婦科手術病患基本資料與硬脊膜外自控式止痛總用量間之相關性

Correlations between Patient-controlled Epidural Analgesia Requirements and Individual Characteristics among Gynecologic Patients

背景：硬脊膜外病患自控式給藥方式已被廣泛運用在術後止痛。雖然很多研究已證實其安全性與效用，但未曾有人研究其用量與病人基本資料間的相關性，因此我們進行這個回溯性研究以探討兩者之間的關聯。方法：我們收集20到65歲的婦科手術病患並接受硬脊膜外自控式止痛者的基本資料。所有病人均使用硬脊膜外自控式止痛至少三天以上。藥物配方為bupivacaine （0.0625％）加morphine （0.02 mg/mL）。在病人使用完三天的藥物後記錄其總用量並利用逐步迴歸分析（Stepwise regression analysis）以篩選出影響其總用量最重要的因素。結果：共有170位病人被納入分析（81個良性病例，89個惡性病例）。良性與惡性病例在年齡組成與總用量上有顯著差異。逐步迴歸分析結果顯示病例種類，BMI和年齡是總用量最重要的決定因子，其複迴歸係數與調整後的迴歸係數平方值分別是0.339和0.099。而標準迴歸係數的比較顯示BMI對總用量的影響力比年齡高。結論：病例型態，BMI和年齡都與硬脊膜外自控式止痛的總用量有關。身高與總劑量無關，惡性病例總用量較良性病例高，BMI與總用量呈正相關但年齡則與其呈負相關。

Background: Patient-controlled epidural analgesia (PCEA) has been used widely to relieve postoperative pain. Although many studies have demonstrated the safety and effectiveness of PCEA, the relationship between patients' characteristics and requirements of PCEA has not been investigated yet. We conducted this retrospective study to explore the correlations between total PCEA demand and patients' characteristics. Methods: We collected data from patients aged from 20 to 65, receiving gynecologic operations and consenting to epidural analgesia. All patients used postoperative PCEA for at least 3 days. An analgesic solution of bupivacaine (0.0625%) and morphine (0.02 mg/mL) was prepared for PCEA in all patients. The total PCEA consumption was recorded at the end of the 3-day course. Stepwise regression analysis was conducted to sort out influential factors which could determine the total PCEA demand. Results: There were 170 patients (81 benign and 89 malignant cases) included in the analysis. Significant differences existed in age and total PCEA requirement between different disease patterns. The stepwise regression model selection showed that disease patterns, body mass index (BMI) and age were most significant determinants of total PCEA demand. The R and adjusted R square values of the final selected model are 0.339 and 0.099, respectively. The comparison between the standardized regression coefficient of BMI and age suggested that the influence of BMI is greater than that of age. Conclusions: Disease patterns, BMI and age are associated with total PCEA requirements. Gynecologic patients receiving procedures for malignant diseases consumed more PCEA solution than benign cases. Height is not associated with total PCEA demand. There is a close correlation between BMI and PCEA consumption but age is a negative correlate.