[The predictive value of low T3 syndrome for delayed encephalopathy caused by severe acute carbon monoxide poisoning]

Objective: To explore the predictive value of low T3 syndrome (LT3S) for patients with delayed encephalopathy after acute carbon monoxide poisoning (DEACMP) . Methods: In May 2020, 137 severe acute carben monoxide poisoning (SACMP) patients were selected from Harrison International Peace Hospital Affiliated to Hebei Medical University from January 2019 to January 2020 as subjects. Blood samples were taken after admission to test thyroid function. Followed up for 60 d, the patients were divided into DEACMP group (45 cases) and non DEACMP group (92 cases) according to their prognosis. Clinical data of patients in two groups were collected and compared. The Cox regression with multiple independent variables was used to analyze the independent risk factors of DEACMP. Pearson correlation analysis was used to evaluate the correlation between totall triiodochyronine (TT3) level and Acute Physiology and Chronic Health Evaluation (APACHE) Ⅱ score. The receiver operating characteristic (ROC) curve of TT3 and APACHE Ⅱ scores for predicting DEACMP were drawn. Results: Compared with non DEACMP group, the age, APACHE II score, LT3S rate and diabetes prevalence in DEACMP group were higher, and the Glasgow coma scale (GCS) score was lower (P<0.05) . Cox regression analysis showed that age, APACHEⅡ score and LT3S were independent risk factors of DEACMP in patients with SACMP (OR=1.040, 95%CI:1.005-1.077; OR=1.070, 95%CI: 1.002-1.143; OR=4.210, 95%CI: 1.707-10.379; P<0.05) . Pearson correlation analysis showed that TT3 level was negatively correlated with APACHE Ⅱ score (r=-0.397, P=0.000) . ROC curve showed that the cut-off value of TT3 level for DEACMP prediction was 1.078 nmol/L, the area under curve (AUC) was 0.755, the sensitivity was 82.6%, and the specificity was 73.3%. The cut-off value of the APACHE Ⅱ score for predicting DEACMP was 16, and the AUC was 0.725, sensitivity was 93.3%, and specificity was 60.9%. Conclusion: This study showed that LT3S minght be an independent predictor of DEACMP in patients with SACMP. Thyroid function is closely related to the severity of SACMP patients.