Preoperative Low Serum Bicarbonate Levels Predict Acute Kidney Injury After Cardiac Surgery

Abstract

Acute kidney injury (AKI) after cardiac surgery is a common and serious complication. Although lower than normal serum bicarbonate levels are known to be associated with consecutive renal function deterioration in patients with chronic kidney injury, it is not well-known whether preoperative low serum bicarbonate levels are associated with the development of AKI in patients who undergo cardiac surgery. Therefore, the clinical implication of preoperative serum bicarbonate levels on AKI occurrence after cardiac surgery was investigated. Patients who underwent coronary artery bypass or valve surgery at Yonsei University Health System from January 2013 to December 2014 were enrolled. The patients were divided into 3 groups based on preoperative serum bicarbonate levels, which represented group 1 (below normal levels) <23 mEq/L; group 2 (normal levels) 23 to 24 mEq/L; and group 3 (elevated levels) >24 mEq/L. The primary outcome was the predicated incidence of AKI 48 hours after cardiac surgery. AKI was defined according to Acute Kidney Injury Network criteria. Among 875 patients, 228 (26.1%) developed AKI within 48 hours after cardiac surgery. The incidence of AKI was higher in group 1 (40.9%) than in group 2 (26.5%) and group 3 (19.5%) (P < 0.001). In addition, the duration of postoperative stay in a hospital intensive care unit (ICU) was longer for AKI patients and for those in the low-preoperative-serum-bicarbonate-level groups. A multivariate logistic regression analysis showed that low preoperative serum bicarbonate levels were significantly associated with AKI even after adjustment for age, sex, hypertension, diabetes mellitus, operation type, preoperative hemoglobin, and estimated glomerular filtration rate. In conclusion, low serum bicarbonate levels were associated with higher incidence of AKI and prolonged ICU stay. Further studies are needed to clarify whether strict correction of bicarbonate levels close to normal limits may have a protective role in preventing further AKI development.

Clinical and ultrasound variables for early diagnosis of septic acute kidney injury in bitches with pyometra

“…Regarding bicarbonate, its utility in the diagnosis of AKI has already been described and subtle reduction is associated with worsening renal function 35 . Bicarbonate acts on tissue by increasing the availability of oxygen in the medullary region and reducing free radicals' formation 36 . In metabolic acidosis, ammonia production occurs in the medullary region, leading to increased inflammation and tubular injury 37 .…”

Early detection of cardiac surgery‑associated acute kidney injury by microRNA-21

“…Despite the fact that during recent years several studies have tried to introduce reliable markers such as cystatin C, kidney injury molecule-1 (Kim-1), neutrophil gelatinase-associated lipocalin (NGAL), etc. for early diagnosis or preventive treatment of CSA-AKI (8)(9)(10)(11), no reliable marker exists for early diagnosis of CSA-AKI, and the researchers keep working on the available markers, their accuracy and prognostic value for diagnosis of CSA-AKI (12)(13)(14)(15)(16).…”

Short-term and long-term effects of low serum bicarbonate level at admission in hospitalised patients

“…Jung et al . also demonstrated that patients with low serum bicarbonate levels before cardiac surgery had a higher incidence of postoperative AKI independent of other risk factors for AKI development 19 . Similarly, recent observational studies found that lower serum bicarbonate levels predicted the development of AKI 5,20 , thereby supporting a close association between serum bicarbonate level and renal dysfunction.…”