Clindamycin, Ciprofloxacin, and Co-trimoxazole Wound Penetration in Open-Heart Surgery Patients Receiving Negative Pressure Wound Therapy for Deep Sternal Wound Infection: A Single-Center Prospective Observational Study

Abstract Background and Objective Achieving sufficient antibiotic concentration in the tissue is a key prerequisite for effective wound infection treatment. We evaluated clindamycin, ciprofloxacin, and co-trimoxazole penetration into exudate among patients treated with negative pressure wound therapy (NPWT). Methods Ten consecutive patients receiving NPWT for deep sternal wound infection (DSWI) after open-heart surgery were enrolled in this prospective observational study. Serum and exudate samples were synchronously collected at 0 (pre-dose), 0.5, 1, 2, 3, and 5 h after clindamycin administration, and at 0, 0.5, 1, 2, 3, and 6 h after ciprofloxacin and co-trimoxazole administration. Wound penetration was assessed as the ratio of the average antibiotic concentration in the wound exudate to that found in serum. Results The wound penetration ratio was significantly higher for free clindamycin concentrations (4.19 ± 1.43) than for total clindamycin concentrations (0.83 ± 0.23) ( p = 0.007). Wound penetration was similar for both total and free ciprofloxacin concentrations (0.87 ± 0.35 vs. 0.81 ± 0.32; p = 0.777). The total and free exudate penetration ratios were about twofold higher for sulfamethoxazole (0.8 and 1.1, respectively) compared to trimethoprim (0.36 and 0.42, respectively). The hospital stay of open-heart surgery patients with DSWI was significantly longer (49 ± 20 days) than in those without infection (14 ± 12 days; p < 0.001). No 90-day mortality was observed. One patient experienced late DSWI recurrence. During the median follow-up of 2.3 years, all-cause mortality was 4.8%. Conclusion Clindamycin, ciprofloxacin, and co-trimoxazole effectively penetrated wound exudate in patients on NPWT for post-sternotomy DSWI. The protocol for this study was retrospectively registered at ClinicalTrials.gov on July 16, 2024 (NCT06506032).