Hypothermia Due to Cold EnvironmentNCT07219290
Pulmonary Function by Litter Position
A study testing LItter position PFTs in people with Hypothermia Due to Cold Environment and Trauma Patients, run by University of California, San Francisco at 1 site in United States.
Trial summary
A litter is often needed to extract a person from an austere environment like the wilderness or from confined, urban spaces. A horizontal litter is generally assumed to be better for patient care, but often makes for a more difficult, if not impossible, evacuation from some settings such as confined space rescue, cave… Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Hypothermia Due to Cold Environment, Trauma Patients
- What is being tested?
- LItter position PFTs
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 12 participants
- Where
- 1 siteUnited States
- Study dates
- 15 Feb 2026to Apr 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- 130-310 pounds
Who cannot join
- Significant cardiac or pulmonary diseae
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
About this study
A litter is often needed to extract a person from an austere environment like the wilderness or from confined, urban spaces. A horizontal litter is generally assumed to be better for patient care, but often makes for a more difficult, if not impossible, evacuation from some settings such as confined space rescue, cave rescue, or wilderness rescue when the litter must be moved up or down a cliff with an undercut edge. A litter in a vertical orientation is easier to move in these situations, which may expedite movement towards definitive care. In some wilderness rescue circles, the mantra is that movement IS definitive care. It is already known that lying flat on the ground negatively affects pulmonary function compared to a sitting baseline.1 It is possible that a vertically oriented litter is better for a subset of patients with respiratory issues than a horizontal litter. The investigators hypothesize that pulmonary function measured by FEV1, FVC, and FEV1/FVC, is better in simulated patients in a vertically oriented litter compared to a horizontally oriented one.
Read the detailed description
Objective To quantify changes in pulmonary function tests (PFTs) based on litter position.
Hypotheses:
- Compared to sitting baseline, all PFTs in the litter will have decreased forced vital capacity (FVC) and 1 second forced expiratory volume (FEV1).
- Compared to lying down, persons straight upright and pitched forward will have better forced vital capacity (FVC) and 1 second forced expiratory volume (FEV1).
- We do not hypothesize any changes in FEV1/FVC.
Study Design This randomized crossover study will use twelve healthy volunteers. All subjects will do baseline sitting pulmonary testing. Experimental order is balanced to avoid any training effects. Choice of sequence will be by random selection of envelope.
Methods Once consented, included subjects will do baseline sitting measurement of FEV1 and FVC which will give FEV1/FVC. Each subject will then be secured in a Ferno-Washington Model 71 litter wearing their own type 2 or 3 harness, or in a UL tested CMC ATOM Global Harness (California Mountain Corporation, Santa Barbara, CA) meeting ANSI Z359.11-2014 and NFPA 1983-2017 standards, if they don't have their own. The person will be secured with double Vs from the litter sides to the harness and footloops supporting them so their weight is on their feet and only minimally on the harness (if vertical). This process is consistent with industry standards for securing a patient in the litter and follows the specific model of the National Cave Rescue Commission.3 See figure 1 Prior to being secured in the litter the patient will do sitting baseline FEV1 and FVC with an NDDD spirograph. Once there is baseline data the subject will be secured in the litter. The investigators will then repeat spirometry, pulse, and blood pressure in a horizontal position (see figure 2), in a vertical position (see figure 3), and pitched slightly forward in a position that results from a Pike and Pivot rigging for raising up past a difficult cliff edge (see figure 4). The subject will get a rest period in their preferred position until pulse returns to within 5 beats of baseline.
Litter suspension will be with a four-legged litter spider when horizontal, with a high bridle tied directly to the litter head for the full vertical position, and from a low bridle in Pike-and-Pivot formation when pitched forward. The litter will be lifted into position with a 3:1 mechanical advantage system tied to an anchor. No matter the position, the lowest point of the litter will be no more than 6 inches off of the ground. The system will be configured for immediate lower for any expressed concern. The PI (RM) is a technical rescue instructor for the National Cave Rescue Commission and Assistant Training Officer-Technical Rescue for Fresno County search and rescue. The Co-PIs (SS and SD) are on the rope team of Fresno County search and rescue. Each is well versed in rope systems, anchor selection, and patient packaging.
- Being tested
- LItter position PFTs
- Keywords
- search and rescue, pulmonary function, Suspension
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
LItter position PFTsOther
Testing basic pulmonary function in three positions in a rescue litter, compared to sitting baseline
| Study group | Role | What they receive |
|---|---|---|
| Flat | Active comparator | Secured in a flat litter Receives: Other: LItter position PFTs |
| Vertical | Active comparator | Secured in a vertical litter Receives: Other: LItter position PFTs |
| Pitched forward | Active comparator | Secured in a litter leaning forward Receives: Other: LItter position PFTs |
| Baseline | Placebo comparator | Sitting baseline pulmonary function Receives: Other: LItter position PFTs |
What is being measured
The primary outcome is the main question the study is designed to answer.
Forced Vital Capacity
Measurable lung volume on expiration
Measured: Immediately
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted21 Oct 2025
- Study start15 Feb 2026
- Primary completion1 Apr 2026 (estimated)
- Study completionApr 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Hypothermia Due to Cold EnvironmentStudies of the same condition, open and under way.
