Hypothalamus is a vital organ for survival and has a luxuriant blood supply in the brain. Blood supply is only lost during brain death (BD) which is supposed to result in hypothermia and hypopituitarism. The aim of this study is to measure the changes in thyroid hormone levels in patients with BD.Methods
Thyroid hormones were measured on the day of ICU admission and on the day of BD diagnosis among the patients with cerebrovascular accidents. Age-matched a healthy-control group (controls, 66 (50-69) vs patients, 57 (38-74), p = 0.533] was used for the comparison.Results
Eleven patients were included. Three patients were found to be hypothyroid. After they were excluded, the patients had lower TSH and fT3 levels on admission and BD day than the controls (TSHcontrol:1.56 (0.75-2.63) vs TSHadmission:0.47 (0.16-1.42) and TSHBDday:0.52 (0.18-1.62) μIU/mL, padmission = 0.042, pBDday = 0.035; fT3control:3.12 (2.92-3.85) vs fT3admission:2.43 (0.99-2.51) and fT3BDday:1.44 (1.19-2.18) pg/mL, padmission = 0.001, pBDday = 0.002). When thyroid functions of 11 patients measured on admission and BD day were compared with each other, an important decrease in TSH was uncovered, while the decrease in fT4 could not reach a significance (TSHadmissinon:1.14 (0.27-6.51) vs TSHBDday:0.75 (0.19-3.51) μIU/mL, p = 0.046; sT4admission:1.28 (0.98-2.02) vs sT4BDday:1.17 (0.87-1.47) ng/dL p = 0.075). Admission APACHE II was 26 (25-37) and Glasgow coma score 3 (3-4). SOFA scores increased significantly [SOFAadmission:9 (9-12) vs SOFABDday:12 (10-14), p = 0.011]. There was no correlation between the hormones and SOFA scores. BD diagnosis was done in 2.9 (1.5-4) and 2.7 (1.5-3.6) days after hospital and ICU admissions. All patients had vasopressor, 10 patients had corticosteroid and 6 patients had insulin treatments on the day of BD diagnosis. Four (36%) patients became donor.Conclusion
Thyroid hormone levels decrease in severe cerebrovascular accidents. Further reduction in the hormones is encountered in those patients who develop BD.Conclusion
The study protocol was approved by the ethics review board of Düzce University.Conclusion
1. Youn TS, Greer DM. Crit Care Clin 2014;30:813–831.