Does Intraoperative Cell Salvage Reduce Postoperative Infection Rates in Cardiac Surgery?

Objective: Primary outcome was the risk for infections after cell salvage in cardiac surgery. Design: Data of a randomized controlled trial on cell salvage and filter use (ISRCTN58333401). Setting: Six cardiac surgery centers in the Netherlands. Participants: All 716 patients undergoing elective coronary artery bypass grafting, valve surgery, or combined procedures over a 4-year period who completed the trial. Interventions: Postoperative infection data were assessed according to Centre of Disease Control and Prevention/National Healthcare Safety Network surveillance definitions. Measurements and Main Results: Fifty-eight (15.9%) patients with cell salvage had infections, compared with 46 (13.1%) control patients. Mediation analysis was performed to estimate the direct effect of cell salvage on infections (OR 2.291 [1.177;4.460], p = 0.015) and the indirect effects of allogeneic transfusion and processed cell salvage blood on infections. Correction for confounders, including age, seks and body mass index was performed. Allogeneic transfusion had a direct effect on infections (OR = 2.082 [1.133;3.828], p = 0.018), but processed cell salvage blood did not (OR = 0.999 [0.999; 1.001], p = 0.089). There was a positive direct effect of cell salvage on allogeneic transfusion (OR = 0.275 [0.176;0.432], p < 0.001), but a negative direct effect of processed cell salvage blood (1.001 [1.001;1.002], p < 0.001) on allogeneic transfusion. Finally, there was a positive direct effect of cell salvage on the amount of processed blood. Conclusions: Cell salvage was directly associated with higher infection rates, but this direct effect was almost completely eliminated by its indirect protective effect through reduced allogeneic blood transfusion

Preoperative anaemia and outcome after elective cardiac surgery:a Dutch national registry analysis

Background: Previous studies have shown that preoperative anaemia in patients undergoing cardiac surgery is associated with adverse outcomes. However, most of these studies were retrospective, had a relatively small sample size, and were from a single centre. The aim of this study was to analyse the relationship between the severity of preoperative anaemia and short- and long-term mortality and morbidity in a large multicentre national cohort of patients undergoing cardiac surgery. Methods: A nationwide, prospective, multicentre registry (Netherlands Heart Registration) of patients undergoing elective cardiac surgery between January 2013 and January 2019 was used for this observational study. Anaemia was defined according to the WHO criteria, and the main study endpoint was 120-day mortality. The association was investigated using multivariable logistic regression analysis. Results: In total, 35 484 patients were studied, of whom 6802 (19.2%) were anaemic. Preoperative anaemia was associated with an increased risk of 120-day mortality (adjusted odds ratio [aOR] 1.7; 95% confidence interval [CI]: 1.4–1.9; P<0.001). The risk of 120-day mortality increased with anaemia severity (mild anaemia aOR 1.6; 95% CI: 1.3–1.9; P<0.001; and moderate-to-severe anaemia aOR 1.8; 95% CI: 1.4–2.4; P<0.001). Preoperative anaemia was associated with red blood cell transfusion and postoperative morbidity, the causes of which included renal failure, pneumonia, and myocardial infarction. Conclusions: Preoperative anaemia was associated with mortality and morbidity after cardiac surgery. The risk of adverse outcomes increased with anaemia severity. Preoperative anaemia is a potential target for treatment to improve postoperative outcomes

Angiopoietin/Tie2 Dysbalance Is Associated with Acute Kidney Injury after Cardiac Surgery Assisted by Cardiopulmonary Bypass

Introduction The pathophysiology of acute kidney injury (AKI) after cardiac surgery is not completely understood. Recent evidence suggests a pivotal role for the endothelium in AKI. In experimental models of AKI, the endothelial specific receptor Tie2 with its ligands Angiopoietin (Ang) 1 and Ang2 are deranged. This study investigates their status after cardiac surgery, and a possible relation between angiopoietins and AKI. Methods From a cohort of 541 patients that underwent cardiac surgery, blood and urine was collected at 5 predefined time points. From this cohort we identified 21 patients who had at least 50% post-operative serum creatinine increase (AKI). We constructed a control group (n = 21) using propensity matching. Systemic levels of Ang1, Ang2, and sTie2 were measured in plasma and the AKI markers albumin, kidney injury molecule-1 (KIM-1) and N-acetyl-beta-D-glucosaminidase (NAG) were measured in the urine. Results Ang2 plasma levels increased over time in AKI (from 4.2 to 11.6 ng/ml) and control patients (from 3.0 to 6.7 ng/ml). Ang2 levels increased 1.7-fold more in patients who developed AKI after cardiac surgery compared to matched control patients. Plasma levels of sTie2 decreased 1.6-fold and Ang1 decreased 3-fold over time in both groups, but were not different between AKI and controls (Ang1 P = 0.583 and sTie2 P = 0.679). Moreover, we found a positive correlation between plasma levels of Ang2 and urinary levels of NAG. Conclusions The endothelial Ang/Tie2 system is in dysbalance in patients that develop AKI after cardiac surgery compared to matched control patients

