Nonthyroidal illness syndrome and prolonged mechanical ventilation in patients admitted to the ICU.
BACKGROUND
The effect of the nonthyroidal illness syndrome (NTIS) on the duration of mechanical ventilation (MV) has not been extensively investigated. This study aims to determine whether the NTIS is associated with the duration of MV in patients admitted to the ICU.


METHODS
We evaluated all patients admitted over a 6-year period to our ICU who underwent invasive MV and had measurement of serum free triiodothyronine (fT3), free thyroxine (fT4), and thyroid-stimulating hormone (TSH) performed in the first 4 days after ICU admission and, subsequently, at least every 8 days during the time they received MV. The primary outcome measure was prolonged MV (PMV), which was defined as dependence on MV for > 13 days.


RESULTS
Two hundred sixty-four patients were included. Fifty-six patients (normal-hormone group) had normal thyroid function test results, whereas 208 patients (low-fT3 group) had, at least in one hormone dosage, low levels of fT3 with normal (n = 145)/low (n = 63) levels of fT4 and normal (n = 189)/low (n = 19) levels of TSH. Patients in the low-fT3 group showed significantly higher mortality and simplified acute physiology score II, and significantly longer duration of MV and ICU length of stay compared with the normal-hormone group. Two of the variables studied were associated with PMV, as follows: the NTIS (odds ratio [OR], 2.25; 95% confidence interval [CI], 1.18 to 4.29; p = 0.01); and the presence of pneumonia (OR, 1.17; 95% CI, 1.06 to 3.01; p = 0.03).


CONCLUSIONS
The NTIS represents a risk factor for PMV in mechanically ventilated, critically ill patients.
Bello
Giuseppe
G
Department of Anesthesiology and Intensive Care, Policlinico Universitario A. Gemelli, Università Cattolica del Sacro Cuore, Rome, Italy. Electronic address: gbello.gb@libero.it.
Pennisi
Mariano Alberto
MA
Department of Anesthesiology and Intensive Care, Policlinico Universitario A. Gemelli, Università Cattolica del Sacro Cuore, Rome, Italy.
Montini
Luca
L
Department of Anesthesiology and Intensive Care, Policlinico Universitario A. Gemelli, Università Cattolica del Sacro Cuore, Rome, Italy.
Silva
Serena
S
Department of Anesthesiology and Intensive Care, Policlinico Universitario A. Gemelli, Università Cattolica del Sacro Cuore, Rome, Italy.
Maviglia
Riccardo
R
Department of Anesthesiology and Intensive Care, Policlinico Universitario A. Gemelli, Università Cattolica del Sacro Cuore, Rome, Italy.
Cavallaro
Fabio
F
Department of Anesthesiology and Intensive Care, Policlinico Universitario A. Gemelli, Università Cattolica del Sacro Cuore, Rome, Italy.
Bianchi
Antonio
A
Institute of Endocrinology, Policlinico Universitario A. Gemelli, Università Cattolica del Sacro Cuore, Rome, Italy.
De Marinis
Laura
L
Institute of Endocrinology, Policlinico Universitario A. Gemelli, Università Cattolica del Sacro Cuore, Rome, Italy.
Antonelli
Massimo
M
Department of Anesthesiology and Intensive Care, Policlinico Universitario A. Gemelli, Università Cattolica del Sacro Cuore, Rome, Italy.
D017677:Age Distribution; D000368:Aged; D000704:Analysis of Variance; D015331:Cohort Studies; D003422:Critical Care / Q000379:methods; D016638:Critical Illness / Q000401:mortality / Q000628:therapy; D005067:Euthyroid Sick Syndromes / Q000453:epidemiology* / Q000209:etiology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D015994:Incidence; D007362:Intensive Care Units; D007902:Length of Stay; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011336:Probability; D011379:Prognosis; D012121:Respiration, Artificial / Q000009:adverse effects* / Q000379:methods; D012189:Retrospective Studies; D018570:Risk Assessment; D017678:Sex Distribution; D018709:Statistics, Nonparametric; D016019:Survival Analysis; D013960:Thyroid Function Tests; D013972:Thyrotropin / Q000097:blood; D013997:Time Factors
D013972:Thyrotropin