Lin Shih-Pin, Chang Kuang-Yi, Tsou Mei-Yung, Chen Tony Hsiu-Hsi
*Department of Anesthesiology, Taipei Veterans General Hospital and School of Medicine, National Yang-Ming University, Taipei, Taiwan †Division of Biostatistics, Graduate Institute of Epidemiology and Preventive Medicine, College of Public Health, College of Public Health, National Taiwan University.
Clin J Pain. 2016 Jun;32(6):488-94. doi: 10.1097/AJP.0000000000000312.
To elucidate the dynamics of analgesic consumption regarding intravenous patient controlled analgesia (IVPCA) during postoperative period is rather complex partly due to between-patient variation and partly due to within-patient variation. A statistical method was proposed to classify serial analgesic consumption into different classifications that were further taken as the multiple outcomes on which to explore the associated predictors.
We retrospectively included 3284 patients administrated by IVPCA for 3 days after surgery. A repeated measurement design corresponding to serial analgesic consumption variables defined as six-hour total analgesic consumptions was adopted. After determining the numbers of clusters, serial analgesic consumptions were classified into several homogeneous subgroups. Factors associated with new classifications were identified and quantified with a multinominal logistic regression model.
Three distinct analgesic classifications were aggregated, including "high", "middle" and "low" level of analgesic consumption of IVPCA. The mean analgesic consumptions on 12 successive analgesic consumptions at 6-hour interval of each classification consistently revealed a decreasing trend. As the trends were almost parallel with time, this suggests the time-invariant proportionality of analgesic consumption between the levels of analgesic consumption of IVPCA. Patient's characteristics, like age, gender, weight, height, and cancer status, were significant factors associated with analgesic classifications. Surgical sites had great impacts on analgesic classifications.
The serial analgesic consumptions were simplified into 3 analgesic consumptions classifications. The identified predictors are useful to recognize patient's analgesic classifications before using IVPCA. This study explored a new approach to analysing dynamic changes of postoperative analgesic consumptions.
阐明术后静脉自控镇痛（IVPCA）期间镇痛药物消耗的动态变化相当复杂，部分原因是患者之间的差异，部分原因是患者自身的差异。提出了一种统计方法，将连续的镇痛药物消耗分类为不同类别，这些类别进一步作为多个结果，用以探索相关的预测因素。
我们回顾性纳入了3284例术后接受3天IVPCA治疗的患者。采用重复测量设计，对应定义为6小时总镇痛药物消耗量的连续镇痛药物消耗变量。确定聚类数量后，将连续的镇痛药物消耗分类为几个同质亚组。使用多项逻辑回归模型识别并量化与新分类相关的因素。
汇总出三种不同的镇痛分类，包括IVPCA镇痛药物消耗的“高”、“中”和“低”水平。每种分类在6小时间隔的12次连续镇痛药物消耗中的平均消耗量持续呈现下降趋势。由于这些趋势几乎与时间平行，这表明IVPCA不同水平镇痛药物消耗之间的镇痛药物消耗具有时间不变的比例关系。患者的特征，如年龄、性别、体重、身高和癌症状态，是与镇痛分类相关的重要因素。手术部位对镇痛分类有很大影响。
连续的镇痛药物消耗被简化为3种镇痛药物消耗分类。所确定的预测因素有助于在使用IVPCA之前识别患者的镇痛分类。本研究探索了一种分析术后镇痛药物消耗动态变化的新方法。
