IntroductionDelirium is a common complication in the intensive care unit. The attention of researchers has shifted from the treatment to the prevention of the syndrome necessitating the study of associated risk factors.MethodsIn a multicenter study at one university hospital, two community hospitals and one private hospital, all consecutive newly admitted adult patients were screened and included when reaching a Glasgow Coma Scale greater than 10. Nurse researchers assessed the patients for delirium using the NEECHAM Confusion Scale. Risk factors covered four domains: patient characteristics, chronic pathology, acute illness and environmental factors. Odds ratios were calculated using univariate binary logistic regression.ResultsA total population of 523 patients was screened for delirium. The studied factors showed some variability according to the participating hospitals. The overall delirium incidence was 30%. Age was not a significant risk factor. Intensive smoking (OR 2.04), daily use of more than three units of alcohol (OR 3.23), and living alone at home (OR 1.94), however, contributed to the development of delirium. In the domain of chronic pathology a pre-existing cognitive impairment was an important risk factor (OR 2.41). In the domain of factors related to acute illness the use of drains, tubes and catheters, acute illness scores, the use of psychoactive medication, a preceding period of sedation, coma or mechanical ventilation showed significant risk with odds ratios ranging from 1.04 to 13.66. Environmental risk factors were isolation (OR 2.89), the absence of visit (OR 3.73), the absence of visible daylight (OR 2.39), a transfer from another ward (OR 1.98), and the use of physical restraints (OR 33.84).ConclusionsThis multicenter study indicated risk factors for delirium in the intensive care unit related to patient characteristics, chronic pathology, acute illness, and the environment. Particularly among those related to the acute illness and the environment, several factors are suitable for preventive action.

IntroductionThis study hypothesised that a reduction of sound during the night using earplugs could be beneficial in the prevention of intensive care delirium. Two research questions were formulated. First, does the use of earplugs during the night reduce the onset of delirium or confusion in the ICU? Second, does the use of earplugs during the night improve the quality of sleep in the ICU?MethodsA randomized clinical trial included adult intensive care patients in an intervention group of 69 patients sleeping with earplugs during the night and a control group of 67 patients sleeping without earplugs during the night. The researchers were blinded during data collection. Assignment was performed by an independent nurse researcher using a computer program. Eligible patients had an expected length of stay in the ICU of more than 24 hours, were Dutch- or English-speaking and scored a minimum Glasgow Coma Scale of 10. Delirium was assessed using the validated NEECHAM scale, sleep perception was reported by the patient in response to five questions.ResultsThe use of earplugs during the night lowered the incidence of confusion in the studied intensive care patients. A vast improvement was shown by a Hazard Ratio of 0.47 (95% confidence interval (CI) 0.27 to 0.82). Also, patients sleeping with earplugs developed confusion later than the patients sleeping without earplugs. After the first night in the ICU, patients sleeping with earplugs reported a better sleep perception.ConclusionsEarplugs may be a useful instrument in the prevention of confusion or delirium. The beneficial effects seem to be strongest within 48 hours after admission. The relation between sleep, sound and delirium, however, needs further research.Trial registrationCurrent Controlled Trials ISRCTN36198138

No abstract