Topical Neck Cooling Prolongs Survival of Rats with Intra-Abdominal Feculent Sepsis by Activation of the Vagus Nerve.

Global hypothermia prolongs survival in rats with intraabdominal feculent sepsis by inhibiting inflammatory responses. We hypothesized that topical neck cooling (TNC) has similar benefits. Septic shock was induced by cecal ligation and incision (CLI) in Sprague Dawley rats. Rats were randomized to sham laparotomy, control with CLI, CLI with TNC, or vagotomy at the gastroesophageal junction before CLI and TNC. Two more groups underwent peritoneal washout with and without TNC two hours after CLI. TNC significantly lowered neck skin temperature (16.7 ± 1.4 vs. 30.5 ± 0.6 °C, p < 0.05) while maintaining core body normothermia. TNC rats recovered from anesthesia 70 min earlier than the control (p < 0.05). Three hours following CLI, the control and vagotomy with TNC groups had significantly more splenic contraction, fewer circulating leukocytes and higher plasma IL-1ß, IL-10 and TNF-α levels than TNC rats (p < 0.05). TNC prolonged survival duration after CLI by a median of four hours vs. control (p < 0.05), but no benefit was seen if vagotomy preceded TNC. Peritoneal washout alone increased survival by 3 h (9.2 (7.8-10.5) h). Survival duration increased dramatically with TNC preceding washout, to a 56% survival rate (>10 days). TNC significantly prolonged the survival of rats with severe intraabdominal sepsis by inhibiting systemic proinflammatory responses by activating vagal anti-inflammatory pathways.

Does it Matter if we get it right? Impact of appropriateness of empiric antimicrobial therapy among surgical patients.

Previous studies have shown conflicting evidence regarding the impact of inappropriate, initial antibiotic therapy. The purpose of this study was to evaluate the impact of inappropriate empiric antimicrobial therapy for the treatment of infection among surgical patients. We hypothesized that inappropriate empiric antimicrobial therapy would predict increased mortality risk compared with appropriate therapy. This was a retrospective analysis of a prospectively maintained database of all surgical patients admitted to a tertiary care center from 1996 to 2007 and treated for sepsis. "Appropriate" empiric antibiotic treatment was determined by sensitivity testing. Demographics and comorbidities, infection sites, infection organisms, and outcomes were compared between inappropriately and appropriately treated groups. Multivariable log-binomial regression was performed. There were 2,855 patients (7,158 infectious episodes) identified by culture analysis as either appropriately or inappropriately treated. Three hundred seventeen (15%) inappropriately treated infectious episodes resulted in death compared with 718 (14%) of the appropriately treated infectious episodes. After adjusting for statistically significant variables, inappropriately treated episodes of infection were not found to be associated with an increased risk for mortality compared with appropriately treated episodes of infection (relative risk, 1.0; 95% confidence interval, 0.99 - 1.02; P = 0.36). Our study observed no difference in mortality between appropriately and inappropriately treated infections within a surgical population.

Does enteral glutamine supplementation decrease infectious morbidity?

BACKGROUND: Although some studies have demonstrated lower infectious morbidity in patients receiving supplemental glutamine, there remains no consensus on the utility of such treatment. This study was designed to investigate the effects of supplemental enteral glutamine on the rate and outcomes of infection in critically ill surgical patients. METHODS: All 185 surgical and trauma patients admitted to a single university surgical trauma intensive care unit (STICU) over an approximately three-year period who were to receive enteral nutrition support were assigned sequentially to one of three diets: standard 1-kCal/mL feedings with added protein (Group 1), standard feedings with glutamine 0.6 g/kg per day (Group 2), or immune-modulated feedings with a similar amount of glutamine (Group 3). Group compositions and patient characteristics were similar at baseline. Data were collected prospectively on infections acquired during hospitalization. RESULTS: A total of 119 patients had at least one infection: 59% of the patients in Group 1, 64% of Group 2, and 69% of Group 3 (p = NS). There were no differences among the groups in the mean number of infections. The most common sites in all groups were the lungs, blood, and urine; and the frequencies of these infections did not differ between groups. Minor differences were found between groups in the organisms isolated. Antibiotic usage did not differ. CONCLUSION: Supplemental enteral glutamine in the dose studied does not appear to influence the acquisition or characteristics of infection in patients admitted to a mixed STICU.

Does the addition of glutamine to enteral feeds affect patient mortality?

OBJECTIVE: Studies have failed to consistently demonstrate improved survival in intensive care unit (ICU) patients receiving immune-modulating nutrient-enhanced enteral feeds when compared with standard enteral feeds. The objective was to study in a prospective fashion the effects of adding glutamine to standard or immune-modulated (supplemented with omega-3 fatty acids, beta-carotene, and amino acids such as glutamine and arginine) tube feeds. DESIGN: Prospective, unblinded study using sequential allocation. SETTING: A university surgical trauma ICU. PATIENTS: All surgical and trauma patients admitted to the surgical trauma ICU at a university hospital over a 3-yr period who were to receive enteral feeds (n = 185). INTERVENTIONS: Sequential assignment to three isocaloric, isonitrogenous diets was performed as follows: standard 1-kcal/mL feeds with added protein (group 1), standard feeds with the addition of 20-40 g/day (0.6 g/kg/day) glutamine (group 2), or an immune-modulated formula with similar addition of glutamine (group 3). The goal for all patients was 25-30 kcal/kg/day and 2 g/kg/day protein. MEASUREMENTS AND MAIN RESULTS: Patients were followed until discharge from the hospital. The primary end point was in-hospital mortality, and multiple secondary end points were recorded. In-hospital mortality for group 1 was 6.3% (four of 64) vs. 16.9% (ten of 59, p = .09) for group 2 and 16.1% (ten of 62, p = .09) for group 3. After controlling for age and severity of illness, the difference in mortality between patients receiving standard tube feeds and all patients receiving glutamine was not significant (p < or = .11). There were no statistically significant differences between the groups for secondary end points. CONCLUSIONS: The addition of glutamine to standard enteral feeds or to an immunomodulatory formula did not improve outcomes. These findings suggest that enteral glutamine should not be routinely administered to patients with surgical critical illness.