Department of Anesthesiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
Division of Cardiothoracic Surgery, Department of Surgery, Faculty of Medicine Siriraj Hospital, Mahidol University, Thailand.
Ann Card Anaesth. 2021 Apr-Jun;24(2):149-154. doi: 10.4103/aca.ACA_106_19.
The guideline for antibiotic prophylaxis in pediatric cardiac surgery is currently unavailable, and the effects of cardiopulmonary bypass (CPB) may result in low plasma cefazolin concentrations and subsequent postoperative surgical site infections (SSIs).
To demonstrate the calculated-unbound plasma concentrations of cefazolin during uncomplicated pediatric cardiac surgery.
A prospective observational study that included 18 patients <seven years of age, undergoing elective cardiac surgery with CPB.
An intravenous infusion of cefazolin (25 mg.kg) was administered to patients over 30 minutes within 1 hour before skin incision (first dose). Another 25 mg.kg infusion was administered to the CPB prime volume (second dose). Blood samples were obtained at eight time points: 15 minutes after the first dose (T1); before aortic cannulation (T2); immediately after CPB initiation (T3); 30 (T4), 60 (T5), and 120 (T6) minutes after CPB; 15 minutes after CPB discontinuation (T7), and at skin closure (T8). The total plasma cefazolin concentrations were measured using liquid chromatography tandem mass spectrometry.
The unbound cefazolin concentrations were calculated assuming 80%-protein binding. The median cefazolin levels were 18.1 (range 4.3-27.0), 11.9 (2.8-24.1), 31.4 (18.3-66.1), 23.4 (13.7-35.9), 20.2 (15.4-24.9), 17.7 (14.8-18.0), 15.6 (9.8-26.2), and 13.3 (8.3-24.6) μg.mL from T1-T8, respectively. The cefazolin levels remained four times above the minimum inhibitory concentrations (MICs) for Methicillin-sensitive S. aureus (MSSA) and S. epidermidis in most patients, but they were inadequate for Enterobacter and E. coli.
This regimen produced adequate plasma cefazolin concentrations for common organisms that cause SSIs after cardiac surgery.
小儿心脏外科学中预防性使用抗生素的指南目前尚未明确，体外循环（CPB）可能导致头孢唑林的血浆游离浓度较低，进而引发术后手术部位感染（SSI）。
旨在展示心脏手术中无并发症的小儿患者的头孢唑林计算游离血浆浓度。
这是一项前瞻性观察研究，纳入了 18 名年龄小于 7 岁、接受 CPB 心脏择期手术的患者。
在皮肤切开前 1 小时内（首剂），患者静脉输注头孢唑林（25mg/kg），30 分钟以上完成输注。CPB 预充液中加入 25mg/kg 头孢唑林（二剂）。在 8 个时间点采集血样：首剂后 15 分钟（T1）；主动脉插管前（T2）；CPB 启动即刻（T3）；CPB 启动后 30 分钟（T4）、60 分钟（T5）和 120 分钟（T6）；CPB 停止后 15 分钟（T7）；皮肤缝合时（T8）。采用液相色谱串联质谱法测量总血浆头孢唑林浓度。
假设蛋白结合率为 80%，计算出游离头孢唑林浓度。头孢唑林中位数水平分别为 18.1（4.3-27.0）、11.9（2.8-24.1）、31.4（18.3-66.1）、23.4（13.7-35.9）、20.2（15.4-24.9）、17.7（14.8-18.0）、15.6（9.8-26.2）和 13.3（8.3-24.6）μg/mL，时间点从 T1 到 T8。在大多数患者中，头孢唑林水平仍保持在甲氧西林敏感金黄色葡萄球菌（MSSA）和表皮葡萄球菌的最低抑菌浓度（MIC）的 4 倍以上，但对肠杆菌科和大肠杆菌则不足。
该方案为心脏手术后引起 SSI 的常见病原体提供了足够的头孢唑林血浆浓度。
