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).
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
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