Delirium in the critically ill: risk factors, diagnosis, management and prevention

Lolita Grygalytė1, Agnė Timlerytė1, Raimundas Vaitkevičius2

1Lithuanian University of Health Sciences, Medical academy, Faculty of Medicine

2Department of Intensive Care, Lithuanian University of Health Sciences


Delirium is an acute illness and is a frequent condition in the intensive care unit (ICU) setting. It is characterized by an altered state of consciousness, impaired perception, cognition and attention, alongside with the patients’ ability to receive, process, store and recall information. Hallucinations, circadian rhythm and emotional dysregulation might also be present. There are three subtypes of delirium – hyperactive, hypoactive and mixed. Elderly patients and those with many underlying diseases are most at risk for developing delirium. Persistent monitoring for ICU delirium should be performed as early detection and treatment could result in better outcome. Delirium is diagnosed clinically, using diagnostic tools such as Richmond Agitation Sedation Scale (RASS), Confusion Assessment Method (CAM)-ICU or Intensive Care Delirium Screening Checklist (ICDSC). The diagnostic criteria for delirium are described in the DSM-5 classification. While treating delirium, it is important to treat any predisposing conditions or diseases. Typical and atypical antipsychotics, although frequently used to treat this syndrome, are not proven to shorten the duration of delirium, mechanical ventilation or lower mortality rates. Dexmedetomidine is recommended for mechanically ventilated patients who cannot be extubated due to agitation.

Keywords: ICU delirium, delirium in the critically ill, delirium risk factors, delirium management, delirium prevention, CAM-ICU, critical care.