Intraoperative cell salvage during cardiac surgery is associated with reduced postoperative lung injury

OBJECTIVES: In addition to its blood-sparing effects, intraoperative cell salvage may reduce lung injury following cardiac surgery by removing cytokines, neutrophilic proteases and lipids that are present in cardiotomy suction blood. To test this hypothesis, we performed serial measurements of biomarkers of the integrity of the alveolar-capillary membrane, leucocyte activation and general inflammation. We assessed lung injury clinically by the duration of postoperative mechanical ventilation and the alveolar arterial oxygen gradient. METHODS: Serial measurements of systemic plasma concentrations of interleukin-6 (IL-6), myeloperoxidase, elastase, surfactant protein D (SP-D), Clara cell 16 kD protein (CC16) and soluble receptor for advanced glycation endproducts (sRAGEs) were performed on blood samples from 195 patients who underwent cardiac surgery with the use of a cell salvage (CS) device (CS, n = 99) or without (CONTROL, n = 96). RESULTS: Postoperative mechanical ventilation time was shorter in the CS group than in the CONTROL group [10 (8-15) vs 12 (9-18) h, respectively, P = 0.047]. The postoperative alveolar arterial oxygen gradient, however, was not different between groups. After surgery, the lung injury biomarkers CC16 and sRAGEs were lower in the CS group than in the CONTROL group. Biomarkers of systemic inflammation (IL-6, myeloperoxidase and elastase) were also lower in the CS group. Finally, mechanical ventilation time correlated with CC16 plasma concentrations. CONCLUSIONS: The intraoperative use of a cell salvage device resulted in less lung injury in patients after cardiac surgery as assessed by lower concentrations of lung injury markers and shorter mechanical ventilation times

Plasma levels of Angiopoietin-1, Angiopoietin-2 and soluble Tie2 in patients with and without acute kidney injury after cardiac surgery.

<p><b>A:</b> Angiopoietin-1 (Ang1); <b>B:</b> Angiopoietin-2 (Ang2); <b>C:</b> Ang1/Ang2; <b>D:</b> soluble Tie2 (sTie2). AKI: <b>acute kidney injury. Time points are before (pre-op) and at the end of the operation (end-op), after 3 hours in the intensive care unit (3h ICU) and on the first and second post-operative day (day 1 and day 2).</b> P-values are given for differences between the groups (^# P_<i>group</i>) and differences in time (P_<i>time</i>) using two-way ANOVA with repeated measurements.</p

Correlations between plasma Ang2 levels and urinary levels of markers renal injury on the first post-operative day in patients after cardiac surgery.

<p><b>A:</b> serum creatinine; <b>B: urine</b> Kidney Injury Molecule-1 (KIM-1); <b>C:</b> urine Albumin; <b>D:</b> urine N-acetyl-β-D-glucosaminidase (NAG); Correlation (R) is given when significant. Statistics are analyzed using the Pearson correlation coefficient.</p

Urinary levels of markers for renal injury in patients with and without acute kidney injury after cardiac surgery.

<p><b>A:</b> Albumin; <b>B:</b> Kidney Injury Molecule-1 (KIM-1); <b>C:</b> N-acetyl-β-D-glucosaminidase (NAG). AKI: acu<b>te kidney injury. Time points are before (pre-op) and at the end of the operation (end-op), after 3 hours in the intensive care unit (3h ICU) and on the first and second post-operative day (day 1 and day 2).</b> P-values are given for differences between the groups (^# P_<i>group</i>) and differences in time (P_<i>time</i>). using two-way ANOVA with repeated measurements.</p

Transfusion and post-operative data.

<p>RBC: red blood cell concentrate, FFP: fresh frozen plasma, LOS: length of stay in the ICU. Data are presented as mean ± SD or as a percentage for the whole patient group (overall), the patients with acute kidney injury (AKI), and a matched control group (control). Length of stay is expressed as median and interquartile range. <i>P</i>-values are given for AKI versus control group.</p><p>Transfusion and post-operative data.</p

Patient demographics.

<p>PCI: percutaneous coronary intervention, COPD: chronic obstructive pulmonary disease, CABG: coronary artery bypass grafting, CPB: cardiopulmonary bypass. Data are presented as mean ± SD or as a percentage where indicated. Standardized differences are shown between the whole patient group (overall) and the patients with acute kidney injury (AKI), and between AKI and a matched control group (control). <i>P</i>-values are given for AKI versus control group.</p><p>Patient demographics.</p