Chest computed tomography semi-quantitative pleural effusion and pulmonary consolidation are early predictors of acute pancreatitis severity

Abstract

Background: To study the predictive value of semi-quantitative pleural effusion and pulmonary consolidation for acute pancreatitis (AP) severity.

Methods: Thorax-abdominal computed tomography (CT) examinations were performed on 309 consecutive AP patients in a single center. Among them, 196 were male, and 113 were female, and the average age was 50±16 years. The etiology of AP was biliary in 43.7% (n=135), hyperlipidemia in 22.0% (n=68), alcoholic in 7.4% (n=23), trauma in 0.6% (n=2), and postoperative status in 1.6% (n=5) cases; 24.6% (n=76) of patients did not have specified etiologies. The prevalence of pleural effusion and pulmonary consolidation was noted. The pleural effusion volume was quantitatively derived from a CT volume evaluation software tool. The pulmonary consolidation score was based on the number of lobes involved in AP. Each patient's CT severity index (CTSI), acute physiology and chronic health evaluation II (APACHE II) scoring system, and bedside index for severity in acute pancreatitis (BISAP) scores were obtained. The semi-quantitative pleural effusion and pulmonary consolidation were compared to these scores and clinical outcomes by receiver operator characteristic (ROC) curve and area under the curve (AUC) analysis.

Results: In the 309 patients, 39.8% had pleural effusion, and 47.9% had pulmonary consolidation. The mean pleural effusion volume was 41.7±38.0 mL. The mean pulmonary consolidation score was 1.0±1.2 points. The mean CTSI was 3.7±1.8 points, the mean APACHE II score was 5.8±5.1 points, and the mean BISAP score was 1.3±1.0 points; 5.5% of patients developed severe AP, and 13.9% of patients developed organ failure. Pleural effusion volume and pulmonary consolidation scores correlated to the scores for the severity of AP. In predicting severe AP, the accuracy (AUC 0.839) of pleural effusion volume was similar to that of the CTSI score (P=0.961), APACHE II score (P=0.757), and BISAP score (P=0.906). The accuracy (AUC 0.805) of the pulmonary consolidation score was also similar to that of the CTSI score (P=0.503), APACHE II score (P=0.343), and BISAP score (P=0.669). In predicting organ failure, the accuracy (AUC 0.783) of pleural effusion volume was similar to that of the CTSI score (P=0.473), APACHE II score (P=0.119), and BISAP score (P=0.980), and the accuracy (AUC 0.808) of the pulmonary consolidation score was also similar to that of the CTSI score (P=0.236), APACHE II score (P=0.293), and BISAP score (P=0.612).

Conclusions: Pleural effusion and pulmonary consolidation are common in AP and correlated to the severity of AP. Furthermore, the pleural effusion volume and pulmonary consolidation lobes can provide early prediction of severe AP and organ failure.

Keywords: Acute pancreatitis (AP); organ failure; pleural effusion; pulmonary consolidation.

Figure 1

Using the Syngo MMWP VE 31H workstation software to semi-automatic measure the volume of pleural effusion. (A) A sample of axial computed tomography (CT) scans on the patient's right side with a crude outline is drawn with an electronic cursor. The pink highlighted pixels within the outlined region have the CT densities of −50 to 100 Hounsfield units; (B) coronary reconstruction; (C) sagittal reconstruction with cursor-marked regions for volume calculation; (D) volume of pleural effusion.

Figure 2

CT images of a 60-year-old male with moderately severe AP. (APACHE II score of 15 points, CTSI of 4 points, BISAP score of 2 points, and without organ failure). (A) Chest axial image CT showing right pleural effusion and right pulmonary consolidation; (B) abdomen contrast CT. The arrows show the local complication (acute necrotic collection).

Figure 3

CT images of a 70-year-old female with moderately severe AP (APACHE II score of 12 points, CTSI of 4 points, BISAP score of 4 points, and with transient organ failure). (A) Chest axial image CT showing bilateral pleural effusion and bilateral pulmonary consolidation; (B) Abdomen contrast CT. The arrows show the pancreatic necrosis.

Figure 4

CT images of a 49-year-old male with severe AP (APACHE II score of 25 points, CTSI of 10 points, and BISAP score of 4 points, and with persistent organ failure). (A) Chest axial image CT showing left pleural effusion; (B) abdomen contrast CT. Triangles show the pancreatic necrosis, and arrows show local complications (acute necrotic collection).

Figure 5

ROC curves of the pleural effusion volume, pulmonary consolidation scores, and different scoring systems in predicting severe AP (A) and organ failure (B).