Factors Associated With Short and Long Term Cognitive Changes in Patients With Sepsis.

This study aimed to assess cognition in patients with severe sepsis or septic shock and whether cognitive impairment was associated with clinical and laboratory parameters. We conducted a cohort study of patients with severe sepsis and septic shock evaluated within 24 h and one year after ICU discharge. Demographic, clinical and laboratory data were analyzed, and the following neuropsychological tests were applied: Consortium to Establish Registry for Alzheimer's Disease, Mini-Mental State Examination, and Trail Making Test forms A and B. We included 33 patients, mean age of 49, 19% were female. Patients underperformed on most measures 24 h after ICU discharge, with improvement on follow-up. IQCODE, APACHE II scores, NSE and IFN-γ levels at ICU discharge were associated with poor cognitive performance, while higher educational level was associated with good cognitive performance. The time to first antibiotic dose, accumulated dose of haloperidol during UCI stay and mean glycemia were also associated with poor cognitive outcome. In general, patients with severe sepsis or septic shock have cognitive impairment that can improve over time. This improvement was associated with factors identified during their ICU stay, such as cognitive reserve, educational level, mean glycemia during ICU stay and NSE level.

Behavioral deficits in sepsis-surviving rats induced by cecal ligation and perforation.

Sepsis and its complications are the leading causes of mortality in intensive care units, accounting for 10-50% of deaths. Intensive care unit survivors present long-term cognitive impairment, including alterations in memory, attention, concentration, and/or global loss of cognitive function. In the present study, we investigated behavioral alterations in sepsis-surviving rats. One hundred and ten male Wistar rats (3-4 months, 250-300 g) were submitted to cecal ligation and puncture (CLP), and 44 were submitted to sham operation. Forty-four rats (40%) survived after CLP, and all sham-operated animals survived and were used as control. Twenty animals of each group were used in the object recognition task (10 in short-term memory and 10 in long-term memory), 12 in the plus-maze test and 12 in the forced swimming test. Ten days after surgery, the animals were submitted individually to an object recognition task, plus-maze and forced swimming tests. A significant impairment of short- and long-term recognition memory was observed in the sepsis group (recognition index 0.75 vs 0.55 and 0.74 vs 0.51 for short- and long-term memory, respectively (P < 0.05). In the elevated plus-maze test no difference was observed between groups in any of the parameters assessed. In addition, sepsis survivors presented an increase in immobility time in the forced swimming test (180 vs 233 s, P < 0.05), suggesting the presence of depressive-like symptoms in these animals after recovery from sepsis. The present results demonstrated that rats surviving exposure to CLP, a classical sepsis model, presented recognition memory impairment and depressive-like symptoms but not anxiety-like behavior.

Behavioral deficits in sepsis-surviving rats induced by cecal ligation and perforation

Sepsis and its complications are the leading causes of mortality in intensive care units, accounting for 10-50 percent of deaths. Intensive care unit survivors present long-term cognitive impairment, including alterations in memory, attention, concentration, and/or global loss of cognitive function. In the present study, we investigated behavioral alterations in sepsis-surviving rats. One hundred and ten male Wistar rats (3-4 months, 250-300 g) were submitted to cecal ligation and puncture (CLP), and 44 were submitted to sham operation. Forty-four rats (40 percent) survived after CLP, and all sham-operated animals survived and were used as control. Twenty animals of each group were used in the object recognition task (10 in short-term memory and 10 in long-term memory), 12 in the plus-maze test and 12 in the forced swimming test. Ten days after surgery, the animals were submitted individually to an object recognition task, plus-maze and forced swimming tests. A significant impairment of short- and long-term recognition memory was observed in the sepsis group (recognition index 0.75 vs 0.55 and 0.74 vs 0.51 for short- and long-term memory, respectively (P < 0.05). In the elevated plus-maze test no difference was observed between groups in any of the parameters assessed. In addition, sepsis survivors presented an increase in immobility time in the forced swimming test (180 vs 233 s, P < 0.05), suggesting the presence of depressive-like symptoms in these animals after recovery from sepsis. The present results demonstrated that rats surviving exposure to CLP, a classical sepsis model, presented recognition memory impairment and depressive-like symptoms but not anxiety-like behavior.

Neural substrate of cold-seeking behavior in endotoxin shock.

Systemic inflammation is a leading cause of hospital death. Mild systemic inflammation is accompanied by warmth-seeking behavior (and fever), whereas severe inflammation is associated with cold-seeking behavior (and hypothermia). Both behaviors are adaptive. Which brain structures mediate which behavior is unknown. The involvement of hypothalamic structures, namely, the preoptic area (POA), paraventricular nucleus (PVH), or dorsomedial nucleus (DMH), in thermoregulatory behaviors associated with endotoxin (lipopolysaccharide [LPS])-induced systemic inflammation was studied in rats. The rats were allowed to select their thermal environment by freely moving in a thermogradient apparatus. A low intravenous dose of Escherichia coli LPS (10 microg/kg) caused warmth-seeking behavior, whereas a high, shock-inducing dose (5,000 microg/kg) caused cold-seeking behavior. Bilateral electrocoagulation of the PVH or DMH, but not of the POA, prevented this cold-seeking response. Lesioning the DMH with ibotenic acid, an excitotoxin that destroys neuronal bodies but spares fibers of passage, also prevented LPS-induced cold-seeking behavior; lesioning the PVH with ibotenate did not affect it. Lesion of no structure affected cold-seeking behavior induced by heat exposure or by pharmacological stimulation of the transient receptor potential (TRP) vanilloid-1 channel ("warmth receptor"). Nor did any lesion affect warmth-seeking behavior induced by a low dose of LPS, cold exposure, or pharmacological stimulation of the TRP melastatin-8 ("cold receptor"). We conclude that LPS-induced cold-seeking response is mediated by neuronal bodies located in the DMH and neural fibers passing through the PVH. These are the first two landmarks on the map of the circuitry of cold-seeking behavior associated with endotoxin shock.