1
|
Lee SH, Yoon H, Park J, Choi JM, Kim KM, Lee EK, Noh GJ, Moon JY, Cho BM. External validation of a pharmacokinetic model for target-controlled infusion of cefazolin as a prophylactic antibiotic. Br J Clin Pharmacol 2024; 90:582-587. [PMID: 37897050 DOI: 10.1111/bcp.15943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Revised: 10/18/2023] [Accepted: 10/19/2023] [Indexed: 10/29/2023] Open
Abstract
AIMS This study aimed to evaluate the predictive performance of previously constructed cefazolin pharmacokinetic models and determine whether cefazolin administration via the target-controlled infusion (TCI) method may be possible in clinical practice. METHODS Twenty-five gastrectomy patients receiving cefazolin as a prophylactic antibiotic were enrolled. Two grams of cefazolin was dissolved in 50 mL of normal saline to give a concentration of 40 mg mL-1 . Before skin incision, cefazolin was administered using a TCI syringe pump, and its administration continued until the end of surgery. The target total plasma concentration was set to 100 μg mL-1 . Total and unbound plasma concentrations of cefazolin were measured in three arterial blood samples collected at 30, 60 and 120 min after the start of cefazolin administration. The predictive performance of the TCI system was evaluated using four measures: inaccuracy, divergence, bias and wobble. RESULTS Total (n = 75) and unbound (n = 75) plasma concentration measurements from 25 patients were included in the analysis. The pooled median (95% confidence interval) biases and inaccuracies were 6.3 (4.0-8.5) and 10.5 (8.6-12.4) for the total concentration model and -10.3 (-16.8 to -3.7) and 22.4 (18.2-26.7) for the unbound concentration model, respectively. All unbound concentrations were above 10 μg mL-1 . CONCLUSION Administration of cefazolin by the TCI method showed a clinically acceptable performance. Applying the TCI method by setting the total concentration as the target concentration rather than the unbound concentration is effective in maintaining a constant target concentration of cefazolin.
Collapse
Affiliation(s)
- Sou Hyun Lee
- Department of Anesthesiology and Pain Medicine, Dongsan Medical Center, Keimyung University School of Medicine, Daegu, South Korea
| | - Hyeongseo Yoon
- University of Ulsan College of Medicine, Seoul, South Korea
| | - Junik Park
- Department of Anesthesiology and Pain Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea
| | - Jae Moon Choi
- Department of Anesthesiology and Pain Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea
| | - Kyung Mi Kim
- Department of Anesthesiology and Pain Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea
| | - Eun-Kyung Lee
- Department of Statistics, Ewha Womans University, Seoul, South Korea
| | - Gyu-Jeong Noh
- Departments of Anesthesiology and Pain Medicine and Clinical Pharmacology and Therapeutics, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea
| | - Ju-Yeon Moon
- Department of Pharmaceutical Analysis, International Scientific Standards, Inc, Chucheon-si, South Korea
| | - Byung-Moon Cho
- Department of Anesthesiology and Pain Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea
| |
Collapse
|
2
|
Zelenitsky SA. Effective Antimicrobial Prophylaxis in Surgery: The Relevance and Role of Pharmacokinetics-Pharmacodynamics. Antibiotics (Basel) 2023; 12:1738. [PMID: 38136772 PMCID: PMC10741006 DOI: 10.3390/antibiotics12121738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2023] [Revised: 12/09/2023] [Accepted: 12/11/2023] [Indexed: 12/24/2023] Open
Abstract
Appropriate surgical antimicrobial prophylaxis (SAP) is an important measure in preventing surgical site infections (SSIs). Although antimicrobial pharmacokinetics-pharmacodynamics (PKPD) is integral to optimizing antibiotic dosing for the treatment of infections, there is less research on preventing infections postsurgery. Whereas clinical studies of SAP dose, preincision timing, and redosing are informative, it is difficult to isolate their effect on SSI outcomes. Antimicrobial PKPD aims to explain the complex relationship between antibiotic exposure during surgery and the subsequent development of SSI. It accounts for the many factors that influence the PKs and antibiotic concentrations in patients and considers the susceptibilities of bacteria most likely to contaminate the surgical site. This narrative review examines the relevance and role of PKPD in providing effective SAP. The dose-response relationship i.e., association between lower dose and SSI in cefazolin prophylaxis is discussed. A comprehensive review of the evidence for an antibiotic concentration-response (SSI) relationship in SAP is also presented. Finally, PKPD considerations for improving SAP are explored with a focus on cefazolin prophylaxis in adults and outstanding questions regarding its dose, preincision timing, and redosing during surgery.
