REASONS FOR PERFORMING STUDY: Vasopressin dysregulation occurs in critically ill human patients and in neonatal foals. Limited data about serial plasma vasopressin dynamics exist in sick neonatal foals. OBJECTIVES: To evaluate serial plasma arginine vasopressin (AVP) concentrations in sick neonatal foals. STUDY DESIGN: Prospective, longitudinal clinical study. METHODS: Plasma samples were collected from 7 healthy and 26 sick foals before and after initial fluid resuscitation and 12, 24, 36, 48 and 96 h after presentation. Foals with a modified sepsis score ≥ 11 were considered septic. RESULTS: Admission AVP was increased in septic foals compared to healthy and to sick, nonseptic foals. There were no significant differences between groups on subsequent days. Nonsurvivors had higher AVP concentrations than survivors. CONCLUSIONS: Plasma AVP concentrations are higher in septic foals on admission than in healthy and sick nonseptic foals. Higher early plasma AVP concentrations are associated with increased mortality.
REASONS FOR PERFORMING STUDY: Vasopressin dysregulation occurs in critically ill humanpatients and in neonatal foals. Limited data about serial plasma vasopressin dynamics exist in sick neonatal foals. OBJECTIVES: To evaluate serial plasma arginine vasopressin (AVP) concentrations in sick neonatal foals. STUDY DESIGN: Prospective, longitudinal clinical study. METHODS: Plasma samples were collected from 7 healthy and 26 sick foals before and after initial fluid resuscitation and 12, 24, 36, 48 and 96 h after presentation. Foals with a modified sepsis score ≥ 11 were considered septic. RESULTS: Admission AVP was increased in septic foals compared to healthy and to sick, nonseptic foals. There were no significant differences between groups on subsequent days. Nonsurvivors had higher AVP concentrations than survivors. CONCLUSIONS: Plasma AVP concentrations are higher in septic foals on admission than in healthy and sick nonseptic foals. Higher early plasma AVP concentrations are associated with increased mortality.