Air Entrainment vs. Standard Treatment in Non-Expandable Lung With Persistent Pleural Effusion: A Randomised Controlled Double-Blind Trial
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 发起方
- 入组人数
- 41
- 试验地点
- 2
- 主要终点
- Pain Relief
研究概览
简要总结
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
详细描述
Background and Rationale Air entrainment during pleural effusion drainage may improve pain control, increase fluid removal, and reduce repeat procedures in patients with non-expandable lung (NEL). A local evaluation showed greater pain relief than opioids without adverse events. This study compares air entrainment with standard drainage in NEL.
Objectives
Primary: Determine if air entrainment offers superior pain relief vs standard drainage.
Secondary: Compare fluid volume drained, time to repeat drainage, complication rates (infection, hypotension, air leaks, persistent pain), and patient satisfaction. The questionnaire assessed patient experience across four areas: pre-procedure, during the procedure, post-procedure, and overall care. Each item used 5-point Likert scales. Pre-procedure: Satisfaction with information, understanding, scheduling, and communication. During: Comfort, pain management, staff professionalism, and privacy. Post-procedure: Clarity of aftercare, symptom control, and follow-up. Overall: General satisfaction and likelihood to recommend.
Study Design Prospective, double-blind, randomised intervention study (2:1 ratio) at Cambridge University Hospital. All patients undergoing thoracentesis will be screened; only those with confirmed NEL will be analysed.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Treatment
- 盲法
- Double (Participant, Outcomes Assessor)
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •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.
排除标准
- •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.
结局指标
主要结局
Pain Relief
时间窗: From the procedure start until 15 minutes after the procedure
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.
次要结局
- 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))