Is There an Optimal Time Window of Placement of Intracranial Pressure (ICP) Monitor for Elderly Patients With Severe Traumatic Brain Injury? An 11-Year Institutional Cohort Study With Restricted Cubic Spline Analysis

Severe traumatic brain injury (sTBI) is a prominent contributor to both morbidity and mortality in the elderly population. The monitoring of intracranial pressure (ICP) is crucial in the management of sTBI patients. Nevertheless, the appropriate timing for the placement of ICP monitor in elderly sTBI patients remains uncertain. To determine the optimal timing for the placement of ICP monitor in elderly sTBI patients, in this retrospective cohort study, we collected data from elderly patients (> 65 years) who suffered sTBI and received ICP monitors at Tangdu Hospital, The Fourth Military Medical University, between January 2011 and December 2021. To examine the relationship between the time of ICP monitor placement and in-hospital mortality, we conducted a multi-variate-adjusted restricted cubic spline (RCS) analysis. Additionally, logistic regression analysis was applied to further analyze the influencing factors contributing to early or late ICP monitor placements. A total of 283 eligible elderly TBI patients were included in the current analysis. The in-hospital mortality rate was 73 out of 283 (26%). The RCS analysis demonstrated an inverted U-shaped curve in the relationship between the timing of ICP monitor placement and in-hospital mortality. For the elderly sTBI patient cohort, 6 h was identified as the crucial moment for the treatment strategy. In addition, the protective time window for ICP placement was less than 4.92 h for the GCS 3-5 group, and less than 8.26 h for the GCS 6-8 group. However, the clinical benefit of ICP placement decreased gradually over time. The relationship between ICP placement and in-hospital mortality was non-linear, exhibiting an inverted U-shaped curve in elderly patients with sTBI. For elderly patients with sTBI, early (≤ 6 h) ICP placement was associated with reduced in-hospital mortality. The clinical benefit of ICP placement decreased beyond the optimal time window.

The nonlinear relationship between thyroid function parameters and metabolic dysfunction-associated fatty liver disease

BACKGROUND

The relationship between thyroid function parameters and metabolic dysfunction-associated fatty liver disease (MAFLD) remains controversial. Additionally, little is known about the relationship between thyroid function parameters and MAFLD in the Chinese population.

METHODS

We conducted a retrospective cross-sectional study involving 177,540 individuals with thyroid function tests and MAFLD diagnosis from 2010-2018. The association between thyroid function parameters and MAFLD was evaluated on a continuous scale with restricted cubic spline (RCS) models and by the prior-defined centile categories with multivariable-adjusted logistic regression models. Thyroid function parameters included free triiodothyronine (FT3), free tetra-iodothyronine (FT4), and thyroid stimulating hormone (TSH). Additionally, fully adjusted RCS models stratified by sex, age, and location were studied.

RESULTS

In the RCS models, the risk of MAFLD increased with higher levels of FT3 when FT3 <5.58pmol/L, while the risk of MAFLD decreased with higher levels of FT3 when FT3 ≥5.58pmol/L (P nonlinearity <0.05). While RCS analysis suggested that the FT4 levels had a negative association with MAFLD (P nonlinearity <0.05), indicating an increase in FT4 levels was associated with a decreased risk of MAFLD. RCS analysis suggested an overall positive association between the concentration of TSH and MAFLD risk (P nonlinearity <0.05). The rising slope was sharper when the TSH concentration was less than 1.79uIU/mL, which indicated the association between TSH and MAFLD risk was tightly interrelated within this range. The multivariable logistic regression showed that populations in the 81st-95th centile had the highest risk of MAFLD among all centiles of FT3/TSH, with the 1st-5th centile as the reference category.

CONCLUSIONS

Our study suggested nonlinear relationships between thyroid function parameters and MAFLD. Thyroid function parameters could be additional modifiable risk factors apart from the proven risk factors to steer new avenues regarding MAFLD prevention and treatment.