---
title: "Distribution of Ventilation, Respiratory Drive and Gas Exchange: Measurements and Monitoring"
nct_id: NCT05462600
overall_status: ENROLLING_BY_INVITATION
sponsor: University of California, San Diego
study_type: OBSERVATIONAL
primary_condition: Pulmonary Disease
countries: United States
canonical_url: "https://parkinsonspathways.com/agent/trials/NCT05462600.md"
clinicaltrials_gov: "https://clinicaltrials.gov/study/NCT05462600"
ct_last_update_post_date: 2025-04-11
last_seen_at: "2026-05-12T06:32:17.785Z"
source: ClinicalTrials.gov (mirrored, no enrichment)
---
# Distribution of Ventilation, Respiratory Drive and Gas Exchange: Measurements and Monitoring

**NCT ID:** [NCT05462600](https://clinicaltrials.gov/study/NCT05462600)

## Key Facts

- **Status:** ENROLLING_BY_INVITATION
- **Study Type:** OBSERVATIONAL
- **Target Enrollment:** 40
- **Lead Sponsor:** University of California, San Diego
- **Conditions:** Pulmonary Disease, Respiratory System Abnormalities, OSA, Respiratory Failure
- **Start Date:** 2022-07-19
- **Completion Date:** 2026-12-30
- **CT.gov Last Update:** 2025-04-11

## Brief Summary

Respiratory physiology involves a complex interplay of elements including control of breathing, respiratory drive, pulmonary mechanics, distribution of ventilation and gas exchange. Body position may also play an important role in respiratory mechanics. While effective methods exist for measuring these variables, they are typically measured in isolation rather than in combination. In pulmonary disease, decreasing mechanical stress and strain and optimizing transpulmonary pressure or the distending pressure across the lung, minimizing overdistention and collapse are central to clinical management. Obesity has a significant impact on pulmonary mechanics and is a risk factor for obstructive sleep apnea (OSA). However, our understanding of these elements is limited even in the general population. The investigators plan to use various validated methods to assess control of breathing, respiratory drive, distribution of ventilation and gas exchange to obtain a better understanding of underlying physiologic signatures in patients with and without obesity and the role of posture/position, with a secondary analysis comparing participants with and without obstructive sleep apnea.

## Eligibility

- **Minimum age:** 18 Years
- **Sex:** ALL
- **Healthy Volunteers:** Yes

```
Inclusion Criteria:

* 18 years or older
* Non-smokers

Exclusion Criteria:

* \<18 years old
* Significant history of pulmonary disease
* Chest wall, anatomical, physical abnormalities, skin integrity issues precluding placement of electrode belt in direct contact with skin
* Skin integrity issues precluding placement of nose clips, or transcutaneous carbon dioxide monitoring
* Inability to form a seal around a mouthpiece
* Known esophageal strictures, webs, or varices (if esophageal manometry to be included)
* Known platelet count \< 100,000 (if esophageal manometry to be included)
* On therapeutic anticoagulation (if esophageal manometry to be included)
* Known multidrug resistant (MDR) pulmonary infection
* Non-English language speakers
* Chronic hypoxemic respiratory failure
* Confirmed or suspected intracranial bleed, stroke, edema
* Active implants (i.e. implantable electronic devices such as pacemakers, cardioverter defibrillators or neurostimulators) or if device compatibility is in doubt
* Pregnant or lactating patients as safety and efficacy for use of EIT in such cases has not been verified
```

## Arms

- **BMI>24.9 kg/m2**
- **BMI 18-24.9 kg/m2**

## Interventions

- **Position change** (OTHER) — Distribution of ventilation, respiratory drive, pulmonary mechanics and gas exchange will be measured in 3 unique positions: prone, head of bed (HOB) flat (i.e. 0 degrees) and HOB elevated (i.e. 30 degrees).

## Primary Outcomes

- **Distribution of ventilation** _(time frame: 3 hours)_ — Change in regional ventilation distribution (ventral/dorsal) measured through electrical impedance tomography (EIT)
- **Respiratory drive** _(time frame: 3 hours)_ — Respiratory drive differences will be measured by mean desaturation (change from baseline percent oxygen saturation) following breath-hold maneuvers
- **Respiratory drive** _(time frame: 3 hours)_ — Respiratory drive differences will be assessed by the duration of maximal breath-hold (seconds)
- **Respiratory drive** _(time frame: 3 hours)_ — Respiratory drive will also be assessed by measurement of occlusion pressure (cm H2O) at 100 ms (P0.1) after the initiation of an inspiratory effort against a closed circuit.

## Secondary Outcomes

- **Pulmonary mechanics** _(time frame: 3 hours)_
- **Dead space fraction** _(time frame: 3 hours)_
- **Ventilatory ratio** _(time frame: 3 hours)_

## Locations (1)

- University of California San Diego Health, La Jolla, California, United States

## Recent Field Changes (last 30 days)

- `status.overallStatus` — added _(2026-05-12)_
- `status.primaryCompletionDate` — added _(2026-05-12)_
- `status.completionDate` — added _(2026-05-12)_
- `status.lastUpdatePostDate` — added _(2026-05-12)_
- `design.enrollmentCount` — added _(2026-05-12)_
- `eligibility.criteria` — added _(2026-05-12)_
- `eligibility.minAge` — added _(2026-05-12)_
- `eligibility.sex` — added _(2026-05-12)_
- `outcomes.primary` — added _(2026-05-12)_
- `outcomes.secondary` — added _(2026-05-12)_
- `armsInterventions.arms` — added _(2026-05-12)_
- `armsInterventions.interventions` — added _(2026-05-12)_
- `sponsor.lead` — added _(2026-05-12)_
- `results.hasResults` — added _(2026-05-12)_
- `locations.university of california san diego health|la jolla|california|united states` — added _(2026-05-12)_

---

*Canonical: https://parkinsonspathways.com/agent/trials/NCT05462600.md*  
*Source data (authoritative): https://clinicaltrials.gov/study/NCT05462600*  
*This page is a raw mirror with no AI summary, no editorial enrichment, and no Parkinson's-specific filtering.*