Circadian rhythm of PCA-based opioid consumption in children with chemotherapy-related mucositis

In order to match the interindividual and intraindividual differences in opioid requirements of pediatric oncology patients with mucositis, patient-controlled analgesia (PCA) seems to be the optimal pain therapy option, but scientific data are lacking. A retrospective chart review of PCA-treated children with mucositis was carried out over a 6-year period (2000-2006) at the university hospital for children in Erlangen. The median age of the patients was 12.6 years and they mainly suffered from forms of acute leukemia. Daily morphine equivalent dose (MED) requirements increased with the start of the PCA therapy from 14.5 mg/day to 18.7 mg/day (p=0.021; Wilcoxon test). Children required more opioids by bolus request during the night (10:01 p.m. to 06:00 a.m.; 6.28 mg; 13%) than during the other 8-hour intervals (06:01 a.m. to 02:00 p.m. and 02:01 p.m. to 10:00 p.m.; both 21.3 mg (43.5%) during the whole 10-day study period. In 8 out of 10 days there was a significant diurnal variation in opioid requirement with significantly lower requirement during the night (p