Perioperative antibiotic prophylaxis in the gastric bypass patient: do we achieve therapeutic levels?

Abstract

BACKGROUND:

Perioperative surgical antibiotic prophylaxis requires that therapeutically effective drug concentrations be present in the tissues.

METHODS:

Patients undergoing Roux-en-Y gastric bypass for morbid obesity were given 2 g cefazolin preoperatively, followed by a second dose at 3 hours. Thirty-eight patients were each assigned to 1 of 3 body mass index (BMI) groups: (A) BMI=40-49 (N = 17); (B) BMI=50-59 (N=11); (C) BMI > or= 60 (N=10). Multiple timed serum (baseline; incision, 15, 30, 60 minutes; prior to second prophylactic dose; and closure) and tissue (skin, subcutaneous fat, and omentum) specimens were collected and cefazolin concentration analyzed by microbiological assay.

RESULTS:

No significant difference was observed in intraoperative fluid replacement or blood loss among BMI groups. Serum antimicrobial concentrations exceeded resistance breakpoint (32 microg/mL) in 73%, 68%, and 52% of BMI groups A, B, and C, respectively. No significant difference in cefazolin concentration was observed in mean incisional skin and closure tissue specimens in groups A, B, and C. A significant decrease in cefazolin concentration was noted in closure adipose (p=.04), initial (p=.03) and closure omentum (p=.05) tissues in groups B and C compared with A. Over 90% of serum samples exhibited therapeutic concentrations covering 53.8% of gram-positive and 78.6% of gram-negative surgical pathogens. However, therapeutic tissue levels were achieved in only 48.1%, 28.6%, and 10.2% of groups A, B, and C, respectively.

CONCLUSIONS:

Pharmacokinetic analysis suggests that present dosing strategies may fail to provide adequate perioperative prophylaxis in gastric bypass patients.

• Authors: Charles E Edmiston, Candace Krepel, Holly Kelly, Jeffery Larson, Deborah Andris, Cindy Hennen, Atilla Nakeeb, James R Wallace
• Journal: Surgery (Surgery) Vol. 136 Issue 4 Pg. 738-47 (Oct 2004) ISSN: 0039-6060 [Print] United States
• PMID: 15467657 (Publication Type: Journal Article)

Chemical References

• Anti-Bacterial Agents
• Cefazolin

Topics

• Adult
• Anastomosis, Roux-en-Y
• Anti-Bacterial Agents (pharmacokinetics, therapeutic use)
• Antibiotic Prophylaxis
• Cefazolin (pharmacokinetics, therapeutic use)
• Drug Monitoring (methods)
• Female
• Gastric Bypass (methods)
• Humans
• Male
• Middle Aged
• Omentum (metabolism)
• Perioperative Care
• Skin (metabolism)
• Subcutaneous Tissue (metabolism)