ANAESTHESIA IN OBSTETRICS AND ROLE OF MIDWIFE.pptx

obgn anasthesia

1. ANAESTHESIA IN OBSTETRICS AND ROLE OF MIDWIFE

2. Labour analgesia “Delivery of the infant into the arms of a conscious and pain-free mother is one of the most exciting and rewarding moments in medicine.”

3. DEFINITION According to the American Society of Anaesthesiology (ASA) “in the absence of a medical contraindication, maternal request is a sufficient medical indication for pain relief during labor”

4. Ideal goal of obstetric analgesic Attenuate maternal anxiety, fatigue and deliver healthy baby Drugs should not cross placental barrier Minimal effects on mother, foetus or neonate Could be administered late in labour Easy to administer with minimal monitoring: IV, bolus, intermittent or continuous infusion, PCA Rapid, Profound, Consistent Analgesia (Stage I & II) & preserve Uterine contractility Onset, offset should match time-course of Uterine contractions Easily reversible if necessary Facilitate Surgical Anaesthesia avoiding GA

5. cont… • No motor effect: Ambulation Maternal Expulsive Efforts Progress of Labour Achieves labour analgesia in 1st stage of labour Should maintain Uterine blood flow.

6. Normal labour Series of events that take place in the genital organs in an effort to expel the fetus out of the uterus through the vagina

7. Criteria of normal labour Spontaneous in onset At term Vertex presentation Natural termination

8. Onset of labour Regular painful uterine Contractions accompanied by Ruptured membranes Bloody show Complete cervical effacement Painful rhythmic contractions with cervical dilatation of 3-4 cm

9. Patho-physiology of labour pain Visceral pain First stage T10 - L1 Distension and stretching of LUS Somatic pain Second stage S2-S4 Distension of pelvic and perineal structures and compression of LS plexus

10. Pain pathway in I stage and II stage of labour First stage : Uterine contraction + cervical dilatation Afferent –visceral afferent from uterus T10,11,12,L1 Posterior segments Second stage : Distension of pelvic floor ,vagina,perineum by descending head Afferent –sensory fibers of S2,3,4 (Pudendal nerve)

11. Effect of pain and stress Release of adreno-cortisol ,catecholamine’s , and beta endorphins Beta –adnergic agents have uterine relaxant effects and higher epinephrine level are associated with anxiety and prolonged labour Maternal psychological stress can determentally affect uterine blood flood and fetal acid base status.

12. Effect of labour pain on mother and fetus Labour pain causes- Marked stimulation of respiration and circulation in mother. Activation of sympathetic nervous system Mental disturbance- postpartum depression and post traumatic stress disorder

13. Techniques of labour analgesia Complementary or Alternative treatment Mind–body interventions Bio electromagnetic Physical methods : massage, heating pads, warm bath Alternative medication : Acupuncture, hypnosis Conventional Treatments Systemic analgesia: IV , inhalational Regional techniques General anaesthesia

14. Regional anaesthesia techniques Most commonly performed regional techniques for labor are- Epidural analgesia Spinal block/analgesic Combined spinal-epidural blocks. Less frequently performed- Paravertebral block Paracervical block Pudendal block

15. Perineal infiltration  Direct infiltration of 1% lignocaine is used for perineal and lower vaginal lacerations. Advance the needle and inject and aspirate to avoid intravascular injection. Dose of lignocaine is 3-4 mg/kg plain solution, and 7-8 mg/kg with added epinephrine. 1% solution = 10 mg/ml After local infiltration one should wait 3 minutes before proceeding.

16. Para cervical nerve block INDICATIONS: Relieve the pain of uterine contractions and the perineal discomfort is removed by Pudendal nerve block TECHNIQUES: Place the patient in dorsal lithotomy

17. cont… Place speculum to obtain good visualization of the entire cervix Place 2 to 3 ml of lidocaine at the 6 or 12 clock position Grasp the anesthetized portion of the cervix with a tentaculum or a traumatic vulsellum forceps Inject 10cc of lidocaine at or just above each utero sacral ligament 1cm under the mucosa where vagina reflects off the cervix Inspect the injections sites for bleeding Wait 10 minutes before proceeding with the procedure

18. Pudendal nerve block INDICATIONS: Pudendal nerve block is mostly used for forceps and assisted breech delivery. It does not relive the pain of labour but affords perineal analgesia and relaxation TECNIQUES: It may be either blocked by transvaginal or transperineal route.

