Low T3 vs low T3T4 euthyroid sick syndrome in septic shock patients: A prospective observational cohort study.

Background: Both phases of euthyroid sick syndrome (ESS) are associated with worse prognosis in septic shock patients. Although there are still no indications for supplementation therapy, there is no evidence that both phases (initial and prolonged) are adaptive or that only prolonged is maladaptive and requires supplementation.

Aim: To analyze clinical, hemodynamic and laboratory differences in two groups of septic shock patients with ESS.

Methods: A total of 47 septic shock patients with ESS were divided according to values of their thyroid hormones into low T3 and low T3T4 groups. The analysis included demographic data, mortality scores, intensive care unit stay, mechanical ventilation length and 28-day survival and laboratory with hemodynamics.

Results: The Simplified Acute Physiology Score II score (P = 0.029), dobutamine (P = 0.003) and epinephrine requirement (P = 0.000) and the incidence of renal failure and multiple organ failure (MOF) (P = 0.000) were significantly higher for the low T3T4. Hypoalbuminemia (P = 0.047), neutrophilia (P = 0.038), lymphopenia (P = 0.013) and lactatemia (P = 0.013) were more pronounced on T2 for the low T3T4 group compared to the low T3 group. Diastolic blood pressure at T0 (P = 0.017) and T1 (P = 0.007), as well as mean arterial pressure at T0 (P = 0.037) and T2 (P = 0.033) was higher for the low T3 group.

Conclusion: The low T3T4 population is associated with higher frequency of renal insufficiency and MOF, with worse laboratory and hemodynamic parameters. These findings suggest potentially maladaptive changes in the chronic phase of septic shock.