Comparison of activity scores measured by the wrist actigraph, morphine concentrations in blood and visual analogue scale scores before and after the subcutaneous administration of a rescue morphine for patients with cancer pain

Abstract

   The actigraph has been widely used for the assessment of activity patterns, such as insomniac sleep. The reliability of the actigraph has been well proven. Measurement of with the actigraph may make it possible to objectively assess the activity of patients with pain as well as insomnia. The purpose of the present study was to determine the usefulness of the wrist actigraph for the study of the effect of morphine on the activity of patients with cancer pain. Single rescue morphine (1.5 or 3.0 mg) was administered subcutaneously to two patients with continuous morphine injection (37.5 or 67.5 mg/day, respectively). We compared the patient's activity with morphine concentrations in the blood and with pain intensity measured with visual analog scale (VAS). Single rescue morphine significantly decreased activity scores from 15 to 45 minutes after injection in both cases. The average of activity scores after 16 rescue injections (1.5 mg morphine) revealed the significant decrease of the activity from 15 to 180 minutes after injection in case 1. Single rescue injections of morphine significantly decreased VAS scores from 15 to 120 minutes after injection.