Inflammatory and coagulant responses after acute respiratory failure in children of different body habitus

Background Endothelial injury and systemic inflammation are key determinants of acute respiratory failure (ARF) outcome. We sought to determine if childhood obesity alters the degree of injury and inflammation in (ARF) patients with and without sepsis. Methods Plasma markers of endothelial injury (thrombomodulin), thrombosis (plasminogen activator inhibitor, PAI-1), and inflammation (IL-8 and IL-1ra) were measured over 3 days in children with ARF. Weight classification (healthy, overweight, and obesity) was determined by body mass index or weight‐for‐height z scores. Daily biomarker concentration and concentration change over time were compared among weight groups. Secondarily, we stratified by sepsis versus non-sepsis ARF. Results Twenty-six percent of the 229 children had obesity. Obesity was associated with longer duration of mechanical ventilation (median of 12 days compared to 7 days in the healthy weight, p = 0.006) and ICU stay (median of 18 days compared to 10 days in the healthy weight, p = 0.01 and compared to 11 days in the overweight, p = 0.02). Thrombomodulin levels were significantly higher in the obesity group on study days 1 and 2. In those with sepsis-associated ARF, thrombomodulin change over time increased most significantly in the obesity group ( p = 0.015 for the interaction term of weight group and day on thrombomodulin concentration). There were no weight-based differences for IL-8, IL-1ra, or PAI-1. Conclusions Obesity was associated with elevated thrombomodulin, most notably in children with sepsis-associated ARF. This may denote worse endothelial injury in children with obesity and ARF. We found no difference in biomarkers of systemic inflammation among the weight groups.