Thyroid function in neonates with severe respiratory failure on extracorporeal membrane oxygenation

Abstract

The object was to study thyroid function in neonates with severe respiratory failure on extracorporeal membrane oxygenation (ECMO) and determine whether abnormal thyroid function correlates with prognosis. Total and free thyroxine (T4, FT4), total and free triiodothyronine (T3, FT3), reverse triiodothyronine (rT3), thyroid-stimulating hormone, and thyroxine binding globulin were measured in 14 newborn infants with severe respiratory failure (age 1-30 days) from samples collected before anesthesia for cannula placement, at 30, 60, and 360 min after initiation of ECMO, and on days 2, 4, 6, and 8. The patients were divided into survivors and non-survivors for statistical analyses. No differences were noted between survivors and non-survivors in the pre-ECMO mean serum concentrations of the thyroid function tests analyzed. In nine survivors, mean serum T4, FT4, T3, FT3, and rT3 all declined significantly within 30-60 min after initiation of ECMO, compared to baseline values. The values for all mean serum concentrations recovered completely and exceeded baseline between days 2 and 8. In five non-survivors, the decline of all mean serum values was not statistically significant and recovery to baseline was not achieved. The ratios of mean serum concentration of rT3/FT3 were significantly different between survivors and non-survivors across all times during the ECMO course (p < 0.0005). These findings indicate that abnormalities in thyroid function occur in neonates with severe respiratory failure on ECMO and that the rT3/FT3 ratio correlates with prognosis over the ECMO course. Survival was associated with a significant reduction of serum thyroid hormone concentrations followed by recovery. We speculate that, in neonates with respiratory failure on ECMO, adaptive mechanisms which enhance survival include the capacity to down-regulate the pituitary-thyroid axis.

Nationwide Evaluation of Congenital Hypothyroidism Screening during Neonatal Extracorporeal Membrane Oxygenation

“…Reduced thyroid hormone concentrations have been found in critically ill term neonates treated with or without ECMO [7,8,9,10]. The effect of neonatal ECMO on thyroid hormone concentrations has been studied only by Stewart et al [10].…”

“…The effect of neonatal ECMO on thyroid hormone concentrations has been studied only by Stewart et al [10]. They found a decline in all thyroid hormone concentrations directly after the start of ECMO in a cohort of 14 neonates, which suggests a dilutional effect.…”

“…In previous studies critically ill neonates have had lower thyroid hormone concentrations than healthy neonates [7,8,9], and this has been associated with a prolonged hospital stay and a higher mortality [7,9]. Low thyroid hormone concentrations consistent with NTIS have been found in neonates on extracorporeal membrane oxygenation (ECMO) [10]. However, it is unknown whether ECMO exerts an influence on CH screening results and whether there are any implications of a positive CH screening result during ECMO.…”

Pharmacokinetic changes in patients receiving extracorporeal membrane oxygenation

“…Other data suggest that ECMO may also be associated with loss of vital trace elements, vitamins, micronutrients and macronutrients, and hormones [91,92]. A summary of the key PK changes during ECMO and their clinical implications can be found in Table 2.…”

Triiodothyronine Activates Lactate Oxidation Without Impairing Fatty Acid Oxidation and Improves Weaning From Extracorporeal Membrane Oxygenation

“…3,4 Despite the positive effects, ventricular unloading through ECMO promotes an inflammatory response, which has a deleterious impact on the failing heart. 5,6 The inflammatory cytokine surge associated with ECMO produces a disruption of thyroid hormone homeostasis production, which results in low circulating levels of triiodothyronine (T3). 7 Moreover, T3 decreases in children undergoing cardiac surgery for congenital heart disease.…”