Pharmacological pain management in labor

• Physiologic changes during pregnancy/birth:

  • Increase in metabolic rate and increase demand for oxygen
  • Increase in cortisol and glucagon
  • Catecholamines: increased production of fight or flight hormones (epi and norepinephrine)
  • Ex: pupils dilate, respiration quickens, perspiration begins, HR increases, and muscles tense/tremble
• Hyperventilation:

  • Can result in maternal hypoxemia, dizziness, and loss of consciousness
  • Causes less oxygen to the fetus
  • Can cause utero-placental vasoconstriction and decrease blood flow to the uterus
• Pudenal nerve block

  • Used in second stage of labor
  • Local injection
  • Risk for infection & urinary retention
• Anesthestic (lidocaine injected into perineum)

  • Injected into perineum for episiotomy, laceration and/or repair
  • Risk for hematoma/infection
• Epidural block:

  • Sterile procedure
  • Nurses MONITOR but do not manage
  • May cause *maternal hypotension*
  • Limits mobility
  • Nausea/vomiting, bladder distention, elevation in maternal temp and pruritus
  • May prolong labor/pushing
• IF hypotension occurs....

  -Turn pt on her left side

  -Increase IV rate

  -Administer O2 as ordered

  -Notify anesthesiologist
• Spinal

  • Subarachnoid space
  • Used primarily for C-sections
  • Does not involve a catheter
  • Onset is faster (*5 minutes*)
  • Pain relief lasts for approximately 90 minutes-3 hours
• Spinal Adverse effects

  • Maternal hypotension
  • Bladder distention
  • *Spinal headache*
  • Fetal bradycardia
• Nursing care epidural/spinal:

  • Consent, patient willingness, request, pain level
  • Stable VS
  • Allergies/Contraindications
  • Fetal HR
  • Contraction pattern
  • Obtain blood work (platelets)
  • *Fluid bolus*
• Duramorph: analgesic opioid

  • In combination with anesthetic in epidural/spinal to extend pain relief without loss of motor/sensory/sympathetic function
  • Can last up to 24 hours
  • Can cause respiratory depression, respiratory status checked hourly for first 24 hours
  • Can cause nausea/vomiting -> Phenergan
  • Can cause pruritus -> Benadryl
• Epidural and spinal contraindications:

  • Rash or infection on back
  • Hx of back surgery
  • Scoliosis
  • Anticoagulants like warfarin
  • Thrombocytopenia
• Inhaled Analgesics:

  • Nitrous oxide: 50% oxygen and 50% nitrous oxide
  • Inhaled through hand held mask
  • No respiratory depression in baby
  • Takes effect in approximately 50 seconds
  • Can cause sedation
  • DOCTOR ORDER
• Systemic analgesics

  • IV push
  • Takes 1-3 minutes for the medication to begin working
  • Fentanyl (3-5 min peak)
  • Nubain (30 min peak)
  • Morphine (20 min peak)
  • Opioids do cross the placenta and affect the fetus
  • Demerol (meperidine): prolonged half-life in the baby 2.5 days
• Systemic analgesics side effects:

  Maternal

  -Pain relief only slightly better

  -Itching

  -N/V

  -CNS depression/sedation

  Fetal

  -Decrease HR variability

  -Respiratory depression
• Narcan/Naloxone side effects

  • N/V
  • Tremors
  • Tachycardia
  • Hypo or hypertension
  • V-fib
  • Seizures
  • Cardiac arrest
• Adjunctive medications:

  • Promethazine (phenergan): used for N/V, must be mixed with normal saline & pushed SLOWLY, can cause drowsy/fuzzy feeling
  • Reglan: anti-emetic
  • Zofran: anti-emetic
  • Benadryl: itching
• Emergency anesthesia

  • Causes rapid uterine relaxation
  • Possible retained placenta or uterine inversion
  • Respiratory depression in baby
  • DOCTOR ORDER