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Respiratory Distress SyndromeRMCIPNCT05508724

Recruitment Manoeuvres in Critically Ill Patients

An observational study of Respiratory Distress Syndrome and Respiratory Insufficiency, run by University of Oxford at 1 site in United Kingdom.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

Diseases of the lungs can be life-threatening. When these organs fail to adequately work, treatments to support their function are offered, often in Intensive Care Units (ICU). Respiratory failure patients may need sedation and placement of a tube in their windpipe so that a mechanical ventilator can take over their… Read more about this study

Who is it for?
Ages 18 to 80 years
How many people
48 participants
Where
1 siteUnited Kingdom
Study dates
1 Oct 2022to 1 Aug 2025
Phase
Observational
Are there results?
None posted in the registry

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 80 years
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Study population: Participants will be recruited from Intensive Care Units at the Royal Berkshire Hospital in Reading, England. The study population is constituted of patients receiving mechanical ventilation on ICU due to respiratory failure.

Who may be able to join

  • Male and female, aged 18 years or above
  • Receiving mechanical ventilation for respiratory failure via an endotracheal tube on ICU

Who cannot join

  • Consultee indicates patient would be likely to decline enrolment
  • Patient is receiving palliative care
  • Language barriers prevent sufficiently good communication with patient or consultee for full consent to be obtained

Trial locations and contacts

1 site in 1 country.

United Kingdom1 site
  • Royal Berkshire Hospital, Royal Berkshire Foundation Trust

    Reading, RG1 5AN

Other trials in United Kingdom

About this study

Official title: An Observational Study of the Relationship Between Pressure-volume Curves and Recruitability of the Lung in Mechanically Ventilated Critically Ill Patients With Respiratory Failure

Diseases of the lungs can be life-threatening. When these organs fail to adequately work, treatments to support their function are offered, often in Intensive Care Units (ICU). Respiratory failure patients may need sedation and placement of a tube in their windpipe so that a mechanical ventilator can take over their breathing until they have recovered enough to breathe again on their own. One problem that occurs in patients under mechanical ventilation is that parts of the lung tissue tend to collapse (atelectasis), reducing the amount of the lung that is able to transfer oxygen and carbon dioxide effectively and even progressing to pneumonia.

To address this problem, ICU doctors often perform a procedure named 'recruitment manoeuvre', which involves briefly inflating the patient's lungs with enough pressure to try to open up the collapsed areas of lung. However, fundamental aspects of the change in the functioning of the heart and lungs that occur during and after such manoeuvre are not fully understood.

Read more

In this study, funded by the University of Oxford, the investigators wish to study patients with respiratory failure who are receiving mechanical ventilation. Participants will be recruited at the ICU of the Royal Berkshire Hospital having their cardiopulmonary data collected over the course of a day. During this period, some patients will be assessed to determine whether they may benefit from a recruitment manoeuvre using a pressure-volume curve. As this assessment is not perfect, the investigators wish to study which features of this curve predict a successful recruitment. The investigators will do this by evaluating the volume of the lung before and after the recruitment manoeuvre is performed using a device named Optical Gas Analyser.

A better understanding of the effects of the recruitment manoeuvre will help the investigators to determine how and when such manoeuvres should be performed in critically ill patients.

Read the detailed description

Critical care units provide supportive therapies to help patients survive a period of life-threatening illness. Among such treatments, mechanical ventilation constitutes an essential asset to assist in patient recovery from respiratory failure and to provide airway protection in neurologically compromised patients. The need for mechanical ventilation is more often driven by respiratory failure than a need for neuroprotection. In excess of 100,000 adult patients are mechanically ventilated in UK ICUs annually, and this number has risen considerably recently due to the emergence of the COVID-19 pandemic.

Respiratory failure may be triggered by pulmonary (e.g., pneumonia, acute respiratory distress syndrome, interstitial fibrosis) or extra-pulmonary (e.g., sepsis, shock) disturbances. The abnormal function of the cardiorespiratory system in these critical conditions results in carrying degrees of hypoxaemia and hypercapnia, leading to the need for respiratory support by mechanical ventilation.

