Evaluation of Perfusion and Ventilation Distribution in Children: a Pilot Study.

Hospices Civils de Lyon20 enrolled

Overview

Electrical impedance tomography (EIT) is a recent monitoring technique that provides information on regional ventilation distribution. Following the injection of a hypertonic saline bolus, EIT can also assess regional pulmonary perfusion distribution, allowing evaluation of the ventilation/perfusion (V/Q) ratio. In adults, protocols for assessing perfusion distribution require the injection of 10 mL of a 7.5% or 10% NaCl solution or sodium bicarbonate over a few seconds. Studies have reported good hemodynamic tolerance, adequate image quality, and no significant changes in serum sodium levels. However, this volume and sodium load are not appropriate for small children. To date, no pediatric protocol exists for assessing pulmonary perfusion distribution and the ventilation/perfusion ratio using EIT. It is therefore proposed to conduct a pilot study to evaluate the feasibility of assessing pulmonary perfusion by EIT using a weight-adjusted bolus of hypertonic saline (NaCl or sodium bicarbonate).

Study Type

INTERVENTIONAL

Allocation

NON_RANDOMIZED

Purpose

OTHER

Masking

NONE

Enrollment

Conditions

Acute Respiratory Failure

Interventions

All patients will undergo EIT monitoring (Enlight 2100, Timpel, Brazil) using a belt adjusted to the thoracic circumference. Ventilation distribution will be assessed with a tidal volume of 8 mL/kg. Following a breath hold, a saline solution (sodium chloride or sodium bicarbonate) will be injected over a few seconds. Perfusion distribution, as well as impedance signal variation, will be recorded using dedicated software (Timpel, Brazil). Data acquisition will be considered valid if the impedance signal variation induced by the saline solution injection is at least equivalent to the amplitude variation observed during ventilation with a tidal volume of 8 mL/kg. 2 measurements at 4 to 6-hours intervals with volume or concentration adjustment after the first injection if needed in the group 1

Eligibility

Sex: ALLMax age: 12 Years

Medical Language ↔ Plain English

Inclusion Criteria: * patients \< 12 years hospitalized in pediatric intensive care * intubated, under conventional invasive mechanical ventilation and sedated * between 3 and 40 kg * with central venous access in the superior vena cava * consent signed by parents or legal guardians Exclusion Criteria: * Patients with significant leaks \> 20% around the endotracheal tube * Patients receiving spontaneous ventilation (inspiratory support, NIV, etc.) * Natremia \> 150 mmol/L at inclusion * Hyperchloremia ≥ 115 mmol/L and/or hypokaliema ≤ 3 mmol/L * Patients with intracranial hypertension * Patients with active bleeding or persistent hemodynamic instability despite amines * Patients with heart failure, uncorrected cyanotic heart disease, or a history of cardiac arrhythmia * Patients with contraindications to the use of the electrical impedance pulmonary tomography belt (skin lesions, burns, or recent thoracic surgery) * Conditions in which EIT data acquisition will be disrupted (chest dressings, pneumothorax, ECMO) * Patients with severe hypoxemia defined as FiO2 \> 90% to maintain SpO2 \> 88% * Individuals not affiliated with a social security system or beneficiaries of a similar system

Outcomes

Primary Outcomes

Proportion of patients with pulmonary perfusion acquisition consider as valid

Data acquisition will be considered valid if the impedance signal variation induced by the saline solution injection is at least equivalent to the amplitude variation observed during ventilation with a tidal volume of 8 mL/kg.

Time frame: Hour 0 ; Between Hour 4 and Hour 6

Secondary Outcomes

Proportion of patients requiring an increase in volume and/or concentration of saline solution

Increase in the volume and/or concentration of the saline solution due to insufficient signal detection during the first injection (Group 1).

Time frame: Between Hour 4 and Hour 6

Proportion of respiratory acquisition failures explained by breathing movements

Data acquisition failure related to variations in the airway pressure waveform recorded by the software.

Time frame: Hour 0 ; Between Hour 4 and Hour 6

Distribution of pulmonary perfusion

Description of the distribution of regional pulmonary perfusion in children, expressed as percentages across predefined regions of interest (right versus left and anterior versus posterior).

Time frame: Hour 0 ; Between Hour 4 and Hour 6

Natremia variation after injection

Serum sodium concentration (mmol/L) measured before and after injection, with calculation of absolute (mmol/L) and relative (%) changes.

Time frame: Hour 0 ; Hour 1 ; Between Hour 5 and Hour 7

Natremia variation at day one

Serum sodium concentration (mmol/L) measured at baseline and on day 1, with calculation of absolute (mmol/L) and relative (%) changes from baseline.

Time frame: Hour 0 ; Hour 24

Heart rate variation

Heart rate (beats/min) measured before and after saline solution injection, with calculation of absolute (beats/min) and relative (%) changes

Time frame: Hour 0 ; Hour 1 ; Between Hour 5 and Hour 7

Blood pressure variation

Systolic, diastolic, and mean arterial blood pressure measured before and after saline solution injection, with calculation of absolute (mmHg) and relative (%) changes.

Time frame: Hour 0 ; Hour 1 ; Between Hour 5 and Hour 7

Significant hemodynamic events

Any change in heart rate or systolic blood pressure \> 15% from baseline

Time frame: Through study completion, an average of 24 hours

Evaluation of Perfusion and Ventilation Distribution in Children: a Pilot Study.

Overview

Conditions

Interventions

Eligibility

Locations (1)

Outcomes

Primary Outcomes

Secondary Outcomes

Central Contacts