Department of Surgery, Weill Cornell Medical College, New York, New York, USA.
Surg Infect (Larchmt). 2012 Feb;13(1):33-7. doi: 10.1089/sur.2010.097. Epub 2012 Feb 8.
Cefazolin is used commonly to prevent surgical site infection (SSI) after operations on patients with morbid obesity (MO), but specific dosing guidelines are lacking. We hypothesized that cefazolin 2 g given by intravenous (IV) push over 5 min (IVP) or infusion over 30 min (INF) would suffice for SSI prophylaxis in MO (body mass index [BMI] 40-50 kg/m(2)), and cefazolin 3 g would be sufficient in patients with super-morbid obesity (SMO) (BMI >50 kg/m(2)).
Twenty-five patients undergoing elective surgical procedures were given a single dose of cefazolin: Ten with MO received 2 g via IVP (MO2-IVP), five with MO received 2 g via 30-min infusion (MO2-INF), five with SMO received 2 g via infusion (SMO2-INF), and five with SMO received 3 g via infusion (SMO3-INF). Serum cefazolin concentrations were measured 5, 30, 120, and 360 min after initiation of the dose. The half-life of the drug was calculated for each patient, as was the time the concentration was above the minimum inhibitory free concentration (fT>MIC) using 8 mcg/mL as the breakpoint. The protective duration of each cefazolin dose was assessed using the pharmacodynamic target for fT>MIC of 70%.
The mean cefazolin concentrations after 30 min were similar in all groups; the mean concentrations at 120 and 360 min were 67.1-84.8 mcg/mL and 22.9-40.8 mcg/mL, respectively. The half-life ranged from 2.3 to 3.6 h and was unaffected by administration method. The protective duration was 5.1 h for MO2-IVP, 4.8 h for MO2-INF, 5.8 h for SMO2-INF, and 6.8 h for SMO3-INF.
A single 2-g dose of cefazolin appears to provide antibiotic exposures sufficient for most common general surgical procedures of <5-h duration, regardless of BMI.
头孢唑林常用于预防病态肥胖（MO）患者手术后的手术部位感染（SSI），但缺乏具体的剂量指南。我们假设，MO（体重指数[BMI]为 40-50 kg/m²）患者静脉推注（IVP）5 分钟以上给予 2 g 头孢唑林或输注 30 分钟以上（INF）可满足 SSI 预防用药，而超病态肥胖（SMO）（BMI>50 kg/m²）患者给予 3 g 头孢唑林即可。
25 例择期手术患者给予单次头孢唑林剂量：10 例 MO 患者静脉推注 2 g（MO2-IVP），5 例 MO 患者静脉输注 2 g（MO2-INF），5 例 SMO 患者输注 2 g（SMO2-INF），5 例 SMO 患者输注 3 g（SMO3-INF）。在给药后 5、30、120 和 360 分钟测量血清头孢唑林浓度。计算每位患者的药物半衰期，以 8 mcg/mL 作为临界点，计算浓度高于最低抑菌游离浓度（fT>MIC）的时间。使用 fT>MIC 为 70%的药效学目标评估每种头孢唑林剂量的保护持续时间。
所有组在 30 分钟后的平均头孢唑林浓度相似；在 120 和 360 分钟时的平均浓度分别为 67.1-84.8 mcg/mL 和 22.9-40.8 mcg/mL。半衰期范围为 2.3-3.6 h，不受给药方式的影响。MO2-IVP 的保护持续时间为 5.1 h，MO2-INF 为 4.8 h，SMO2-INF 为 5.8 h，SMO3-INF 为 6.8 h。
单次 2 g 头孢唑林剂量似乎可提供足够的抗生素暴露，适用于大多数持续时间<5 小时的普通外科手术，而与 BMI 无关。
