DuraEEG - Duration of EEG and Treatment Outcomes in Critical Care

The aim of this retrospective, observational, single-center study is to evaluate how electroencephalography (EEG) monitoring duration affects diagnosis and treatment in adult critical care patients.

Study Overview

• Status: Completed
• Conditions: Neurologic Dysfunction

Detailed Description

Electroencephalography (EEG) is a diagnostic tool that records the brain's real-time electrical activity, helping detect or rule out causes of altered mental or neurological status, including life-threatening emergencies such as status epilepticus or encephalopathies. EEG can be performed as short "Spot-EEG" sessions or continuously over several days using continuous video EEG monitoring (CVEM). Prolonged EEG recordings can increase the detection of epileptic seizures or nonconvulsive status epilepticus, although previous studies have not shown a clear effect on patient outcomes. EEG findings guide treatment decisions, including starting, adjusting, or stopping therapies, and inform investigations and interventions in conditions such as encephalopathy or after cardiac arrest.

This retrospective, observational, single-center cohort study aims to identify the EEG duration that balances the benefits of detecting therapy-relevant events with the risks, resource requirements, and potential complications of prolonged monitoring.

The results of this study may help improve individualized patient care, optimize EEG use in intensive care, and guide treatment and monitoring strategies to achieve better outcomes for critically ill patients.

• Study Type: Observational
• Enrollment (Actual): 800

Contacts and Locations

Study Locations

• Switzerland
  • Canton of Basel-City
    • Basel, Canton of Basel-City, Switzerland, 4031
      • University Hospital Basel, Clinic for Intensive Care Medicine

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Probability Sample

Study Population

The study population will include all consecutive adult patients (i.e., ≥18 years of age) who were treated at the University Hospital Basel and/or were selected for a close monitoring on a monitoring Unit for EEG or continuous EEG between 2014 and until the end of 02/2025.

Description

Inclusion Criteria:

• Adult patients (i.e., patients ≥18 years of age)
• Received an EEG/continuous EEG
• Treated at the University Hospital of Basel on a suitable monitoring unit from 01.01.2014 - 28.02.2025.

Exclusion Criteria:

• Patients younger than 18 years
• Patients who did not receive suitable EEG monitoring
• Patients with documented refusal of the general consent

