[Application of electrical impedance tomography technology in the study of awake prone position ventilation in elderly acute respiratory distress syndrome patient].

OBJECTIVE: To observe changes in blood gas analysis and lung ventilation using electrical impedance tomography (EIT) in elderly patients with mild to moderate acute respiratory distress syndrome (ARDS) undergoing awake prone position ventilation (APPV), and to evaluate the rate of tracheal intubation.

METHODS: A randomized controlled study was conducted, involving 58 elderly patients with mild to moderate ARDS admitted to the respiratory intensive care unit (RICU) of Henan Provincial People's Hospital from August 2022 to April 2023. Patients were randomly divided into a control group (n = 27) and an experimental group (n = 31) using a random number table. The control group received conventional treatments, including sputum suction, anti-infection therapy, and non-invasive ventilation. The experimental group received additional prone position therapy. The gender, age, heart rate (HR), respiratory rate (RR), pH value, arterial partial pressure of carbon dioxide (PaCO2), oxygenation index (PaO2/FiO2), acute physiology and chronic health evaluation II (APACHE II), and regional ventilation values (ROIs 1-4) at baseline and on days 1, 3, 5, and 7 were collected and compared between the two groups. The 7-day tracheal intubation rate was also recorded and analyzed.

RESULTS: There were no statistically significant differences in gender, age, HR, RR, pH value, PaCO2, PaO2/FiO2, and APACHE II scores between the two groups of patients at the time of enrollment. After intervention, both groups showed varying degrees of improvement in RR and the PaO2/FiO2, with the rate of improvement slowing after day 5, and the experimental group demonstrated more significant improvements in the PaO2/FiO2 (P < 0.05 for group, time, and group-time interaction). In terms of lung ventilation ROIs, the ROI 1 and ROI 2 values in both groups gradually decreased over time, while the ROI 3 and ROI 4 values increased. The magnitude of change in the experimental group was greater than in the control group, which showed limited improvement during the same period. significant time effects were found for ROI 1-4 values over time in both groups (time effect: F = 25.364, 21.475, 39.895, 41.579, all P < 0.05). and significant group effects were observed for ROI 2 and ROI 3 values (group effect: F = 4.481 and 11.409, both P < 0.05). On day 1, the experimental group showed significant improvements in ROI 1-3 values compared to the control group (F = 10.536, 25.637, 28.451, all P < 0.05). By day 3, significant differences were observed in ROI 1-4 values between the two groups (F = 6.356, 25.734, 23.678, 19.254, all P < 0.05). On day 5, gas distribution in lung tissues became more uniform in the experimental group, with statistically significant differences in ROI 1-4 values (F = 8.342 and 18.345, both P < 0.05). By day 7, the experimental group showed better ventilation distribution in gravity-dependent lung regions, with statistically significant differences in ROI 3 and ROI 4 values compared with the control group (F = 6.820 and 7.350, both P < 0.05). The 7-day tracheal intubation rate of the experimental group was significantly lower than that of the control group [32.3% (10/31) vs. 52% (14/27), P < 0.05].

CONCLUSIONS: For elderly patients with mild to moderate ARDS, APPV can improve the PaO2/FiO2, enhance uniformity in regional lung ventilation, and reduce the tracheal intubation rate.