[Adrenal function evaluation using ACTH stimulation test in children with sepsis and septic shock]

Sepsis and septic shock remain a common problem that results in significant mortality and morbidity in pediatric intensive care units (PICU). According to literature, the use of more physiologic steroid replacement therapy is associated with hemodynamic and survival benefits in adult patients with relative adrenal insufficiency (RAI) and catecholamine-resistant septic shock. But little information is available in children. The aim of the current prospective study was to determine the prevalence of adrenal insufficiency in children with sepsis and septic shock using a low-dose adrenocorticotropic hormone (ACTH) stimulation test (1 microg/1.73 m2) in children.

The authors performed cortisol estimation at baseline and after low-dose (1 microg/1.73 m2) ACTH stimulation at 30 mins in children during the first 24 hours in patients with sepsis or septic shock admitted to our PICU. Adrenal insufficiency was defined as a response < or = 90 microg/L. Absolute adrenal insufficiency (AAI) was further defined as baseline cortisol (T0) < 200 microg/L and RAI insufficiency by T0 > or = 200 microg/L.

Sixty-two consecutive cases with sepsis and septic shock admitted to PICU of Shanghai Jiaotong University Affiliated Children's Hospital from April, 2006 to March, 2007. The median age was 37.6 months (range, 2 - 168 months), and their gender distribution was 42 (67.7%) males and 20 (32.3%) females, 53 cases had sepsis (85.5%) and 9 had septic shock (14.5%). The mean pediatric critical illness score (PCIS) was 79.3 +/- 9.2 and median pediatric risk of mortality score (PRMSIII) 11.3 (5 - 19), respectively. Overall mortality of sepsis and septic shock was 27.42%. The evaluation of adrenal insufficiency was conducted as follows. (1) The mean cortisol levels at baseline (T0) and 30 mins after ACTH stimulation (T1) were (318.6 +/- 230.4) microg/L, (452.3 +/- 230.7) microg/L and (454.7 +/- 212.7) microg/L, (579.3 +/- 231.9) microg/L in patients with severe sepsis and septic shock group, respectively. There were no significant difference between the two groups (P > 0.05). (2) The proportion of patients with adrenal insufficiency in the study population was 40.3% as defined by a response < or = 90 microg/L post test. The proportion of patients with adrenal insufficiency in sepsis and septic shock were 39.6% and 44.4%, respectively (chi2) = 0.073, P > 0.05). (3) The serum T0 and T1 levels were (320.5 +/- 223.9) microg/L, (462.3 +/- 212.0) microg/L and (384.3 +/- 258.3) microg/L, (500.7 +/- 470.6) microg/L, respectively, and the proportion of patients with adrenal insufficiency were 37.8% and 47.1% in the survivors and the dead (P > 0.05). The levels of T0 and T1 were related to the PCIS (P < 0.05). The morbidity of adrenal insufficiency was not related to the PCIS, PRISMIII, and number of organ that developed functional insufficiency (P > 0.05).

Adrenal insufficiency may occur in patients with sepsis and septic shock in children. ACTH stimulation test may be helpful to determine whether corticosteroid therapy has a survival benefit in patients with relative adrenal insufficiency. A low-dose ACTH stimulation test can be used to evaluate the adrenal function status of severe sepsis and septic shock in children.