Mohamed, S.A.B., Abdel-Ghaffar, H.S., Kamal, S.M., Fares, K.M., & Hamza, H.M. (2016). Effect of topical morphine on acute and chronic postmastectomy pain: What is the optimum dose? Regional Anesthesia and Pain Medicine, 41, 704–710.
To determine if using a different morphine amount in a morphine/bupivacaine combination would be more effective in pain management in patients after a radical mastectomy for breast cancer.
Registered clinical trial with 90 patients allocated to receive 10 ml plain bupivacaine 0.5% plus either 5, 10, or 15 mg morphine diluted with saline 0.9% to 20 ml and topically to mastectomy site prior to closing. The three groups were compared for the following: time to first postoperative analgesia; IV patient-controlled analgesia (PCA) morphine consumption; pain scores; hemodynamics; sedation; adverse events in first postoperative 48 hours; and Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) scores in first and third postoperative months. Each patient participated in two study phases: an initial two-day treatment phase (48 hours post-op), phase 1, followed by a one- and three-month follow-up, phase 2. All clinical staff and patients were blinded to treatment group assignment.
PHASE OF CARE: Active anti-tumor treatment
Prospective, randomized, double-blind comparative study.
Visual analog scale (VAS), analgesia time, cumulative morphine consumption in first 48 hours, LANSS pain scale
There was a significant difference in analgesia-free time between the three groups. Morphine 15 mg had no patients requiring postoperative analgesics in the first 48 hours compared to 8 patients (27%) in the morphine 10 mg group and 19 patients (63%) in the morphine 5 mg group (p < 0.002). Regarding the time to analgesia use, the morphine 5 mg group was 7.31 hours (SD = 3.12) versus 14 hours (SD = 3.54) in the morphine 10 mg group (p < 0.000).
The morphine 15 mg group had the lowest LANSS recorded score in the first postoperative month when compared to the morphine 5 mg and 10 mg groups (1.1 [SD = 0.37] versus 5.76 [SD = 3.26] versus 4.73 [SD = 2.87], respectively) (p < 0.0001).
The increase in topical morphine (specifically up to 15 mg) in combination with bupivacaine, when compared to lower doses of morphine, has shown a decrease in postmastectomy pain through the reduction of analgesic use within 48 hours after surgery as well as lower LANSS scores within the first postoperative month.
15 mg topical morphine with bupivacaine may decrease postoperative pain and reduce the rate of PMPS.