Exploring the Role of Central Venous Pressure in Cardiac Surgery-Associated Acute Kidney Injury: A Comprehensive Scoping Review.

Case Scenario: Hemodynamic Management of Postoperative Acute Kidney Injury

Association of cardiopulmonary bypass with acute kidney injury in patients undergoing coronary artery bypass grafting: a retrospective cohort study.

First step toward uncovering perioperative congestive encephalopathy

The Relevance of Renal Oxygen Saturation Over Other Markers in Cardiac Surgery–Associated Acute Kidney Injury

Venous congestion has been implied in cardiac surgery-associated acute kidney injury (CSA-AKI). The mean systemic filling pressure may provide a physiologically more accurate estimate of renal venous pressure and renal perfusion pressure but its association with CSA-AKI has not been reported. Patients admitted to ICU following cardiac surgery without pre-operative renal dysfunction were included with monitoring of mean arterial pressure (MAP) and central venous pressure (CVP) and cardiac output (CO) to calculate the mean systemic filling pressure analogue (Pmsa ). The AKI-KDIGO guidelines were used to define CSA-AKI. Logistic regression models including CO, heart rate, MAP, CVP and Pmsa were used to ascertain the association with CSA-AKI and reported by odds ratio (OR) with 95% confidence interval (95%CI) and area under the curve (AUROC). One hundred and thirty patients (out of 221 screened) were included of whom 66 (51%) developed CSA-AKI. Patients with CSA-AKI were older, with greater weight and increased stay in ICU while the proportion of comorbidities, type of surgical procedures, APACHE III scores and fluid volumes administered were similar to patients without AKI. The Pmsa , but not CVP, was associated with CSA-AKI (OR 1.2 95%CI [1.16-1.25]). Renal perfusion pressure was associated with CSA-AKI estimated as MAP-Pmsa (OR 0.81 [0.76-0.86]) and MAP-CVP (OR 0.89 [0.85-0.93]) with the former generating a higher AUROC (median difference 0.10 [0.07-0.12], P<.001) in the regression model. The Pmsa in post-operative cardiac surgery patients was associated with the development of CSA-AKI also when incorporated into estimates of renal perfusion pressure.

ObjectiveThe present study aimed to investigate the association of postoperative central venous pressure (CVP) with acute kidney injury (AKI) and mortality in patients undergoing coronary artery bypass grafting (CABG).MethodPatients who underwent CABG in the MIMIC-III database were included and divided into two groups according to the optimal cutoff value of CVP for postoperative AKI determined by the receiver operating characteristic (ROC) curves. The association of CVP with AKI and mortality was determined by multivariate regression models. A 1:1 propensity score matching (PSM) was performed to balance the influence of potential confounding factors.ResultsA total of 3,564 patients were included and divided into High CVP group (CVP ≥ 10.9 mmHg) and Low CVP group (CVP < 10.9 mmHg) according to the ROC analysis. Patients in High CVP group presented with higher AKI incidence (420 (28.2%) vs. 349 (16.8), p < 0.001), in-hospital mortality (28 (1.9%) vs. 6 (0.3%), p < 0.001) and 4-year mortality (149 (15.8%) vs. 162 (11.1%), p = 0.001). Multivariate regression model showed that CVP was an independent risk factor for the postoperative AKI (OR: 1.071 (1.035, 1.109), p < 0.001), in-hospital mortality (OR: 1.187 (1.026, 1.373), p = 0.021) and 4-year mortality (HR: 1.049 (1.003, 1.096), p = 0.035). A CVP above 10.9 mmHg was significantly associated with about 50% higher risk of AKI (OR: 1.499 (1.231, 1.824), p < 0.001). After PSM, 1004 pairs of score-matched patients were generated. The multivariate logistic model showed that patients with CVP ≥ 10.9 mmHg had a significantly higher risk of AKI (OR: 1.600 (1.268, 2.018), p < 0.001) in the PSM subset. However, CVP, as a continuous or a dichotomic variable, was not independently associated with in-hospital mortality (OR: 1.202 (0.882, 1.637), p = 0.244; OR: 2.636 (0.399, 17.410), p = 0.314) and 4-year mortality (HR: 1.030 (0.974, 1.090), p = 0.297; HR: 1.262 (0.911, 1.749), p = 0.162) in the PSM dataset.ConclusionA mean CVP ≥ 10.9 mmHg within the first 24 h after CABG was independently associated with a higher risk of postoperative AKI.