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Patient demographics	Demographic information (e.g. age, sex) is collected.	2014 - 02/2025
Acute prehospital management data	Data from acute prehospital management, as documented in emergency medical services (EMS) treatment protocols, is collected. The collected data elements are aggregated to describe the overall EMS response.	2014 - 02/2025
Duration of intensive care unit stay	The length of intensive care unit (ICU) stay is recorded.	2014 - 02/2025
Duration of hospital stay	The length of the total hospital stay is recorded.	2014 - 02/2025
Discharge destination	The destination at discharge is recorded.	2014 - 02/2025
Neurological deficits	The date(s) of onset and clinical course of neurological deficits, aggregated with additional clinical features are collected to capture the overall clinical presentation.	2014 - 02/2025
Number of Nonconvulsive Status Epilepticus in ectroencephalogram	Electroencephalograms (EEGs) are collected to assess neurological activity and monitor for abnormalities that may affect treatment.	2014 - 02/2025
Medical history	Patients' medical history, especially neurological and infectious disease history, is collected to provide a comprehensive overview of relevant clinical background.	2014 - 02/2025
Disease etiology	The underlying causes of relevant diseases, particularly neurological and infectious conditions, are collected provide a comprehensive overview of relevant clinical background.	2014 - 02/2025
Previous episodes of altered neurologic function	Information on previous episodes of altered neurological function, including their number and duration, is collected to provide a comprehensive measure of past disease burden.	2014 - 02/2025
Imaging features	Neuroimaging features and other imaging features obtained during diagnostic work-up are aggregated to provide a comprehensive assessment of structural and functional abnormalities.	2014 - 02/2025
Comprehensive assessment of the neurological status based on Richmond Agitation-Sedation Scale (RASS)	Neurological status during ICU stay is assessed using available data in the patient register from validated neurological assessments. These may include the Richmond Agitation-Sedation Scale (RASS), Sedation-Agitation Scale (SAS), Glasgow Coma Scale (GCS), or Intensive Care Delirium Screening Checklist (ICDSC). If multiple scores are available, they will be aggregated to provide a comprehensive assessment of neurological status. This outcome will be reported as a descriptive summary, synthesizing findings across tools, rather than as a single quantitative score. Richmond Agitation-Sedation Scale (RASS) is a 10-point validated tool (ranging from +4 to -5) used in intensive care to quickly assess a patient's level of sedation or agitation. A RASS score of 0 indicates an alert and calm patient, while positive scores represent agitation and negative scores indicate sedation.	2014 - 02/2025
Comprehensive assessment of critical illness severity based on standardized scoring including the Acute Physiology and Chronic Health Evaluation II (APACHE II)systems	Disease severity during ICU stay is assessed using standardized scoring systems, including the Acute Physiology and Chronic Health Evaluation II (APACHE II), Simplified Acute Physiology Score II (SAPS II), and Sequential Organ Failure Assessment (SOFA), depending on data availability in the patient register. The specific scoring system applied, as well as the scale and interpretation of the score, varies based on routine clinical practice and available documentation. Where multiple severity scores are available, they will be synthesized to provide a descriptive summary of overall illness severity rather than a single quantitative score. APACHE II uses 12 routine physiologic measurements, age, and chronic health status-collected within 24 hours of ICU admission-to calculate a score (0 to 71) predicting mortality risk. Higher scores correspond to higher disease severity.	2014 - 02/2025
Charlson Comorbidity Index	The Charlson Comorbidity Index (CCI) is calculated based on pre-existing comorbidities and additional diagnoses. The CCI predicts the ten-year mortality for a patient who may have a range of comorbid conditions. It assigns weighted scores (from 0 to maximal 6) to 17 comorbid conditions (e.g., heart disease, diabetes, cancer), resulting in a total score ranging from 0 to 33, if the patient had the most severe form of each of the 17 conditions.	2014 - 02/2025
Laboratory parameters	Routine laboratory value are collected. The specific parameters recorded may vary depending on the laboratory assessments documented in the patient register. All values will be reported using their respective units of measurement. These parameters are aggregated to support an overall clinical interpretation rather than a single numerical value. This approach reflects standard clinical practice, where multiple lab values are considered together to assess a patient's condition.	2014 - 02/2025
Complications	Complications occurring during intensive care treatment or clinical monitoring are collected, including but not limited to community-acquired and nosocomial infections, shock, hemorrhage, ischemic events, arrhythmia, cardiopulmonary arrest, and organ failure. These events are aggregated to provide a comprehensive overview of serious adverse clinical outcomes during critical care rather than reported as isolated parameters.	2014 - 02/2025
Glasgow Outcome Score	The Glasgow Outcome Score (GOS) is calculated based on the assessment of key clinical outcomes such as inhospital mortality, survival, survival with neurofunctional alteration, return to premorbid neurological function, and hospital readmission to determine the patient outcome. The GOS ranges from 1 (death) to 5 (good recovery).	2014 - 02/2025
Therapeutic intervention	Therapeutic interventions are documented, including duration, dosage, and number of medications, the number of drugs, administration of fluids (including blood products, crystalloids, enteral and parenteral nutrition, etc.), invasive procedures (such as intubation, mechanical ventilation, vasopressor use, and placement of central lines), and changes to any of these treatments, including the date of treatment adaptation.	2014 - 02/2025
