Chapter 54: Neuraxial Morphine

BACKGROUND

• Neuraxial morphine (intrathecal or epidural) has been used since the early 1980s to provide safe and effective postpartum postsurgical pain relief.^1,2

• Respiratory depression associated with neuraxial morphine is extremely rare. It occurs with an average time of onset of 8 to 12 hours after neuraxial morphine installation.¹

  • Vigilant monitoring of the patient’s respiratory status for 24 hours after injection.

  • Respiratory depression is most often associated with the use of supplemental narcotics or sedatives.

• For breastfeeding patients, the newborn is not appreciably affected by morphine excretion in the colostrum after neuraxial administration of morphine.

• Only administer neuraxial morphine when the postpartum floor has the capability to monitor the patients and monitoring policy is in place.

PROCEDURE FOR IMPLEMENTATION

• It is prohibited to administer any opioids or sedatives for the first 24 hours after neuraxial morphine installation. Please discuss with the obstetric anesthesiologist if the patient needs an early dose of opioid.

• Document the dose, time, and route of neuraxial morphine using the obstetric anesthesia neuraxial morphine order set.

• This order set should also include orders for:

  • The protocol of monitoring respiratory status.

  • Ketorolac and acetaminophen for the first 24 hours postsurgery for prevention of breakthrough pain.

  • Naloxone (both single dose and infusion as needed) for management of severe pruritus, respiratory depression, or oversedation.

  • Antiemetics for management of nausea and vomiting.

• Inform the recovery room nurse when giving the report that the patient has received neuraxial morphine.

• Hand over the neuraxial morphine monitoring form to the recovery room nurse and be sure to fill out:

  • Date, time, and route of morphine administration.

  • Date, time, and mode of delivery.

POSTPARTUM CARE AND MONITORING

• The monitoring modality and frequency depends on the dose of neuraxial morphine (Table 54-1). The patients at high risk for respiratory depression require higher level of monitoring.³ The patients include:

  • Patients who received any additional opioid for breakthrough pain.

  • Morbidly obese patients.

  • Patients diagnosed with obstructive sleep apnea.

  • Patients who have received or are still receiving an infusion of magnesium sulfate for treatment of preeclampsia.

• The obstetric anesthesiology team should be consulted within the first 24 hours of morphine administration to manage breakthrough pain or adverse effects of neuraxial morphine.

• Please discuss with the attending anesthesiologist regarding the treatment plan for breakthrough pain.