Objective: Critical illness survivors present long-term cognitive impairment, including problems with memory and learning. We evaluated cognitive performance in rats that survived from sepsis induced by cecal ligation and puncture (CLP).
Design: Prospective, controlled experiment.
Setting: Animal basic science laboratory.
Subjects: Male Wistar rats, weighing 300-350 g.
Interventions: The rats underwent CLP (sepsis group) with "basic support" (saline at 50 mL/kg immediately and 12 hrs after CLP plus ceftriaxone at 30 mg/kg and clindamycin at 25 mg/kg 6, 12, and 18 hrs after CLP) or sham-operated (control group).
Measurements and main results: Ten days after surgery, the animals underwent three behavioral tasks: a) inhibitory avoidance task; b) habituation to an open field; and c) continuous multiple-trials step-down inhibitory avoidance task (CMSIA). In the habituation to an open-field task, there were no differences in the number of crossings and rearings. The sepsis group showed significantly decreased performance in latency retention compared with the sham group in inhibitory avoidance. Furthermore, when tested by the habituation to an open-field task, the sepsis group did not show any difference between training and test, indicating memory impairment. In the CMSIA, the sepsis group showed a significant increase in the number of training trials required to reach the acquisition criterion.
Conclusion: Our data provide the first experimental demonstration that survivors from CLP show learning and memory impairment after complete physical recovery from sepsis.