Condition category
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status

Plain English Summary

Background and study aims
The main function of lungs is gas exchange through gas transport. Due to the complexity of the lung structure, gas transport can only be optimized to a certain extent and is easily affected by changes in the small airways.
The overall aim of this study is to prospectively associate various pulmonary function tests with clinical, laboratory, histological and radiological characteristics.

Who can participate?
People aged 18 years or above.

What does the study involve?
Participants will undergo several lung function tests during a single visit.

What are the possible benefits and risks of participating?

Where is the study run from?
University Hospital Basel, Clinic for Respiratory Medicine and Pulmonary Cell Research (Switzerland)

When is the study starting and how long is it expected to run for?
April 2019 to April 2023.

Who is funding the study?
University Hospital Basel (Switzerland)

Who is the main contact?
Prof Daiana Stolz

Trial website

Contact information



Primary contact

Prof Daiana Stolz


Contact details

University Hospital of Basel
Clinic for Respiratory Medicine and Pulmonary Cell Research
Petersgraben 4
+41 612654422



Additional contact

Dr Desiree Schumann


Contact details

University hospital of Basel
Clinic of Respiratory Medicine and Pulmonary Cell Research
Petersgraben 4
+41 328 5519

Additional identifiers

EudraCT number

Nil known number

Nil known

Protocol/serial number

PFT_Prosp_Amendment 01

Study information

Scientific title

Pulmonary function test association with clinical, laboratory, histological and radiological characteristics – a prospective study



Study hypothesis

The overall aim of this study is to prospectively associate various pulmonary function tests with clinical, laboratory, histological and radiological characteristics.

Ethics approval

Approved 22/02/2019, EKNZ (Ethics Committee Northern and Central Switzerland, Hebelstrasse 53, Basel 4056, Switzerland; +41 612681350;, ref : 2018-0286, Amendment approved 27/11/2019

Study design

Observational longitudinal study

Primary study design


Secondary study design

Longitudinal study

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet


Respiratory diseases


Non-invasive measurements specific to the project and performed in all participants, include:
N2 washout (single and multiple breath):
Single breath - the measurements are carried out with the patient sitting upright and breathing normally. The test subjects breathe through a mouthpiece with a nose clamp that is attached to the measuring device. A bacteria filter is installed upstream of the measuring device. The filter, mouthpiece and nose clip are replaced after each patient. The measurement device is based on an ultrasonic flow head, the Exhalyzer® (Eco Medics AG, Dürnten, Switzerland), connected to a bypass element that provides constant air intake. The gas used as part of the study (100% O2, DTG) is supplied to the patient via this bypass element. During the measurement procedure, the accurate recording of the flow volume curve and the gas signals (O2, CO2 and the derived N2, molar mass signal) enable good online monitoring of the measurement quality. Any changes to the patient’s breathing pattern, hyperventilation or leaks are identified immediately and the measurement procedure is terminated.
Multiple breath - for N2 MBW, the supply of 100% O2 flushes out the nitrogen in the lungs. The test ends when < 2% end-expiratory N2 (1/40 of the starting concentration) is reached over three consecutive breaths. For the evaluation, all signals are aligned in terms of time, and the respiratory flows and derived breathing volumes are corrected for body temperature, ambient pressure and humidity. To calculate the functional residual capacity (FRC), the ratio (net volume of expirated tracer gas) / [(end-expiratory N2 concentration at start of washout measurement) – (end-expiratory N2 concentration at end of the washout measurement)] is calculated. Over the course of the three requisite measurements per patient, the FRC must not deviate by more than 20%; otherwise, the measurement must be rejected. The LCI is calculated via FRC as the ratio of the cumulative expirated volume.
Forced oscillation technique (FOT) - the sound waves, generated with the help of a loudspeaker are transmitted into the lungs of the subject. These sound waves, which are essentially pressure waves, cause changes in the pressure and this change in pressure drives changes in airflow. By measuring the magnitude of change in the pressure and flow, one can determine the mechanical properties of the lung. Waves of lower frequencies travel deep into the lungs till and into the alveoli and are reflected back while those of higher frequencies are reflected from the larger airways. Thus, the parameters calculated at different frequencies give measures of different regions in the lungs.
Aeonose – Measured data consists of an individual breath-print of volatile organic compounds. Patients breathe into the portable Aeonose for five minutes. The system learns from each data entered and is updating consistently. The device is CE-certified and therefore there is no risk in using it for our patients.
Sleepiz One – A contactless, non-invasive device that measures vital parameters while patient is at rest. It is a radar-based sensor that does not pose any risks. The electromagnetic emission is around 100 times lower than that of a typical mobile phone.
Along with the study-specific interventions, routine interventions such as body plethysmography are also performed.

Intervention type



Drug names

Primary outcome measure

Measured at a single time point:
1. LCI measured using the multiple-breath nitrogen washout (N2-MBW)
2. Phase III slope (SIII) measured using the single-breath nitrogen washout (N2-SBW) and single-breath double tracer gas washout (DTG-SBW)

Secondary outcome measures

Measured at a single time point:
1. Scond, Sacin, area under the curve of DTG-SBW measured using the multiple-breath nitrogen washout (N2-MBW)
2. Bronchoprovocation test outcomes such as PD20 and PD40
3. Volatile organic compounds in the breath measured using Aeonose
4. Sleepiz One measurements (breathing, heart rate, movement during sleep)
5. Known clinical, laboratory, histological and radiological characteristics measured using patient records

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Older than 18
2. Capable to perform an acceptable spirometry
3. Able to answer questionnaires
4. With or without respiratory symptoms
5. With or without diagnosed respiratory disease

Participant type


Age group




Target number of participants


Participant exclusion criteria

Does not meet inclusion criteria

Recruitment start date


Recruitment end date



Countries of recruitment


Trial participating centre

University Hospital Basel
Clinic for Respiratory Medicine and Pulmonary Cell Research Petersgraben 4

Sponsor information


University Hospital of Basel

Sponsor details

Clinic for Respiratory Medicine and Pulmonary Cell Research
Petersgraben 4
+41 612654422

Sponsor type

Hospital/treatment centre



Funder type

Hospital/treatment centre

Funder name

University Hospital Basel

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Planned publication in a high-impact peer-reviewed journal.

IPD sharing statement:
The datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request.

Intention to publish date


Participant level data

Available on request

Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes

03/07/2020: Uploaded protocol Version 5, 27 November 2019 (not peer reviewed). 17/04/2020: Trial’s existence confirmed by Ethics Committee Northern and Central Switzerland