# The use of intrathecal morphine in non-abdominal surgery: a scoping review

## TL;DR

This review examines how using intrathecal morphine for non-abdominal surgery can reduce pain and opioid use but may cause side effects like itching and nausea.

## Contribution

The study provides a comprehensive analysis of intrathecal morphine's effectiveness and side effects in non-abdominal surgery through a scoping review of 75 trials.

## Key findings

- Intrathecal morphine reduced postoperative pain and opioid consumption in spinal, thoracic, and orthopedic surgeries.
- It was associated with increased itching, nausea, vomiting, and urinary retention, especially in orthopedic procedures.
- Low to moderate doses (<500 μg) did not cause delayed respiratory depression.

## Abstract

Intrathecal morphine can reduce pain and opioid requirements needed for postoperative pain relief. It can potentially aid in the effectiveness of enhanced recovery protocols in non-abdominal surgery. However, concerns about side-effects may have hindered its use. This scoping review evaluates the effectiveness, appropriate dosage, and adverse effects of intrathecal morphine in non-abdominal surgery.

We systematically searched for randomised controlled trials examining the use of intrathecal morphine in non-abdominal surgery.

The search identified 75 trials involving 4685 patients. We undertook a scoping review of these randomised controlled trials, including bias assessments, to comprehensively analyse the effectiveness and side-effects of intrathecal morphine. The findings indicate that intrathecal morphine reduced postoperative pain and opioid consumption after spinal surgery, thoracic surgery, and orthopaedic lower extremity surgery. However, it was associated with an increased incidence of itching, postoperative nausea and vomiting, and urinary retention, particularly in orthopaedic procedures. Delayed respiratory depression was absent with low to moderate doses (<500 μg) in the reviewed studies.

This review supports the effectiveness of intrathecal morphine in non-abdominal surgery. However, the benefits must be carefully weighed against potential side-effects that could lead to prolonged hospital stays.

PROSPERO-registry CRD42021233936.