In patients undergoing mechanical ventilation for respiratory failure, the lung is characterized by a much-enhanced tendency to collapse. This collapse worsens hypoxaemia, and increases the stress and strain applied to those regions of the lung that remain aerated, leading to ventilator-induced lung injury (VILI). Re-aeration of non-aerated lung (recruitment) improves oxygenation and prevents VILI. For this reason, some clinicians employ recruitment manoeuvres following intubation, or subsequently during their ICU stay. However, it remains unclear which patients benefit from this intervention, at what time point(s) it is most beneficial, and the underlying mechanisms.

It is recognised that the volume of lung that is potentially recruitable (recruitability) varies widely from patient to patient, being influenced by: (i) the underlying disease precipitating respiratory failure (pulmonary versus extrapulmonary injury); (ii) the distribution of lung injury (lobar versus non lobar); and (iii) the time from initiation of lung injury.

An ability to assess recruitability is a pre-requisite for a rational recruitment strategy and selecting parameters for mechanical ventilation. The gold standard to assess recruitability involves performing a CT scan at two different levels of inspiratory pressure and assessing the mass of lung tissue (grams) that transitions from a non-aerated to an aerated state. This is not feasible in everyday clinical practice since it is time consuming, requires transfer of a critically ill patient to the radiology suite, and involves a significant exposure to ionising radiation. An alternative is to use some measure of the change in lung volume between the different pressure levels, but this is not the same as a change in non-aerated lung mass and indeed the two measures may not even be correlated.

It has been suggested that certain parameters derived from a low-flow inflation and deflation pressure-volume (PV) curve might be useful in the prediction of lung recruitability. When a sustained inflation recruitment manoeuvre is performed, the increase in volume evident on the curve should theoretically give a measure of the volume recruited during the manoeuvre. Based on a similar PV curve principle, recruitment-to-inflation ratio (RI) was developed as a single-breath assessment of lung recruitability. However, these strategies for the bedside assessment of recruitability have received limited validation and currently provide only a qualitative analysis, whereby the patient's lungs will be considered to have either a high or a low potential of recruitment.

Finally, electric impedance tomography has been advocated by some as an alternative tool to assess recruitment but has not been widely adopted into clinical use.

The decision as to whether or not to perform a recruitment manoeuvre in a given patient currently relies on individual consultant preference and clinical judgement, leading to variation within medical practice. Due to an inadequate understanding of the full physiological effects associated with this intervention, it can be difficult to decide whether lung recruitment is likely to prove useful for a given patient. For example, a recruitment manoeuvre that increases lung volume is more likely to be beneficial if it results in an even inflation of a larger alveolar volume than if it arises purely as an increase in dead space.

To date, there is no consensus regarding recruitment manoeuvres and the existing guidance is limited.

The broad objective of this prospective, observational study is to gain a better understanding of how to predict the effects of recruitment manoeuvres in patients who are being mechanically ventilated for respiratory failure. The opportunity to examine this area more closely than has previously been possible, arises from the development of technology to make highly precise measurements of respiratory exchange non-invasively in these patients: the Optical Gas Analyser (OGA). By employing small, transient variations in gas tensions well within those observed during the normal care of such patients, this approach can provide much more detailed physiological information relating to the lung. By way of example, an increase in end-expiratory lung volume following an inflation manoeuvre can be partitioned between the change relating to the dead space volume and the change relating to the alveolar volume. Furthermore, the measurements also quantify how evenly the lung inflates and deflates during a breathing cycle, and thus changes in ventilation heterogeneity before and after an inflation manoeuvre may also be assessed.

A better understanding of the cardiorespiratory changes that occur in mechanically ventilated patients after a recruitment manoeuvre is performed will aid future studies seeking to determine which patients can benefit from them, when, and why. This will ultimately lead to better medical care and improved ICU survival rates.

