title: Evaluation of adrenal function in critically ill children.
abstract: OBJECTIVE
  There is no consensus on adequate adrenal response to critical illness. We aimed to evaluate adrenal function in critically ill children and its association with clinical outcome. We hypothesized that salivary cortisol would be a more appropriate tool to evaluate adrenal function in critically ill children.
  
  
  METHODS
  This was a prospective cohort study. The concentrations of serum total and salivary cortisol were measured in 34 critically ill children before and after stimulation with 250 μg adrenocorticotropic hormone (ACTH), and values were compared to a control group of healthy children (n = 15). Association between outcome and adrenal insufficiency defined by an increment in serum cortisol ≤250 nm (9 μg/dl) post-ACTH was assessed.
  
  
  RESULTS
  Serum total and salivary cortisol concentrations pre- and post-ACTH were significantly higher in patients, and they were correlated at baseline (r = 0·67; P < 0·0001) and after ACTH (r = 0·41; P = 0·02). The incidence of adrenal insufficiency was 32·3%. This group had higher Paediatric Risk of Mortality III score (P = 0·04) but Paediatric Logistic Organ Dysfunction and vasoactive inotropic scores, duration of mechanical ventilation and length of paediatric intensive care unit and hospital stay were not significantly different compared with those with an increment >250 nm (9 μg/dl) post-ACTH. An inverse correlation between salivary cortisol post-ACTH and vasoactive inotropic score (r = -0·56; P = 0·0008) was observed. A salivary cortisol concentration post-ACTH of ≤226 nm (8·2 μg/dl) had a sensitivity of 79% and a specificity of 62% to discriminate need for vasoactive or inotropic support (area under receiver operating characteristic (ROC) curve 0·74).
  
  
  CONCLUSIONS
  Adrenal insufficiency defined by the 'delta criterion' was not associated with outcome. A post-ACTH salivary cortisol of ≤226 nm (8·2 μg/dl) may be suggestive of an insufficient adrenal response to critical illness.
authors.affiliation: Department of Paediatrics, Division of Paediatric Critical Care, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil.
authors.forename: Viviane M P
authors.initials: VM
authors.lastname: Balbão
authors.forename: Marcela M A
authors.initials: MM
authors.lastname: Costa
authors.forename: Margaret
authors.initials: M
authors.lastname: Castro
authors.forename: Ana P C P
authors.initials: AP
authors.lastname: Carlotti
mesh_terms: D000311:Adrenal Glands / Q000502:physiology*; D000324:Adrenocorticotropic Hormone / Q000097:blood / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D016638:Critical Illness; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood* / Q000378:metabolism*; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011446:Prospective Studies
chemical_list: D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone