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4th Year Drugs > Obstetrics > Flashcards

Flashcards in Obstetrics Deck (19):
1

What are the non-medical pain relief options avaliable in labour? 

  • Antenatal class preperation - relaxationand breathing
  • Immersion in water (body temp) 
  • Mobilisation
  • TENs
  • Hypnotherapy 
  • Acupuncture 
  • Localised pressure on back 
  • Superficial heat or cold application
  • Massage/aromatherapy 

2

What are the inhalational agents avaliable for labour? What are the pros and cons/SEs?

  • Entonox -  nitrous oxide and oxygen (50:50) 
    • PROS: rapid onset and mild analgesic 
    • CONS: insufficient pain relief for most 
    • SEs: light headedness, nausea, hypervent

3

What systemic opiates can you offer in labour? What are the pros and cons/SEs? 

  • IM Pethidine/meperidine or diamorhine
    • CONS: small analgesic effect
    • SEs: Nausea and vomiting (anti-emetics usually needed), sedation, confusion, respiratory depression in newborn - requires reversal with naloxone,  reduced breastf feeding rates

4

What other medical treatments are avaliable for pain relief in pregnancy and labour? What analgesics should be avoided? 

  • Paracetamol - throguhout preg. Little use in established labour 
  • Codeine (if more severe)
  • Aspirin - ONLY if high risk of pre-eclampsia  

AVOID NSAIDs

  • Pot miscarriage and malformation in 1st T
  • Closure of fetal ductus arteriousus (3rd T) 
  • Fetal oliguria 
  • Possible cerebral haem 

5

What are the gold standard pain relief for labour?

Regional techniques

6

What spinal level are epidurals delivered? 

  • L3 - L4 or L4 - L5

7

What three ligaments must you pass through to deliver an epidural? Where is the local anaesthetic delivered to?

  • Supraspinous ligament
  • Infraspinous ligament 
  • Ligamentum flavum 

Local anaesthetic delivered into the epidural space (ie the space outside the dura mater)

8

What is the effect of epidural analgesia?

  • Variable effect. IDEALLY:
    • Complete sensory blockade (except pressure)
    • Partial motor blockade from upper abdomen to lower abdomen 

9

What local anaesthetics are used for epidurals? How do they work?  

  • Ropivacaine/bupivacaine in combo with an opioid (fentanyl) via indwelling catheter
    • Combo associated with sig reduction in postop pain vs alone
  • Inhibition of conduction at the intradural nerve roots arising from the spine

10

What are the general indications for epidural infusion?

Thoracic, abdominal and lower-limb surgical procedures:

Intraoperative analgesia

Postoperative analgesia

Analgesia for chest, abdomen, pelvis or lower-limb trauma.

11

What are the indications for epidural anaesthesia in context of obstetrics? 

  • Suitable for ENTIRE labour - patient controlled doses are also available.
  • Higher dosages if further obstetric interventions required (C-section or instrumental delivery). 
    • For C section, combo of spinal and epidural = best! (rapid onset - spinal - and longer lasting anaesthesia - epidural)

 

12

What are the cons of epidural anaesthesia? 

CONS: 

  • Occassionally ineffective/incomplete (1 in 8)
  • IV access required and epidural site = tender
  • Transient hypotension, maternal fever and itching = common
  • Reduced mobility
  • Reduced bladder sensation (urinary retenion)
  • ↑ risk of instrumental delivery (but NOT C-section)
  • Pushing = directed as sensation ↓
  • Prolonged labour (2nd stage delayed by 1 hr)
  • Fetal ↓HR
  •  

 

13

What are the pros of epidural anaesthesia? 

PROS:

  • Only method which renders mum pain free
  •  ↓  BP in HTN
  • Abolishes premature urge to push

14

What are the major complications of epidural anaesthesia? 

  • Sig hypotension (1 in 50)
  • Spinal Tap (0.5%) - puncture of dura mater, causing leakage of CSF and often severe headache (↑ sitting up, ↓ lying)
    • Tx - analgesia. If >48hrs: 'Blood patch' to seal leak 
  • LA toxicity - Intravenous injection - tingling around mouth, numb tongue, tinnitus, confusion, convulsions, coma, cardiac arrest)
  • Total spinal analgesia (v rare) - injection of LA into CSF. Travel upwards, causing total spinal analgesia + respiratory paralysis
  • Severe injury - nerve damage/paralysis (v v rare)

15

What are the CIs for epidural analgesia?

Absolute CIs

  • Severe sepsis
  • LA allergy
  • Coagulopathy or anticoagulation (unless low dose heparin)
  • Local infection at the site of insertion.

Relative contraindications

  • ↑ ICP
  • Hypovolaemia
  • Some skeletal anomalies
  • Following some types of back surgery.

16

What are the differences between spinal and epidural anaesthesia? 

17

When are spinal anesthesias used in context of pregnancy?

  • For C-section or mid cavity instrumental vaginal delivery 

18

What are the major complications of spinal anesthesia?

  • ↓ BP and RARELY total spinal analgesia (respiratory paralysis) 

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