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BACKGROUND AND INITIAL EVALUATION
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Pruritus is a side effect of neuraxial opioids.
Evaluate the patient and assess the relative degree of itching.
Itching is an expected side effect that is often mild and may be self-limiting if associated with spinal fentanyl for labor. Approximately an hour and a half after the spinal dose for labor, itching improves in the majority of patients.
The majority of patients do not need medications to treat pruritus. An explanation and reassurance are often sufficient until the spinal dose of fentanyl no longer has an effect.
Only if itching is significantly bothersome to the patient should a treatment option be offered.
Treatment with antagonists and agonist-antagonist could intrinsically reverse the labor analgesia. Use with caution.
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OMISSION OF NEURAXIAL OPIOID—FIRST CHOICE
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For patients with severe itching during labor or prior history of unremitting, severe itching, opioids may be omitted from labor epidural infusion or neuraxial morphine from cesarean analgesia.
For labor, fentanyl has been shown to reduce the necessary local anesthetics dose by 25% to 40%. Omission of fentanyl usually requires an increase in bupivacaine concentration to 0.125% for the labor epidural.
It has been this author’s experience that the vast majority of patients who request a switch to an opioid-free epidural solution ultimately request to be changed back, either due to increased pain or increased sensory and motor blockade. Careful counseling and exhaustion of the above options are essential before making this switch.
Replace fentanyl with 0.5 µg/mL dexmedetomidine (with bupivacaine) for labor epidural (Chapter 6, “Dexmedetomidine”).
Increased pain should be expected and may necessitate higher local anesthetic concentration infusion or alternative epidural adjuncts for labor or additional post-cesarean pain relief treatment options.
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TREATMENT OPTIONS—SECOND CHOICE
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Caution to use nalbuphine or naloxone for the laboring patients who may undergo intrapartum cesarean delivery or for who is during cesarean surgery. It may cause refractory pain after cesarean section.
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Nalbuphine1–3:
Dose: 2.5 mg IV/IM, may repeat two times.
Shown to be more effective than placebo, diphenhydramine, propofol, or naloxone.
May also improve opioid-induced nausea/vomiting and respiratory depression.
However, it can cause sedation at higher doses.
Four or more doses have been shown to decrease the effectiveness of neuraxial opioids.
Naloxone:
Found to be less effective than nalbuphine.
Dose: 40 to 80 µg IV, may repeat three times or utilize infusion.
As an opioid-antagonist, it will also improve opioid-induced nausea/vomiting and respiratory depression.
Does not cause sedation.
However, can cause increased pain scores at higher doses.
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This should NOT be considered a treatment if the itching is thought to be caused by a neuraxial (spinal or epidural) opioid.
Opioid-induced histamine release from mast cells is not the mechanism for pruritus after neuraxial opioid administration.
Studies have shown limited success when compared to placebo and markedly reduced effect when ...