interleukin-8 and Burns--Inhalation

To investigate incipient inflammatory changes as first steps in the development of a systematic inflammatory response syndrome in the lungs of burn victims.. At the Institute of Legal Medicine of the University Hospital of Freiburg a collection of 40 forensic autopsy cases of burn victims was established that had died within 1 h after fire exposure. This group was compared with a total of 48 autopsy cases in three control groups (postmortem burns vs deaths from haemorrhagic shock vs railway suicide deaths). In all cases, immunohistochemical studies of lung tissue probes were performed to detect the presence of pro-inflammatory mediators using antibodies against tumour necrosis factor α (TNF-α), interleukin-8 (IL-8) and inter-cellular adhesion molecule 1 (ICAM-1).. The lungs of burn victims showed a significantly higher extent of intra-alveolar oedema than the other groups. Immunohistochemically, macrophages in all groups mostly showed a distinct expression of TNF-α, but not of IL-8 or ICAM-1. Interestingly, intravascular erythrocytes often showed a positivity of TNF-α that was strongest in the group of burn victims and differed significantly from all the control groups.. In burn victims with short survival times of ≤1 h after fire exposure, the immunohistochemical expression profiles of TNF-α, IL-8 and ICAM-1 in the lungs were not altered enough to prove an instant inflammatory reaction in these cases. Nevertheless, the positive reaction of TNF-α in erythrocytes of burn victims may indicate the beginning of a non-specific immune response to fire-induced inhalation trauma.

Topics: Adult; Burns, Inhalation; Erythrocytes; Female; Fires; Humans; Inflammation Mediators; Intercellular Adhesion Molecule-1; Interleukin-8; Lung; Macrophages, Alveolar; Male; Middle Aged; Systemic Inflammatory Response Syndrome; Tumor Necrosis Factor-alpha

OBJECTIVES AND SUMMARY BACKGROUND: Low tidal volume ventilation (LTV) has improved survival with acute respiratory distress syndrome (ARDS) by reducing lung stretch associated with volutrauma and barotrauma. Additional strategies to reduce lung stretch include arteriovenous carbon dioxide removal (AVCO2R), and high frequency percussive ventilation (HFPV). We performed a prospective, randomized study comparing these techniques in our clinically relevant LD100 sheep model of ARDS to compare survival, pathology, and inflammation between the 3 ventilator methods.. Adult sheep (n = 61) received smoke inhalation (48 breaths) and a 40% third-degree burn. After ARDS developed (Pao2/FiO2 <200), animals were randomized. In experiment 1, animals were killed at 48 hours after randomization. Hemodynamics, pulmonary function, injury scores, myeloperoxidase (MPO) in lung tissues and neutrophils, IL-8 in lung tissues, and apoptosis were evaluated. In experiment 2, the end point was survival to 72 hours after onset of ARDS or end-of-life criteria with extension of the same studies performed in experiment 1.. There were no differences in hemodynamics, but minute ventilation was lower in the AVCO2R group and Paco2 for the HFPV and AVCO2R animals remained lower than LTV. Airway obstruction and injury scores were not different among the 3 ventilation strategies. In experiment 1, lung tissue MPO and IL-8 were not different among the ventilation strategies. However, in experiment 2, lung tissue MPO was significantly lower for AVCO2R-treated animals (AVCO2R < HFPV < LTV). TUNEL staining showed little DNA breakage in neutrophils from experiment 1, but significantly increased breakage in all 3 ventilator strategies in experiment 2. In contrast, AVCO2R tissue neutrophils showed significant apoptosis at 72 hours post-ARDS criteria as measured by nuclear condensation (P < 0.001). Survival 72 hours post-ARDS criteria was highest for AVCO2R (71%) compared with HFPV (55%) and LTV (33%) (AVCO2R vs. LTV, P = 0.05).. Significantly more animals survived AVCO2R than LTV. In experiment 2, Lung MPO was significantly lower for AVCO2R, compared with LTV (P < 0.05). This finding taken together with the TUNEL and neutrophil apoptosis results, suggested that disposition of neutrophils 72 hours post-ARDS criteria was different among the ventilatory strategies with neutrophils from AVCO2R-treated animals removed chiefly through apoptosis, but in the cases of HFPV and LTV, dying by necrosis in lung tissue.

Topics: Analysis of Variance; Animals; Apoptosis; Burns, Inhalation; Carbon Dioxide; Disease Models, Animal; In Situ Nick-End Labeling; Interleukin-8; Prospective Studies; Pulmonary Gas Exchange; Random Allocation; Respiration, Artificial; Respiratory Distress Syndrome; Sheep, Domestic; Smoke Inhalation Injury; Survival Rate; Tidal Volume

Topics: Adult; Aged; Aged, 80 and over; Bronchoalveolar Lavage Fluid; Burns, Inhalation; Female; Humans; Interleukin-8; Male; Middle Aged; Respiratory Insufficiency