The Effects of Ventilatory Strategies on Pulmonary Function After Cardiopulmonary Bypass Evaluated by Electrical Impedance Tomography in Patients Undergoing Cardiac Surgery

Pulmonary complications after cardiac surgeries are common. It is one of the most crucial concerns of cardiac surgeons and anesthesiologists. These adverse events may vary from a mild respiratory dysfunction to acute respiratory distress syndrome (ARDS). One of the most public reasons of these complications is atelectasis that would result in hypoxia and pneumonia. Any of these adverse events rises the prevalence of morbidity and mortality. The chief inducing causes for atelectasis are CPB and dropped blood perfusion and ventilation of the lungs. The ventilation arrest is related with a high frequency of retained bronchial sections, local atelectasis, decrease in arterial O2 concentrations as a effect of surge in arteriovenous shunt, declined lung compliance, pulmonary edema and hence increased risk of nosocomial infections.

Electrical Impedance Tomography (EIT) is a non-invasive, radiation-free, real time bedside imaging modality, which provide the assessment of regional gas volume and lung ventilation. EIT has been experienced in quite a lot of animal and clinical applications including optimization of mechanical ventilator strategies and recognition of respiratory adverse events. Besides, EIT has been used to recognize ideal PEEP by detection of homogenous ventilation in non-dependent and dependent lung regions. Homogeneous ventilation is key for inhibition of ventilator-induced lung injury.