Vital signs	Vital signs are analyzed based on the data available in the patient register. The specific parameters recorded depend on the clinical documentation available.These values are aggregated to support an overall clinical assessment rather than a single numerical score. This reflects standard practice, where multiple vital signs are interpreted together to evaluate a patient's condition.	2014 - 02/2025
Comprehensive assessment of the neurological status based on Sedation-Agitation Scale (SAS)	Neurological status during ICU stay is assessed using available data in the patient register from validated neurological assessments. These may include the Richmond Agitation-Sedation Scale (RASS), Sedation-Agitation Scale (SAS), Glasgow Coma Scale (GCS), or Intensive Care Delirium Screening Checklist (ICDSC). The specific tool used, as well as the scale of the score and meaning behind the score, depends on routine clinical practice and available documentation in the register. If multiple scores are available for a patient, they will be aggregated to provide a comprehensive assessment of neurological status. This outcome will be reported as a descriptive summary, synthesizing findings across tools, rather than as a single quantitative score. The sedation-Agitation Scale is a tool to assess both levels of sedation and agitation. In this tool scores 1-2 are for unawake patients and doesn't request use of sedative, while 3-7 are awake patients of which 5-7 are in need of Sedative use.	2014 - 02/2025
Comprehensive assessment of the neurological status based on Glasgow Coma Scale (GCS)	Neurological status during ICU stay is assessed using available data in the patient register from validated neurological assessments. These may include the Richmond Agitation-Sedation Scale (RASS), Sedation-Agitation Scale (SAS), Glasgow Coma Scale (GCS), or Intensive Care Delirium Screening Checklist (ICDSC). The specific tool used, as well as the scale of the score and meaning behind the score, depends on routine clinical practice and available documentation in the register. The Glasgow Coma Scale (GCS) is a standardized neurological tool used to objectively measure and track a person's level of consciousness, particularly following traumatic brain injury. It assesses three components:eye opening (1-4), verbal response (1-5), motor response (1-6), where higher scores indicate better function.	2014 - 02/2025
Comprehensive assessment of the neurological status based on Comprehensive assessment of the neurological status based on Intensive Care Delirium Screening Checklist (ICDSC)	Neurological status during ICU stay is assessed using available data in the patient register from validated neurological assessments. These may include the Richmond Agitation-Sedation Scale (RASS), Sedation-Agitation Scale (SAS), Glasgow Coma Scale (GCS), or Intensive Care Delirium Screening Checklist (ICDSC). The specific tool used, as well as the scale of the score and meaning behind the score, depends on routine clinical practice and available documentation in the register. The Intensive Care Delirium Screening Checklist (ICDSC) is an 8-item, validated tool used by ICU bedside nurses to rapidly screen for delirium in critically ill patients, including those who are intubated. It assesses behavioral, cognitive, and physiological symptoms over a 12-to-24-hour period, with a total score of indicating the presence of delirium.	2014 - 02/2025
Comprehensive assessment of critical illness severity based on standardized scoring systems, including the Simplified Acute Physiology Score II (SAPS II)	Disease severity during ICU stay is assessed using standardized scoring systems, including the Acute Physiology and Chronic Health Evaluation II (APACHE II), Simplified Acute Physiology Score II (SAPS II), and Sequential Organ Failure Assessment (SOFA), depending on data availability in the patient register. The specific scoring system applied, as well as the scale and interpretation of the score, varies based on routine clinical practice and available documentation. Where multiple severity scores are available, they will be synthesized to provide a descriptive summary of overall illness severity rather than a single quantitative score. The Simplified Acute Physiology Score II (SAPS II) is a severity-of-illness scoring system that estimates the risk of in-hospital mortality for adult ICU patients. Assessed within the first 24 hours of admission, it assigns 0-163 points based on age, admission type, chronic diseases, and 12 physiological variables	2014 - 02/2025
Comprehensive assessment of critical illness severity based on standardized scoring systems, including the Sequential Organ Failure Assessment (SOFA)	Disease severity during ICU stay is assessed using standardized scoring systems, including the Acute Physiology and Chronic Health Evaluation II (APACHE II), Simplified Acute Physiology Score II (SAPS II), and Sequential Organ Failure Assessment (SOFA), depending on data availability in the patient register. The specific scoring system applied, as well as the scale and interpretation of the score, varies based on routine clinical practice and available documentation. Where multiple severity scores are available, they will be synthesized to provide a descriptive summary of overall illness severity rather than a single quantitative score. The Sequential Organ Failure Assessment (SOFA) evaluates six organ systems (respiratory, cardiovascular, hepatic, coagulation, renal, and neurological), with scores ranging from 0 to 4 per system.	2014 - 02/2025

Collaborators and Investigators

• Sponsor: University Hospital, Basel, Switzerland
• Investigators: Principal Investigator: Raoul Sutter, Prof. Dr. med., University Hospital Basel, Clinic for Intensive Care Medicine

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2014
• Primary Completion (Actual): February 28, 2025
• Study Completion (Actual): February 28, 2025

Study Registration Dates

• First Submitted: February 10, 2026
• First Submitted That Met QC Criteria: February 23, 2026
• First Posted (Actual): March 2, 2026

Study Record Updates

• Last Update Posted (Actual): March 2, 2026
• Last Update Submitted That Met QC Criteria: February 23, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: Intensive Care Unit; Electroencephalography
• Additional Relevant MeSH Terms: Nervous System Diseases; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Neurologic Manifestations
• Other Study ID Numbers: 2025-00337; am25Sutter5

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No