Anisocoria in the Intensive Care Unit (AICU Study)

University Hospital Basel

Status: Active, not recruiting

Conditions: Anisocoria

Study type: Observational

Funder types: Other

Identifiers

NCT06964997

2024-02347 am25Sutter3;

Details and patient eligibility

About

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.

Full 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.

Enrollment: 920 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

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.