Collapse
Affiliation(s)
- Sheryl A. Zelenitsky
- College of Pharmacy, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3E 0T5, Canada;
- Department of Pharmacy, St. Boniface Hospital, Winnipeg, MB R2H 2A6, Canada
| |
Collapse
|
3
|
Russo M, Monnin C, Zhang YL, Montreuil J, Tanzer M, Avizonis D, Hart A. A novel method for quantification of cefazolin local tissue concentration in blood, fat, synovium, and bone marrow using liquid chromatography - mass spectrometry. J Pharm Biomed Anal 2023; 234:115566. [PMID: 37441887 DOI: 10.1016/j.jpba.2023.115566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 06/26/2023] [Accepted: 07/05/2023] [Indexed: 07/15/2023]
Abstract
To be effective, the concentration of antibiotic used must exceed the minimum inhibitory concentration (MIC) against infecting organisms at and in the surgical site. Few studies follow antibiotic levels for tissues that are manipulated during surgery. The aim of this work was to develop and validate a novel LC-MS method as well as an efficient extraction technique for the quantification of cefazolin in local tissues and whole blood. This method uses the same efficient extraction method across multiple tissue types affected by orthopedic surgery: blood, fat, synovium, and bone marrow. The ability to quantify cefazolin in these tissues will help identify surgical techniques and antibiotic dosing protocols that better protect patients from infection. The internal standard, 13C2,15N-cefazolin, co-elutes with cefazolin, and was used in calibration curves and tissue extracts as well as for cefazolin recovery and matrix effects. The protocol was rigorously tested, including measurements of reproducibility and calibration curve quality. The recovery of the extraction method ranges from 94% to 113% across all sample types. There is little to no matrix effect on cefazolin signal (98-120%). The developed method was used to determine cefazolin concentrations in tissues of 10 patients undergoing a total knee replacement. Cefazolin blood concentrations were approximately 500 times higher than in adipose, synovium, and bone marrow tissues. This clinical data shows that although the minimum inhibitory concentration is largely surpassed in blood, the concentration of cefazolin in fat, synovium, and bone marrow could be insufficient during a knee replacement. This method of cefazolin quantification will help surgeons optimize antibiotic concentrations in the local tissues during knee replacement surgery and potentially reduce serious post-surgical infections.
Collapse
Affiliation(s)
- M Russo
- Metabolomics Innovation Resource, Rosalind and Morris Goodman Cancer Institute, McGill University, Canada
| | - C Monnin
- Metabolomics Innovation Resource, Rosalind and Morris Goodman Cancer Institute, McGill University, Canada
| | - Y L Zhang
- Research Institute, McGill University Health Centre, Canada
| | - J Montreuil
- Division of Orthopedic Surgery, McGill University, Canada
| | - M Tanzer
- Division of Orthopedic Surgery, McGill University, Canada
| | - D Avizonis
- Metabolomics Innovation Resource, Rosalind and Morris Goodman Cancer Institute, McGill University, Canada.