Medical subject headings
Respiratory Distress Syndrome, Respiratory Insufficiency

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

Study groups in NCT05508724
Study groupRoleWhat they receive
Critically-ill mechanically ventilated patientsIntensive Care patients receiving mechanical ventilation due to respiratory failure

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Functional residual capacity

    To determine whether parameters derived from the airway pressure-volume curve predict changes in static measures of lung volume in response to recruitment manoeuvres

    Measured: Changes from FRC baseline value measured immediately after PV curve determination and lung recruitment manoeuvre

Secondary outcomes (2)
  1. Anatomic dead space

    To determine if and how anatomic dead space changes in response to recruitment. manoeuvres

    Measured: Changes from anatomic dead space baseline value measured immediately after PV curve determination and lung recruitment manoeuvre

  2. Ventilation inhomogeneity

    To determine if and how ventilatory inhomogeneity changes in response to recruitment manoeuvres. Standard deviation of compliance, dead space, and pulmonary vascular conductance will be used as surrogates of ventilation inhomogeneity.

    Measured: Changes from ventilation inhomogeneity baseline value measured immediately after PV curve determination and lung recruitment manoeuvre

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted19 Aug 2022
  2. Study start1 Oct 2022
  3. Primary completion1 Aug 2025
  4. Study completion1 Aug 2025

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Observational model
Case only
Time perspective
Cross-sectional
Enrolment
48 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05508724
Sponsor's protocol ID
PID16097
Other IDs
IRAS 306692
Acronym
RMCIP
Status last verified
Feb 2026
First submitted
22 Jul 2022
Last updated
17 Feb 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Publications

  • Esteban A, Anzueto A, Frutos F, Alia I, Brochard L, Stewart TE, Benito S, Epstein SK, Apezteguia C, Nightingale P, Arroliga AC, Tobin MJ; Mechanical Ventilation International Study Group. Characteristics and outcomes in adult patients receiving mechanical ventilation: a 28-day international study. JAMA. 2002 Jan 16;287(3):345-55. doi: 10.1001/jama.287.3.345.

    PubMed 11790214
  • Esteban A, Frutos-Vivar F, Muriel A, Ferguson ND, Penuelas O, Abraira V, Raymondos K, Rios F, Nin N, Apezteguia C, Violi DA, Thille AW, Brochard L, Gonzalez M, Villagomez AJ, Hurtado J, Davies AR, Du B, Maggiore SM, Pelosi P, Soto L, Tomicic V, D'Empaire G, Matamis D, Abroug F, Moreno RP, Soares MA, Arabi Y, Sandi F, Jibaja M, Amin P, Koh Y, Kuiper MA, Bulow HH, Zeggwagh AA, Anzueto A. Evolution of mortality over time in patients receiving mechanical ventilation. Am J Respir Crit Care Med. 2013 Jul 15;188(2):220-30. doi: 10.1164/rccm.201212-2169OC.

    PubMed 23631814
  • Chiumello D, Carlesso E, Cadringher P, Caironi P, Valenza F, Polli F, Tallarini F, Cozzi P, Cressoni M, Colombo A, Marini JJ, Gattinoni L. Lung stress and strain during mechanical ventilation for acute respiratory distress syndrome. Am J Respir Crit Care Med. 2008 Aug 15;178(4):346-55. doi: 10.1164/rccm.200710-1589OC. Epub 2008 May 1.

    PubMed 18451319
  • Huh JW, Jung H, Choi HS, Hong SB, Lim CM, Koh Y. Efficacy of positive end-expiratory pressure titration after the alveolar recruitment manoeuvre in patients with acute respiratory distress syndrome. Crit Care. 2009;13(1):R22. doi: 10.1186/cc7725. Epub 2009 Feb 24.

    PubMed 19239703
  • Caironi P, Cressoni M, Chiumello D, Ranieri M, Quintel M, Russo SG, Cornejo R, Bugedo G, Carlesso E, Russo R, Caspani L, Gattinoni L. Lung opening and closing during ventilation of acute respiratory distress syndrome. Am J Respir Crit Care Med. 2010 Mar 15;181(6):578-86. doi: 10.1164/rccm.200905-0787OC. Epub 2009 Nov 12.

    PubMed 19910610
  • de Matos GF, Stanzani F, Passos RH, Fontana MF, Albaladejo R, Caserta RE, Santos DC, Borges JB, Amato MB, Barbas CS. How large is the lung recruitability in early acute respiratory distress syndrome: a prospective case series of patients monitored by computed tomography. Crit Care. 2012 Jan 8;16(1):R4. doi: 10.1186/cc10602.

