Pediatric trauma susceptibility to sepsis

Interaction Between 2 Nutraceutical Treatments and Host Immune Status in the Pediatric Critical Illness Stress-Induced Immune Suppression Comparative Effectiveness Trial

BACKGROUND AND AIMS

The pediatric Critical Illness Stress-induced Immune Suppression (CRISIS) trial compared the effectiveness of 2 nutraceutical supplementation strategies and found no difference in the development of nosocomial infection and sepsis in the overall population. We performed an exploratory post hoc analysis of interaction between nutraceutical treatments and host immune status related to the development of nosocomial infection/sepsis.

METHODS

Children from the CRISIS trial were analyzed according to 3 admission immune status categories marked by decreasing immune competence: immune competent without lymphopenia, immune competent with lymphopenia, and previously immunocompromised. The comparative effectiveness of the 2 treatments was analyzed for interaction with immune status category.

RESULTS

There were 134 immune-competent children without lymphopenia, 79 previously immune-competent children with lymphopenia, and 27 immunocompromised children who received 1 of the 2 treatments. A significant interaction was found between treatment arms and immune status on the time to development of nosocomial infection and sepsis ( P < .05) and on the rate of nosocomial infection and sepsis per 100 patient days ( P < .05). Whey protein treatment protected immune-competent patients without lymphopenia from infection and sepsis, both nutraceutical strategies were equivalent in immune-competent patients with lymphopenia, and zinc, selenium, glutamine, and metoclopramide treatment protected immunocompromised patients from infection and sepsis.

CONCLUSIONS

The science of immune nutrition is more complex than previously thought. Future trial design should consider immune status at the time of trial entry because differential effects of nutraceuticals may be related to this patient characteristic.

Inherent Risk Factors for Nosocomial Infection in the Long Stay Critically Ill Child Without Known Baseline Immunocompromise: A Post Hoc Analysis of the CRISIS Trial

BACKGROUND

Nosocomial infection remains an important health problem in long stay (>3 days) pediatric intensive care unit (PICU) patients. Admission risk factors related to the development of nosocomial infection in long stay immune competent patients in particular are not known.

METHODS

Post-hoc analysis of the previously published Critical Illness Stress induced Immune Suppression (CRISIS) prevention trial database, to identify baseline risk factors for nosocomial infection. Because there was no difference between treatment arms of that study in nosocomial infection in the population without known baseline immunocompromise, both arms were combined and the cohort that developed nosocomial infection was compared with the cohort that did not.

RESULTS

There were 254 long stay PICU patients without known baseline immunocompromise. Ninety (35%) developed nosocomial infection, and 164 (65%) did not. Admission characteristics associated with increased nosocomial infection risk were increased age, higher Pediatric Risk of Mortality version III score, the diagnoses of trauma or cardiac arrest and lymphopenia (P < 0.05). The presence of sepsis or infection at admission was associated with reduced risk of developing nosocomial infection (P < 0.05). In multivariable analysis, only increasing age, cardiac arrest and existing lymphopenia remained significant admission risk factors (P < 0.05); whereas trauma tended to be related to nosocomial infection development (P = 0.07).

CONCLUSIONS

These data suggest that increasing age, cardiac arrest and lymphopenia predispose long stay PICU patients without known baseline immunocompromise to nosocomial infection. These findings may inform pre-hoc stratification randomization strategies for prospective studies designed to prevent nosocomial infection in this population.

Role of the host defense system and intestinal microbial flora in the pathogenesis of necrotizing enterocolitis

BACKGROUND

Necrotizing enterocolitis (NEC) is a devastating disease that affects primarily the intestine of premature infants. Despite recent advances in neonatology, NEC remains a major cause of morbidity and mortality in neonates. Neonatal mucosal defenses and adherence of bacterial pathogens may play an important role in the pathogenesis of NEC.

METHODS

Review and synthesis of pertinent literature.

RESULTS

Putative factors that have been implicated in the pathogenesis of NEC include abnormal patterns of gut colonization by bacteria, immaturity of the host immune system and mucosal defense mechanisms, intestinal ischemia, formula feeding, and loss of intestinal epithelial barrier integrity.

CONCLUSION

Host defenses and intestinal microbial ecology are believed to play important roles in the pathogenesis of NEC. Commensal bacteria and probiotic therapy may be of therapeutic utility in the maintenance of the gut epithelial barrier.