///2012 Abstract Details
2012 Abstract Details2019-08-02T19:38:42-06:00

Post-cesarean analgesic efficacy and side effects: A comparison of 100 and 200 mcg of intrathecal morphine

Abstract Number: T-29
Abstract Type: Original Research

Jocelyn Wong B.A1 ; Edward Riley MD2; Brendan Carvalho MBBCH3; N/A N/A N/A4; N/A N/A N/A5; N/A N/A N/A6


Intrathecal (IT) morphine is highly effective for post-cesarean analgesia, however, the optimal dose is yet to be established. (1,2,3) The aim of this study was to compare the analgesia and side effects associated with 100 versus 200 mcg intrathecal morphine.


We conducted a retrospective chart review of 241 patients who had had an elective cesarean delivery, receiving either 100 or 200 mcg of IT morphine. The primary outcome variables were mean and peak verbal pain scores (VPS 0-10) and analgesic use (mg-morphine equivalents). Postoperative administration of antiemetics and nausea scores (0-10) were recorded. Data are reported as mean ± SD or percentages. P <0.05 was considered statistically significant.


The 200 mcg group had significantly lower VPS and opioid use. Mean VPS were (1.6±1.1 versus 2.0±1.1; P=0.0114) and peak VPS’s were (4.9± 2.0 versus 5.6±1.8; P=0.0079). The 200 mcg group used less opioid in the first 24 hours after surgery (44 ± 35 versus 54 ± 35 mg-morphine equivalents; P=0.04) and a lower percentage used intravenous opioids (18% versus 30% P=0.02). However, the 200 mcg group suffered more nausea (mean nausea score of 1.9±1.3 versus 1.6±1.3; P=0.0374 and 52% use of antiemetics versus 24%; P<0.0001).


Doses greater than 100 mcg of IT morphine provide better analgesia, but the nausea is significantly greater with the 200 mcg dose. Results from this study can be used to help guide IT morphine dosing in the cesarean delivery setting, basing dosages on patient preference for analgesia and side effects.


1. Anesthesiology. 1999;90:437.

2. Anesthesiology. 1999;91:1919.

SOAP 2012