Time Course of Neuro-ventilatory Efficiency During a Spontaneous Breathing Training (TONES)

Antwerp University Hospital (UZA)

Status: Completed

Conditions: Respiratory Muscles; Critical Care; Ventilator Weaning; Respiratory Failure; Respiration, Artificial

Treatments: Other: PEEP 10; Diagnostic Test: Ultrasound of respiratory muscles; Other: PEEP 5; Other: PEEP 0; Diagnostic Test: Expiratory hold; Diagnostic Test: Inspiratory hold

Study type: Interventional

Funder types: Other

Identifiers

NCT05380687

002418

Details and patient eligibility

About

The TONES trial aims to evaluate the neuroventilatory efficiency (NVE = tidal volume / peak voltage of diaphragm contraction) measured during a zero-assist manoeuvre (ZAM, i.e. with PEEP but without pressure support). This novel parameter, NVE-ZAM, will be studied in a blocked, crossover, repeated measures design.

Possible confounders, such as activity of respiratory muscles other than the diaphragm, are included.

The investigators hypothesized that

• the NVE during a zero-assist maneuver has a low variability and high repeatability at the same level of PEEP (within subjects, within blocks)
• NVE-ZAM trends differ between participants (between subjects, within blocks) and between PEEP levels (within subjects, between blocks)

The primary aim is to study the variability and repeatability of the NVE-ZAM within subjects and within blocks.

Additionally, the effect of PEEP, muscle fatigue and recruitment of the accessory and expiratory muscles of respiration on the NVE-ZAM will be studied in an exploratory analysis (in multiple combinations of within and between subjects and/or blocks).

Enrollment: 1 patient

Sex: All

Ages: 18 to 80 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• adult (18-80 yrs.)
• admitted to the ICU
• intubated and mechanically ventilated
• Edi catheter (Maquet, Solna, Sweden) in situ as part of their clinical care
• ventilated in a support mode (e.g. pressure support) with a support between 7 and 15 cmH2O, a PEEP ≤10 cmH2O and an Fi02 <0.6, all since ≥6 hours.
• can participate in the trial as judged by their attending physician

Exclusion criteria

• pregnancy
• refusal of participation
• pre-existing neuromuscular disorders (e.g., Guillain-Barré)

Trial design

Primary purpose: Diagnostic

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: None (Open label)

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1 participants in 2 patient groups

Training A - PEEP 10-5-5-5

Experimental group

Description:

The respiratory muscles of all participants will be trained in 4 consecutive blocks of 30 minutes during ventilation in neural pressure support mode (NPS) with a pressure support of 7 cmH2O. During training A, the 4 blocks are A1. PEEP 10 cmH2O \| A2. PEEP 5 cmH2O \| A3. PEEP \*5\* cmH2O \| A4. PEEP 5 cmH2O During the training, ventilator data will be recorded and respiratory muscles will be imaged using ultrasound. Before and after each training block, an inspiratory and an expiratory hold (both ≤ 30 seconds) will be performed to assess fatigue.

Treatment:

Diagnostic Test: Expiratory hold

Diagnostic Test: Inspiratory hold

Other: PEEP 5

Diagnostic Test: Ultrasound of respiratory muscles

Other: PEEP 10

Training B - PEEP 10-5-0-5

Experimental group

Description:

The respiratory muscles of all participants will be trained in 4 consecutive blocks of 30 minutes during ventilation in neural pressure support mode (NPS) with a pressure support of 7 cmH2O. During training B, the 4 blocks are B1. PEEP 10 cmH2O \| B2. PEEP 5 cmH2O \| B3. PEEP \*0\* cmH2O \| B4. PEEP 5 cmH2O During the training, ventilator data will be recorded and respiratory muscles will be imaged using ultrasound. Before and after each training block, an inspiratory and an expiratory hold (both ≤ 30 seconds) will be performed to assess fatigue.

Treatment:

Other: PEEP 0

Diagnostic Test: Expiratory hold

Diagnostic Test: Inspiratory hold

Other: PEEP 5

Diagnostic Test: Ultrasound of respiratory muscles

Other: PEEP 10