Background and aims Intrathecal morphine provides effective and stable analgesia during the first postoperative day, being used as a safe tool for pain control in different surgical procedures. The incidence of side effects such as nausea and vomiting, itching or respiratory depression are its main disadvantages because it can delay the recovery of our patients and diminish their general satisfaction.

Methods Local committee authorizes observational anonymous retrospective study without Ethics Committee approval, in which 123 cases were analyzed using intrathecal morphine in patients over 18 years old with recent surgery. We collected demographic data, dosage use and the appearance of side effects. In all our patients, we used the dosage of 80 µg of intrathecal morphine.

Results The average age was 54.05 years old. Most patients were ASA-II (41.55%). Most of our patients (77.23%) shown a VAS of 0 at resting. 42 patients (34.1%) had side effects: the most frequent was pruritus (50%), followed by dizziness (23.81%). The incidence of side effects in gynecology and obstetrics was significantly higher than the rest of specialties (p=0,005), being pruritus (31,11%) and dizziness (20%), the two main complications. 54.5% of our patients expressed ‘very good’ satisfaction for pain management, showing only ‘regular’ satisfaction in 4.1%. None of our patients classified its satisfaction as ‘bad’ or ‘very bad’.

Conclusions The use of 80 µg of intrathecal morphine is a very effective and safe technique for acute pain control during the first day of postoperative surgery. It provides great satisfaction among patients and shows a low incidence of side effects and complications.