Risk and outcome analysis of renal replacement therapies in patients after cardiac surgery with pre-operatively normal renal function

Hyperlactatemia in patients undergoing pulmonary endarterectomy with deep hypothermic circulatory arrest: Risk factors and its effects on the outcome

INTRODUCTION

To determine the risk factors of hyperlactatemia in pulmonary endarterectomy (PEA) surgery and assess whether elevated blood lactate levels are associated with adverse outcomes.

METHODS

In this retrospective observational study, a total of 111 consecutive patients who underwent PEA for chronic thromboembolic pulmonary hypertension at the XXX Hospital between December 2016 and January 2022 were included. We retrospectively evaluated arterial blood samples analyzed intraoperatively. The pre- and intraoperative risk factors for hyperlactatemia and the postoperative outcomes were recorded.

RESULTS

Lactate levels gradually increased during surgery. The optimal cut-off lactate level for major postoperative complications, calculated using receiver operating characteristic analysis, was 7.0 mmol/L. Deep hypothermic circulatory arrest (DHCA) duration, nadir hematocrit, and preoperative pulmonary vascular resistance were risk factors for lactate levels >7 mmol/L. Moreover, the intraoperative peak lactate level during PEA under DHCA was found to be a statistically significant predictor of major complications being associated with longer mechanical ventilation time (r = 0.294; p = .003) and intensive care unit length of stay (r = 0.327; p = .001).

CONCLUSIONS

Deep hypothermic circulatory arrest duration, nadir hematocrit, and preoperative pulmonary vascular resistance were associated with hyperlactatemia. Increased lactate levels were independent predictors of longer mechanical ventilation time, intensive care unit length of stay, and major complications.

HYPERBILIRUBINEMIA AGGRAVATES RENAL ISCHEMIA REPERFUSION INJURY BY EXACERBATING PINK1-PARKIN-MEDIATED MITOPHAGY

ABSTRACT

Background: Hyperbilirubinemia is a common perioperative complication, which is associated with acute kidney injury. Bilirubin permeabilizes mitochondrial membranes leading to mitochondrial swelling and dysfunction. In this study, we aimed to determine the association between PINK1-PARKIN-mediated mitophagy and renal ischemia-reperfusion (IR) injury aggravated by hyperbilirubinemia. Methods: A C57BL/6 mouse hyperbilirubinemia model was induced via intraperitoneal injection of bilirubin solution. In addition, a hypoxia/reoxygenation (H/R) injury model of TCMK-1 cells was established. In these models, we determined the effects of hyperbilirubinemia on oxidative stress, apoptosis, mitochondrial damage, and fibrosis. Results:In vitro , colocalization of GFP-LC3 puncta and Mito-Tracker Red showed that the number of mitophagosomes increased in TCMK-1 cells under H/R and bilirubin condition. Silencing of PINK1 or inhibition of autophagy alleviated mitochondrial damage, oxidative stress, and apoptosis in H/R injury aggravated by bilirubin and decreased cell death detected by methyl-thiazolyl-tetrazolium. In vivo , hyperbilirubinemia increased serum creatinine level in the renal IR injury mice model. Hyperbilirubinemia enhanced apoptosis induced by renal IR. In addition, hyperbilirubinemia increased mitophagosomes and autophagosomes and disrupted mitochondrial cristae in the IR kidney. Inhibition of PINK1 or autophagy reduced histological damages by alleviating apoptosis in renal IR injury, aggravated by hyperbilirubinemia. 3-MA or PINK1-shRNA-AAV9 treatment decreased the area of collagen and proteins related to fibrosis in renal IR injury, aggravated by hyperbilirubinemia. Conclusions: We have demonstrated that hyperbilirubinemia aggravated oxidative stress, apoptosis, mitochondrial damage, and fibrosis in renal IR injury by exacerbating PINK1-PARKIN-mediated mitophagy.

