Download Analgesia and Anasthesia During Labor

Pain Relief During Labor
Lecture 7
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.
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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.
Assessment
– Maternal assessment
 informed consent ; VS stable
– Fetal assessment
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FHR 110-160/min with no late/variable decels.
Variability average.
Normal fetal movement and accelerations present.
Term Fetus
No Meconium
– Labor assessment
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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.
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.
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
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.
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
Usually uses 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
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Analgesia block from T-10 to S-5
Epidurals slow labor and may require Pitocin (oxytocin)
augmentation.
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
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.
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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.
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.
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
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 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.
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.