Abstract
Background In consequence of systemic inflammation, up to 70% of septic patients develop a diffuse brain dysfunction, accompanying with an increase in mortality, which is referred to as “septic associated encephalopathy”. Subsuming septic associated encephalopathy as a category of delirium, there is a common pathophysiology (neuro-inflammation and cholinergic transmitter imbalance). This can be approximated by measuring the acetylcholinesterase activity as a surrogate parameter of cholinergic activity. However, conflicting results for acetylcholinesterase activity exists, if single-point measurements have been done. Therefore, we wanted to test the hypothesis, whether longitudinal analysis of acetylcholinesterase activity in Intensive Care Unit patients displays septic associated encephalopathy/delirium in septic patients and reveals significant differences in comparison with non-septic, critically ill patients.Methods In this prospective, observational, single-center study, 175 patients, admitted to the surgical Intensive Care Unit of the University hospital Ulm, Germany, were included. Patients were divided into septic (n = 45) and non-septic (n = 130) patients and were screened for delirium/cognitive dysfunction. Subgroups for patients with delirium and altered acetylcholinesterase activity were built, dependent if an increase/decrease of the acetylcholinesterase activity was observed. Acetylcholinesterase activity was analysed over the course of time by using a linear regression model accounting for repeated measures. By using a time adjusted model, the effect of further possible predictors of acetylcholinesterase activity was analyzed. For nonparametric distributions, quantitative data were compared using Wilcoxon matched-pairs test. For the analysis of the independent samples, we used the Mann-Whitney test. Results There was a statistically significant, time-dependent change in acetylcholinesterase activity (decrease/increase) over a period of at least 5 days in septic patients which revealed septic associated encephalopathy/delirium in about 90%.Conclusion The longitudinal measurement of acetylcholinesterase activity over several consecutive days revealed a shift compared to baseline values exclusively in septic patients with septic associated encephalopathy/delirium. Acetylcholinesterase activity alteration compared to baseline values at the onset of sepsis may help to detect and differentiate septic associated encephalopathy from other delirium entities.Trial registration Retrospectively registered at German Clincial Trials Register, registration number DRKS 00020542, date of registration: January 27, 2020
AChE-activity in critically ill patients with suspected septic encephalopathy: a prospective, single-centre study
