Thyroid hormone levels and their relations to survival in children with bacterial sepsis and septic shock

Objectives

Reported studies showed alternations of thyroid hormones in critical illness, mostly in adults and some in children. In this study, we aimed to measure thyroid hormone levels in children with sepsis and septic shock and to investigate the relation of these hormones with clinical state and survival.

Patients and methods

Thyroid hormone levels of children with sepsis, with septic shock, and age-matched and sex-matched controls were measured.

Results

There were 51 children in the sepsis group (Group S), 21 children in the septic shock group (Group SS) and 30 in the control group (Group C). Total tri-iodothyronin (TT3) levels were (nmol/l): 0.91 ± 0.22, 0.64 ± 0.23, 2.11 ± 0.59; free tri-iodo-thyronin (FT3) levels were (pmol/l): 0.027 ± 0.006, 0.018 ± 0.007, 0.049 ± 0.010; total thyroxin (TT4) levels were (nmol/l): 100.62 ± 21.93, 65.79 ± 19.35, 109.65 ± 19.35; free thyroxin (FT4) levels were (pmol/l): 18.06 ± 3.87, 10.32 ± 1.29, 19.35 ± 3.87; and thyroid stimulating hormone (TSH) levels were (mIU/ml): 5.0 ± 2.0, 4.8 ± 2.4 and 5.2 ± 3.0, respectively, in children with sepsis, with septic shock, and controls. The TT3, FT3, TT4, and FT4 levels of group SS were significantly lower than those of groups S and C. The TT3 and FT3 levels of group S were lower than the levels of group C, but there was no significant difference between TT4, FT4 levels of groups S and C. TSH levels were slightly decreased both in sepsis and septic shock, but the difference was not significant (P > 0.05). Eleven (21.6%) children with sepsis and 15 (71.4%) children with septic shock died (P < 0.001). The levels of TT3, FT3, TT4, and FT4 were impressively lower in nonsurvivors of groups S and SS compared with survivors (P < 0.001).

Conclusion

These changes in the hypothalamo-pituitary thyroidal axis may suggest a possible prognostic value of thyroid hormone levels in children with sepsis and septic shock. In addition, to the best of our knowledge, this report is the first study to compare the thyroid hormone levels in sepsis and septic shock in a large number of patients with healthy controls in childhood.