Pharmacokinetic and Pharmacodynamic Evaluation of a Weight-Based Dosing Regimen of Cefoxitin for Perioperative Surgical Prophylaxis in Obese and Morbidly Obese Patients.

The objective of this study was to determine the pharmacokinetics and pharmacodynamics (PK/PD) of a weight-based cefoxitin dosing regimen for surgical prophylaxis in obese patients. Patients received a single dose of cefoxitin at 40 mg/kg based on total body weight. Cefoxitin samples were obtained over 3 h from serum and adipose tissue, and concentrations were determined by validated high-performance liquid chromatography. Noncompartmental pharmacokinetic analysis was performed, followed by Monte Carlo simulations to estimate probability of target attainment (PTA) for Staphylococcus aureus, Escherichia coli, and Bacteroides fragilis over 4-h periods postdose. Thirty patients undergoing bariatric procedures were enrolled. The body mass index (mean ± standard deviation [SD])was 45.9 ± 8.0 kg/m(2) (range, 35.0 to 76.7 kg/m(2)); the median cefoxitin dose was 5 g (range, 4.0 to 7.5 g). The mean maximum concentrations were 216.15 ± 41.80 µg/ml in serum and 12.62 ± 5.89 in tissue; the mean tissue/serum ratio was 8% ± 3%. In serum, weight-based regimens achieved ≥90% PTA (goal time during which free [unbound] drug concentrations exceed pathogen MICs [fT>MIC] of 100%) for E. coli and S. aureus over 2 h and for B. fragilis over 1 h; in tissue this regimen failed to achieve goal PTA at any time point. The 40-mg/kg regimens achieved higher PTAs over longer periods in both serum and tissue than did the standard 2-g doses. However, although weight-based cefoxitin regimens were better than fixed doses, achievement of desired pharmacodynamic targets was suboptimal in both serum and tissue. Alternative dosing regimens and agents should be explored in order to achieve more favorable antibiotic performance during surgical prophylaxis in obese patients.

Laparoscopic sleeve gastrectomy: long-term weight loss outcomes.

BACKGROUND: Laparoscopic sleeve gastrectomy (LSG) has become an increasingly popular stand-alone weight loss surgery, but there is a paucity of long-term efficacy data. OBJECTIVE: To determine long-term outcomes for patients undergoing LSG. SETTING: Tertiary care university hospital in the United States. METHODS: This study presents a case series of the first 16 patients undergoing LSG at our institution. Inclusion criteria were accepted indications for bariatric surgery, and exclusion criteria were any prior bariatric surgery, gastrectomy, substance abuse, uncontrolled psychiatric illness, end-stage organ disease, or advanced-stage cancer. Patients were followed for 7 years. Outcomes included percent excess weight loss (%EWL), percent weight loss (%WL), resolution of co-morbidities, and major and minor complications. RESULTS: Patients enrolled in this study had a mean body mass index (BMI) of 43.5 kg/m(2) and a mean age of 49, and 14 of 16 patients were women. Fourteen of 16 patients had 7-year follow-ups with a mean %WL of 29.6%±8.95 and a mean %EWL of 59.6%±89.9%. At 7 years, 11 of 14 patients achieved>50% EWL. One-year follow-up data revealed a mean EWL of 72%±20%, which was significantly greater than the %EWL at 7 years (P = .005). Complications included 1 partial obstruction at the gastric incisura angularis and 1 subacute leak; both were managed endoscopically. There were no reoperations and no deaths. Five of 14 patients experienced new-onset gastroesophageal reflux disease. CONCLUSIONS: At 7 years postoperative, the LSG remained a durable and successful operation.