Pain Relief During Labor

1. Pain Relief During Labor Lecture 7

2. Principles of Pain Relief Treatments for pain relief during labor depends on: 1. client’s tolerance for pain 2. ability to focus on labor 3. ability to remain motivated. Some of labor process done @ home: aromatherapy, warm bath, music, visualization, breathing exercises, massage. hypnosis, acupuncture. ~ 70% clients ask for epidural Method of Pain Relief Should Exhibit: • Simplicity • Safety • Preservation of fetal homeostasis Monitor client closely: B/P, Pulse, RR, FHR, anesthetic levels, maternal oxygenation.

3. Analgesia and Sedation During Labor Analgesia: loss of sensitivity to pain. • Pain meds can be sufficient to get through labor along with: aromatherapy, music, visualization, etc. • Systemic drugs - 3 factors to consider • effects on mother • effects on fetus - all systemic drugs cross placenta by simple diffusion. • Fetal liver & kidney function immature, drugs metabolized slowly & effects last longer • Affect progress of labor; can slow labor.

4. Assessment • Maternal assessment • informed consent ; VS stable • Fetal assessment • FHR 110-160/min with no late/variable decels. • Variability average. • Normal fetal movement and accelerations present. • Term Fetus • No Meconium • Labor assessment • Contraction pattern well established. • Cervix 4-5 cm dilated in primips and 3-4 in multips • Progressive descent of presenting part • no complications • Delivery at least 2-3 hours away.

5. Narcotic Pain Relief: Meperidine (Demerol) and Promethazine (Phenergan) • Demerol 25-100mg with Phenergan 25 mg IM or IVP q 2-4 hours • crosses placenta • Half-life is 2.5 hrs. (mother) & 13 hrs. (newborn) • Right > administration, FHR variability may decrease • Narcan (naloxone) antagonist Butorphanol (Stadol) 1-2 mg IVP/IM x2. • Stronger than Morphine & Demerol. Starts working in < 5 min. Has minimal fetal effects; may cause hallucinations in mom. Nalbuphine (Nubain) – 15-20 mg IVP/IM • does not cause neonatal depression. Fentanyl –short-acting potent synthetic opioid. • 50-100 mcg IV q 1hr. Used in spinal/epidural.

6. Anesthesia Anesthesia: reversible loss of sensation & movement in region of body. Types of Anesthesia • Local anesthesia: local anesthetic directly into perineum. Used for minor procedures. No effects on newborn. • Lidocaine 1% typically used for NSVD • Relieves pain from episiotomies or when suturing episiotomy and/or lacerations from vaginal deliveries. • Rapid onset • Client awake

7. Pudendal Block • Relieves pain associated with 2nd (pushing) stage of labor. Lidocaine 1% used. • through vaginal wall and into pudendal nerve in pelvis, numbs area between vagina & anus • 22 gauge needle [bilateral] • Does not relieve pain of contractions. • Works quickly; does not affect baby. • Given shortly before delivery, but cannot be used if baby's head is too far down in birth canal. • Can prolong 2nd stage labor d/t loss of bearing-down reflex. • Provides satisfactory perineal anesthesia for normal delivery, low forceps manipulation, episiotomy. 

8. Regional anesthesia - injection of local anesthetic around nerves of spinal cord to block pain from larger but still limited part of body. Types: 1. Epidural Anesthesia Usuallyuses Marcaine (bupivicaine) - into epidural space at 3rd - 4th lumbar interspace. • single dose to be repeated or as continuous infusion; common in USA • administered > active labor established • Good analgesia without CNS depression in mom or fetus; Relieves pain from uterine contractions, vaginal delivery, C/S • Analgesia block from T-10 to S-5 • Epidurals slow labor and may require Pitocin (oxytocin) augmentation.

9. Most common complications: • Maternal hypotension > can lead to> fetal bradycardia and late decelerations. • Preloading 1000ml of RL IVF • Tx hypotension with ephedrine. • Less w. continuous infusion than single dose • Other complications: total spinal block & respiratory paralysis (improper placement of catheter) • Does not prolong 1st stage labor if established • Can interfere with woman's ability to push. May ^ C/S • Can elevate maternal temp. • Bladder sensation lost – insert foley catheter • Interfere with descent and rotation of fetus • Long-term problems • Backache; headaches; Migraine headache • Neckache; Tingling in hands or fingers

10. Technique for Epidural Analgesia • Get informed consent • Monitor BP, P, FHR, q 1-2 min. for 15 min. > bolus of local anesthetic. • Maintain verbal communication with patient. • Hydrate w. RL 500-1000 cc. to maintain BP. • Patient maintains lateral or sitting position • Epidural space identified - catheter threaded 3cm • Test dose given - observe for s/s of toxicity (metalic taste, ringing in ears, palpitations) • Place in lateral or semifowler to prevent aortocaval compression. • Maternal BP monitored q 5-15 min. • Analgesia level assessed.

11. 2. Spinal Anesthesia • Subarachnoid space [lumbar region] - provides spinal block. Passes through dura & CSF reached. Meds inserted, needle removed. • Spinal cord above this site. • Used in C/S. Block level from 8th thoracic dermatome [ xiphoid process/breast. Longer anesthetic effects. • Anesthetics used: bupivacaine, lidocaine, fentanyl. Duramorph {morphine} side effects include urinary retention (foley), pruritis, nausea, hypotension. Preload with RL (1000cc). Maintain IVF.

12. Complications: • Hypotension [20% decrease from baseline]; may occur > administration of local anesthetic • Vasodilatation & obstructed venous return from uterine compression of vena cava and large veins • Manage: • L side, hydrate with 500-1000 cc of RL/NS, ephedrine 5-10 mg IV • Spinal Headache (low volume/low pressure in spinal column) • CSF leaks from site of puncture @ dura mater. • Treatment: • lie flat for few hours. • Vigorous IV hydration. • Blood patch – very effective • 5 mL of blood without anticoagulunt - injected into epidural space - forms clot & stops leakage • VS observed for ~ 2 hrs.

13. Post-op Pain Management: administered either by IVP, IM or PCA (Patient control anesthesia) Medications such as: • Fentanyl ; Morphine ; Demerol • Duramorph/astromorph- systemic effects ~ 24 hours without PCA/IM medication. • Vital signs monitored closely • Monitor q 15 minutes for first hour: • BP, P, RR, HR • Pain, Motor Sensory, Alertness, Epidural access • PCA bolus/infusion amount and VTBI • Then, 30 minutes x2 , q hour X 4 hours, q 4 hrs. X 24 hrs. • Patient education - Inform patient – PCA is continuous programmed infusion pump. Patient may self-administer medication • Reassure patient - overdose can’t occur; Infusion programmed – delivers additional med q 10 - 15 minutes; lock out system.

14. General Anesthesia (total induced unconsciousness) C-sec → fetal distress, failed epidural/spinal/allergy • Prophylactic antacid – 30 cc Bicitra • Pre-O2; wedge under R hip - prevents venacaval compression. • Induced unconsciousness [inhalation or IV therapy] • Halothane, ketamine, nitrous oxide, thiopental • Endotracheal intubation • Cricoid pressure on trachea - occludes esophagus & prevents aspiration. • After intubation, additional meds given via IV & ET tube - maintains anesthesia for rest of surgery. • Used for emergency delivery • Complications: Pulmonary aspiration of gastric contents, failed intubation, aspiration pneumonia, neonatal depression. NPO for about 8 hours.