Methods to manage labour pain. Analgesics and anaesthetic techniques used in labour.. Newer modalities in labour pain reduction. Coping with labour pain

1. ANAESTHESIA & ANALGESIA
IN LABOUR
SHARON TREESA ANTONY
FIRST YEAR M.Sc NURSING
GOVT.COLLEGE OF NURSING
KOTTAYAM

2. PHYSIOLOGY OF PAIN
Stimulation of nociceptors
Secretion of mediators
C / A delta fibres
Dorsal horn of spinal cord
Somatostatin/cholecystokinin/substance P
Brain cortex

4. SOMATOSENSORY FUNCTION
Stretching of muscles & ligaments of pelvic
cavity& pressure of descending foetus
Afferent neuron
(pain fibres from skin & viscera run adjacent )
Pain from uterus felt in the back /labia

5. NEUROPEPTIDES
ENDORPHINS
• Present in limbic system, thalamas,
hypothalamas & reticular formation
• Inhibit release of substance P
ENKEPHALINS
• Inhibit neurotransmitters in pain pathway

6. PHYSIOLOGICAL RESPONSES TO PAIN
IN LABOUR
• Increased RR leading to low PaCO2
• Increased cardiac output in 1st &2nd stage of
labour

7. ANALGESIA IN LABOUR
• Must relieve pain
• Relax woman
• Low systemic effects on
 uterine contractions
Pushing effort
fetus

8. Factors Affecting Placental Transfer
• Molecular weight
>1000 – cross poorly
<600 - cross readily
• Highly charged –cross slowly
• Protein bound – cross poorly
• Fat soluble –cross easily

9. SYSTEMIC NARCOTIC ANALGESICS
• Meperidine hydrochloride
• Nalbuphine
• Butorphenol tartrate
• Morphine sulphate
• Fentanyl
• Pethidine

10. Mepiridine
• Dose :25 mg IV
50-100 mg IM Q3-4H
• Analgesic/antispasmodic/sedative/produce
euphoria
• Begins to act 30 mts after IM & 5 mts after IV
• Duration of action :2- 3hrs
• Slows labour contractions
• Give 3 hour before birth
• Reduce beat to beat variability of FHS

11. Nalbuphine
• Dose:10-20mg Q3-6H
0.3- 3 mg/kg over 10-15 mts
• Effect on mother:slows RR/Sedative/analgesic
• causes respiratory depression in fetus

12. Butorphanol
• Dose:1-2mg IM/IV Q3-4H
• Causes slowing of labour & fetal respiratory
depression

13. Morphine sulphate
• Dose :0.2-1mg intrathecally/5mg epidurally
• effective analgesic /Cause Pruritus
• Slows labour contractions
• Cause some respiratory depression in foetus

14. Fentanyl
• Dose: 50-100 microgram IM/25-50 Microgram
IV
• Cause maternal hypotension & respiratory
depression
• Slows labor
• Some foetal respiratory depression

15. INTRATHECAL NARCOTIC
• Fentanyl / morphine
• Take effect in 15 -30 mts
• Pain relief lasts 4- 7 hrs
• Can feel urge to push
• Side effects: intense pruritus
nausea & vomiting

16. • ANTIDOTE : NALOXONE

17. NON OPIOID ANALGESICS
• Sedative –Transquilizers
Eg: barbiturates,hydroxizine,benzodiazepines
• Used for sedation& anxiolysis
• Causes prolonged depressive effect on fetus

18. INHALATIONAL ANALGESIA
• 50% nitrous oxide + 50% oxygen (Entonox )
• Mixture is stable at normal temperature
• Delivered in cylinders placed in horizontal
position( nitrous oxide is heavier than oxygen)
• N2O limits the neuronal & synaptic
transmission within the central nervous
system
• Administered with entonox apparatus

19. • Gases take effect within 20sec
• Maximum efficacy within 45-50 sec
• Take it before contraction

20. • ANAESTHESIA IN LABOUR

21. Spinal cord

22. REGIONAL ANAESTHESIA
• Injects bupivocaine/tetracaine to block
specific nerve
• Acts by blocking sodium & potassium
transport
• Effect on newborn
flaccidity, bradycardia, hypotension
• Woman is awake
• Donot depress uterine tone

23. EPIDURAL ANAESTHESIA
• Anaesthetic agent is placed inside epidural space
• Usually given at L2 -L3/L3-L4/L4-L5 interspace
• Blocks spinal & sympathetic nerves
• Pain relief for labour & birth
• Causes hypotension
• May impede rotation of fetal head due to
relaxation of levator ani
• Do not affect the ability to push

24. • Prevention of hypotension:
Use fentanyl + bupivacaine
500 -1000ml extra IV fluid
Make her lie on side
• Treatment
Raise legs
Administer O2
Administer IVF + ephedrine

25. Technique of administration
• Lie on side without flexing back
• 3-4 inch needle is inserted into L3-L4
interspace
• Poly ethylene catheter is inserted& taped in
place
• Inject small dose of anaesthetic into the
catheter
• Flushing & warmness in legs after 5mts
indicates correct catheter placement

26. • Produces anaesthesia upto umbilicus in 10- 15
mts
• Effect lasts for 40 mts – 2hrs
• Another dose of anaesthetic/continuous
infusion/patient controlled analgesia
• Look for toxic reaction( slurring of speech,lack
of fine motor coordination)
• Remind her to void every 2 hours

27. • Monitor BP
• Check sensation & movement of legs after
delivery
• Stay with woman when she ambulates for the
first time after anaesthesia
• AGENTS : Ropivacaine, bupivacaine,
Levobupivacaine

28. Spinal anaesthesia
• Inject local anaesthetic agent into
subarachnoid space at L3 –L4 interspace
• Procedure
• Hypotension from sympathetic blockage can
occur immediately turn to left side
• don’t give trendelenberg position

29. • Postpartal Dural Puncture headache/spinal
headache
• Prevention
use small gauge needle
Hydrate
• Treatment
Lie flat
Analgesic

30. Spinal Epidural Technique
• Epidural needle is inserted first & catheter is
placed & taped
• Spinal needle is inserted into CSF
• a small dose of narcotic is then added to
CSF& spinal needle is withdrawn

31. LOCAL ANAESTHESIA
(ANALGESIA FOR VAGINAL DELIVERY)
PUDENDAL NERVE BLOCK
• Injection of agent near the left & right
pudendal nerves at the level of ischial spines
• Provides pain relief in 2- 10 mts & lasts for at
least 1 hour
• For episiotomy repair & use of low forceps

32. Local infiltration
• Injects Lidocaine into the superficial nerves of
perineum
• Used when fetal head is too low for a
pudendal block
• Effect lasts for 1 hour

33. Saddle block
• A form of spinal anaesthesia limited to
buttocks, perineum& inner thigh
• Injection of anaesthetic agent intoS2-S5 spinal
space
• No pain& cannot move legs for 1-2 hours

34. GENERAL ANAESTHESIA
• Never preferred for child birth
• May be necessary in emergencies like abruptio
placenta
• Thiopental sodium+ N2O+O2

35. Preparation for safe administration of
General Anaesthesia
• Ephedrine
• Atropine
• Thiopental sodium
• Succinyl choline
• Isoproterenol
• Laryngoscope + AMBU bag+ 100% O2+
suctionsource