Abstract
Objective: To identify the correlation between arterial-venous carbon dioxide partial pressure difference (PCO2 gap) and cardiac surgery associated-acute kidney injury (CSA-AKI) in Dr. Wahidin Sudirohusodo Hospital.
Design: This was an observational analytical study with a prospective approach and cohort study design.
Setting: The study was conducted in the Cardiac Centre of Dr. Wahidin Sudirohusodo Hospital, Makassar, Indonesia, from December 2024 to February 2025.
Patients: The population of this study was all patients who underwent open heart surgery at Dr. Wahidin Sudirohusodo Hospital.
Measurements: We measured the PCO2 gap from blood gas analysis and urinary neutrophil gelatinase-associated lipocalin (NGAL) before incision and following the surgical procedure (2 hours following off of the cardiopulmonary bypass [CPB] or graft implanted for off bypass procedure). We also observed urine output and serum creatinine in the first 48 hours following surgery to diagnose acute kidney injury (AKI) according to the Kidney Disease Improving Global Outcomes (KDIGO) classification.
Results: There was a significant difference in PCO2 gap following surgical procedure between the AKI and non-AKI groups (p=0.004), with the PCO2 gap found to be higher in the AKI group at 7.76±2.22 vs 4.61±2.21. PCO2 gap was also found to be highly correlated to AKI incidence (r=0.604, p<0.003).
The receiver operating characteristic (ROC) curve found that the PCO2 gap following surgical procedure cut-off point value to determine the incidence of AKI was 5.7 mmHg (sensitivity 87.5%, specificity 78.6%) with 81.8% accuracy (OR=25.6). The ROC curve also found that NGAL following surgical procedure cut-off point value to determine the incidence of AKI was 100.09 ng/ml (sensitivity 87.5%, specificity 85.7%) with 86.4% accuracy.
Conclusions: A higher PCO2 gap following a surgical procedure correlated to AKI following open heart surgery. The PCO2 gap following a surgical procedure was a good marker to predict AKI incidence, with a cut-off point value as high as 5.7 mmHg, which was not better than NGAL.
Muh Khaerul Muqsith AS, Hisbullah, Andi Adil, Syafri Kamsul Arif, Haizah Nurdin, Ari Santri Palinrungi
