Anisocoria in the Intensive Care Unit (AICU Study)

NCT ID: NCT06964997

Last Updated: 2025-05-11

Basic Information

• Recruitment Status: ACTIVE_NOT_RECRUITING
• Total Enrollment: 920 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2025-03-01
• Study Completion Date: 2025-12-31

Brief Summary

This retrospective single-center cohort study aims to determine the prevalence of acute "new onset" pupillary abnormalities in adult intensive care unit patients, assess their clinical impact, identify the contexts leading to treatment changes, and evaluate their prognostic implications.

Detailed Description

Assessment of the pupil symmetry and reactivity to light are important parts of the neurological evaluation of critically ill patients in intensive care units (ICUs). Anisocoria, a condition where the pupils are unequal in size, can be found in up to 60% of patients with acute neurologic injuries. It may indicate serious underlying issues like traumatic brain injury, cerebrovascular accidents, brain tumors or viral encephalitis. However, anisocoria or impaired pupillary reactivity can also be caused from less severe conditions, such as drug effects (e.g., ipratropium bromide),Horner's syndrome after central venous cannulation, or intoxications with substances like anticholinergics, opioids, and cannabinoids. Despite these well-known causes, there is limited data on the prevalence and clinical consequences of anisocoria in ICU patients.

New onset of pupillary abnormalities often requires immediate neurological evaluation and neuroimaging (computed tomography (CT) or magnetic resonance imaging (MRI)), but many of these scans may not reveal clinically relevant findings and could expose patients to unnecessary risks. This is particularly concerning as benign causes of pupillary abnormalities are common, while more serious conditions can sometimes be overlooked. Current studies do not fully address when CT or MRI scans are necessary, or when they provide no significant clinical benefit.

This retrospective single-center cohort study has four primary objectives:

1. to determine the prevalence of acute "new onset" pupillary abnormalities (anisocoria and/or impaired light-reactive pupillary response) in adult ICU patients.

2. to assess the clinical impact of these abnormalities, particularly in terms of the frequency of diagnostic tests like CT or MRI scans, and ophthalmologic and neurologic consultations.

3. to identify when pathological findings lead to treatment modifications

4. to evaluate the prognostic implications of these pupillary abnormalities on patient outcomes.

The results of this study may improve the understanding of acute pupillary abnormalities in ICU patients, helping to optimize diagnostic strategies, reduce unnecessary neuroimaging, and enhance patient safety and outcome prediction.

Conditions

Anisocoria

Study Design

• Observational Model Type: COHORT
• Study Time Perspective: RETROSPECTIVE

Eligibility Criteria

Inclusion Criteria

• Adult patients (i.e., patients ≥18 years of age)
• Reported incident of pupillary abnormality (either anisocoria or non-normal pupillary reactivity) in the intensive care unit at the University Hospital Basel between 2013-2024.

Exclusion Criteria

• Patients younger than 18 years
• Patients with documented refusal of data use.

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

University Hospital, Basel, Switzerland

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Raoul Sutter, Prof. Dr. med.

Role: PRINCIPAL_INVESTIGATOR

University Hospital Basel, Clinic for Intensive Care Medicine

Locations

University Hospital Basel, Clinic for Intensive Care Medicine

Basel, Canton of Basel-City, Switzerland

Countries

Switzerland

Other Identifiers

2024-02347; am25Sutter3

Identifier Type: -

Identifier Source: org_study_id