Pain relief in labour

1. Pain relief in labour Dr. SuraFindakly MBChB, DGO, CABOG

2. Leaning objectives: • 1. Describe the pain pathways during labor • 2. Recognize the types of analgesia and anesthesia, method of administration, their side effects and complications of each one.

3. Pain pathways during labor • Pain resulting from stimulation of specialized nerve endings. • During labor, pain sensation is relayed to the spinal cord from T10, L1, S1-S4. These sensory fibers make synaptic connections in dorsal horn of spinal cord with cells that provide axons that make up the spinothalamic tract.

4. Early 1st stage: before fetal head reaches zero station, pains impulses arise primarily from uterus  via visceral afferents enter spinal cord at T10-L1. • Late 1st stage & 2nd stage: pain impulses arise from uterus, pelvic structures, vagina, & perineum. • 3rd stage of labor is usually well tolerated with spontaneous placental delivery.

6. The method of Pain relief depends on: • previous obstetrical record of the woman • The course of labor. • The estimated length of labor

7. The ideal analgesic in labour • Good analgesia • Easy to administer • Safe to the mother & baby • Easily reversible if necessary • Does NOT interfere with uterine contractions • Does NOT affect mobility

8. Non pharmacological methods: • Relaxation & breathing exercises • acupuncture & hypnosis • TENS (transcutaneous electrical nerve stimulation)

9. pharmacological methods: Opiate side effects • sedation ,nausea& vomiting. • convulsant properties (! severe hypertension) • Neonatal respiratory depression(naloxone to the newborn to reverse). • delayed maternal gastric emptying( ! general anesthesia).

10. Opiates: • pethidine • diamorphine is better analgesic than pethidine but has potentially greater respiratory depressant effect on newborn.

11. Inhalational analgesia NITROUS OXIDE(NO) in the form of Entonox • quick onset , • short duration of effect • more effective than TENS & pethidine. Side effect: • light headache • nausea • it is not suitable for prolonged use from early labour because hyperventilation may result in hypocapnoea ,dizziness , tetany & fetal hypoxia.

12. Nitrous oxide side effects: • light headache • nausea • not suitable for prolonged use from early labour because hyperventilation may result in hypocapnoea ,dizziness , tetany & fetal hypoxia.

13. Pudendal Block Safe and simple providing analgesia for spontaneous delivery. • The vaginal mucosa just beneath the tip of the ischial spine( 1 mL of 1-percent lidocaine). aspiration • The sacrospinous ligament (3 mL of lidocaine). • The loose areolar tissue behind the ligament(3 mL of solution) • Just above the ischial spine.(3 mL is deposited). • The procedure is then repeated on the other side.

14. Pudendal block complications • intravascular injection of a local anesthetic(serious syst.) • Hematoma formation • severe infection may spread posterior to the hip joint, into the gluteal musculature, or into the retropsoas space

15. Paracervical Block • Pain relief during the first stage of labor. • lidocaine or chloroprocaine, 5 to 10 mL of a 1-percent solution, is injected into the cervix laterally at 3 and 9 o'clock. Complications • Fetal bradycardia (15%)

16. Epidural analgesia • the most reliable analgesia in labour Indications: • prolonged labor, oxytocin aug. • multiple gestation • certain maternal medical conditions hypertensive dis. • where there is a high risk of operative intervention being necessary .

18. Epidural contraindications: • coagulations disorders • local or systemic sepsis • hypovolaemia • lack of trained staff

19. Technique: • intravenous infusion (preload of 500-1000ml crystalloid) • epidural catheter inserted at the L2-L3, L3-L4 or L4-L5 interspace, aspirate to check for position. If no blood or CSF is obtained a test dose (2 ml of 0.5%bupivacaine) is given to confirm catheter position, which has little effect if injected into the epidural space ,but a subarachnoid injection usually result in a sensory block . • If none of these signs are observed 5 minute after injection of the test dose ,loading dose can be inserted.

20. Spinal analgesia: • A fine needle atraumatic spinal needle is passed through the epidural space ,through the dura & into the subarachnoid space which contain the CSF . • A small volume of local anaesthetic is injected, after which the spinal needle is withdrawn,this may be used as anesthesia for CS.

21. Complications of regional analgesia • hypotension • Accidental dura puncture during the search for the epidural space. • post dural puncture headache • accidental total spinal anesthesia causes severe hypotension, respiratory failure, unconsciousness & death if not treated immediately. • neurological complication are rare • bladder dysfunction ,catheterization should be done to avoid overfill & damage to the bladder. • Back ache. • increases operative delivery.

22. General anasthesia • Used for emergencies • for surgery when regional anasthesia contraindicated Patient Preparation • Antacids • Lateral uterine displacement • Preoxygenation

23. Anesthetic high risk patient • Marked obesity • Severe edema or anatomical abnormalities of the face, neck, or spine, including trauma or surgery • Abnormal dentition, small mandible, or difficulty opening the mouth • Extremely short stature, short neck, or arthritis of the neck • Goiter • Serious maternal medical problems, such as cardiac, pulmonary, or neurological disease • Bleeding disorders • Severe preeclampsia • Previous history of anesthetic complications

24. Summary • Knowing the types of analgesia and anasthesia and their complications to diagnose and prevent any complication from happening .

25. THANK YOU