The Feasibility of Pulmonary Perfusion Assessment Using Sodium Bicarbonate Contrast With Electrical Impedance Tomography: A Prospective Pilot Study
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
- 1
- 主要终点
- Proportion of analyzable sodium bicarbonate-enhanced EIT perfusion recordings
研究概览
简要总结
The goal of this observational pilot study is to learn if sodium bicarbonate can be used safely and effectively as a contrast agent to map lung blood flow using electrical impedance tomography (EIT) in adults on mechanical ventilation. Electrical impedance tomography (EIT) is a bedside imaging method that uses a soft belt with small sensors around the chest to track changes in electrical signals related to breathing and blood flow.
The main questions are:
Does sodium bicarbonate create clear, readable lung blood flow images with EIT? Are these images similar in quality and pattern to images made with hypertonic saline (10% sodium chloride)? Is the short-term safety profile acceptable, including effects on blood pressure, heart rhythm, and blood tests?
Researchers will compare two contrast agents within the same participant to see if image quality and lung blood flow patterns match:
Hypertonic saline (10% sodium chloride) Sodium bicarbonate (5%)
Participants will:
Have an EIT belt placed around the chest during routine ICU care Pause the ventilator briefly during image capture to reduce motion Receive two small intravenous boluses through an existing central line, one of hypertonic saline and one of sodium bicarbonate, with time between doses Have routine monitoring of vital signs; blood gases and electrolytes may be checked per clinical care Be observed for any short-term side effects Findings from this study will show whether sodium bicarbonate is a practical and safe option for EIT-based lung blood flow assessment and will guide larger future studies.
详细描述
This single-center, prospective, observational pilot study evaluates sodium bicarbonate as a conductivity contrast agent for electrical impedance tomography (EIT) to assess pulmonary perfusion in mechanically ventilated adults. EIT uses a belt with surface electrodes placed at a standard chest level to measure changes in electrical impedance. A small intravenous bolus of a conductive solution produces a short first-pass signal that can be analyzed to map relative lung blood flow.
Procedure:
Placement: An EIT belt is positioned around the thorax and signal quality is verified.
Acquisition: Perfusion-focused recordings are obtained during brief end-expiratory pauses on the ventilator to limit breathing-related signal changes.
Contrast sequence: Each participant receives two small contrast boluses through a central venous catheter in a prespecified order with adequate washout between injections:
研究设计
- 研究类型
- Observational
- 观察模型
- Cohort
- 时间视角
- Prospective
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
- •Age ≥ 18 years
- •Admitted to the intensive care unit (ICU)
- •Receiving invasive mechanical ventilation with controlled or assisted-controlled mode
- •Presence of a central venous catheter suitable for contrast bolus injection
- •Hemodynamically stable (no ongoing cardiopulmonary resuscitation; no uncontrolled shock judged by treating physician)
- •Expected to remain on mechanical ventilation for the duration of the EIT examination
- •Written informed consent obtained from the patient or legally authorized representative
排除标准
- •Known pregnancy
- •Known allergy, intolerance, or contraindication to sodium bicarbonate or hypertonic saline
- •Severe arrhythmia or unstable cardiovascular status in which small bolus injection is deemed unsafe by the treating physician
- •Uncontrolled agitation or conditions that preclude correct EIT belt placement (e.g., extensive chest wounds, large chest dressings, chest wall deformity that prevents belt use)
- •Implanted electronic devices or metallic implants in the thoracic area considered a contraindication to EIT by the manufacturer's instructions
- •End-stage disease with expected survival of only a few hours, in whom participation is not appropriate as judged by the treating physician
- •Participation in another interventional trial that, in the opinion of the investigator, could interfere with EIT measurements or safety assessment
研究组 & 干预措施
Mechanically Ventilated ICU Cohort
Adult ICU participants on controlled mechanical ventilation with a central venous catheter. Participants undergo bedside electrical impedance tomography (EIT) perfusion imaging during brief end-expiratory pauses. Two small intravenous contrast boluses are given in a prespecified sequence with adequate washout: 10% sodium chloride (hypertonic saline) and 5% sodium bicarbonate. Continuous physiologic monitoring is performed; blood gases/electrolytes may be obtained per clinical care. No randomization. Within-participant comparison of image quality, perfusion patterns, and short-term safety. Observational; EIT monitor used per routine care.
结局指标
主要结局
Proportion of analyzable sodium bicarbonate-enhanced EIT perfusion recordings
时间窗: During the single EIT session on the study day (from contrast injection to completion of image reconstruction; within ~2 hours of enrollment)
Feasibility defined as the proportion of 5% sodium bicarbonate (NaHCO3) EIT perfusion acquisitions that meet predefined analyzable image quality criteria (clear first-pass bolus curve, no noncorrectable artifacts, successful reconstruction over expected thoracic region). Reported as n analyzable / n attempted, with 95% CI.
次要结局
- Overall first-pass impedance reduction amplitude (AU): NaCl vs NaHCO3(During the single EIT session (immediately after each bolus).)
- Global V/Q match and mismatch (%): NaCl vs NaHCO3(During the single EIT session.)
- Global intrapulmonary shunt (%) and dead space (%): NaCl vs NaHCO3(During the single EIT session.)
- Agreement between agents for global V/Q indices (ICC and Bland-Altman)(Derived from paired acquisitions within the same session on the study day.)
- Correlation between agents for global and regional parameters (Pearson R)(Same-session paired measurements on the study day.)
- Correlation of EIT-derived global indices with PaO2/FiO2(Paired with each EIT acquisition on the study day.)
研究者
Qiancheng Xu
Principal Investigator
First Affiliated Hospital of Wannan Medical College