- More trials run by University of California, San FranciscoThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Supportive care
- Allocation
- Randomised
- Intervention model
- Sequential
- Masking
- None (open label)
- Enrolment
- 12 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of California, San Francisco
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Roger B Mortimer, MD, Principal investigator, UCSF - Fresno
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07219290
- Sponsor's protocol ID
- 25-45106
- Status last verified
- Apr 2026
- First submitted
- 19 Sep 2025
- Last updated
- 8 Apr 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Deidentified data will be submitted to a statistician
Study at a glance
From the registry record, last updated by the sponsor on 8 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Pulmonary Function by Litter Position
- ClinicalTrials.gov ID
- NCT07219290
- Acronym / sponsor ID
- 25-45106
- Keywords
- search and rescue, pulmonary function, Suspension
- Study type
- Interventional
- Recruitment status
- Enrolling by invitation
- Enrolment
- 12 participants (estimated)
- Lead sponsor
- University of California, San FranciscoUniversity, hospital or other
- Study start
- 15 Feb 2026 (actual)
- Primary completion
- 1 Apr 2026 (estimated)
- Study completion
- Apr 2026 (estimated)
- First posted
- 21 Oct 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
A litter is often needed to extract a person from an austere environment like the wilderness or from confined, urban spaces. A horizontal litter is generally assumed to be better for patient care, but often makes for a more difficult, if not impossible, evacuation from some settings such as confined space rescue, cave rescue, or wilderness rescue when the litter must be moved up or down a cliff with an undercut edge. A litter in a vertical orientation is easier to move in these situations, which may expedite movement towards definitive care. In some wilderness rescue circles, the mantra is that movement IS definitive care. It is already known that lying flat on the ground negatively affects pulmonary function compared to a sitting baseline.1 It is possible that a vertically oriented litter is better for a subset of patients with respiratory issues than a horizontal litter. The investigators hypothesize that pulmonary function measured by FEV1, FVC, and FEV1/FVC, is better in simulated patients in a vertically oriented litter compared to a horizontally oriented one.
Detailed description
Objective To quantify changes in pulmonary function tests (PFTs) based on litter position.
Hypotheses:
- Compared to sitting baseline, all PFTs in the litter will have decreased forced vital capacity (FVC) and 1 second forced expiratory volume (FEV1).
- Compared to lying down, persons straight upright and pitched forward will have better forced vital capacity (FVC) and 1 second forced expiratory volume (FEV1).
- We do not hypothesize any changes in FEV1/FVC.
Study Design This randomized crossover study will use twelve healthy volunteers. All subjects will do baseline sitting pulmonary testing. Experimental order is balanced to avoid any training effects. Choice of sequence will be by random selection of envelope.
Methods Once consented, included subjects will do baseline sitting measurement of FEV1 and FVC which will give FEV1/FVC. Each subject will then be secured in a Ferno-Washington Model 71 litter wearing their own type 2 or 3 harness, or in a UL tested CMC ATOM Global Harness (California Mountain Corporation, Santa Barbara, CA) meeting ANSI Z359.11-2014 and NFPA 1983-2017 standards, if they don't have their own. The person will be secured with double Vs from the litter sides to the harness and footloops supporting them so their weight is on their feet and only minimally on the harness (if vertical). This process is consistent with industry standards for securing a patient in the litter and follows the specific model of the National Cave Rescue Commission.3 See figure 1 Prior to being secured in the litter the patient will do sitting baseline FEV1 and FVC with an NDDD spirograph. Once there is baseline data the subject will be secured in the litter. The investigators will then repeat spirometry, pulse, and blood pressure in a horizontal position (see figure 2), in a vertical position (see figure 3), and pitched slightly forward in a position that results from a Pike and Pivot rigging for raising up past a difficult cliff edge (see figure 4). The subject will get a rest period in their preferred position until pulse returns to within 5 beats of baseline.
Litter suspension will be with a four-legged litter spider when horizontal, with a high bridle tied directly to the litter head for the full vertical position, and from a low bridle in Pike-and-Pivot formation when pitched forward. The litter will be lifted into position with a 3:1 mechanical advantage system tied to an anchor. No matter the position, the lowest point of the litter will be no more than 6 inches off of the ground. The system will be configured for immediate lower for any expressed concern. The PI (RM) is a technical rescue instructor for the National Cave Rescue Commission and Assistant Training Officer-Technical Rescue for Fresno County search and rescue. The Co-PIs (SS and SD) are on the rope team of Fresno County search and rescue. Each is well versed in rope systems, anchor selection, and patient packaging.
Study design
- Primary purpose
- Supportive care
- Allocation
- Randomised
- Intervention model
- Sequential
- Masking
- None (open label)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Flat | Active comparator | Other: LItter position PFTsSecured in a flat litter |
| Vertical | Active comparator | Other: LItter position PFTsSecured in a vertical litter |
| Pitched forward | Active comparator | Other: LItter position PFTsSecured in a litter leaning forward |
| Baseline | Placebo comparator | Other: LItter position PFTsSitting baseline pulmonary function |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- 130-310 pounds
Key exclusion criteria (1 listed)
- Significant cardiac or pulmonary diseae
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| LItter position PFTsTesting basic pulmonary function in three positions in a rescue litter, compared to sitting baseline | Other | Baseline, Flat, Pitched forward, Vertical |
Primary outcome
Forced Vital Capacity
Time frame: Immediately
Measurable lung volume on expiration
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 8 Apr 2026.
- Individual participant dataSharing planned: Yes. Deidentified data will be submitted to a statistician
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Roger B Mortimer, MD principal investigator
UCSF - Fresno
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing LItter position PFTs in people with Hypothermia Due to Cold Environment and Trauma Patients, run by University of California, San Francisco at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: enrolling by invitation, as of the sponsor's last update on 8 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Forced Vital Capacity (time frame: Immediately). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 8 Apr 2026.