ARMSTRONG - Air entRainMent vS sTandard tReatment in nOn-expandable luNG

NCT06959719 | Recruiting

• 1 other identifier: A097090
• Study Type: interventional
• Target: 41
• Locations: 1 country
• Sites: 1

Brief Summary

This is a randomised controlled trial evaluating whether controlled air introduction into pleural space (air entrainment) during pleural effusion drainage reduces pain, improves patient satisfaction, and facilitates more effective drainage in patients with non-expandable lung (NEL). NEL lung is a common complication in patients with malignant or chronic pleural effusions, where the lung fails to fully re-expand after fluid removal due to pleural disease or fibrosis. In these patients, drainage often creates excessive negative pressure within the pleural cavity, leading to pain, vasovagal episodes, early termination of drainage, and the need for repeated procedures. This study investigates a simple, safe, and low-cost intervention using a standard 3-way tap attached to the drainage system. By intermittently opening the tap to atmospheric air during drainage, air enters the pleural cavity in a controlled fashion, reducing negative pressure and potentially reducing pain, improving drainage tolerance, and minimising the need for repeated procedures. Pleural effusion drainage is a common procedure in patients with advanced malignancy or chronic pleural disease. In patients with NEL, fluid removal creates a vacuum effect within the pleural space due to the inability of the lung to fully re-expand. This negative pressure is a key driver of severe procedural pain, vasovagal symptoms, and premature cessation of drainage. It may also necessitate multiple drainage procedures over a short period. Currently, there are limited strategies to mitigate this problem, often relying on stopping the procedure prematurely or on analgesia, which does not address the underlying cause. This trial evaluates the introduction of atmospheric air into the pleural space during drainage as a pragmatic, low-cost solution. The technique uses standard equipment - a 3-way tap - allowing air to be introduced safely and intermittently during drainage to reduce the vacuum effect. Patients undergoing therapeutic pleural drainage with an indwelling catheter or chest drain will be randomised in a 2:1 ratio to: Standard drainage care (control group) Drainage with intermittent controlled air introduction (intervention group) Air entrainment will be performed by briefly opening the 3-way tap to atmospheric air during drainage up to five times, based on patient discomfort and operator discretion. This aims to equalise pleural pressures, reduce pain, and improve drainage outcomes. Randomisation is weighted 2:1 towards the intervention group to maximise the number of patients who may benefit, following favourable preliminary data. Both patients and outcome assessors will be blinded to group allocation. Outcomes collected Primary Outcomes: Patient-reported pain scores during drainage - Pain will be assessed using the Visual Analogue Scale (VAS), ranging from 0 to 10 cm, where 0 indicates "no pain" and 10 indicates "worst imaginable pain." Higher scores represent a worse outcome. Secondary Outcomes: Volume of pleural fluid drained Number of pleural drainage procedures required Time interval between drainage procedures Incidence of complications (e.g., pneumothorax, re-expansion pulmonary oedema, infection) Reasons for incomplete drainage, including the presence and characteristics of non-expandable lung Patient-reported satisfaction with the drainage procedure

Conditions

Non-expandable Lung; Trapped Lung; Pleural Effusion; Malignant Pleural Effusions (Mpe)

Keywords

air entrainment; trapped lung; non-expandable lung (NEL); pleural effusion; malignant pleural effusion

Outcome Measures

Primary Outcomes (1)

• Pain Relief

  Pain will be measured using the Visual Analog Scale (VAS) before, during, and immediately after the drainage procedure and again 10-15 minutes later to capture the progression of relief.

  From the procedure start until 15 minutes after the procedure

Secondary Outcomes (5)

• Drainage Volumes

  Up to 6 months post-randomization

• Number of pleural drainage procedures required.

  Up to 6 months post-randomization

• Time interval between drainage procedures.

  Up to 6 months post-randomization

• Complications

  Up to 6 months post-randomization

• Patient Satisfaction

  At each in-person visit, through study completion (6 months)

Study Arms (2)

Standard practice

NO INTERVENTION

Fluid drainage will be performed according to standard practice, with cessation of fluid removal at the first sign of patient discomfort to prevent pain.

Air Entrainment

EXPERIMENTAL

During pleural effusion drainage, atmospheric air will be intentionally introduced into the pleural space by opening the 3-way tap to air. This aims to reduce excessive negative pressure, which can create a vacuum effect within the pleural space and is thought to contribute to patient pain during drainage. The tap allows controlled air entry without fluid leakage, helping to minimise pain while maintaining safe drainage.

Procedure: Air Entrainment - intentional introduction of the atmospheric air into the pleural space.

Interventions

Air Entrainment - intentional introduction of the atmospheric air into the pleural space. PROCEDURE

This intervention is distinct in that it uses a standard 3-way tap, already present in routine pleural drainage procedures, to intentionally introduce atmospheric air into the pleural space in a controlled and repeatable manner. Unlike other studies where air entrainment may occur incidentally or as part of more invasive procedures, this method specifically utilises precise manipulation of the tap handle to allow intermittent air entry, aiming to reduce negative intrapleural pressure and associated pain during fluid drainage. Air entry is carefully controlled, can be repeated up to five times per procedure, and does not interfere with fluid drainage or introduce additional equipment or complexity.

Air Entrainment

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Adults aged 18 years or older with a suspected or confirmed diagnosis of NEL and persistent pleural effusion.
• Patients who are scheduled for pleural effusion drainage as part of their standard care.
• Ability to adequately understand verbal or written information in English and provide informed consent in English.

You may not qualify if:

• Patients with a history of pleurodesis or other procedures that may affect pleural dynamics.
• Patients with active infections or other acute medical conditions that could interfere with the study.
• Patient with multifactorial pain and high baseline score pain defined as VAS \>= 5
• Patients requiring IPC
• Individuals with known contraindications to pleural drainage or air entrainment.
• Patients who cannot provide informed consent in English, do not adequately understand verbal or written information in English or have special communication needs.

Sponsors & Collaborators

• Cambridge University Hospitals NHS Foundation Trust: lead

Study Sites (1)

Addenbrooke's Hospital

Cambridge, Cambridgeshire, CB2 0BB, United Kingdom

RECRUITING

MeSH Terms

Conditions

Pleural Effusion; Pleural Effusion, Malignant; Myeloproliferative Disorder, Chronic, with Eosinophilia

Condition Hierarchy (Ancestors)

Pleural Diseases; Respiratory Tract Diseases; Pleural Neoplasms; Respiratory Tract Neoplasms; Thoracic Neoplasms; Neoplasms by Site; Neoplasms

Central Study Contacts

Emilia M SWIETLIK, MD PhD

CONTACT

+447736750560; e.swietlik@nhs.net

Jurgen Herre, PhD

CONTACT

jurgen.herre1@nhs.net

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: This is a two-arm, parallel-group, randomized controlled trial with a 2:1 allocation ratio (intervention:control). The unequal allocation was chosen to maximise the number of participants receiving the potentially beneficial intervention, following favourable initial data from service evaluation. Randomization will be performed centrally, and both participants and outcome assessors will be blinded to group allocation to minimize bias.

Study Record Dates

• First Submitted: April 8, 2025
• First Posted: May 7, 2025
• Study Start: April 14, 2025
• Primary Completion: April 1, 2026
• Study Completion (Estimated): October 30, 2026
• Last Updated: May 7, 2025

Record last verified: 2025-05

Data Sharing

• IPD Sharing: Will share
• Shared Documents: ICF

Locations

GB (1)