Delayed diagnosis of acute kidney injury (AKI) is common because the changes in renal function markers often lag injury. We aimed to find optimal non-invasive hemodynamic variables for the prediction of postoperative AKI and AKI renal replacement therapy (RRT). The data were collected from 1,180 patients who underwent cardiac surgery in our hospital between March 2015 and Feb 2016. Postoperative central venous pressure (CVP), mean arterial pressure (MAP), heart rate, PaO2, and PaCO2 on ICU admission and daily fluid input and output (calculated as 24 h PFO) were monitored and compared between AKI vs. non-AKI and RRT vs non-RRT cases. The AKI and AKI-RRT incidences were 36.7% (n = 433) and 1.2% (n = 14). Low cardiac output syndromes (LCOSs) occurred significantly more in AKI and RRT than in non-AKI or non-RRT groups (13.2% vs. 3.9%, P < 0.01; 42.9% vs. 7.1%, P < 0.01). CVP on ICU admission was significantly higher in AKI and RRT than in non-AKI and non-RRT groups (11.5 vs. 9.0 mmHg, P < 0.01; 13.3 vs. 9.9 mmHg, P < 0.01). 24 h PFO in AKI and RRT cases were significantly higher than in non-AKI or non-RRT patients (1.6% vs. 0.9%, P < 0.01; 3.9% vs. 0.8%, P < 0.01). The areas under the ROC curves to predict postoperative AKI by CVP on ICU admission (> 11 mmHg) + LCOS + 24 h PFO (> 5%) and to predict AKI-RRT by CVP on ICU admission (> 13 mmHg) + LCOS + 24 h PFO (> 5%) were 0.763 and 0.886, respectively. The volume-associated hemodynamic variables, including CVP on ICU admission, LCOS, and 24 h PFO after surgery could predict postoperative AKI and AKI-RRT.

The triglyceride-glucose (TyG) index, indicative of insulin resistance, is recognized for predicting cardiovascular disease and metabolic disorders, notably kidney disease. In coronary artery bypass grafting (CABG) surgery, its association with postoperative renal injury is significant, suggesting its potential as a predictor for acute kidney injury (AKI) in these patients. This single-center, retrospective study included 296 patients. Patients were divided into AKI and non-AKI groups postoperatively according to the KDIGO grading criteria. Multiple linear regression was employed to identify factors influencing the TyG index. Logistic regression was utilized to examine the TyG index's association with AKI in CABG patients. The TyG index's predictive power for postoperative AKI was assessed using receiver operating characteristic (ROC) curve analysis. Assessment of the Predictive Performance of the Prediction Model via Calibration plot and Clinical Decision Curve Analysis. In comparison between the AKI group and the non- AKI group post-CABG surgery, there was statistically significant differences in TyG index [7.53 [7.25, 7.95] vs. 6.99 [6.64, 7.39], P < 0.05]. Logistic regression analysis indicated that for each unit increase in the TyG index, the odds of developing acute kidney injury post-CABG surgery increased by 30.573 times [odds ratio (OR) = 30.573, 95% confidence interval (CI) 3.930-237.807, P < 0.001]. The area under the curve (AUC) for the TyG index in predicting postoperative AKI in CABG patients was 0.802 (P < 0.001; 95% CI: 0.753-0.851). The calibration plot of the model closely approximated the ideal diagonal line, and the clinical decision curve analysis demonstrated favorable clinical applicability. Elevated levels of the TyG index are closely associated with the occurrence of AKI in patients following CABG surgery, and the TyG index is a potential indicator for the development of AKI post-CABG.

Introduction: Cardiac surgery-associated acute kidney injury (CS-AKI) affects almost half of children undergoing cardiac surgery and is associated with increased morbidity and mortality. Adult literature suggests lower renal perfusion pressure (RPP)—defined by mean arterial pressure (MAP) - central venous pressure (CVP)—after cardiac surgery is associated with increased CS-AKI risk. This study evaluates the relationship of MAP, CVP, and RPP to CS-AKI in children. Methods: We performed a single-center retrospective study and included all children who underwent cardiac surgery from 2017-2024. We excluded infants < 30 days, children with dialysis dependence, or renal transplant in the prior 90 days. We collected demographics, intraoperative, and postoperative variables. Hourly MAP, CVP, and RPP was calculated daily on postoperative days (POD) 0-3. The primary outcome was AKI defined by the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. The relationship of MAP < 5th percentile for age and CVP > 5 mmHg to CS-AKI was assessed by Chi-square analysis. We performed univariate logistic regression on daily mean MAP, CVP, and RPP on AKI presence by POD3. Results: In total, 663 patients were included: 48.6% had AKI, 35.8% had advanced AKI (KDIGO stage 2/3), 55.5% were male, and median age was 13 months. Children with >10% of MAP values < 5th percentile had statistically significant risk for developing CS-AKI (X2=16.5, p< 0.001). Children with >50% of CVP values > 5 mmHg had statistically significant risk for developing CS-AKI (X2= 9.28, p=0.002). CS-AKI risk increased by 2.7% per 1 mmHg CVP > 5 mmHg (OR 1.27, 95%CI [1.25-1.28], p< 0.001). Mean daily RPP < 35 mmHg was associated with significantly higher odds of development of CS-AKI by 42% (OR 1.42, 95%CI [1.29-1.57], p< 0.001). Conclusions: Our study establishes a relationship between RPP, MAP, CVP, and CS-AKI risk in children who underwent cardiac surgery. MAP < 5th percentile for age, CVP > 5 mmHg, and RPP < 35 mmHg during POD0-3 were all independently associated with significantly higher risk of developing CS-AKI on POD3. Further multi-center and prospective studies are needed to better assess the relationship and impact of improving RPP on CS-AKI.

