Targeting prEssure-Muscle-index to Avoid Ventilatory Over-Assistance During Pressure
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 发起方
- 入组人数
- 36
- 试验地点
- 1
- 主要终点
- Pressure Support-Tidal Volume (PS-Vt) Relationship
研究概览
简要总结
The TEMA study (Targeting prEssure-Muscle-index to avoid ventilatory over-Assistance during pressure support ventilation) is a prospective, interventional crossover trial investigating the relationship between pressure support (PS) and tidal volume (Vt) in ICU patients with acute hypoxemic respiratory failure (AHRF) receiving pressure support ventilation (PSV). The study aims to assess whether the Pressure-Muscle Index (PMI)-a marker derived from the difference between plateau and peak inspiratory pressure-can help identify the optimal level of ventilatory assistance, preventing over-assistance and its associated complications such as diaphragm atrophy and patient self-inflicted lung injury (P-SILI). By exploring the sigmoidal relationship between PS and Vt, the study seeks to define a physiological threshold (PMI=0) that may serve as a personalized target for PSV titration.
详细描述
The TEMA study is a prospective, interventional crossover trial designed to explore the physiological relationship between levels of pressure support (PS) and tidal volume (Vt) in mechanically ventilated ICU patients diagnosed with acute hypoxemic respiratory failure (AHRF). The goal is to identify a pressure support threshold beyond which over-assistance occurs, leading to excessive tidal volumes and suppression of respiratory muscle activity.
The central hypothesis is that the PS-Vt curve follows a sigmoidal pattern: an initial plateau phase with stable Vt is followed by a steep, compliance-driven increase in Vt at higher PS levels. The Pressure-Muscle Index (PMI), calculated as the difference between plateau pressure (Pplat) and peak airway pressure (Ppeak) during an inspiratory occlusion, is used to define this inflection point (PMI=0), which marks the transition from physiologically appropriate to excessive assistance.
Study Design: The study is conducted at the ICU of Santa Chiara Hospital (Trento, Italy) and includes seven levels of pressure support modulation-three above and three below the identified PMI=0 point. At each level, key physiological variables such as Vt, respiratory rate (RR), minute ventilation, PMI, and patient-ventilator asynchrony index are recorded.
A second evaluation between days 4-6 post-enrollment is planned for patients who remain intubated, to assess whether the PS-Vt relationship evolves over time, reflecting changes in respiratory drive and mechanics during the ICU course.
Technical Aspects:
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Treatment
- 盲法
- None
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
- •Mechanically ventilated in the ICU
- •Diagnosis of Acute Hypoxemic Respiratory Failure (AHRF)
- •Normocapnia or non-severe hypercapnia
- •Receiving Pressure Support Ventilation (PSV) for at least 24-72 hours
- •Presence of an arterial line for blood gas sampling
排除标准
- •Age < 18 years
- •Known neurological or neuromuscular disorders affecting diaphragm function
- •Chronic Obstructive Pulmonary Disease (COPD) or hypercapnic respiratory failure
- •Psychomotor agitation or inadequate sedation
研究组 & 干预措施
Pressure Support +2
Above PSPMI=0: +2 cmH₂O above PSPMI=0 (over-assistance zone).
干预措施: Variation of Pressure Support Levels (Procedure)
Pressure Support +6
Above PSPMI=0: +6 cmH₂O above PSPMI=0 (over-assistance zone).
干预措施: Variation of Pressure Support Levels (Procedure)
Pressure Support -2
Below PSPMI=0: -2 cmH₂O below PSPMI=0 (under-assistance zone).
干预措施: Variation of Pressure Support Levels (Procedure)
Pressure Support -4
- Below PSPMI=0: -4 cmH₂O below PSPMI=0 (under-assistance zone).
干预措施: Variation of Pressure Support Levels (Procedure)
Pressure Support -6
- Below PSPMI=0: -6 cmH₂O below PSPMI=0 (under-assistance zone).
干预措施: Variation of Pressure Support Levels (Procedure)
Pressure Support PMI=0
The PS level at which PMI is zeroed, meaning the patient's inspiratory effort contributes minimally to tidal volume
干预措施: Variation of Pressure Support Levels (Procedure)
Pressure Support +4
Above PSPMI=0: +4 cmH₂O above PSPMI=0 (over-assistance zone).
干预措施: Variation of Pressure Support Levels (Procedure)
结局指标
主要结局
Pressure Support-Tidal Volume (PS-Vt) Relationship
时间窗: Up to 5 minutes after each PS level adjustment during the interventional phase (Day 1)
The primary aim is to determine whether the PS-Vt curve exhibits a flat region (where tidal volume remains stable) before transitioning into a steep, compliance-dependent increase at higher PS levels. This transition point, identified as PSPMI=0, is hypothesized to represent the threshold for over-assistance.
次要结局
- Validation of Pressure-Muscle Index (PMI) as an Over-Assistance Marker(Up to 5 minutes after each PS level adjustment during the interventional phase (Day 1) and during follow-up assessment on Days 4-6 (if patient remains intubated))
- Rate of Ineffective Efforts During Over-Assistance(Up to 5 minutes after each PS level adjustment during the interventional phase (Day 1) and during follow-up assessment on Days 4-6 (if patient remains intubated))
- Effect of Over-Assistance on Ventilatory Asynchronies(Up to 5 minutes after each PS level adjustment during the interventional phase (Day 1) and during follow-up assessment on Days 4-6 (if patient remains intubated))
- Weaning failure(Up to 100 months or until the of death from any cause, whichever came first.)
- Duration of mechanical ventilation(From date of randomization until the date of extubation or date of death from any cause, whichever came first, assessed up to 100 months)
- ICU length of stay (LOS)(Up to 100 months or until the of death from any cause, whichever came first.)
- Hospital length of stay (LOS)(Up to 100 months or until the of death from any cause, whichever came first.)
- Spontaneous breathing failure(From date of randomization until the date of first documented progression or date of death from any cause, whichever came first, assessed up to 100 months)
- Impact of Respiratory Mechanics on PS-Vt Relationship(From the randomization to 5 minutes.)
- Impact of Respiratory Mechanics on PS-Vt Relationship(During the interventional phase on Day 1 and during follow-up assessment on Days 4-6 (if patient remains intubated))
研究者
Centre for Medical Sciences
Professor Giacomo Bellani
Università degli Studi di Trento