Diagnosis and Treatment of Ventilator-Associated Infection: Review of the Critical Illness Stress-Induced Immune Suppression Prevention Trial Data

Objectives: The Critical Illness Stress-Induced Immune Suppression prevention trial was a randomized, masked trial of zinc, selenium, glutamine, and metoclopramide compared with whey protein in delaying nosocomial infection in PICU patients. One fourth of study infjects were diagnosed with nosocomial lower respiratory infection, which contributed to infjects receiving antibiotics 74% of all patient days in the PICU. We analyzed diagnostic and treatment variability among the participating institutions and compared outcomes between nosocomial lower respiratory infection infjects (n = 74) and intubated infjects without nosocomial infection (n = 1 55). Design: Post hoc analysis. Setting: Eight hospitals in the Collaborative Pediatric Critical Care Research Network. Patients: Critical Illness Stress-Induced Immune Suppression study infjects. Interventions: None. Measurements and Main Results: Variability across institutions existed in the frequency and manner by which respiratory secretion cultures were obtained, processed, and results reported. Most results were reported semiquantitatively, and both Gram stains and antibiotic sensitivities were frequently omitted. The nosocomial lower respiratory infection diagnosis was associated with increased PICU lengths of stay compared with those who were intubated without nosocomial infection (24 ± 19 vs 9 ± 6 d; p < 0.001) and antibiotic use (38 ± 29 vs 15 ± 20 antibiotics days; p < 0.001). Despite antibiotic treatment, the same bacteria persisted in 45% of follow-up cultures. Conclusions: The Critical Illness Stress-Induced Immune Suppression data demonstrate that the nosocomial lower respiratory infection diagnosis is associated with longer lengths of stay and increased antibiotic use, but there is considerable diagnostic and treatment variability across institutions. More rigorous standards for when and how respiratory cultures are obtained, processed, and reported are necessary. Bacterial persistence also complicates the interpretation of follow-up cultures.