxation (deep layers)
- esp. obese animals
Higher anaesthetic dose needed (costly, risk of toxicity)
What is the proximal paravertebral block used for in cattle C-sections?
Desensitises T13, L1, L2 spinal nerves
Provides analgesia to skin, muscles & peritoneum of paralumbar fossa
Used for flank laparotomy & C-sections
Why is the proximal paravertebral block beneficial for C-sections?
Small anaesthetic dose needed
Uniform & deep muscle relaxation
No anaesthetic at incision margins (less swelling)
Reduces intra-abdominal pressure