Perioperative Acute Kidney Injury

Background and Aims With increasing global burden of cardiovascular diseases and advances in managing them, the number of cardiac surgeries performed in India has been increasing in the last couple of decades.A lot of western data from the last 5 to 10 years say that AKI episodes can cause significant renal damage and progress to chronic kidney disease (CKD) ,however the association between acute kidney injury (AKI) and chronic kidney disease (CKD) remains elusive in cardiac surgery. We investigated the association between postoperative AKI and CKD development, emphasizing the role of AKI in post cardiac surgery patients. Method We observed the incidence of cardiac surgery associated AKI (CSA-AKI), determinants of progressive kidney disease after CSA-AKI and followed the patients with CSA-AKI for three months to find out the incidence of CKD or progressive renal dysfunction. Results 150 consecutive post cardiac surgery patients were included in the study. CSA-AKI incidence was 35.4%[Figure 1].Incidence of AKI was significant with prior AKI episodes(P&amp;lt;0.01) and with pre-existing CKD (P&amp;lt;0.01)[Figure 2].Among intraoperative risk factors for CSA-AKI, need for CPB(P-0.01), prolonged pump time(P-0.01), blood transfusion(P-0.04) and ultrafiltration(P-0.01) during surgery were found to be significant[Figure 3,4].Duration of ICU stay (P&amp;lt;0.01), hospital stay (P&amp;lt;0.01) and death rate (P-0.04) was higher in patients with AKI[Table 1]. Out of 53 patients who developed CSA-AKI, follow up for the progression of renal disease was done for 50 patients, as 3 patients with AKI died during hospital stay. Progressive renal dysfunction (new development of CKD or progressive CKD ) after 90 days was seen in 48% of patients with CSA-AKI. All the risk factors for the progression of renal disease after AKI like increased age, low serum albumin, presence of hypertension, diabetes mellitus, protein loss in urine, severe AKI(KDIGO stage&amp;gt;2) and multi factorial AKI was higher in patients who had progressive renal disease after AKI in the study group, however the relation was not statistically significant[Table 2]. Conclusion AKI is not uncommon after cardiac surgery, progressive renal dysfunction was seen in 48% of patients after CSA-AKI and progressive renal dysfunction was common in those with increased age, low serum albumin, presence of hypertension, diabetes mellitus, protein loss in urine, severe AKI(KDIGO stage&amp;gt;2) and multi factorial AKI. Mean age of patients with AKI in the study group was found to be 61±10 years and for NO AKI group mean age was found to be 58±12 years. This variation was not found to be statistically significant. Among other pre-operative risk factors, though there was some difference in percentage for many risk factors, but the percentage variation was quite significant for subjects with prior AKI episodes and those with existing CKD. The increased incidence of AKI in patients with prior AKI episodes (P&amp;lt;0.01) and in those with pre-existing CKD (P&amp;lt;0.01) was found to be statistically significant. Low socioeconomic status was found to be high in NO AKI group, however this was not found to be statistically significant (P-0.11). When compared to both the groups, duration of stay in ICU (P&amp;lt;0.01), overall duration of hospital stay (P&amp;lt;0.01) and death rate (P-0.04) was higher in AKI group and this variation was found to be statistically significant. All the risk factors for the progression of renal disease after AKI like increased age, low serum albumin, presence of hypertension, diabetes mellitus, protein loss in urine, severe AKI(KDIGO stage&amp;gt;2) and multifactorial AKI was higher in patients who had progressive renal disease after AKI in the study group, however the relation was not statistically significant.

