Immediate pro-inflammatory cytokine response associated with asphyxia and volume infusions in a neonatal piglet model

Abstract

A neonatal piglet model was used to determine IL6, IL8 and CRP responses to asphyxia and subsequent volume infusion. Mechanically ventilated swine (n=37, age: 8 ± 2 days, weight: 2.2 ± 0.7 kg) were progressively asphyxiated by changing the ventilator gases until heart rate < 100 bpm and mean arterial blood pressure < 20 mmHg. After 5 minutes of ventilatory resuscitation, piglets were randomized to receive volume infusion with either 5% Albumin (ALB), Normal Saline (NS), or no volume (SHAM). IL6, IL8 and CRP were measured at baseline, at the end of asphyxia (ASPYHXIA), and 2 hrs after resuscitation (RESUSCITATION). IL6 (median and [25–75 percentiles] pg/ml) increased from 163 [55,193] at baseline, to 263 [196,393] at ASPHYXIA, and 441 [309,875] at RESUSCITATION (p<0.001). Both IL8 and CRP were similar to baseline at all time intervals. Animals randomized to volume (ALB and NS) vs. SHAM had higher IL6 levels following RESUSCITATION (749 [383,1163] vs. 303 [204,465], p<0.02). In this model of severe neonatal asphyxia, serum IL-6 was elevated following volume infusion. The lack of change in IL8 and CRP suggests selectivity in the immediate inflammatory responses following asphyxia and volume resuscitation.