Recovery of Awareness after Hyperacute Hepatic Encephalopathy with “Flat” EEG, Severe Brain Edema and Deep Coma

Promoting the process of determining brain death through standardized training

Objective

This study aims to explore the training mode for brain death determination to ensure the quality of subsequent brain death determination.

Methods

A four-skill and four-step (FFT) training model was adopted, which included a clinical neurological examination, an electroencephalogram (EEG) examination, a short-latency somatosensory evoked potential (SLSEP) examination, and a transcranial Doppler (TCD) examination. Each skill is divided into four steps: multimedia theory teaching, bedside demonstration, one-on-one real or dummy simulation training, and assessment. The authors analyzed the training results of 1,577 professional and technical personnel who participated in the FFT training model from 2013 to 2020 (25 sessions), including error rate analysis of the written examination, knowledge gap analysis, and influencing factors analysis.

Results

The total error rates for all four written examination topics were < 5%, at 4.13% for SLSEP, 4.11% for EEG, 3.71% for TCD, and 3.65% for clinical evaluation. The knowledge gap analysis of the four-skill test papers suggested that the trainees had different knowledge gaps. Based on the univariate analysis and the multiple linear regression analysis, among the six factors, specialty categories, professional and technical titles, and hospital level were the independent influencing factors of answer errors (p < 0.01).

Conclusion

The FFT model is suitable for brain death (BD) determination training in China; however, the authors should pay attention to the professional characteristics of participants, strengthen the knowledge gap training, and strive to narrow the difference in training quality.

A novel nomogram for early prediction of death in severe neurological disease patients with electroencephalographic periodic discharges

OBJECTIVE

To investigate death-related factors in patients with electroencephalographic (EEG) periodic discharges (PDs) and to construct a model for death prediction.

METHODS

This case-control study enrolled a total of 80 severe neurological disease patients with EEG PDs within 72 h of admission to the neuroscience intensive care unit (NICU). According to modified Rankin scale (mRS) scores half a year after discharge, patients were divided into a survival group (<6 points) and a death group (6 points). Their relevant clinical and biochemical indicators as well as EEG characteristics were retrospectively analyzed. Logistic regression analysis was used to identify the risk factors associated with the death of patients with EEG PDs. A death risk prediction model and an individualized nomogram prediction model were constructed, and the prediction performance and concordance of the models were evaluated.

RESULTS

Multivariate logistic regression analysis showed that the involvement of both gray and white matter in imaging, disappearance of EEG reactivity, occurrence of stimulus-induced rhythmic, periodic, or ictal discharges (SIRPIDs), and an interval time of 0.5-4 s were independent risk factors for death. A regression model was established according to the multivariate logistic regression analysis, and the area under the curve of this model was 0.9135. The accuracy of the model was 87.01%, the sensitivity was 87.17%, and the specificity was 89.17%. A nomogram model was constructed, and a concordance index of 0.914 was obtained after internal validation.

CONCLUSION

The regression model based on risk factors has high accuracy in predicting the risk of death of patients with EEG PDs.

SIGNIFICANCE

This model can help clinicians in the early assessment of the prognosis of severe neurological disease patients with EEG PDs.

Frontal electroencephalogram variables are associated with the outcome and stage of hepatic encephalopathy in acute liver failure

Acute liver failure (ALF) and hepatic encephalopathy (HE) can lead to an elevated intracranial pressure (ICP) and death within days. The impaired liver function increases the risks of invasive ICP monitoring, whereas noninvasive methods remain inadequate. The purpose of our study was to explore reliable noninvasive methods of neuromonitoring for patients with ALF in the intensive care unit (ICU) setting; more specifically, we wanted to track changes in HE and predict the outcomes of ALF patients treated with albumin dialysis. The study included 20 patients with severe ALF at admission who had been referred to the ICU of the liver transplantation (LT) center for albumin dialysis treatment and evaluation for transplantation. Data were collected from all study patients in the form of continuous frontal electroencephalography (EEG) recordings and transcranial Doppler (TCD) measurements of cerebral blood flow. Among the studied EEG variables, the 50% spectral edge frequency decreased and the delta power increased as the HE stage increased. Both variables were predictive of the stage of HE [prediction probability (PK) of 50% spectral edge frequency = 0.23, standard error (SE) = 0.03; PK of delta power = 0.76, SE = 0.03]. The total wavelet subband entropy, a novel variable that we used for tracking abnormal EEG activity, predicted the outcome of ALF patients treated with albumin dialysis (PK = 0.88, SE = 0.09). With a threshold value of 1.6, the TCD pulsatility index had an odds ratio of 1.1 (95% confidence interval = 0.1-9.3) for a poor outcome (LT or death). In conclusion, EEG variables are useful for the monitoring of HE and can be used to predict outcomes of ALF. TCD measurements do not predict patient outcomes.

Spectral analysis of thioacetamide-induced electroencephalographic changes in rats

Thioacetamide (TAA) is widely used as a model of hepatic encephalopathy (HE). The aim of our study was to investigate the effects of TAA on electroencephalographic (EEG) changes in rats and to compare them with human HE. Male Wistar rats were divided into groups: (1) saline-treated group and (2) TAA-treated groups: TAA300 (300 mg/kg), TAA600 (600 mg/kg), and TAA900 (900 mg/kg). Daily dose of TAA (300 mg/kg) was administered intraperitoneally once (TAA300), twice (TAA600), or thrice (TAA900) in subsequent days. EEG changes were recorded about 24 h after the last dose of TAA. Absolute and relative power density in alpha bands were significantly higher in TAA300 versus control group. In TAA300, absolute beta power density was higher and relative beta power density was lower versus control group. Absolute alpha, theta, delta, and relative theta power were significantly lower, while relative power in delta band was significantly higher in TAA900 versus control group ( p < 0.01). In conclusion, decrease in EEG voltage with an increase in delta relative power, which correspond to the EEG manifestations of severe HE in humans, was observed in TAA900 group. Electrical activity in TAA300 group correlates with mild HE in humans.

Behavioral and electroencephalographic manifestations of thioacetamide-induced encephalopathy in rats

The aim of our study was to investigate the behavioral and electroencephalographic manifestations of thioacetamide-induced encephalopathy in rats. Male Wistar rats were divided among (i) control, saline-treated, and (ii) thioacetamide-treated groups (TAA(300) (300 mg/kg body mass); TAA(600) (600 mg/kg); and TAA(900) (900 mg/kg)). The daily dose of thioacetamide (300 mg/kg) was administered intraperitoneally once (TAA(300)), twice (TAA(600)), or 3 times (TAA(900)), on subsequent days. Behavioral manifestations were determined at 0, 2, 4, 6, and 24 h, while electroencephalographic changes were recorded 22-24 h after the last dose. General motor activity and exploratory behavior, as well as head shake, auditory startle reflex, placement, and equlibrium tests were diminished in the TAA(600) and TAA(900) groups compared with the control, and were absent in the TAA(900) group 24 h after treatment. Corneal, withdrawal, grasping, and righting reflexes were significantly diminished in the TAA(900) group compared with the control. Mean electroencephalographic power spectra density was significantly higher in TAA(300) and TAA(600) and lower in the TAA(900) group by comparison with the control. Only a score of 3 (mean dominant frequency ≤ 7.3 Hz and δ relative power ≥ 45%) was observed in the TAA(900) group. Thioacetamide induces encephalopathy in rats in a dose-dependent manner. A dose of 900 mg/kg TAA may be used as a suitable model of all stages of hepatic encephalopathy.