| | - A Hart
- Division of Orthopedic Surgery, McGill University, Canada
| |
Collapse
|
4
|
Ryan RL, Jackson D, Hopkins G, Eley V, Christensen R, Van Zundert AAJ, Wallis SC, Lipman J, Parker SL, Roberts JA. Plasma and Interstitial Fluid Pharmacokinetics of Prophylactic Cefazolin in Elective Bariatric Surgery Patients. Antimicrob Agents Chemother 2022; 66:e0041922. [PMID: 35762797 PMCID: PMC9295570 DOI: 10.1128/aac.00419-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 06/09/2022] [Indexed: 12/30/2022] Open
Abstract
Guidelines for surgical prophylactic dosing of cefazolin in bariatric surgery vary in terms of recommended dose. This study aimed to describe the plasma and interstitial fluid (ISF) cefazolin pharmacokinetics in patients undergoing bariatric surgery and to determine an optimum dosing regimen. Abdominal subcutaneous ISF concentrations (measured using microdialysis) and plasma samples were collected at regular time points after administration of cefazolin 2 g intravenously. Total and unbound cefazolin concentrations were assayed and then modeled using Pmetrics. Monte Carlo dosing simulations (n = 5,000) were used to define cefazolin dosing regimens able to achieve a fractional target attainment (FTA) of >95% in the ISF suitable for the MIC for Staphylococcus aureus in isolates of ≤2 mg · L-1 and for a surgical duration of 4 h. Fourteen patients were included, with a mean (standard deviation [SD]) bodyweight of 148 (35) kg and body mass index (BMI) of 48 kg · m-2. Cefazolin protein binding ranged from 14 to 36% with variable penetration into ISF of 58% ± 56%. Cefazolin was best described as a four-compartment model including nonlinear protein binding. The mean central volume of distribution in the final model was 18.2 (SD 3.31) L, and the mean clearance was 32.4 (SD 20.2) L · h-1. A standard 2-g dose achieved an FTA of >95% for all patients with BMIs ranging from 36 to 69 kg · m-2. A 2-g prophylactic cefazolin dose achieves appropriate unbound plasma and ISF concentrations in obese and morbidly obese bariatric surgery patients.
Collapse
Affiliation(s)
- Rochelle L. Ryan
- Department of Anaesthesia and Perioperative Medicine, Royal Brisbane and Women’s Hospital, Herston, Queensland, Australia
- Department of Anaesthesia and Perioperative Medicine, Sunshine Coast University Hospital, Birtinya, Queensland, Australia
- Faculty of Medicine, The University of Queensland, Herston, Queensland, Australia
| | - Dwane Jackson
- Department of Anaesthesia and Perioperative Medicine, Royal Brisbane and Women’s Hospital, Herston, Queensland, Australia
- Faculty of Medicine, The University of Queensland, Herston, Queensland, Australia
| | - George Hopkins
- Department of Surgery, Royal Brisbane and Women’s Hospital, Herston, Queensland, Australia
| | - Victoria Eley
- Department of Anaesthesia and Perioperative Medicine, Royal Brisbane and Women’s Hospital, Herston, Queensland, Australia
- Faculty of Medicine, The University of Queensland, Herston, Queensland, Australia
| | - Rebecca Christensen
- Department of Anaesthesia and Perioperative Medicine, Royal Brisbane and Women’s Hospital, Herston, Queensland, Australia
- Faculty of Medicine, The University of Queensland, Herston, Queensland, Australia
| | - Andre A. J. Van Zundert
- Department of Anaesthesia and Perioperative Medicine, Royal Brisbane and Women’s Hospital, Herston, Queensland, Australia
