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

Abstract

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 (P K ) of 50% spectral edge frequency 5 0.23, standard error (SE) 5 0.03; P K of delta power 5 0.76, SE 5 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 (P K 5 0.88, SE 5 0.09). With a threshold value of 1.6, the TCD pulsatility index had an odds ratio of 1.1 (95% confidence interval 5 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.

Neurocritical care monitoring of encephalopathic children with acute liver failure: A systematic review

“…Furthermore, evidence of the predictive validity of TCD in ALF is limited. PI at a threshold value of ≥1.6 was not found to be predictive of mortality in one study, although in a more recent cohort a non‐significant trend toward higher PI and lower MFV was identified in patients who died from the condition …”

“…Furthermore, evidence of the predictive validity of TCD in ALF is limited. PI at a threshold value of ≥1.6 was not found to be predictive of mortality in one study, 86 although in a more recent cohort a non-significant trend toward higher PI and lower MFV was identified in patients who died from the condition. 87 Clinically significant intracranial hypertension rarely occurs in adults with CLD, 88 a feature which has been attributed to the prevalence of cerebral atrophy in adults with cirrhosis, in particular where alcohol is an etiological factor.…”

Noninvasive Neuromonitoring of Hypothermic Circulatory Arrest in Aortic Surgery

“…The continuous EEG data were subjected to power spectral analysis, as described in an earlier study (20). For EEG asymmetry quantification, the revised BSI (16) was used with a frequency band of 0.5–25 Hz to derive two separate BSI indices for symmetrical pairs of the frontal and temporal channels between the hemispheres.…”

Characterization of EEG patterns in brain-injured subjects and controls after a Snoezelen® intervention

“…It is important to note that the term MF is also known as 50% spectral edge frequency (SEF50) [23,24]. A parameter strongly related to MF is the mean frequency whose original definition is based on the computation of the spectral centroid.…”