1. Anaesthesia for Obstetric Surgical Procedures
September 2010

2. Retained placenta Sensory block to T10 required
Spinal/existing epidural
Patient potentially hypovolaemic

3. Repair of perineal tear
Spinal/existing epidural
Good quality saddle block required
Potentially hypovolaemic patient

4. Anaesthesia for Cervical Suture
1st/2nd trimester
Spinal/GA
If GA
Avoid prolonged exposure to nitrous oxide
Potentially teratogenic in first trimester
Avoid hypotension/hypercarbia – fetal acidosis

5. Introduction
NHS maternity statistics : UK c/section rate = 24.6%
RJMH c/section rate = 36.2%
NOAD 2007: anaesthesia for c/section
Spinal – 59.6%
Epidural top-up – 22.1%
GA – 10.1%
CSE – 7.2%
De novo epidural – 0.8%

6. RCOA Audit Standards Elective c/section > 95% RA
Emergency c/section> 85% RA
Elective c/section <1% RA to GA
Emergency c/section < 3% RA to GA

7. Elective c/section Common indications: Maternal request!
Breech presentation
Previous c/section
Placenta praevia
Significant medical conditions

8. Choice of Anaesthetic Patients preference
Patients physical profile, health considerations, pregnancy factors
Anticipated surgical difficulties
Experience and speed of surgeon

10. Preparation for Anaesthesia
Preop assessment
Informed consent
Antacid prophylaxis
Fully prepared anaesthetic room/theatre
Checked anaesthetic machine
Monitoring equipment
Tilting operating table
Resuscitation equipment
Trained anaesthetic assistant
Large bore I.V. access

11. Spinal Anaesthesia Used >90% elective LSCS
Incidence of PDPH approx 1:400 due to small gauge PP needles
Technically simple
Consistent, dense quality of block
Failure rate approx 1%

12. Spinal Anaesthesia Standard technique
PP needle, no larger than 25G to minimise PDPH risk
Injection at, or below L3/L4 interspace to avoid damage to conus
Diamorphine 300mcg
Injection performed in sitting position, then moved immediately to L tilted supine position on completion
Phenylephrine ivi to prevent hypotension

13. Spinal Anaesthesia Hyperbaric Bupivicaine 0.5% - most used LA in UK
Recommended doses vary
Surgery requires sensory blockade to T4
Patient factors influencing dose
Height
Abdominal size

14. Intrathecal Opiates Fentanyl Morphine Diamorphine Side Effects:
Highly lipid soluble
Reduced intraop discomfort
Provides no post op analgesia
Morphine
Long duration of action
Little intraop effect due to poor lipophillicity
Diamorphine
Rapid onset
Side Effects:
PONV approx 30%
Pruritus

15. Spinal induced hypotension
Can cause fetal distress
Symptoms: dizziness, N&V
Should be treated aggressively
Approp positioning
Fluid preloading
Use of Phenylephrine ivi
Titrated to maternal BP
Higher fetal pH than Ephedrine

16. Spinal after epidural
Technique most likely to lead to high/total spinal anaesthesia. ? Dural sac compression by epidural fluid
No formula for reducing spinal dose. NB inadequate block
Precautions
Warn patient of risk of conversion to GA
Assess airway
Perform spinal in approp environment
Reduction of spinal dose
Consider leaving epidural catheter in situ

17. Epidural ‘top-up’ Category 2 LSCS with epidural in situ
Slow onset anaesthesia
Inferior anaesthesia to spinal during surgery
L-Bupivicaine 0.5%; Ropivicaine 0.75%; supplemental Diamorphine.

18. CSE 3 approaches ‘Needle through needle’
‘Full’ dose spinal with epidural back up if inadequate block height/duration
Reduced dose spinal with supplemental epidural top-ups
Epidural volume extension-low dose spinal extended by dural sac compression using epidural saline
‘Needle through needle’
Separate needle, separate interspace

19. CSE Used to reduce incidence of spinal failure
Tall patients
IUGR
Prolonged surgery
Reduces haemodynamic changes by more gradual onset anaesthesia; reduced risk of excessive block height
Cardiac patients
Short patients
Short duration of blockade esp motor blockade

20. Continuous Spinal Niche role ‘Difficult’ equipment PDPH
Careful titration of dose
Haemodynamic stability
Cardiac disease
Extremely small stature
Severe skeletal deformity
Extended period of anaesthesia

21. Pain during LSCS Leading cause of litigation Informed consent
Closed claims analysis
Pain during surgery - 31% (57)
Informed consent
Give adequate doses of drugs including opioid
Produce and document adequate sensory and motor block
Management
Alfentanil 250mcg iv
Entonox
Conversion to GA
NB. Clear documentation of management esp if patient refuses GA

22. GA Indications Refusal of RA Contraindications eg. Coagulopathy
Insufficient time to establish RA
Serious haemorrhage anticipated
Failed RA

23. GA Reliable and safe if Aspiration prophylaxis
Trained anaesthetic assistance
Meticulous pre-oxygenation
Well rehearsed failed intubation drill
Approp drug regimen to reduce incidence of awareness
Awake extubation

24. Drugs used for GA RSI with cricoid pressure Thiopentone/Propofol?
Poorer neonatal profile
Shorter duration of amnesia
Longer time to recovery of spontaneous ventilation
Suxamethonium/Rocuronium?
Inadequate doses assoc with difficult intubations
NB 1.5mg/kg; Increased Vd
Prolonged action of Rocuronium
NB. Sugammadex

25. Perioperative Drugs Opiates at induction and post op analgesia
On delivery of neonate
Syntocinon 5IU and IVI
Prophylactic antibiotics
Thromboprophylaxis

26. Complications Failed intubation (1 in 300) Aspiration (1 in 400-600)
Increased fatty tissue
Complete dentition
Increased pharnygeal and laryngeal oedema
Incorrect drug dosages
Large tongue
Large breasts
Increasing obesity
Aspiration (1 in )
Awareness
Increased intaop blood loss
PONV

27. Post op pain relief Introp: Post op: Diclofenac 100mg PR
Intrathecal Diamorphine
IV Morphine and TAP blocks
Post op:
Diclofenac 50mg PO TID
Paracetamol 1g PO QID
Codeine 30-60mg PO QID

28. Emergency LSCS Grades of urgency – category 1 to 4
Nationally accepted classification
‘Continuum of risk’
Facilitates audit
Improves multidisciplinary communication
Individual, ‘case by case’ approach to decision to delivery interval

30. Emergency LSCS Category 1 & 2 In utero fetal resuscitation
Syntocinon off
Position full L lateral
Oxygen
I.V fluids
Low BP – vasopressors
Tocolysis: GTN 400mcg/B2 agonist
Choice of anaesthesia
Post op analgesia
Post op care