Assessment of lung aeration and muscle thickening fraction in infants with bronchiolitis using high-flow nasal cannula: association of electrical impedance tomography and ultrasound.

• Grant number: 23/07418-2
• Support Opportunities: Regular Research Grants
• Start date: February 01, 2024
• End date: January 31, 2026
• Field of knowledge: Health Sciences - Medicine - Maternal and Child Health
• Principal Investigator: Milena Siciliano Nascimento
• Grantee: Milena Siciliano Nascimento
• Host Institution: Instituto Israelita de Ensino e Pesquisa Albert Einstein (IIEPAE). Sociedade Beneficente Israelita Brasileira Albert Einstein (SBIBAE). São Paulo , SP, Brazil
• Associated researchers: Caio César Araújo Morais ; Celso Moura Rebello ; Eduardo Leite Vieira Costa ; Marcelo Britto Passos Amato

Abstract

Electrical impedance tomography (EIT) is a noninvasive modality for respiratory monitoring that is free of radiation, and because it is portable, safe, and low cost, it has shown great advantages for use at the bedside. This technology allows regional lung ventilation to be mapped over time, cycle by cycle, in addition to identifying changes in ventilation and aeration distribution in real time. High-flow nasal cannula (HFNC) is a relatively recent therapy that has been changing outcomes in the treatment of respiratory failure, including for infants with bronchiolitis. The improvement in clinical outcomes, such as improved oxygenation, decreased effort and respiratory rate, reflects the need for escalation of care, such as the use of noninvasive ventilation (NIV) and orotracheal intubation, which interferes with the length of stay in the ICU, length of hospital stays and consequently costs. The understanding of the mechanisms by which HFNC therapy reduces respiratory work and improves gas exchange has been evolving in recent years, but some points remain. The complexity of respiratory mechanics with the action of the diaphragm and expiratory muscles added to pulmonary response are points of attention in current studies with intensive care patients. To evaluate the effect of different flow rates of HFNC on diaphragmatic and abdominal muscle contraction and to study whether this effect depends on the action of flow rates of HFNC on functional residual capacity (FRC) are the focus of this project. To date, 3 studies have used TIE with the aim of evaluating aspects related to the variation in FRC, evaluated through EELZ (end-expiration lung impedance) in TIE, one of which was performed by our group. Guglielmo et al, presented results and perspectives similar to ours, which sparked interest in carrying out this new study in partnership with Children's Hospital Los Angeles.Ultrasound has been described as a highly reproducible and sensitive method for the structural and functional assessment of muscles by a multidisciplinary team. Muscle assessment, especially of the diaphragm, has been studied and associated with failure of weaning in critically ill patients. The evaluation of muscle activity (diaphragm and abdominal) associated with TIE data will help in the understanding of respiratory mechanics in infants with bronchiolitis, expanding our knowledge regarding the best adjustment of parameters but also to recognize the absence of response to therapy, helping in the decision making for escalation of ventilatory support. (AU)