Evaluation of the relationship between red blood cell distribution (RDW) with mortality and morbidity in the peroperative period

Purpose: Anesthesia applications and surgical stresses are inflammatory processes, and such inflammations affect the patient's prognosis through the perioperative period. In our study, the RDW level, which is considered an inflammatory marker, was recorded in the perioperative period together with its alterations, and these values' relationships with mortality and morbidity were analyzed. RDW is a parameter measured in routine hemograms in the preoperative and postoperative periods. Our study aimed to evaluate the usefulness of this low-cost and easily accessible parameter regarding predicting patients' intraoperative and postoperative prognosis. Materials and Methods: This was an observational study. Among the cases on the daily operating room schedule, 300 patients in all ASA groups aged 18 years and over who had undergone routine hemogram tests in the preoperative and postoperative periods were included in the study. The patients who had undergone open cardiac surgery, transplantation, and thoracic surgery with single lung ventilation were excluded. Regarding the preoperative period, demographic data, surgical indications, comorbidities (classified as cardiovascular, respiratory, urinary, central nervous, gastrointestinal, and endocrine systems, hematologic-oncologic and rheumatic disorders), surgical specialty and type of surgery, routine hemogram test data, risk scores (ASA and ACS NSQIP), whether intensive care and/or mechanical ventilatory support had been made ready according to the preoperative risk scores were recorded. Regarding the intraoperative period, the operation time, anesthesia duration and method (induction and maintenance protocols), the agent used for neuromuscular blocker antagonism, the amount of bleeding, the replacement fluids (crystalloids, colloids, blood products), data concerning inotropic support (whether it was administered, the drug and its dosage) were recorded. Regarding the postoperative period, routine hemogram data in the first postoperative blood sample, intensive care requirement, mechanical ventilatory support, data concerning inotropic use (whether it was administered, the drug and its dosage), duration of intensive care stay and hospitalization, and complications throughout these processes classified as patient-, anesthesia-, and surgery-related were recorded. Results: The preoperative and postoperative RDW values were determined to increase with advanced age, cardiovascular-respiratory-urinary system diseases, a surgical indication of malignancy, presence of an oncologic disease other than the reason for surgery, and a high preoperative risk score. The patients who needed intraoperative and postoperative inotropes and were admitted postoperatively to the intensive care unit had higher RDW values. No relationships of anesthesia and surgical procedure with RDW were determined. In the postoperative period, patients developing patient-related complications were determined to have higher RDW values. The ROC analysis revealed that the patients with a preoperative RDW above 14.25% and a postoperative RDW above 14.35% had a high risk for patient-related complications. Conclusions: RDW is a parameter usable in the intraoperative and postoperative periods to predict prognosis in patients with risks and comorbidities. Further studies are required to determine a precise cut-off RDW value for complication development and investigate the relationships of RDW with anesthesia / surgical procedure. Keywords: preoperative-postoperative period; immune system; RDW