預防性抗生素使用對甲狀腺手術部位感染之危險因素探討

Thyroidectomies: Surgical Site Infection Risk Factors of Using Prophylactic Antibiotics

背景：手術部位感染是常見的院內感染部位之一，也是造成死亡和醫療成本增加的重要因素；而手術前預防性抗生素是否使用對於甲狀腺手術傷口的影響值得進一步探討。
目的：比較是否投予預防性抗生素對於甲狀腺手術部位感染、平均住院天數及平均醫療費用之影響。
方法：採橫斷比較性研究設計，研究對象為某醫學中心一般外科病房在2007年至2008年間實施甲狀腺手術病人。研究分二組進行，第一組以病歷回溯方式調查2007年1月1日至2007年10月31日在手術前30分鐘有投予預防性抗生素病人之相關病歷紀錄與檢查報告。第二組研究醫院推動甲狀腺切除術於手術前30分鐘不投予預防性抗生素政策，續收集2007年11月1日至2008年10月31日手術前30分鐘不投予預防性抗生素病人之相關資料。
結果：共收案310人，二組均未發生手術部位感染。但二組中有15位（4.8%）病人手術後服用抗生素治療，且有6位（40.0%）出現手術部位腫（x2 = 120.33; p < .01）。得知手術前罹患糖尿病（x2 = 6.39; p = .03）、手術時間超過2小時（x2 = 4.40; p = .04）、手術部位引流管留置（x2 = 4.58; p = .03）及引流管留置天數 > 2天（x2 = 6.24; p = .03）都與甲狀腺手術後服用抗生素治療具顯著關聯性。而手術前不投予預防性抗生素可顯著縮短平均住院天數（3.65天 ± 1.04; p < .01）及藥費成本支出（p < .01），當住院天數超過4天以上，術後服用抗生素治療藥費增加5,851元、醫療費用支出也由32,436元增加到63,895元，但住院天數控制在4天內，術後有服用抗生素治療的處置，其藥費及醫療費用支出並無顯著差異。
結論：實施甲狀腺手術在手術前不給予預防性抗生素並不會增加手術部位感染的風險。

Background: Surgical site infection is one of the most common types of nosocomial infection and an important factor in increased mortality and medical costs. The effectiveness of prophylactic antibiotics use on thyroidectomy wound sites merits further examination. Purpose: This study compared the influence of prophylactic antibiotics use or non-use on surgical site infection risk, average hospital stay length and average medical costs in thyroidectomy patients. Methods: This cross-sectional study targeted patients undergoing thyroidectomies at the general surgery ward of a medical center during the period 2007 to 2008. Subjects were divided into two groups. The first comprised patients who received prophylactic antibiotics thirty minutes before receiving a thyroidectomy between January 1, 2007 and October 31, 2007. A retrospective review of patient charts and reports was conducted for this group. The second consisted of patients that did not receive prophylactic antibiotics 30 minutes before receiving a thyroidectomy between November 1, 2007 and October 31, 2008 in line with a new antibiotics policy enforced at the research hospital. Results: A total of 310 subjects were enrolled in the study. All subjects were free of surgical site infection. Fifteen patients (4.8%) received a course in antibiotics after surgery and six (40.0%) of these showed surgical site swelling (x2 = 120.33; p < .01). Statistically significant risk factors of post-surgery antibiotics use included diabetes mellitus (x2 = 6.39; p = .03), a surgery duration in excess of 2 hours (x2 = 4.40; p = .04), drainage tube remaining in place at the surgical site (x2 = 4.58; p = .03) and drainage tube insertion for more than 2 days (x2 = 6.24; p = .03). Significant reductions in average hospital stay length (3.65days ± 1.04; p < .01) and medical costs (p < .01) were observed when prophylactic antibiotics were not used before surgery. The cost of post-operative antibiotics increased by $5,851 and medical costs increased from $32,436 to $63,895 when hospital stay length exceeded four days. If hospital stay length was kept within four days and post-operative antibiotics were used, this study found no significant difference in drug or medical costs. Conslusion: Not using prophylactic antibiotics before thyroidectomy does not increase surgical site infection risk.