title: 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 (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.
authors: Department of Medicine, University of Helsinki, Helsinki, Finland; Department of Anesthesiology and Intensive Care, Helsinki University Central Hospital, Helsinki, Finland; Department of Anesthesiology and Intensive Care, Helsinki University Peijas Hospital, Helsinki, Finland.
authors: Juhani
authors: J
authors: Stewart
authors: Mika
authors: M
authors: Särkelä
authors: Anna-Maria
authors: AM
authors: Koivusalo
authors: Johanna
authors: J
authors: Wennervirta
authors: Tapani
authors: T
authors: Salmi
authors: Helena
authors: H
authors: Isoniemi
authors: Ulf-Håkan
authors: UH
authors: Stenman
authors: Hanna
authors: H
authors: Viertiö-Oja
authors: Petteri
authors: P
authors: Lapinlampi
authors: Leena
authors: L
authors: Lindgren
authors: Ulla-Stina
authors: US
authors: Salminen
authors: Anne
authors: A
authors: Vakkuri
mesh_terms: D000328:Adult; D000368:Aged; D002560:Cerebrovascular Circulation; D004569:Electroencephalography; D005260:Female; D005500:Follow-Up Studies; D005625:Frontal Lobe / Q000503:physiopathology*; D006501:Hepatic Encephalopathy / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology*; D006801:Humans; D007427:Intracranial Pressure; D017114:Liver Failure, Acute / Q000150:complications / Q000601:surgery*; D016031:Liver Transplantation; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D017585:Ultrasonography, Doppler, Transcranial; D055815:Young Adult