Source control within 12 h attenuates lung injury and systemic bacterial burden in a rat model of polymicrobial...

Early and adequate source control (SC) is a cornerstone of sepsis management, yet experimental data linking delays in SC to bacterial dissemination and remote organ injury remain limited. We aimed to determine how the timing of surgical SC after polymicrobial abdominal sepsis influences bacterial burden, host inflammatory response, and lung injury. Hemodynamic recovery was assessed as a secondary outcome, and survival as an exploratory outcome.

Adult Wistar rats underwent cecal ligation and puncture (CLP) and received standardized fluid resuscitation and meropenem. Surgical SC (cecal resection plus peritoneal lavage) was performed at 6, 12, 18 or 24 h after CLP, or not performed, and outcomes were assessed at 72 h (hemodynamics, lactate, bacterial counts in blood/peritoneal lavage/bronchoalveolar lavage, systemic and pulmonary cytokines, bronchoalveolar lavage cellularity and histology). Surgical SC within 6-12 h was associated with lower bacterial burden across blood, peritoneal lavage, and bronchoalveolar lavage, together with attenuation of systemic and pulmonary inflammatory mediators and reduced lung injury. These biological effects were accompanied by improved mean arterial pressure, lower lactate, and preservation of body weight. Survival analysis suggested a numerically time-dependent pattern according to SC timing; however, these data were exploratory and the study was not powered to detect mortality differences.

In this clinically relevant CLP rat model, earlier surgical SC (≤ 12 h) was associated with lower bacterial burden, attenuation of systemic and pulmonary inflammation, reduced sepsis-associated lung injury, and improved physiological recovery. These findings reinforce the importance of timely source control in abdominal sepsis and provide experimental support for avoiding unnecessary delay.