Gelatin and the risk of acute kidney injury after cardiac surgery

BACKGROUND

Gelatin has been used as a plasma volume expander because of its ability to preserve intravascular volume more effectively than crystalloids. However, gelatin may have detrimental effects on kidney function and increase the risk of acute kidney injury (AKI).

METHOD

We investigated by retrospective analysis of prospectively collected data whether the administration of 4% succinyl gelatin is associated with an increased risk of AKI after cardiac surgery. We compared two propensity score-matched groups of 1,187 patients (crystalloid group and gelatin group).

RESULTS

The incidence of AKI was similar in both groups (gelatin 21% and crystalloid 20%) (p = 0.414). The incidence of moderate AKI (8% vs. 6%) was higher in the gelatin group, but there was no difference in mild or severe AKI. Postoperative serum creatine on the first (70 vs. 70 μmol L^-1 , p = 0.689) or fourth (71 vs. 70, p = 0.313) postoperative day was similar between groups and there was no difference in the need for new renal replacement therapy (p = 0.999). Patients in the gelatin group received less crystalloids (2080 ml vs. 4130 ml, p = 0.001) and total fluids (3760 ml vs. 4180 ml, p = 0.001), their fluid balance was less positive (p = 0.001) and they required less vasoactive and inotropic medication (p = 0.001). Gelatin was not associated with increased mortality compared to the crystalloid group.

CONCLUSION

Gelatin was not associated with AKI after cardiac surgery.

Lactate Elevation During and After Major Cardiac Surgery in Adults: A Review of Etiology, Prognostic Value, and Management

Elevated lactate is a common occurrence after cardiac surgery. This review summarizes the literature on the complex etiology of lactate elevation during and after cardiac surgery, including considerations of oxygen delivery, oxygen utilization, increased metabolism, lactate clearance, medications and fluids, and postoperative complications. Second, the association between lactate and a variety of outcomes are described, and the prognostic role of lactate is critically assessed. Despite the fact that elevated lactate is strongly associated with many important outcomes, including postoperative complications, length of stay, and mortality, little is known about the optimal management of postoperative patients with lactate elevations. This review ends with an assessment of the limited literature on this subject.

Daptomycin for the treatment of major gram-positive infections after cardiac surgery

Background

Infection is a main cause of morbidity and mortality after heart surgery, with multi-resistant pathogens increasingly representing a challenge. Daptomycin provides bactericidal activity against gram-positive organisms that are resistant to standard treatment including vancomycin.

Methods

A cohort of cardiac surgical patients, treated with daptomycin for major infection at two tertiary care centers, were retrospectively studied with a particular focus on the type of infection, causative pathogens and co-infections, daptomycin dosage, adverse events and outcome in order to provide evidence for the efficiency and safety of daptomycin in a distinct high-risk patient population.

Results

Sixty-five patients (87.7 % males, 60.4 ± 13.5 years) who had undergone aortic surgery (20.0 %), ventricular assist device (VAD) implantation (21.5 %), combined procedures (21.5 %), coronary artery bypass grafting (12.3 %), isolated valve surgery (15.4 %) and heart transplantation (7.7 %) were diagnosed with catheter-related infection (26.1 %), valve endocarditis (18.8 %), sternal wound (13.0 %), VAD-associated (11.6 %), cardiac implantable electrophysiological device (CIED)-associated (4.1 %), respiratory tract (4.3 %), bloodstream (4.3 %) and other infection (4.3 %). In 13.0 %, no focus of infection was identified though symptoms of severe infection were present. The most frequent pathogens were Staphylococcus epidermidis (30.4 %), Staphylococcus aureus (23.1 %) and Enterococcus species (10.1 %). Daptomycin doses ranging from 3 mg/kg every 48 h to 10 mg/kg every 24 h were administered for 15.4 ± 11.8 days. 87.0 % of the cases were classified as success, 7.2 % as treatment failure and 5.8 as non-evaluable. Adverse events were limited to one case of mild and one case of moderate neutropenia with recovery upon termination of treatment.