    PubMed 22226331
  • Gattinoni L, Caironi P, Cressoni M, Chiumello D, Ranieri VM, Quintel M, Russo S, Patroniti N, Cornejo R, Bugedo G. Lung recruitment in patients with the acute respiratory distress syndrome. N Engl J Med. 2006 Apr 27;354(17):1775-86. doi: 10.1056/NEJMoa052052.

    PubMed 16641394
  • Gattinoni L, Pelosi P, Suter PM, Pedoto A, Vercesi P, Lissoni A. Acute respiratory distress syndrome caused by pulmonary and extrapulmonary disease. Different syndromes? Am J Respir Crit Care Med. 1998 Jul;158(1):3-11. doi: 10.1164/ajrccm.158.1.9708031.

    PubMed 9655699
  • Vincent JL, Sakr Y, Groeneveld J, Zandstra DF, Hoste E, Malledant Y, Lei K, Sprung CL. ARDS of early or late onset: does it make a difference? Chest. 2010 Jan;137(1):81-7. doi: 10.1378/chest.09-0714. Epub 2009 Oct 9.

    PubMed 19820081
  • Chiumello D, Marino A, Brioni M, Cigada I, Menga F, Colombo A, Crimella F, Algieri I, Cressoni M, Carlesso E, Gattinoni L. Lung Recruitment Assessed by Respiratory Mechanics and Computed Tomography in Patients with Acute Respiratory Distress Syndrome. What Is the Relationship? Am J Respir Crit Care Med. 2016 Jun 1;193(11):1254-63. doi: 10.1164/rccm.201507-1413OC.

    PubMed 26699672
  • Victorino JA, Borges JB, Okamoto VN, Matos GF, Tucci MR, Caramez MP, Tanaka H, Sipmann FS, Santos DC, Barbas CS, Carvalho CR, Amato MB. Imbalances in regional lung ventilation: a validation study on electrical impedance tomography. Am J Respir Crit Care Med. 2004 Apr 1;169(7):791-800. doi: 10.1164/rccm.200301-133OC. Epub 2003 Dec 23.

    PubMed 14693669
  • Luepschen H, Meier T, Grossherr M, Leibecke T, Karsten J, Leonhardt S. Protective ventilation using electrical impedance tomography. Physiol Meas. 2007 Jul;28(7):S247-60. doi: 10.1088/0967-3334/28/7/S18. Epub 2007 Jun 26.

    PubMed 17664639
  • Wrigge H, Zinserling J, Muders T, Varelmann D, Gunther U, von der Groeben C, Magnusson A, Hedenstierna G, Putensen C. Electrical impedance tomography compared with thoracic computed tomography during a slow inflation maneuver in experimental models of lung injury. Crit Care Med. 2008 Mar;36(3):903-9. doi: 10.1097/CCM.0B013E3181652EDD.

    PubMed 18431279
  • Lundin S, Stenqvist O. Electrical impedance tomography: potentials and pitfalls. Curr Opin Crit Care. 2012 Feb;18(1):35-41. doi: 10.1097/MCC.0b013e32834eb462.

    PubMed 22201705
  • Maggiore SM, Jonson B, Richard JC, Jaber S, Lemaire F, Brochard L. Alveolar derecruitment at decremental positive end-expiratory pressure levels in acute lung injury: comparison with the lower inflection point, oxygenation, and compliance. Am J Respir Crit Care Med. 2001 Sep 1;164(5):795-801. doi: 10.1164/ajrccm.164.5.2006071.

    PubMed 11549535

Questions about this trial

What is this clinical trial studying?

An observational study of Respiratory Distress Syndrome and Respiratory Insufficiency, run by University of Oxford at 1 site in United Kingdom.

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 2 inclusion and 3 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: finished, as of the sponsor's last update on 17 Feb 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 Kingdom. 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. 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?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

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?

Functional residual capacity (time frame: Changes from FRC baseline value measured immediately after PV curve determination and lung recruitment manoeuvre). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05508724, which also lists 19 linked publications.

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 17 Feb 2026.

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