From the Guidelines
Pruritus is the most common side effect of narcotic spinal administration. According to the most recent and highest quality study available, a meta-analysis of 58 RCTs (5904 patients) found that epidural analgesia, which often includes narcotic spinal administration, was associated with an increased risk of pruritus 1. This is consistent with other studies that have reported pruritus as a common side effect of opioid administration, occurring in 10% to 50% of patients receiving opioids 1. The mechanism of opioid-induced pruritus is thought to be related to the activation of mu-receptors in the spinal cord, which trigger itching sensations. While hypotension is also a recognized side effect of spinal anesthesia, it is more commonly associated with the local anesthetic component rather than the opioid itself. Hypotension from spinal anesthesia occurs due to sympathetic blockade causing vasodilation. For patients experiencing opioid-induced pruritus, treatment options include low-dose naloxone (0.25-1 mcg/kg/hr), nalbuphine (5-10 mg IV), or antihistamines, though the latter are often less effective since the mechanism is not primarily histamine-related.
Some key points to consider when managing narcotic spinal administration include:
- Pruritus is a common side effect, occurring in 10% to 50% of patients receiving opioids 1
- Hypotension is more commonly associated with the local anesthetic component rather than the opioid itself 1
- Treatment options for opioid-induced pruritus include low-dose naloxone, nalbuphine, or antihistamines 1
- Neuraxial blocks and catheters should be placed with caution in any patient on concurrent anticoagulation therapy or systemic sepsis 1
Overall, pruritus is the most common side effect of narcotic spinal administration, and clinicians should be aware of this potential side effect and have strategies in place to manage it.
From the Research
Narcotic Spinal Administration Side Effects
- The most common side effects of narcotic spinal administration include pruritis and hypotension.
- According to the studies, pruritis is a more frequently reported side effect than hypotension 2, 3, 4, 5, 6.
Pruritis Incidence
- The incidence of pruritis varies between 30% and 100% 6.
- A study found that 57% to 75% of patients experienced pruritis after receiving low-dose intrathecal fentanyl 3.
- Another study reported that 21% to 55% of patients experienced pruritis after receiving fentanyl with lidocaine, bupivacaine, or procaine 4.
Hypotension Incidence
- There is limited information on the incidence of hypotension in the provided studies.
- None of the studies directly compare the incidence of pruritis and hypotension after narcotic spinal administration.
Treatment and Prevention
- Various pharmacological therapies have been studied to treat and prevent neuraxial opioid-induced pruritus, including antihistamines, 5-HT(3)-receptor antagonists, and opiate-antagonists 6.
- Prophylactic ondansetron may decrease the need for rescue medication, but it does not significantly decrease the incidence of pruritus 5.