Retrospective Study
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Aug 28, 2019; 25(32): 4739-4748
Published online Aug 28, 2019. doi: 10.3748/wjg.v25.i32.4739
Prognostic value of red blood cell distribution width for severe acute pancreatitis
Fang-Xiao Zhang, Zhi-Liang Li, Zhi-Dan Zhang, Xiao-Chun Ma
Fang-Xiao Zhang, Zhi-Liang Li, Zhi-Dan Zhang, Xiao-Chun Ma, Department of Critical Care Medicine, First Affiliated Hospital of China Medical University, Shenyang 110001, Liaoning Province, China
Author contributions: Zhang FX, Ma XC, and Zhang ZD designed the research; Zhang FX and Li ZL performed the research; Li ZL contributed new reagents/analytic tools; Zhang FX, Li ZL, and Zhang ZD analyzed the data; Zhang FX and Zhang ZD wrote the paper.
Supported by Health and Birth Control Committee of Liaoning Province, China.
Institutional review board statement: The study was reviewed and approved by the Medical Science Ethics Committee of First Affiliated Hospital of China Medical University.
Informed consent statement: All study participants, or their legal guardian, provided informed written consent prior to study enrollment.
Conflict-of-interest statement: All the authors have no conflict of interest related to the manuscript.
Open-Access: This is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Corresponding author: Zhi-Dan Zhang, Doctor, Department of Critical Care Medicine, First Affiliated Hospital of China Medical University, No. 155, Nanjing North Street, Heping District, Shenyang 110001, Liaoning Province, China.
Telephone: +86-139-9831-8999
Received: April 28, 2019
Peer-review started: April 28, 2019
First decision: May 30, 2019
Revised: July 2, 2019
Accepted: July 19, 2019
Article in press: July 19, 2019
Published online: August 28, 2019
Processing time: 124 Days and 5.5 Hours
Research background

Severe acute pancreatitis (SAP) is a common acute and severe clinical disease. There are a large number of inflammatory mediators and cytokines released, which cause systemic inflammatory response, accompanied by continuous multiple organ dysfunction, such as intestinal dysfunction and metabolic dysfunction. Therefore, it is important to evaluate the prognostic factors for SAP. Red cell distribution width (RDW) is an indicator of erythrocyte variability in the blood circulation, and can reflect the difference in red blood cell size and the dispersion degree of red blood cell volume. At present, it is not yet clear whether RDW is associated with the prognosis of SAP patients or whether it can be used as a prognostic indicator for SAP patients.

Research motivation

Timely and effective judgment of the condition of SAP patients is of great value for the treatment of those patients. RDW may be related to the severity of SAP. Our study aimed to investigate the prognostic value of RDW for SAP patients.

Research objectives

The main aim of our study was to examine the difference of RDW between the surviving SAP patients and non-surviving SAP patients and evaluate the prognostic value of RDW for SAP patients.

Research methods

We retrospectively enrolled SAP patients admitted to intensive care unit for two years. According to the prognosis at 90 d, the SAP patients were divided into a survival group and a non-survival group. The RDW was extracted from a routine blood test. The demographic parameters and RDW were recorded and compared between the two groups. The receiver operator characteristic (ROC) was constructed and the Cox regression analysis was done to investigate the prognostic value of RDW for SAP patients.

Research results

Of 42 SAP patients enrolled in this retrospective cohort study, 22 survived (survival group) and 20 died (non-survival group). The baseline parameters were comparable between the two groups. The coefficient of variation of RDW (RDW-CV), standard deviation of RDW (RDW-SD), Physiology and Chronic Health Evaluation II (APACHE II) score, and Sequential Organ Failure Assessment (SOFA) scores were significantly higher in the non-survival group than in the survival group (P < 0.05). The RDW-CV and RDW-SD were significantly correlated with the APACHE II score and SOFA score, respectively. The areas of the ROC curves (AUCs) of RDW-CV and RDW-SD were all larger than those of APACHE II score and SOFA score, among which the AUC of RDW-SD was the largest one. The results demonstrated that RDW had the better prognostic value for predicting the mortality of SAP patients. When the RDW-SD was higher than 45.5, the sensitivity of predicting prognosis was 77.8% and the specificity was 70.8%. Both RDW-CV and RDW-SD could be used as independent risk factors for predicting mortality of SAP patients in multivariate logistic regression analysis and univariate Cox proportional hazards regression analysis, similar to the APACHE II score and SOFA score.

Research conclusions

The RDW is higher in the non-surviving SAP patients than that in the surviving patients. RDW has better prognostic value for SAP patients than APACHE II and SOFA scores, and it could be easily used for clinicians in treating SAP patients. RDW has superior value in predicting the prognosis of SAP patients. RDW is associated with inflammatory reactions and can predict severity and prognosis of many diseases including cardiovascular diseases, chronic obstructive pulmonary disease, pulmonary hypertension, rheumatoid arthritis, and malignancy. Higher RDW is also associated with poorer outcome in severe sepsis and septic shock. RDW may be associated with mortality of SAP patients and could be used as a predictor of prognosis. Clinicians could rapidly recognize those SAP patients with higher risk for mortality when the RDW level is increased. More active therapy could be given promptly to those patients in order to save their lives.

Research perspectives

This is a retrospective study executed in a single center and the sample of our study is small. We expect large prospective randomized controlled trials to further verify our results. And we would perform a prospective validation study to further confirm the prognostic value of RDW for SAP patients.