Phrenic Identification in the ICU

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

Status

Active, not recruiting

Phases

Unknown

Study type

Observational

Source

ClinicalTrials.gov

Registry ID

NCT05875883

Enrollment

Registered

2023-05-25

Start date

2024-04-21

Completion date

2026-12-04

Last updated

2025-05-20

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Diaphragm Disease, Neck Anatomy, Phrenic Nerve, Phrenic Nerve Stimulation, Ultrasound, Ventilator-Induced Lung Injury, Ventilator Lung

Brief summary

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.

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.

Interventions

PROCEDURENeck ultrasound

The investigators will scan patients' necks with an ultrasound and look for anatomical landmarks to identify the phrenic nerve

Study design

Observational model

COHORT

Time perspective

PROSPECTIVE

Eligibility

Sex/Gender

ALL

Age

18 Years to No maximum

Healthy volunteers

Inclusion criteria

* Age ≥ 18 years * Admitted to ICU

Exclusion criteria

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

Design outcomes

Primary

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

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

Countries

Canada

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026