Abstract
BACKGROUND: Individualized positive end-expiratory pressure (PEEP) titration is a crucial technique in mechanical ventilation therapy for acute respiratory distress syndrome (ARDS) patients with intra-abdominal hypertension (IAH). This study aimed to evaluate the effectiveness of electrical impedance tomography (EIT)-guided PEEP titration in this population. METHODS: This prospective study enrolled 36 ARDS patients, including 22 patients with IAH and 14 without IAH. All the patients underwent EIT-guided PEEP titration at the intersection point between alveolar overdistension and collapse during a decremental PEEP trial. The changes in pulmonary ventilation distribution, respiratory mechanics and hemodynamics during the titration process were observed. RESULTS: After EIT-guided PEEP titration was performed, the PEEP, peak inspiratory pressure and plateau pressure increased significantly (P<0.05). Furthermore, no significant differences were observed in respiratory system compliance, tidal volume, driving pressure, or the 4*DP+RR index between the two groups (P>0.05). The mechanical power increased in the non-IAH (NIAH) group after PEEP titration (P<0.05). Ventilation in gravity-dependent lung regions significantly increased (P<0.05), and the oxygenation index (PaO(2)/FiO(2)) improved significantly (P<0.05) in both groups. However, blood pressure, heart rate, respiratory rate, central venous pressure, and lactate levels did not significantly change. In the IAH group, the PaO(2)/FiO(2) ratio improved less than that in the NIAH group did (P<0.05). CONCLUSION: In our study, individualized PEEP titration guided by EIT improved oxygenation in ARDS patients with concomitant IAH without significantly affecting hemodynamics. The presence of IAH may limit the improvement of oxygenation during EIT-guided PEEP titration.