Outpatient Use of Electrical Impedance Tomography in Patients with Chronic Obstructive Pulmonary Disease: A Scoping Review

Objective: Electrical Impedance Tomography (EIT) has emerged as a non-invasive, radiation- free imaging modality that allows monitoring at the patient's bedside, providing real-time information on the regional distribution of pulmonary ventilation. Although there has been increasing research on EIT in Intensive Care Units (ICUs), few studies use this tool in patients with spontaneous breathing. The objective is to describe the current evidence regarding the outpatient use of EIT in patients with chronic obstructive pulmonary disease (COPD). Methods: A scoping review was performed. An extensive search was conducted in seven healthbased databases, Scopus, Medline, OVID, Scielo, PEDro, EBSCO, and VHL search portal. In this scoping review, the checklist recommended by PRISMA was used. To assess the quality of the studies, the BEME protocol of "questions to ask about the evidence of an investigation or evaluation" was used. Results: In this scoping review, 7 studies published between 2009 and 2019 related to the outpatient use of EIT in COPD patients were identified. The evidence reviewed allowed us to identify that the frequent use is related to the evaluation of the distribution of ventilation, the evaluation of regional respiratory mechanics, and the degree of pre- and post-bronchodilator obstruction. Conclusion: EIT is used on an outpatient basis in patients with COPD as an evaluation tool that complements the information regarding the clinical results of pulmonary function tests, improving the monitoring of the course of the disease in real-time, non-invasively, and without ionizing radiation.