IntroductionThe role of systemic hemodynamics in the pathogenesis of septic acute kidney injury (AKI) has received little attention. The purpose of this study was to investigate the association between systemic hemodynamics and new or persistent of AKI in severe sepsis.MethodsA retrospective study between 2006 and 2010 was performed in a surgical ICU in a teaching hospital. AKI was defined as development (new AKI) or persistent AKI during the five days following admission based on the Acute Kidney Injury Network (AKIN) criteria. We studied the association between the following hemodynamic targets within 24 hours of admission and AKI: central venous pressure (CVP), cardiac output (CO), mean arterial pressure (MAP), diastolic arterial pressure (DAP), central venous oxygen saturation (ScvO2) or mixed venous oxygen saturation (SvO2).ResultsThis study included 137 ICU septic patients. Of these, 69 had new or persistent AKI. AKI patients had a higher Simplified Acute Physiology Score (SAPS II) (57 (46 to 67) vs. 45 (33 to 52), P < 0.001) and higher mortality (38% vs. 15%, P = 0.003) than those with no AKI or improving AKI. MAP, ScvO2 and CO were not significantly different between groups. Patients with AKI had lower DAP and higher CVP (P = 0.0003). The CVP value was associated with the risk of developing new or persistent AKI even after adjustment for fluid balance and positive end-expiratory pressure (PEEP) level (OR = 1.22 (1.08 to 1.39), P = 0.002). A linear relationship between CVP and the risk of new or persistent AKI was observed.ConclusionsWe observed no association between most systemic hemodynamic parameters and AKI in septic patients. Association between elevated CVP and AKI suggests a role of venous congestion in the development of AKI. The paradigm that targeting high CVP may reduce occurrence of AKI should probably be revised. Furthermore, DAP should be considered as a potential important hemodynamic target for the kidney.

Acute kidney injury (AKI) is a common complication after coronary artery bypass grafting (CABG), associated with adverse short- and long-term outcomes. Sodium-glucose cotransporter-2 inhibitors (SGLT2i) have been shown to reduce occurrence of AKI in several populations, yet their perioperative effects in patients undergoing CABG are unknown. We conducted a retrospective study at the Department of Cardiac Surgery, Medical University of Graz (2020-2024) to evaluate the impact of preoperative SGLT2i use on cardiac surgery-associated AKI in adults undergoing urgent or emergent isolated coronary artery bypass grafting in patients with an indication for SGLT2i therapy (type 2 diabetes mellitus, heart failure with reduced ejection fraction, or chronic kidney disease). Patients with preoperative dialysis, sepsis, reoperation, mechanical circulatory support or missing laboratory data were excluded. Exposure was defined as SGLT2i use within two weeks before surgery, and the primary outcome was cardiac surgery-associated AKI (CSA-AKI) according to KDIGO criteria. Secondary outcomes included kidney replacement therapy, ICU length of stay, 30-day mortality and postoperative diabetic ketoacidosis. Causal effects were estimated using entropy balancing. Results were reported as weighted risk differences, risk ratios, and adjusted mean differences, with time-to-event outcomes analyzed via weighted Cox models and Kaplan-Meier estimates. Among 484 patients, 135 were on SGLT2i. CSA-AKI occurred in 23.0% of SGLT2i users vs. 28.1% of non-users (risk ratio of 0.63 [95% CI 0.44-0.91; p=0.014]). The association was pronounced in patients with heart failure with reduced ejection fraction and those with high EuroSCORE II. No differences were observed in other secondary endpoints and no cases of postoperative diabetic ketoacidosis occurred. Preoperative SGLT2i use was associated with a significantly lower risk of CSA-AKI in patients undergoing urgent or emergent CABG. These findings need to be confirmed in prospective multicenter trials but underline the favorable safety profile of this medication.

The extent to which postoperative hypotension contributes to renal injury remains unclear, much less what the harm thresholds might be. We therefore tested the primary hypothesis that there is an absolute hypotensive arterial pressure threshold for acute kidney injury during the initial seven days after noncardiac surgery. We conducted a single-centre historical cohort analysis of adults who had noncardiac surgery and had creatinine recorded preoperatively and postoperatively. Our exposure was the lowest postoperative mean arterial pressure, defined as the average of the three lowest postoperative pressure measurements. Our primary analysis was the association between the lowest mean arterial pressure and acute kidney injury, defined according to Kidney Disease: Improving Global Outcomes initiative criteria. Our analysis was adjusted for potentially relevant confounding factors including intraoperative hypotension. Among 64,349 patients analyzed, 2,812 (4.4%) patients had postoperative acute kidney injury. Each 5-mmHg decrease in the lowest mean arterial pressure was associated with a 28% (97.5% confidence interval [CI], 23 to 32; P < 0.001) increase in the odds of acute kidney injury for lowest mean arterial pressures <80mmHg. Higher lowest pressures were not associated with acute kidney injury (odds ratio, 1.08; 97.5% CI, 0.99 to 1.17; P = 0.04) for each 5-mmHg decrease in the lowest mean arterial pressure. Postoperative hypotension, defined as the lowest postoperative mean arterial pressure <80mmHg, was associated with acute kidney injury after noncardiac surgery. A prospective trial will be required to determine whether the observed association is causal and thus amenable to modification.

High central venous pressure is associated with prolonged mechanical ventilation and increased mortality after lung transplantation