Acute Respiratory Disease

Occlusion pressure at 100 ms (P0.1) is a reliable and non-invasive index of inspiratory drive that can be measured easily on most ventilator. Unfortunately, P0.1 cannot be measured reliably in non-intubated patients. In those receiving non-invasive ventilation, the measurement of P0.1 might be inaccurate due to leaks. P0.1 cannot be measured at all in patients receiving high-flow nasal canulae (HFNC). Ultrasound indices of diaphragm contractile function, namely diaphragm excursion, velocity and thickening fraction, could be reliable and non-invasive proxies of respiratory drive in non-intubated patient. Our hypothesis is that ultrasound indices of diaphragm function may reliably estimate P0.1. To validate this hypothesis, theses indices will be measured simultaneously with P0.1 in intubated patients, during diaphragm loading conditions similar to spontaneous breathing: the spontaneous breathing trial (SBT). The SBT is used to evaluate if patients can breathe without the assistance provided by the ventilator, and thus, be weaned from mechanical ventilation.

Acute respiratory insufficiency is one of the most common causes of hospitalization and death among young children. It often affects small children who, due to infections with RSV (respiratory syncytial virus), other cold viruses, or bacteria, experience difficulty breathing, rapid breathing, increased heart rate, low oxygen levels in the blood, and reduced appetite. If left untreated, a child can become exhausted, lose consciousness, and ultimately die from the condition. Children with severe acute respiratory insufficiency occupy most of the acute care beds in the pediatric wards of hospitals during the winter months. Some children are treated simply with saline inhalations, nasal saline drops, and suctioning of the nose, but many require respiratory support in the form of Continuous Positive Airway Pressure (CPAP) or high-flow oxygen therapy. In adults, it has been observed that prone positioning can improve blood oxygenation compared to supine positioning in cases of acute respiratory insufficiency. The purpose of this study is to investigate whether there are benefits or drawbacks to positioning small children admitted for difficulty breathing due to respiratory infections in a prone position instead of a supine position. The study will include a total of 40 children with acute airway disease who have been prescribed respiratory support in the form of CPAP or high-flow oxygen. The study will last a total of 2 hours and will not involve any uncomfortable procedures or pose any risks to the child. The Study Itself: Once the child has CPAP or high-flow oxygen administered via the nose, the child will be positioned for 1 hour in the prone position and 1 hour in the supine position. The order will be random and determined by lottery. A nurse will record the child's breathing in both the prone and supine positions. After the two hours, the child will be placed in the supine position, which is standard practice in the department. The child will have a pulse oximeter on both during the study and afterwards.