Circadian Rhythm Disruption in the Hospital Intensive Care Environment

Abrupt changes to one's lifestyle disrupt biorhythms. Acute effects are well known from jet lag where transmeridian travel leads to insomnia, fatigue, irritability, gastrointestinal symptoms and other complaints. Several studies in the hospital environment reported dampened and misaligned biorhythms, suggesting that the inpatient experience is replete with circadian disruptors. However, comprehensive assessments of how circadian clocks are affected in intensive care and how this predicts post-operative recovery and risk are largely missing.

Study Overview

• Status: Active, not recruiting
• Conditions: Cardiovascular Diseases; Surgery
• Intervention / Treatment: Other: Observation

• Study Type: Observational
• Enrollment (Estimated): 15

Contacts and Locations

Study Locations

• United States
  • Pennsylvania
    • Philadelphia, Pennsylvania, United States, 19104
      • Institute for Translational Medicine and Therapeutics (ITMAT), University of Pennsylvania School of Medicine

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: N/A

• Sampling Method: Non-Probability Sample

Study Population

Potential patients will be screened from outpatient clinic schedules from cardiac surgery appointments within the Perelman Center for Advanced Medicine. Patients for whom cardiac surgery is advised and who meet eligibility criteria will be approached and enrolled after their consultation with the surgeon.

Description

Inclusion Criteria:

• Adults scheduled for cardiac surgery;
• ≥18 years of age;
• Capable of giving informed consent;
• Own a smartphone (Apple devices only).

Exclusion Criteria:

• Taking sleep aids (antihistamines, melatonin, etc.)
• History of alcohol abuse (more than 2 drinks a day with last drink within the past 3 days)
• History of substance abuse at risk of postoperative withdrawal;
• Active diagnosis of alcohol or substance abuse;
• Recent travel across more than two (2) time zones (within the past month);
• Planned travel across more than two (2) time zones during the planned study activities;
• Subjects, who have received an experimental drug, used an experimental medical device within 30 days prior to screening, or who gave a blood donation of ≥ one pint within 8 weeks prior to screening;
• Subjects without access to WiFi in their or close to home or at work;
• Patients with hearing aids;
• Heart transplant patients;
• Patients in isolation.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Elective cardiac surgery	Other: Observation; No intervention

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Sleep depth	Variance in sleep depth assessed as percent REM sleep of total sleep time (TST)	Up to 48 hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Odds Ratio Product-based sleep depth	Variance in sleep depth assessed as Odds Ratio Product (ORP) which ranges between ORP=0 (deeply asleep) and ORB=2.5 (fully awake).	Up to 48 hours
Cognitive function assessed by the Montreal Cognitive Assessment (MoCA)	Variance in cognitive function	Up to 24 hours
Number of recorded patient visits	Any patient visits by physicians, nurses, maintenance and cleaning staff, family members and friends are documented	24 hours
Purpose of recorded patient visits	The rationale is documented descriptively for each patient visits by physicians, nurses, maintenance and cleaning staff, family members and friends	24 hours

Collaborators and Investigators

• Sponsor: University of Pennsylvania
• Investigators: Principal Investigator: Carsten Skarke, MD, University of Pennsylvania; Principal Investigator: Garret A FitzGerald, MD, University of Pennsylvania

Study record dates

Study Major Dates

• Study Start (Actual): March 15, 2023
• Primary Completion (Estimated): December 1, 2027
• Study Completion (Estimated): December 1, 2028

Study Registration Dates

• First Submitted: March 30, 2023
• First Submitted That Met QC Criteria: April 12, 2023
• First Posted (Actual): April 25, 2023

Study Record Updates

• Last Update Posted (Actual): January 23, 2026
• Last Update Submitted That Met QC Criteria: January 21, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Cardiovascular Diseases; Investigative Techniques; Methods; Observation
• Other Study ID Numbers: 852451

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

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