ĐẶC ĐIỂM KIỂU HÌNH PHÂN BỐ THÔNG KHÍ VÙNG PHỔI THEO CẮT LỚP TRỞ KHÁNG LỒNG NGỰC Ở BỆNH NHÂN SUY HÔ HẤP CẤP TIẾN TRIỂN

Abstract

Objectives: To describe the phenotypes of regional lung ventilation distribution assessed by electrical impedance tomography (EIT) and to evaluate their association with clinical characteristics, laboratory findings, and treatment outcomes in patients with acute respiratory distress syndrome (ARDS). Methods: A prospective, descriptive, longitudinal study was conducted on 66 patients with ARDS monitored by EIT at the Intensive Care Center, Bach Mai Hospital, from October 2024 to February 2026. Regional lung ventilation distribution was evaluated using TV_A (anterior tidal ventilation), TV_P (posterior tidal ventilation), TV_R (right tidal ventilation), and TV_L (left tidal ventilation), corresponding to the proportions of ventilation in the anterior, posterior, right, and left lung regions, respectively, together with the A/P ratio. Based on TV_P, patients were classified into three phenotypes: phenotype 1 (reduced posterior ventilation, TV_P < 40%); phenotype 2 (preserved posterior ventilation, TV_P 40 - 50%); and phenotype 3 (increased posterior ventilation, TV_P > 50%). Results: Patients with regional lung ventilation was unevenly distributed, with predominance in the anterior region (TV_A = 63.0%) and reduced ventilation in the posterior region (TV_P = 37.0%); the A/P ratio was 1.7. Phenotype 1 was the most common (59.1%), followed by phenotype 2 (28.8%) and phenotype 3 (12.1%). Phenotype 1 was associated with a higher proportion of severe ARDS, lower lung compliance, and higher driving pressure and plateau pressure, whereas phenotype 3 had a higher PaO₂/FiO₂ ratio. Conclusion: EIT helps classify ventilation phenotypes and provides additional insights into regional lung ventilation distribution in patients with ARDS.