Cefamandole levels during thoracoabdominal aortic aneurysm surgery

Area of Science:

• Pharmacology
• Surgical Infection Prophylaxis
• Vascular Surgery

Background:

• Pharmacokinetics of prophylactic antibiotics can vary between cardiac and aortic aneurysm surgeries due to differences in blood loss and cardiopulmonary bypass usage.
• Optimizing antibiotic dosing is critical for preventing surgical site infections in major vascular procedures.

Purpose of the Study:

• To evaluate two cefamandole dosing regimens for prophylactic antibiotic coverage in patients undergoing aortic aneurysm surgery.
• To determine the pharmacokinetic profile and efficacy of cefamandole in this patient population.

Main Methods:

• Prospective study of two cefamandole dosing regimens (1 gm at induction vs. 2 gm at induction followed by 1 gm every 2 hours).
• Plasma cefamandole levels measured at key surgical time points (skin incision, cross-clamping, unclamping, closure).
• In phase 2, cefamandole elimination via urine and cell-saver effluent was quantified.

Main Results:

• Only 4 of 14 patients in phase 1 achieved adequate plasma levels (≥10 µg/ml).
• All 10 patients in phase 2 maintained adequate cefamandole plasma levels.
• Cefamandole loss in cell-saver effluent was approximately 13% of the renally excreted amount.

Conclusions:

• The regimen of 2 gm cefamandole intravenously at induction followed by 1 gm every 2 hours is a dependable and practical dosing strategy for aortic aneurysm surgery.
• This optimized prophylactic antibiotic regimen ensures adequate drug levels, potentially reducing the risk of surgical site infections.