Association of Perioperative Hyperchloremia and Hyperchloremic Metabolic Acidosis with Acute Kidney Injury After Craniotomy for Intracranial Hemorrhage

BACKGROUND: The present study evaluated the relationships among perioperative hyperchloremic metabolic acidosis (HCA), hyperchloremia, and postoperative acute kidney injury (AKI) in patients who had undergone craniotomy for intracranial hemorrhage (ICH). METHODS: The present retrospective cohort study included adult patients who had undergone craniotomy for traumatic or spontaneous ICH from January 2005 to December 2017. The association of perioperative hyperchloremia (serum chloride [Cl-] >110 mmol/L during postoperative days 0-3), an increase in Cl- levels (maximum Cl- level in postoperative days 0-3 minus the baseline Cl- level before surgery), and perioperative HCA (Cl- >110 mmol/L; pH <7.35, with a bicarbonate level <24 mmol/L) with the incidence of AKI was analyzed using multivariable logistic regression analysis. RESULTS: A total of 968 patients were included. Of these patients, 117 (12.1%) had postoperative AKI. The multivariable logistic regression analysis showed that the development of HCA was associated with a 1.850-fold increase in the incidence of postoperative AKI (odds ratio [OR], 1.850; 95% confidence interval [CI], 1.102-3.106; P = 0.020). However, hyperchloremia was not significantly related to the incidence of postoperative AKI (P = 0.207). Additionally, the presence of hyperchloremia and an increase in Cl- levels were both associated with an increased incidence of HCA (hyperchloremia group: OR, 2.162; 95% CI, 1.490-3.138; P < 0.001; 1-mmol/L increase in Cl- level: OR, 1.035; 95% CI, 1.008-1.062; P = 0.011). CONCLUSIONS: Perioperative HCA was independently related to an increased incidence of AKI after craniotomy for ICH. An increase in Cl- levels and perioperative hyperchloremia were associated with increased development of HCA but were not significantly related to the development of postoperative AKI.