- Faculty of Medicine, The University of Queensland, Herston, Queensland, Australia
- UQ Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Herston, Queensland, Australia
| | - Steven C. Wallis
- UQ Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Herston, Queensland, Australia
| | - Jeffrey Lipman
- Faculty of Medicine, The University of Queensland, Herston, Queensland, Australia
- UQ Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Herston, Queensland, Australia
- Division of Anaesthesiology Critical Care Emergency and Pain Medicine, Nîmes University Hospital, University of Montpellier, Nîmes, France
| | - Suzanne L. Parker
- UQ Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Herston, Queensland, Australia
| | - Jason A. Roberts
- UQ Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Herston, Queensland, Australia
- Division of Anaesthesiology Critical Care Emergency and Pain Medicine, Nîmes University Hospital, University of Montpellier, Nîmes, France
- Department of Intensive Care Medicine, Royal Brisbane and Women’s Hospital, Herston, Queensland, Australia
- Department of Pharmacy, Royal Brisbane and Women’s Hospital, Herston, Queensland, Australia
| |
Collapse
|
5
|
Siemiątkowska A, Wassef A, Sadek R, Park C, Yohn C, Brunetti L, Kagan L. A validated LC-MS/MS method for the quantitation of cefazolin in human adipose tissue: Application of EMR-Lipid sorbent as an efficient sample clean-up before mass spectrometric analyses. J Pharm Biomed Anal 2022; 213:114696. [PMID: 35259713 PMCID: PMC9034060 DOI: 10.1016/j.jpba.2022.114696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 02/06/2022] [Accepted: 02/25/2022] [Indexed: 11/29/2022]
Abstract
A novel, simple, rapid, and sensitive high-performance liquid chromatography-tandem mass spectrometry method was developed to determine cefazolin concentrations in human adipose tissue. Sample preparation was performed by protein precipitation followed by using Captiva EMR-Lipid plates. The mobile phase consisted of 5 mM ammonium formate and 0.1% formic acid in water and 0.1% formic acid in ACN, and was pumped through a Synergi Fusion-RP column with a gradient elution program at a flow rate of 0.3 mL/min. The mass spectrometer was operated in a positive ion mode. Cloxacillin was used as an internal standard due to the observed cross-signal contribution between cefazolin and 13C2,15N-cefazolin. The method was validated according to the FDA and EMA guidelines and passed all the acceptance criteria. The calibration range was 0.05-50 µg/mL in adipose tissue homogenate (0.15-150 µg/g in adipose tissue), precision CV < 4.5%, accuracy within 93.1-100.4%. The carry-over was negligible, recovery of the method was high, and no significant matrix effect was present. Rat subcutaneous adipose tissue was demonstrated to be a suitable surrogate matrix for human adipose tissue. The validated method was successfully applied in a pilot pharmacokinetic study and will further be used in a large cohort of non-obese and obese patients dosed prophylactically with cefazolin before surgeries.
Collapse
|
6
|
Kim KM, Jung J, Lee JM, Yang HS, Bang J, Lee E, Choi B, Noh G. The expected advantage of administering prophylactic antibiotics using target‐ concentration controlled infusion: Development of a new pharmacokinetic model of cefazolin. Clin Exp Pharmacol Physiol 2022; 49:731-739. [DOI: 10.1111/1440-1681.13648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 03/29/2022] [Accepted: 04/07/2022] [Indexed: 11/30/2022]
