Monitoring multiple rib fractures using pulmonary electrical impedance tomography technology: correlation analysis of pulmonary ventilation changes.

Abstract

Background: Multiple rib fractures are a common and severe form of chest trauma, which can lead to pulmonary ventilation disorders. Assessment primarily relies on imaging examinations and conventional pulmonary function tests. Electrical impedance tomography (EIT) technology can detect ventilation dysfunctions that are difficult to identify through conventional means. This study utilizes EIT technology to quantify global and regional pulmonary ventilation inhomogeneity and to analyze the correlation between these ventilation characteristics and various factors associated with multiple rib fractures, thereby providing preliminary support for subsequent of intervention and prognosis assessment of rib fractures in EIT.

Methods: A cross-sectional exploratory study was conducted. A total of 115 patients with multiple rib fractures admitted to the Department of Cardiothoracic Surgery at Tianjin Hospital in Tianjin City from October 2020 to May 2023 were selected. EIT examinations were performed 24-72 hours after injury, and trauma and EIT data were collected and organized. Whole chest/lung indicators included: pain score [numerical rating scale (NRS)], total number of rib fractures, total number of displaced rib fractures, number of lung contusion lobes, global inhomogeneity index (GI), ventral-to-dorsal ventilation center (CoV_v-d), pendelluft (Ap), inspiration delay time (T_ins-i), expiration delay time (T_exp-i). Regional chest/lung indicators included: total number of (left lateral + left posterior) displaced rib fractures, total number of (right lateral + right posterior) displaced rib fractures, number of left/right lung contusion lobes, left dorsal lung impedance proportion (TIV_D-L%), right dorsal lung impedance proportion (TIV_D-R%), left dorsal lung Ap (Ap_D-L), and right dorsal lung Ap (Ap_D-R). Spearman correlation analysis was used for the data.

Results: The number of lung contusion lobes and EIT global-lung parameters (CoV_v-d, Ap, T_exp-i) all showed a good correlation with the number of rib fractures (P<0.05), especially with the number of displaced rib fractures (P<0.01). The greater the number of rib fractures, the most severe the pain (P<0.01). Changes in EIT parameters were significantly correlated with the degree of pain (P<0.05/0.01). Multiple rib fractures can exacerbate pulmonary injury in the trauma area (P<0.05/0.01), resulting in a reduction of tidal impedance variation in region of interest percentage (TIV_ROI%) (P<0.05/0.01), with Ap in this region being more pronounced than in other regions (P<0.05/0.01). Regional Ap was significantly correlated with the local number of displaced rib fractures (P<0.01).

Conclusions: EIT can provide dynamic ventilation images for patients with rib fractures, quantifying regional ventilation disorders and overall pulmonary ventilation heterogeneity. Current studies have not yet verified the predictive value of EIT for long-term respiratory outcomes. Still, it can provide a basis for future large-sample, interventional, and outcome-oriented research.