Background

Postoperative pulmonary complications following major abdominal surgery are frequent and carry high morbidity and mortality. Early identification of patients at risk of pulmonary complications by lung ultrasound may allow the implementation of preemptive strategies. We hypothesized that lung ultrasound score would be associated with pulmonary postoperative complications. The main objective of the study was to evaluate the performance of lung ultrasound score on postoperative day 1 in predicting pulmonary complications following major abdominal surgery. Secondary objectives included the evaluation of other related measures for their potential prediction accuracy.

Methods

149 patients scheduled for major abdominal surgery were enrolled in a bi-center observational study. Lung ultrasound score were performed before the surgery and on days 1, 4 and 7 following surgery. Pulmonary complications occurring before postoperative day 10 were recorded.

Results

Lung ultrasound score on postoperative day 1 was higher in patients developing pulmonary complications before day 10 (median, 13; interquartile range [IQR], 8.25 to 18; vs median, 10; IQR, 6.5 to 12; Mann–Whitney p = 0.002). The area under the curve for predicting postoperative pulmonary complications before day 10 was 0.65 (95% confidence interval [CI], 0.55 to 0.75; p = 0.003). Lung ultrasound score > 12 had a sensitivity of 0.54 (CI, 0.40 to 0.67), specificity of 0.77 (CI, 0.67 to 0.85), and negative predictive value of 0.74 (CI, 0.65 to 0.83). Lung ultrasound score > 17 had sensitivity of 0.33 (CI, 0.21 to 0.47), specificity of 0.95 (0.88, 0.98), and positive predictive value of 0.78 (CI, 0.56 to 0.93). Anterolateral lung ultrasound score and composite scores using lung ultrasound score and other patient characteristics showed similar predictive accuracies.

Conclusions

An elevated lung ultrasound score on postoperative day 1 is associated with the occurrence of pulmonary complications within the first 10 days after major abdominal surgery.