Studies have documented a correlation between hypothyroxinemia and mortality in critically ill patients; however, there are limited data in sepsis. The objective of this study was to assess baseline thyroid function studies and their association with mortality in surgical sepsis. We hypothesized that the relatively decreased levels of free thyroxine (T4), decreased levels of triiodothyronine (T3), and increased thyrotropin-stimulating hormone levels would be associated with mortality.METHODS
This was a retrospective review of prospectively collected data in a surgical intensive care unit. Data evaluated included patient demographics, baseline thyroid function studies, and mortality. Patients were categorized as having sepsis, severe sepsis, or septic shock. A value of p < 0.05 was considered significant.RESULTS
Within 24 months, 231 septic patients were accrued. The mean age was 59 ± 3 years, and 43% were male. Thirty-nine patients were diagnosed as having sepsis, 131 as having severe sepsis, and 61 as having septic shock. There were no statistically significant differences between the T3, free T4, or thyrotropin-stimulating hormone levels at baseline and the different categorizations of sepsis.RESULTS
T4 levels were increased in all patients but to a significantly lesser extent in those who died. Similarly, T3 levels were significantly decreased in patients who died.CONCLUSION
In surgical sepsis, decreased T3 levels at baseline are associated with mortality. These data do not support the administration of levothyroxine (T4) because it is already elevated and would preferentially be converted to reverse T3 (inactive) in critical illness; however, replacement with liothyronine (T3) might be rational.LEVEL OF EVIDENCE
Epidemiologic study, level III.