Changes in the inflammatory response of the lung during acute respiratory distress syndrome: prognostic indicators.

Abstract

We studied paired bronchoalveolar lavage (BAL) in patients with sepsis-associated acute respiratory distress syndrome (ARDS). Patients were evaluated at one institution and underwent bronchoscopy with BAL within 48 h of the onset of ARDS. Patients were restudied with bronchoscopy and BAL after 4 d of treatment. Fifty-eight patients were initially studied, with 44 patients having follow-up bronchoscopy after 4 d. The overall 30-d survival for the ARDS group was 60%. In the initial lavage, there was no difference in the neutrophils between the survivors and nonsurvivors (survivors: 59 [0-98]%; Median [Range]; nonsurvivors: 55 [0-92]%). The follow-up lavage demonstrated a significant drop in the neutrophils for the survivors (36 [4-89]%, p < 0.002) which was not seen for the nonsurvivors (70 [26-95]%). Initial IL-8 concentrations in the BAL fluid were not significantly different between the two groups. In the follow-up lavage, there was a significant fall for the IL-8 concentrations for the survivors but not the nonsurvivors. We conclude that neutrophil influx in ARDS may rapidly resolve within a week of the onset of ARDS. The resolution of neutrophils was associated with a good prognosis.

G-CSF and IL-8 but not GM-CSF correlate with severity of pulmonary neutrophilia in acute respiratory distress syndrome

“…It also confirms that neutrophil counts and IL-8 levels tend to be higher in nonsurvivors [5,7,14,15]. However, this study shows that these patients also have increased concentrations of G-CSF in BAL, which correlate closely with the levels of neutrophils and IL-8.…”

“…The evidence presented here also supports a role for G-CSF in vivo in the mechanisms that promote the severe pulmonary neutrophilia that is associated with poor survival in ARDS [4,5]. The concentrations of G-CSF in BAL fluid during the first week of injury (median (range) 240 pg .…”

“…Activated neutrophils play a major role in mediating the microvascular damage and also contribute to lung tissue damage [3]. They infiltrate the lungs in large numbers and their persistence in the lungs is an important determinant of poor survival [4,5]. Elucidation of the mechanisms that maintain pulmonary neutrophilia in ARDS may therefore be of considerable prognostic and therapeutic significance.…”

Ventilator associated pneumonia: quality of nonbronchoscopic bronchoalveolar lavage sample affects diagnostic yield

“…There was considerable overlap between the infected and noninfected patients. Several conditions lead to increased neutrophils without infection necessarily being present, including acute respiratory distress syndrome [33,34]. Increased neutrophils are also seen as the result of intubation and ventilation itself [35].…”

Estudo de crianças com síndrome do desconforto respiratório agudo: correlação anatomoclínica radiológica

“…Hoje compreendemos melhor o aumento da permeabilidade vascular, que caracteriza esta síndrome, como devido, pelo menos em parte, à citocinas como o Fator de Necrose Tumoral (Tumor Necrosis Factor ou TNF), à Interleucina-1 (IL 1 ) e ao Fator Inibidor da Migração de Macrófagos (Macrophage Migration Inhibitory Factor ou MIF), liberados por células inflamatórias e que causam lesão celular direta ou indiretamente 6 79 . A liberação de enzimas proteolíticas, radicais tóxicos de oxigênio, mediadores lipídicos como os leucotrienos e o Fator de Ativação Plaquetária (Platelet Activating Factor ou PAF), também causam, direta e indiretamente, lesão endotelial no pulmão e em outros órgãos-alvo, resultando em hipoxemia refratária e em aumento do consumo periférico de oxigênio 8 13 25 45 .…”