Affiliation(s)
- Kyung Mi Kim
- Department of Anesthesiology and Pain Medicine, Asan Medical Center University of Ulsan College of Medicine Seoul South Korea
| | - Jiwon Jung
- Department of Infectious Diseases, Asan Medical Center University of Ulsan College of Medicine Seoul South Korea
| | - Jong Min Lee
- Department of Anesthesiology and Pain Medicine Daejeon Eulji University Hospital Eulji University School of Medicine Daejeon Korea
| | - Hong Seuk Yang
- Department of Anesthesiology and Pain Medicine Daejeon Eulji University Hospital Eulji University School of Medicine Daejeon Korea
| | - Ji‐Yeon Bang
- Department of Anesthesiology and Pain Medicine, Asan Medical Center University of Ulsan College of Medicine Seoul Korea
| | - Eun‐Kyung Lee
- Department of Statistics Ewha Womans University Seoul South Korea
| | - Byung‐Moon Choi
- Department of Anesthesiology and Pain Medicine, Asan Medical Center University of Ulsan College of Medicine Seoul South Korea
| | - Gyu‐Jeong Noh
- Departments of Anesthesiology and Pain Medicine, Clinical Pharmacology and Therapeutics, Asan Medical Center University of Ulsan College of Medicine Seoul South Korea
| |
Collapse
|
7
|
Dorn C, Petroff D, Stoelzel M, Kees MG, Kratzer A, Dietrich A, Kloft C, Zeitlinger M, Kees F, Wrigge H, Simon P. Perioperative administration of cefazolin and metronidazole in obese and non-obese patients: a pharmacokinetic study in plasma and interstitial fluid. J Antimicrob Chemother 2021; 76:2114-2120. [PMID: 33969405 DOI: 10.1093/jac/dkab143] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 04/11/2021] [Indexed: 01/08/2023] Open
Abstract
OBJECTIVES To assess plasma and tissue pharmacokinetics of cefazolin and metronidazole in obese patients undergoing bariatric surgery and non-obese patients undergoing intra-abdominal surgery. PATIENTS AND METHODS Fifteen obese and 15 non-obese patients received an IV short infusion of 2 g cefazolin and 0.5 g metronidazole for perioperative prophylaxis. Plasma and microdialysate from subcutaneous tissue were sampled until 8 h after dosing. Drug concentrations were determined by HPLC-UV. Pharmacokinetic parameters were calculated non-compartmentally. RESULTS In obese patients (BMI 39.5-69.3 kg/m2) compared with non-obese patients (BMI 18.7-29.8 kg/m2), mean Cmax of total cefazolin in plasma was lower (115 versus 174 mg/L) and Vss was higher (19.4 versus 14.2 L). The mean differences in t½ (2.7 versus 2.4 h), CL (5.14 versus 4.63 L/h) and AUC∞ (402 versus 450 mg·h/L) were not significant. The influence of obesity on the pharmacokinetics of metronidazole was similar (Cmax 8.99 versus 14.7 mg/L, Vss 73.9 versus 51.8 L, t½ 11.9 versus 9.1 h, CL 4.62 versus 4.13 L/h, AUC∞ 116 versus 127 mg·h/L). Regarding interstitial fluid (ISF), mean concentrations of cefazolin remained >4 mg/L until 6 h in both groups, and those of metronidazole up to 8 h in the non-obese group. In obese patients, the mean ISF concentrations of metronidazole were between 3 and 3.5 mg/L throughout the measuring interval. CONCLUSIONS During the time of surgery, cefazolin concentrations in plasma and ISF of subcutaneous tissue were lower in obese patients, but not clinically relevant. Regarding metronidazole, the respective differences were higher, and may influence dosing of metronidazole for perioperative prophylaxis in obese patients.
