Imaging the Respiratory Effects of Truncal Adiposity in Acute Hypoxemic Respiratory Failure
试验速览
- 阶段
- 不适用
- 状态
- 尚未招募
- 发起方
- 入组人数
- 80
- 试验地点
- 1
- 主要终点
- Driving pressure with PEEP titration and prone position
研究概览
简要总结
Acute Hypoxemic Respiratory Failure (AHRF) is a condition in which injury to the lungs impairs the ability of the air sacs (alveoli) to ventilate and exchange oxygen. This impairment may be worsened in individuals with elevated body weight, particularly when fat tissue compresses the lungs and promotes alveolar collapse. The impact of body weight on lung function may be greater in individuals with upper-body fat distribution.
Two common interventions for AHRF-positive end-expiratory pressure (PEEP) and prone positioning-are used to improve lung ventilation. However, it is unclear whether these therapies are equally effective across different body weight categories and fat distributions.
This study will evaluate whether body weight and fat distribution affect patients' lung inflation responses to PEEP and prone positioning. Lung inflation will be assessed using electrical impedance tomography (EIT), a bedside imaging tool that maps lung ventilation, and esophageal manometry, which estimates lung compression through a thin catheter placed in the esophagus. Laboratory tests will also be used to measure markers of inflammation and AHRF severity and find correlations with fat distribution and responses to the tested treatments..
Patients with AHRF requiring mechanical ventilation will be enrolled across a range of body weights. Each participant will undergo combinations of two PEEP levels and two body positions (supine and prone) for 30 minutes each. At the end of the study procedures, clinical care will continue as determined by the treating team.
详细描述
This study investigates the relationship between body habitus and the physiological response to ventilatory interventions in patients with Acute Hypoxemic Respiratory Failure (AHRF). The primary objectives are to determine:
- Whether excess body weight affects the regional lung inflation response to PEEP and prone positioning;
- Whether body fat distribution (e.g., central vs. peripheral) is associated with lung recruitment;
- Whether inflation responses correlate with laboratory markers of systemic inflammation and AHRF severity.
Adult patients with AHRF requiring invasive mechanical ventilation will be screened daily in the intensive care units at Massachusetts General Hospital. The study team will coordinate with clinical staff and patient surrogates to obtain informed consent. Enrollment is limited to the period required to perform study-specific procedures. No follow-up visits or post-discharge interventions are planned.
After consent, participants will be equipped with two adhesive EIT electrode belts, placed bilaterally on the thorax, to measure regional ventilation. A pressure and flow sensor will be placed in the breathing circuit at the proximal end of the endotracheal tube. An esophageal balloon catheter will be inserted nasally into the distal esophagus (approximately 35-40 cm) to measure intrathoracic pressure (ITP) via esophageal manometry, recorded through an auxiliary module on the EIT device.
Once all monitoring devices are in place, patients will be evaluated for adequate sedation and ventilator synchrony. Baseline data will be recorded during ventilation at the clinician-selected PEEP level (PEEP_CLIN), including EIT, airway pressure, flow, and ITP signals over 20 consecutive breaths.
研究设计
- 研究类型
- Interventional
- 分配方式
- Na
- 干预模型
- Single Group
- 主要目的
- Diagnostic
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 80 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •AHRF with PaO2/FiO2 <= 300 mmHg) intubated for less than 72 hours
- •Presence of an arterial line for blood gas measurement and blood pressure monitoring
- •18 years or older
排除标准
- •Suspected pregnancy, pregnancy or less than six weeks postpartum
- •Younger than 18 years or older than 80 years.
- •Subject enrolled in another interventional research study
- •Presence of pneumothorax
- •Usage of any devices with electric current generation such as pacemaker or internal cardiac defibrillator
- •Preexisting chronic lung disease or pulmonary hypertension
- •Acute cardiac failure causing pulmonary edema
- •Past medical history of lung malignancy or pneumonectomy, or lung transplant
- •Hemodynamic instability, defined as:
- •Persistent systolic blood pressure <90 mmHg and/or >180 mmHg despite the use of vasopressor or vasodilators, or
- •Requiring an increment in inotropic-vasopressors over the past two hours just before enrollment: more than 15 mcg/min for norepinephrine and dopamine, more than 10 mcg/min in epinephrine; and more than 50 mcg/ min for phenylephrine.
- •Contraindications to placement in the prone position: complex abdominal surgical dressing, recent sternotomy, unstable spine or pelvic fractures, intracranial hypertension, serious facial injury
- •Extracorporeal life support
研究组 & 干预措施
Single Arm: Ventilatory Assessment at Two PEEP Levels and Body Positions
A total of 80 patients will undergo sequential assessments during mechanical ventilation at two levels of PEEP:
- Clinician-set PEEP (PEEP_CLIN)
- PEEP determined by EIT-guided titration (PEEP_TIT) These interventions will be applied first in the supine position, with each PEEP level maintained for approximately 30 minutes. Afterward, patients will be repositioned to the prone position, and the same assessments and EIT-guided PEEP titration will be repeated.
干预措施: PEEP Titration Using Electrical Impedance Tomography (EIT) (Other)
Single Arm: Ventilatory Assessment at Two PEEP Levels and Body Positions
A total of 80 patients will undergo sequential assessments during mechanical ventilation at two levels of PEEP:
- Clinician-set PEEP (PEEP_CLIN)
- PEEP determined by EIT-guided titration (PEEP_TIT) These interventions will be applied first in the supine position, with each PEEP level maintained for approximately 30 minutes. Afterward, patients will be repositioned to the prone position, and the same assessments and EIT-guided PEEP titration will be repeated.
干预措施: Body Positioning: Supine and Prone (Procedure)
结局指标
主要结局
Driving pressure with PEEP titration and prone position
时间窗: Day 1, after 30 minutes in each combination of PEEP and body position
The primary outcome will be the difference in driving pressure (inspiratory plateau pressure minus total PEEP, in cmH2O) in response to PEEP titration strategies and to prone position. Changes in driving pressure will be correlated with body mass index, and with measurements of thoracic, and abdominal circumference.
次要结局
- Regional ventilation(Day 1, after 30 minutes in each combination of PEEP and body position)
研究者
Maurizio F. Cereda, MD
Associate Professor of Anesthesia
Massachusetts General Hospital