Hypothyroidism complicated by low T3 state: An issue in intensive care unit

Abstract

A variety of severe clinical situations, such as organ failure, can determine low serum T3 state in euthyroid patients. Recently various low triiodothyronine (T3) states have been correlated with a poor prognosis in cardiac and respiratory patients. These conditions could have an important impact especially in hypothyroidism. We described one case admitted to our respiratory intensive care unit (RICU) in comatose state, suffering from acute respiratory failure due to pneumonia with untreated subclinical hypothyroidism complicated by low T3 state. In this patient the treatment with levothyroxin alone was ineffective while replacement therapy with synthetic sodic liothyronine proved effective and lead to clinical improvement. The low T3 state is common in RICU patients and this finding could be very important in clinical practice especially when hypothyroidism might be complicated by low T3 state. This report suggest that in this case only the addition of T3 to T4 replacement therapy may improve clinical status.