ObjectiveTo investigate the correlation between lung ultrasonography and pulmonary complications after cardiac surgery.MethodsFifty-two patients after cardiac surgery in our hospital from January to May 2017 were recruited. There were 27 males and 25 females, aged 60.50±10.43 years. Lung ultrasonography was performed by specially trained observers, video data were saved, and lung ultrasound score (LUS) were recorded. The correlation between the LUS and the patients' pulmonary function was evaluated.ResultsLUS was 17.80±3.87, which was negatively correlated to the ratio of arterial PO2 to the inspired oxygen fraction (PaO2/FiO2) during examination, without significant difference (r=–0.363, P=0.095), but significantly negatively correlated to PaO2/FiO2 changes 24 hours postoperatively (r=–0.464, P=0.034).ConclusionThe changes of lung ventilation area may occur earlier than the changes of lung function. Bedside LUS is an effective method for clinical monitoring of pulmonary complications.