[Platelet/white blood cell ratio in the prediction of postoperative acute kidney injury of patients].

OBJECTIVE

To investigate the risk factors and predictive value on acute kidney injury (AKI) following surgery, and to elucidate the relationship between platelet/white blood cell ratio (PWR) and AKI.

METHODS

A retrospective case-control study was conducted. The patients who underwent surgery admitted to Honghui Hospital of Xi'an Jiaotong University from January 2019 to January 2023 were enrolled. The patients who developed AKI during the postoperative hospital stay were categorized as the AKI group, while those with normal renal function or not meeting AKI criteria were categorized as the non-AKI group. Demographic information, clinical characteristics, perioperative medication usage, surgical related information, and preoperative and postoperative laboratory indicators were collected. Binary multivariate Logistic regression analysis was used to identify risk factors for postoperative AKI. Receiver operator characteristic curve (ROC curve) was plotted to assess the predictive efficacy of postoperative PWR for postoperative AKI.

RESULTS

A total of 420 patients were enrolled finally, with 72 developing AKI during hospitalization and 348 not developing AKI. Compared with the non-AKI group, the patients in the AKI group had a higher proportion of hypertension and coronary heart disease, a more usage of angiotensin converting enzyme inhibitor (ACEI), mannitol and vancomycin but a less usage of hydroxyethyl starch, a longer duration from injury to surgery and postoperative hospital stay, a greater intraoperative blood transfusion volume, a lower preoperative albumin (Alb), blood sodium, blood chlorine but a higher serum creatinine (SCr), blood urea nitrogen (BUN)/Alb ratio and N-terminal pro-brain natriuretic peptide (NT-proBNP), and a higher postoperative white blood cell count (WBC), BUN, SCr, BUN/Alb ratio, blood potassium, and blood phosphorus but a lower platelet count (PLT), PWR, and Alb. Binary multivariate Logistic regression analysis revealed that perioperative usage of hydroxyethyl starch [odds ratio (OR) = 8.595, 95% confidence interval (95%CI) was 4.112-17.964, P < 0.001], prolonged duration from injury to surgery (OR = 1.084, 95%CI was 1.034-1.137, P = 0.001), increased intraoperative blood transfusion volume (OR = 1.001, 95%CI was 1.000-1.002, P = 0.017) were risk factors for AKI following surgery, and increased postoperative PWR was protective factor (OR = 0.930, 95%CI was 0.894-0.967, P < 0.001). ROC curve analysis indicated that the area under the ROC curve (AUC) of postoperative PWR for predicting postoperative AKI was 0.684 (95%CI was 0.615-0.754); at the optimal cut-off value of 19.34, the sensitivity was 63.8%, and the specificity was 69.8%.

CONCLUSIONS

Postoperative PWR is an independent risk factor for AKI in patients undergoing surgery. Postoperative PWR reduction in surgical patients can assist in predicting the occurrence of postoperative AKI.