癌性疼痛患者从吗啡向芬太尼持续注入转换的换算比例研究

Equipotent ratio for conversion of morphine to continuous infusion of fentanyl in patients with cancer pain

目的：探讨从吗啡向芬太尼持续注入转换的适当换算比例。方法：通过20例癌性疼痛患者的回顾性临床调查,对疼痛程度、药物不良反应及治疗满意度进行评价。结果：本组转换后1周内稳定(转换前后疼痛强度无明显变化)(Good组)的有17例,不稳定(Poor组)的有3例。芬太尼注射剂和吗啡有同等的镇痛效果；转换后能够减轻副作用、提高满意度。结论：推荐从低剂量吗啡向芬太尼注射剂转换的换算比例是72∶1,并且推测从非低用量吗啡向芬太尼注射剂转换的换算比例小于72∶1有可能达到稳定。但不可能确定从吗啡向芬太尼持续注入转换的具体换算比例,应考虑转换前吗啡用量,再行确定转换的具体比例。

Objective： To investigate the proper equipotent ratio for conversion of morphine to continuous infusion of fentanyl in patients who suffer from cancer pain. Methods： A retrospective study was performed on 20 patients with cancer pain in Shizuoka Cancer Center from 2002 Sep to 2003 Nov. Pain intensity, adverse reaction, and satisfaction index of patients were evaluated. Results：The pain intensity was stable before and after conversion in 17 patients within 1 week after conversion indicating good pain-control. It was unstable in 3 patients after conversion suggesting poor pain-control. Fentanyl injection had equipotent pain- relieving effects with morphine. Conversion of morphine to fentanyl injection could alleviate side effects and increase the satisfaction index of patients. Conclusions： An equipotent ratio for conversion of low dose morphine to fentanyl injection was established as 72 ： 1, and for non low dose morphine a ratio less than 72 ： 1 was proposed to get stable pain-relieving effect. But the equipotent ratio for conversion of morphine to continuous perfusion of fentanyl could not be determined. We must consider the morphine dosage before confirmation of the equipotent ratio.