Phrenic Identification in the ICU

Anatomical Landmarks for Identifying the Phrenic Nerve With Ultrasound in Intensive Care Unit

This will be a prospective observational study where the investigator will scan patients' necks with an ultrasound and look for anatomical landmarks that may help identify the phrenic nerve.

Study Overview

• Status: Active, not recruiting
• Conditions: Ventilator-Induced Lung Injury; Diaphragm Disease; Ventilator Lung; Ultrasound; Phrenic Nerve; Phrenic Nerve Stimulation; Neck Anatomy
• Intervention / Treatment: Procedure: Neck ultrasound

Detailed Description

Patients under protective mechanical ventilation, an intervention that saves lives, may need sedation and paralyzing agents. However, sedation and paralyzing agents are associated with multiple complications, including diaphragm dysfunction.

Several strategies have been proposed to reduce diaphram dysfunction. A novel approach is to stimulate the phrenic nerve, either transvenously or transcutaneously. Transvenous stimulation requires a catheter, which eventually is associated with increased risk of infection and thrombosis. In this scenario, transcutaneous phrenic nerve pacing is attractive but may be more susceptible to patients' anthropometric measures.

The correlation between patients' anthropometric measures and the location of the phrenic has been poorly studied.

• Study Type: Observational
• Enrollment (Estimated): 63

Contacts and Locations

Study Locations

• Canada
  • Ontario
    • Toronto, Ontario, Canada, M5B 1W8
      • St. Michael's Hospital

Participation Criteria

Eligibility Criteria

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

• Sampling Method: Non-Probability Sample

Study Population

Adult patients admitted to the ICU

Description

Inclusion Criteria

• Age ≥ 18 years
• Admitted to ICU

Exclusion Criteria

• Patients with a cervical spine collar
• Patients who refuse to participate in the study

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
To evaluate the number of participants where the investigators will successfully identify the phrenic nerve using only ultrasound and anatomical landmarks	25-30 minutes
To measure both phrenic nerves depth with an ultrasound in a heterogeneous population in the ICU	25-30 minutes
To measure the distance, in milimeters, between each phrenic nerve and other homolateral cervical structures such as the carotid artery and the jugular vein	25-30 minutes

Secondary Outcome Measures

Outcome Measure	Time Frame
To describe potential clinical and anthropometric variables associated with phrenic nerve depth	25-30 minutes
To assess how long it takes to find the phrenic nerve with ultrasound visualization.	25-30 minutes

Collaborators and Investigators

• Sponsor: Unity Health Toronto

Publications and helpful links

General Publications

• Acute Respiratory Distress Syndrome Network; Brower RG, Matthay MA, Morris A, Schoenfeld D, Thompson BT, Wheeler A. Ventilation with lower tidal volumes as compared with traditional tidal volumes for acute lung injury and the acute respiratory distress syndrome. N Engl J Med. 2000 May 4;342(18):1301-8. doi: 10.1056/NEJM200005043421801.
• Reynolds SC, Meyyappan R, Thakkar V, Tran BD, Nolette MA, Sadarangani G, Sandoval RA, Bruulsema L, Hannigan B, Li JW, Rohrs E, Zurba J, Hoffer JA. Mitigation of Ventilator-induced Diaphragm Atrophy by Transvenous Phrenic Nerve Stimulation. Am J Respir Crit Care Med. 2017 Feb 1;195(3):339-348. doi: 10.1164/rccm.201502-0363OC.
• Dres M, de Abreu MG, Merdji H, Muller-Redetzky H, Dellweg D, Randerath WJ, Mortaza S, Jung B, Bruells C, Moerer O, Scharffenberg M, Jaber S, Besset S, Bitter T, Geise A, Heine A, Malfertheiner MV, Kortgen A, Benzaquen J, Nelson T, Uhrig A, Moenig O, Meziani F, Demoule A, Similowski T; RESCUE-2 Study Group Investigators. Randomized Clinical Study of Temporary Transvenous Phrenic Nerve Stimulation in Difficult-to-Wean Patients. Am J Respir Crit Care Med. 2022 May 15;205(10):1169-1178. doi: 10.1164/rccm.202107-1709OC.

Study record dates

Study Major Dates

• Study Start (Actual): April 21, 2024
• Primary Completion (Estimated): December 4, 2026
• Study Completion (Estimated): December 4, 2026

Study Registration Dates

• First Submitted: May 5, 2023
• First Submitted That Met QC Criteria: May 16, 2023
• First Posted (Actual): May 25, 2023

Study Record Updates

• Last Update Posted (Estimated): May 20, 2025
• Last Update Submitted That Met QC Criteria: May 15, 2025
• Last Verified: May 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Wounds and Injuries; Respiratory Tract Diseases; Lung Diseases; Thoracic Injuries; Lung Injury; Ventilator-Induced Lung Injury
• Other Study ID Numbers: 23-083 (Liverpool School Tropical Medicine)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

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