Conclusion

Daptomycin proved safe and effective in major infection in high-risk cardiac surgical patients.

Acute kidney injury after cardiac surgery according to Risk/Injury/Failure/Loss/End-stage, Acute Kidney Injury Network, and Kidney Disease: Improving Global Outcomes classifications

PURPOSE

The epidemiology of acute kidney injury (AKI) after cardiac surgery depends on the definition used. Our aims were to evaluate the Risk/Injury/Failure/Loss/End-stage (RIFLE) criteria, the AKI Network (AKIN) classification, and the Kidney Disease: Improving Global Outcomes (KDIGO) classification for AKI post-cardiac surgery and to compare the outcome of patients on renal replacement therapy (RRT) with historical data.

METHODS

Retrospective analysis of 1881 adults who had cardiac surgery between May 2006 and April 2008 and determination of the maximum AKI stage according to the AKIN, RIFLE, and KDIGO classifications.

RESULTS

The incidence of AKI using the AKIN and RIFLE criteria was 25.9% and 24.9%, respectively, but individual patients were classified differently. The area under the receiver operating characteristic curve for hospital mortality was significantly higher using the AKIN compared with the RIFLE criteria (0.86 vs 0.78, P = .0009). Incidence and outcome of AKI according to the AKIN and KDIGO classification were identical. The percentage of patients who received RRT was 6.2% compared with 2.7% in 1989 to 1990. The associated hospital mortality fell from 82.9% in 1989 to 1990 to 15.6% in 2006 to 2008.

CONCLUSIONS

The AKIN classification correlated better with mortality than did the RIFLE criteria. Mortality of patients needing RRT after cardiac surgery has improved significantly during the last 20 years.

[Daptomycin for the treatment of gram-positive infections after cardiac surgery]

BACKGROUND AND METHOD

Surgical infection remains a main cause of death after heart surgery, despite advances in pharmacological therapy. Daptomycin is a cyclic lipopeptide antibiotic, useful in gram-positive organisms resistant to standard treatment, including vancomycin. The aim of this study was to describe the use of daptomycin regarding efficacy, efficiency and safety in patients with gram-positive infections after heart surgery using a retrospective analysis on 49 adult patients.

CONCLUSION

Daptomycin shows excellent in vitro and in vivo activity against gram-positive organisms, such as Enterococcus faecalis, Enterococcus faecium, Staphylococcus aureus, especially MRSA. Daptomycin is also effective against increasing vancomycin-resistant or vancomycin-intermediate S. aureus.

The impact of major perioperative renal insult on long-term renal function and survival after cardiac surgery

Temporary renal replacement therapy (RRT) facilitates recovery from a major perioperative renal injury and, although RRT can improve the hospital outcome, it is not known as to whether it mitigates long-term renal sequelae. Therefore, we investigated the risk of long-term dialysis after RRT post-cardiac surgery. We analysed prospectively the data collected for all hospital survivors who received RRT following cardiac surgery between March 1996 and July 2010, excluding those on dialysis preoperatively or with a functioning renal transplant. The follow-up data were obtained for all surviving patients. The mean age of the 82 patients was 68.6 ± 9.9 years, and 60 (73%) were male. Severe pre-existing renal dysfunction with a serum creatinine level of >200 μmol/l was present in 15 (18%) patients and diabetes in 31 (38%) patients. Operative procedures included redo surgery (n = 11, 13%) and thoracic aortic surgery (n = 9, 11%). During a 13.4-year follow-up, there were 38 late deaths. Only three patients with severe preoperative renal dysfunction received dialysis. The Kaplan-Meier 5- and 7-year survival rates for this patient cohort were 54% and 38%, respectively. In conclusion, a major renal insult requiring temporary RRT after cardiac surgery does not increase the risk for renal dialysis in the long term for patients with normal renal function preoperatively.