THE APPLICATION OF ENTROPY INDEX IN PREDICTING THE PROGNOSIS OF PATIENTS WITH TRAUMATIC BRAIN INJURY

Min Lu^#, Bo Chen^#, Feng Zheng, Chunyang Xu, Yilan Wang, Hongwei Ye^*

Department of Emergency and Critical Care Medicine, Changshu Hospital Affiliated to Soochow University, Changshu 215500, Jiangsu, China

Introduction: The outcome of patients with traumatic brain injury (TBI) has been widely concerned, and the Glasgow Outcome Scale-Extended (GOS-E) Scale is a commonly used scale to evaluate the prognosis of patients with TBI. Originally used to monitor the depth of anesthesia in patients, entropy has recently been used as an objective monitoring tool to assess levels of consciousness. The purpose of this study was to investigate whether the entropy index before anesthesia can be used to judge the prognosis of patients with craniocerebral injury.

Materials and methods: A total of 192 emergency patients who underwent craniotomy for loss of consciousness due to craniocerebral injury were enrolled. Entropy before successful anesthesia was measured and GOS-E score was evaluated 6 months after injury. Spearman’s correlation coefficients were used to evaluate the correlation between GOS-E score and entropy.

Results: In 192 patients, there were strong correlations (r=0.891/r=0.915, p<0.01) between GOS-E score and preanesthesia entropy (reaction entropy (RE)/state entropy (SE)). According to the entropy value before anesthesia, the formulas for estimating GOS-E were as follows: GOS-E=0.106×RE-2.525 and GOS-E= 0.113×SE-2.184. 

Conclusion: The present study illustrates that entropy before anesthesia strongerly correlates with GOS-E score when assessing conscious state in TBI patients. Entropy index can be used as an objective monitoring method to judge the prognosis of patients with TBI.