19. Transvaginal route of Pudendal block

20. cont… 20 ml syringe -1 15cm 17-20 gauge spinal needle 20ml of 1% lignocaine hydrochloride are required The index and middle finger of one hand are introduced into the vagina ,finger tips are placed on the tip of the ischial spine of one side. The needle is passed along the groove of the fingers and guided to pierce the vaginal wall on the apex of ischial spine and thereafter to push a little to pierce the Sacro- Spinous ligament just above the ischial spine tip. After aspirating to exclude blood about 10ml of the solution is injected .The similar procedure is adopted to block the nerve of the other side by changing the hands.

21. cont….. COMPLICATIONS: Lacerations of vaginal mucosa Prolonged II stage of labour due to loss of bearing down reflex Systemic anesthetic complications like drowsiness ,loss consciousness ,hypotension and bradycardia Hematomas Infections Needle stick injury

22. Lumbar epidural analgesia INDICATIONS: Painless labour TYPES OF EPIDURAL ANALGESIA: Lumbar epidural analgesia Caudal epidural analgesia

23. Pre requisites for epidural analgesia Maternal consent Maternal /fetal status Progress of labour Iv cannula Maternal hydration Monitor vital status Continuous fetal monitor safety

24. Lumbar epidural analgesia

25. Caudal epidural analgesia

26. Benefits of epidural analgesia Pregnancy induced hypertension Breech presentation Twin pregnancy Preterm labour Previous cs

27. Complications of epidural analgesia Hypotension Pain at insertion site Post spinal headache Injury to nerves

28. Contraindications of epidural analgesia Sepsis at injection site Hemorrhagic disease or anti coagulant therapy Supine hypotension Hypovolemic Neurological disease Spinal deformity or chronic low back pain

29. Drugs used in epidural anaesthesia Lidocaine: Rapid onset, dense motor block, risk of cumulative toxicity with repeated doses Bupivacaine: Good sensory block with minimal motor effect

30. Epidural opiods in labour Inadequate analgesics used alone Synergistic with local anaesthetics Speedy onset of analgesia Improves quality of analgesia Permits use of very dilute LA solutions Help relieve persistent perineal pain and unblocked segments

31. cont… Fentanyl and Sufentanil Rapid onset, few side effects Sufentanil slightly more effective No significant fetal drug accumulation No serious adverse neonatal effects with either

32. Role of midwife in epidural analgesia Support for the laboring woman Continuous monitoring of vital signs and fetal status Pain assessment Continues fetal heart rate monitoring Continuous epidural infusion monitoring

33. Spinal anaesthesia INDICATIONS: To alleviate pain during delivery and III stage of labour Forceps or ventose delivery LSCS ADVANTAGES OF SPINAL ANAESTHESIA: Less fetal hypoxia

34. Side effects of spinal analgesia Hypotension due to blocking of sympathetic fibers leading to vasodilatation and low cardiac output Respiratory depression Post spinal headache Transient or permanent paralysis Urinary retention

35. Techniques

36. Combined spinal epidural anaesthesia

37. prerequisites Complete blood count Coagulation profile Back examination Informed consent Detailed history Continuous fetal monitoring

38. Benefits of CSE analgesia CSE provides more effective analgesia CSE is faster in onset CSE has lower failure rate 10% comparing to 14% in epidural only

39. Disadvantages of CSE Risk of threading epidural catheter intrathecally Excessive high block Increase the risk of fetal bradycardia from spinal block Increase equipment cost

40. Contra indications Patient refused Sepsis Hypovolemic Coagulapathy Elevated ICD Back injury Chronic back pain Localized infection in injection site

41. complications Headache Back pain Injury to nerves Epidural hematomas Hypotension Shivering Bladder distension Supine hypotension Leg numbness and weakness

42. General anaesthesia

43. Complications of GA Aspiration of gastric content Tachycardia Hypotension Dyspnea Cyanosis bronchospasm

44. Prevention of complications NPO during labour H2 blocker should be given night before and to be repeated one hour before the administration of GA to raise gastric PH Intubation with adequate cricoids pressure Awake extubation should be routine

45. Management Immediate suctioning of oropharynx and nasopharynx is done to remove the inhaled fluid CPAP is given to maintain the oxygen saturation of 95% Pulseoximeter is useful guide Antibiotics are administered when infection is evident

46. Role of midwife during postoperative LSCS Pain killers to prevent pneumothorax or thrombhophelebitis Pain assessment Comfort measures Early ambulation Assisting in breast feeding Stool softeners High fiber diet Assessing vital signs and wound healing