BACKGROUND AND RATIONALE~Delirium is a complex state of confusion that can be seen as an acute failure of brain function. It is characterised by fluctuating deficits in cognition and attention, dysregulation of emotions and circadian rhythm as well as psychomotor changes.~In intensive care units (ICU) delirium is the most frequent syndromic complications as they are found with a prevalence between 26 - 60%. In mechanically ventilated patients, delirium is even detected in more than 80%.~Occurrence of delirium is associated with several negative repercussions: Delirious patients show a higher prevalence in morbidity and mortality, longer stays in intensive care units and normal wards, as well as impaired cognitive function several months after the acute illness. The intensity of impairment in cognitive and executive function correlates with the duration of delirium. Further, delirious patients cause major additional costs of up to 20% more compared to non-delirious patients.~Although there are several approaches for prevention and treatment of delirium in ICU their impact is still limited. Improvement of existing and development of new prevention strategies is therefore crucial and highly necessary. Further it has to be shown if prevention of delirium has an effect on clinical outcome.~HYPOTHESIS AND STATE OF RESEARCH~Consumption of alcoholic beverages and therewith beer is widespread in Switzerland. Healthy effects of moderate beer consumption, especially benefits for prevention of cardiovascular diseases, are discussed in literature. Beer's major ingredients are water, hop, malt and yeast.~Alcohol:~Surveys in US American ICUs showed a pre-existing alcohol use disorder in 16-31% of ICU patients. Further research showed anamnestic alcohol abuse as a significant risk factor for development of delirium in the ICU. Swiss governmental statistics show a widespread alcohol consumption among the swiss population: While 82% consume alcohol periodically, 10% drink alcoholic beverages on a daily and almost 60% in minimum on a weekly basis. Alcohol consumption increases with age. In the group of the over 75-year-olds around 40% drink alcohol daily. Around 5% of population bear a chronic risky alcohol consumption, 16% get drunk at least once a month. Thereby beer is one of the most popular beverages.~Alcohol, in alcoholic beverages ethanol, targets multiple central receptors and neural networks. In habituated individuals an abrupt abstinence from alcohol consumption leads to generalised central hyperexcitability, due to unchecked excitation and impaired inhibition whereby alcohol withdrawal syndrome (AWS) and delirium tremens (DT) is more likely to occur. Similar mechanisms can be thought of in patients with moderate, non-abusive alcohol consumption favouring and causing delirium.~Hop:~Hop (Humulus lupulus) is a major ingredient of beer. Its main pharmacologically active constituent is humulone. It bears several health enhancing properties: Its main impact is the calming effect, which could be shown in a study in healthy nurses when consuming alcohol-free beer. Improvement of sleep quality and a hypnagogic effect induced by alcohol-free beer and hop extracts could also be shown in different studies.~On molecular level the hop's sedating and hypnotic effect could be shown at the GABA A receptor in a rat model which, positively modulated by ethanol, shortened sleep onset, increased duration of sleep and decreased the spontaneous locomotion.~Yeast - Saccharomyces cerevisiae (boulardii):~Probiotic and preventive effects for diarrhoea of the so-called brewer's yeast could be shown in tube-fed patients in ICUs.~Hypothesis:~Due to the previous evidence, the investigators hypothesise the following:~The daily administration of a moderate alcohol amount decreases the prevalence, duration and intensity of deliriums in intensive care patients whereby duration of ICU stay is shortened.~Withdrawal of alcohol predisposes for development of delirium in critically ill patients with pre-existing moderate non-abusive alcohol consumption.~The hop's constituents and the alcohol have a positive effect on calming, decreasing intensity of delirium.~The yeast contained in beer takes a probiotic effect and decreases the prevalence of diarrhoea and obstipation.~Up to now no clinical trials investigating the administration of a moderate amount of beer for delirium prevention in non-alcoholic patients in ICUs have been published.~Aim of the BABE-D (Basel Beer for Prevention of Delirium) clinical trial is the proof of concept of prevention, mitigation or decrease in length of delirium by daily administering a moderate amount of wheat beer in non-alcoholic ICU patients and simultaneously a decrease of prevalence of obstipation and diarrhoea.
The investigators hypothesise that the daily administration of 0.5L alcohol-containing wheat beer at 8 pm over a study period of 6 days in a row leads to a lower prevalence of delirium compared to alcohol-free wheat beer following the same administration scheme and likewise alcohol-free wheat beer compared to no intervention.