Collapse
Affiliation(s)
- Christoph Dorn
- Institute of Pharmacy, University of Regensburg, Regensburg, Germany
| | - David Petroff
- Clinical Trial Centre, University of Leipzig, Leipzig, Germany.,Integrated Research and Treatment Center (IFB) Adiposity Diseases, University of Leipzig, Leipzig, Germany
| | - Melanie Stoelzel
- Department of Anaesthesiology and Intensive Care Medicine, University of Leipzig Medical Centre, Leipzig, Germany
| | - Martin G Kees
- Department of Anaesthesiology, University Hospital Regensburg, Regensburg, Germany
| | - Alexander Kratzer
- Hospital Pharmacy, University Hospital Regensburg, Regensburg, Germany
| | - Arne Dietrich
- Integrated Research and Treatment Center (IFB) Adiposity Diseases, University of Leipzig, Leipzig, Germany.,Department of Surgery, University of Leipzig, Leipzig, Germany
| | - Charlotte Kloft
- Department of Clinical Pharmacy and Biochemistry, Institute of Pharmacy, Freie Universitaet Berlin, Berlin, Germany
| | - Markus Zeitlinger
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Frieder Kees
- Department of Pharmacology, University of Regensburg, Regensburg, Germany
| | - Hermann Wrigge
- Integrated Research and Treatment Center (IFB) Adiposity Diseases, University of Leipzig, Leipzig, Germany.,Department of Anaesthesiology, Intensive Care and Emergency Medicine, Pain Therapy, Bergmannstrost Hospital Halle, Halle, Germany
| | - Philipp Simon
- Integrated Research and Treatment Center (IFB) Adiposity Diseases, University of Leipzig, Leipzig, Germany.,Department of Anaesthesiology and Intensive Care Medicine, University of Leipzig Medical Centre, Leipzig, Germany
| |
Collapse
|
8
|
Ferraz ÁAB, Santa-Cruz F, Edmiston CE. Antibiotic Prophylaxis in Bariatric Surgical Procedures: Is There an Ideal Antimicrobial Agent? Surg Infect (Larchmt) 2020; 21:654-658. [PMID: 32109196 DOI: 10.1089/sur.2019.275] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
When patients with significant comorbid risk factors undergo surgical procedures, they are at high risk for development of post-operative infectious complications, including surgical site infection (SSI). Obese patients characteristically fit within this risk category, and thus it is of paramount importance to establish evidence-based strategies to mitigate these infectious complications. The use of an antimicrobial prophylactic regimen is a well-established practice and is based on the principle of the "right drug, at the right time, in the right place." The subject of this article is to review the current evidence-based data on antimicrobial prophylaxis in obese patients undergoing bariatric surgical procedures.
Collapse
Affiliation(s)
- Álvaro A B Ferraz
- Department of Surgery, Federal University of Pernambuco, Recife, Pernambuco, Brazil
| | - Fernando Santa-Cruz
- Medical School, Federal University of Pernambuco, Recife, Pernambuco, Brazil
| | - Charles E Edmiston
- Department of Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| |
Collapse
|
9
|
Antibiotic prophylaxis with high-dose cefoxitin in bariatric surgery: an observational prospective single center study. Antimicrob Agents Chemother 2019:AAC.01613-19. [PMID: 31591127 DOI: 10.1128/aac.01613-19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND The optimal dose of cefoxitin for antibiotic prophylaxis in obese patients remains uncertain. We evaluated the adequacy of a 4-gram dosing regimen of cefoxitin against the most frequent pathogens that infect patients undergoing bariatric surgery. METHODS This observational prospective study included obese patients who required bariatric surgery and a 4-gram dose of cefoxitin as an antibiotic prophylaxis. Serum concentrations were measured during surgery (incision, wound closure and in case of reinjection). The pharmacokinetic/pharmacodynamic (PK/PD) target was to obtain free cefoxitin concentrations above 4× MIC, from incision to wound closure (100% ƒT>4xMIC). The targeted MIC was based on the worst-case scenario (the highest ECOFF value of Staphylococcus aureus, Enterobacteriaceae and anaerobic bacteria). The secondary outcomes were the factors related to underdosage. RESULTS Two hundred patients were included. The mean age of the patients was 46 (±12) years-old, and the mean BMI was 45.8 (±6.9) kg/m2 Bypass surgery was the preferred technique (84%). The percentages of patients who met the PK/PD target (100% fT>4xMIC) of cefoxitin were 37.3%, 1.1% and 0% for S. aureus, Enterobacteriaceae and anaerobic bacteria, respectively. BMIs below 50 kg/m2 (OR 0.29, 95% CI [0.11-0.75], P = 0.0107) and a shorter duration of surgery (OR 0.97, 95% CI [0.95-0.99], P = 0.004) were associated with reaching the target concentrations. CONCLUSIONS In obese patients undergoing bariatric surgery, a regimen of 4 grams of cefoxitin led to an inadequate coverage for most common pathogens. A longer surgery duration and BMI over 50 kg/m2 increase the risk of underdosage.
Collapse
|