Mod 8b- practice of obstetric anaesthesia Flashcards
What are the options for analgesia in labour?
Etonox(50/50 mixture of oxygen and NO2)- self administered
Opiods: pethidine, morphine-> resp depression
Epidural anaesthesia
Labour epidural analgesia has 5 characteristics, what are they?
All contraindications of neroaxial block apply
Specifically for analgesia
Sited in lumbar area
Low dose local anaestesia-> preserve motor function to bear down
Mayb prolong 2nd stage of labour
What are the 2 options for anaesthesia in C/S
regional(spinal)
GA
What is the standard for C/S anaesthesia?
Spinal anaesthesia: best outcomes for safety, awake mother present at birth early bonding
What are the contraindications to neuraxial block in obstetrics
same as with any neuraxial block
In obs:
- Haemorrhage + hypovolaemia
- Major placenta praevia
- Thrombocytopenia in pre-eclampsia(<75%)
- CVS comorbid
How does a typical obstetric spinal look?
Regular history and examination and consent checking
Antacid prophylaxis: sodium citrate solution
Good IV access
CO-LOADING of isotonic crystalloids at time of block
Spinal at L3/L4, using pencil point needle
Typical dose: 2 mL 0.5% bupivacaine with dextrose
*Added opioid: 10 µg Fentanyl = total dose 2.2 mL
T4 block is achieved in most cases
Supine with 15º left lateral tilt / wedge
What is included in intraoperative monitoring in epidural anaesthesia?
Standard monitoring (NIBP, pulse oximetry, ECG)
Supplemental O2
Anticipate hypotension:
- fluid bolus
- Phenyephrine
- Ephedrne second line
Oxytocin at delivery:
- 2-3 U IV over 30sec
- Infusion 10-20 U in 1000ml crystalloids
What can be done if there is an inadequate blockade of epidural?
Inhaled NO2
Alfentanil 250ug or fentanyl 50 ug(post delivery)
BZD (midazolam 1-2mg)
- amnesia+resp depression
LA infiltration
Convert to GA
What are the 2 options in a patient with an epidural now needing C/S
Remove epidural and do spinal
Keep epidural for post-analgesia, spinal 1 level lower
What is the indications for GA in C/S?
Maternal request (rare)
Any contraindication for neuraxial blockade
Failed blockade
Obstetric indications
* Severe fetal distress (fetal bradycardia)
* Obstetric haemorrhage (placenta praevia, abruptio placentae)
* HELLP syndrome / sever pre-eclampsia
True or false: you can survive without oxygen in C/S
False, you can survive aspiration, but O2 is PARAMOUNT
True or false: obstetric GA is always an elective sequence induction
False, it is always a rapid sequence induction:
- essential to provide O2
- BVM is essential
- Temporary airway must be added like SGA/LMA
What is the general technique with GA
History, examination
Antacid prophylaxis and good IV access
PREOXYGENATION 100% for 5 minutes, end tidal O2 > 80%
RAPID SEQUENCE INDUCTION
*Classically Thiopentone and Suxamethonium
*Propofol fine if no haemodynamic instability
*No opioids until delivery of baby
How does anaesthesia proceed intraoperatively once airway has been secured?
Pre-delivery analgesia:
- NO2/O2 mixture 50/50, 60/40
- Volatile (isoflurane or sevoflurane)
At delivery, after cord clamping:
- oxytocin as per spinal
- opiod given (fentanyl, morphine)
- IV paracaetamol
- continue NO2
- Carefully titrate volatile-> too much= uterine hypotonia
Exutbate awake:
- preferably on side
- monitor in recovery
- appropiate analgesia
Are opioids contraindicated in breastfeeding?
No, just dose adjust
