Preoperative serum cystatin C combined with dipstick proteinuria predicts acute kidney injury after cardiac surgery

Background: Acute kidney injury (AKI) is common following cardiac surgery and is associated with poor outcomes. However, the detection of those preoperative patients who will develop AKI is still difficult. In this study, we compared serum cystatin C combined with dipstick proteinuria as early markers to predict AKI available before surgery. Methods: We prospectively followed 616 patients undergoing cardiac surgery and identified 179 that developed AKI, defined as an increase in serum creatinine (SCr) of ≥?0.3?mg/dL or ≥?50% increase in creatinine level. Preoperative values for cystatin C were categorized into quartiles. We defined proteinuria, measured with a dipstick, as mild (trace to 1+) or heavy (2?+?to 4+). Univariate as well as multivariate regression was performed. Cystatin C combined with dipstick proteinuria before surgery was assessed for its' predictive value of AKI using receiver operating characteristic (ROC) curves. Results: The final cohort consisted of 616 patients aged 60.7?±?13.2 years, and baseline SCr was 75.8?±?26.4?μmol/L, estimated glomerular filtration rate (eGFR) 96.3?±?29.0?mL/min/1.73?m² and cystatin C 1.05?±?0.33?mg/L. Patients in higher cystatin C quartiles were older (p?p?=?0.021), hyperuricemia (p?p?p?=?0.002). Those with heavy proteinuria were more often to have diabetes mellitus (p?=?0.010), hyperuricemia (p?=?0.043), worse cardiac function (p?p?p?p?p?p?p?p?Conclusion: These data suggest that preoperative serum cystatin C combined with dipstick proteinuria may improve prediction of AKI among patients undergoing cardiac surgery.     

Mild hypothermia attenuate kidney injury in canines with oleic acid-induced acute respiratory distress syndrome

BackgroundHypothermia may attenuate ventilator induced-lung injury in acute respiratory distress syndrome (ARDS). However, the impact of hypothermia on extra-pulmonary organ injury in ARDS remains unclear. The purpose of this study was to investigate whether hypothermia affects extra-pulmonary organ injury in a canine ARDS model induced by oleic acid.ObjectivesTwelve anesthetized canines with oleic acid-induced ARDS were randomly divided (n = 6 per group) into a hypothermia group (core temperature of 33 ± 1 °C, HT group) and a normothermia group (core temperature of 38 ± 1 °C, NT group) and treated for four hours. The liver, small intestine and kidney were assessed by evaluating biochemical parameters, plasma and tissue cytokine levels, and tissue histopathological injury scores.ResultsThe HT group showed a lower plateau pressure, lung elastance and pulmonary vascular resistance. Hypothermia was associated with lower oxygen consumption (138.4 ± 55.0 ml min⁻¹ vs. 72.0 ± 11.2 ml min⁻¹, P < 0.05) and higher oxygen saturation of mixed venous blood (62.8% ± 8.0% vs. 77.5% ± 10.1%, P < 0.05). Both groups had similar levels of tumour necrosis factor-α in the plasma and extra-pulmonary organ, however, plasma interleukin-10 (97.1 ± 25.0 pg ml⁻¹ vs. 131.4 ± 27.0 pg ml⁻¹, P < 0.05) was higher in the HT group. Further, the animals in the HT group had a lower levels of plasma creatinine (54.6 ± 19.1 U L⁻¹ vs. 29.1 ± 8.0 U L⁻¹, P < 0.05), and lower renal histopathological injury scores [4.0(3.5;7.0) vs. 1.5(0.8;3.0), P < 0.05]. Hypothermia did not affect the histopathological injury of the liver and small intestine.ConclusionsShort-term mild hypothermia can reduce lung elastance and pulmonary vascular resistance, increase the systemic anti-inflammatory response and attenuate kidney histopathological injury in a canine ARDS model induced by oleic acid.     

Early postoperative serum cystatin C predicts severe acute kidney injury following pediatric cardiac surgery

Anti-endothelial cell antibodies (AECAs) are thought to be involved in the development of renal allograft rejection. To explore this further, we determine whether AECAs play a role both in predicting the incidence of allograft rejection and long-term outcomes by analysis of serum samples from 226 renal allograft recipients for AECAs pre- and post-transplant. Surprisingly, the presence of pre-existing AECAs was not associated with either an increased risk of rejection or a detrimental impact on recipient/graft survival. Subsequent de novo AECAs, however, were associated with a significantly increased risk of early acute rejection. Moreover, these rejections tended to be more severe with a significantly increased incidence of both steroid-resistant and multiple episodes of acute rejection. The acute rejections associated with de novo AECAs did not correlate with C4d deposition at the time of renal biopsy, but did demonstrate an association with the presence of glomerulitis and peritubular capillary inflammation. Significantly more patients with de novo AECAs developed graft dysfunction. Thus, our prospective study suggests the emergence of de novo AECAs is associated with transplant rejection that may lead to allograft dysfunction.     

Serum and urine acute kidney injury biomarkers in asphyxiated neonates

Background

We evaluated serum (s) cystatin C (CysC) and neutrophil gelatinase-associated lipocalin (NGAL) and urine (u) CysC, NGAL and kidney injury molecule-1 (KIM-1) as markers of acute kidney injury (AKI) in asphyxiated neonates.

Methods

AKI biomarkers were measured in 13 asphyxiated neonates born at ≥36?weeks gestational age (eight with AKI and five without AKI) and 22 controls. AKI was defined as serum creatinine ≥1.5?mg/dl for >24?h or rising values >0.3?mg/dl from day of life (DOL) 1. Biomarkers were measured on DOL 1, 3, and 10.

Results

Asphyxiated neonates had significantly higher sCysC on DOL 1 as well as sNGAL and uCysC and uNGAL (standardized to urine creatinine and absolute values) than controls at all time points. Compared to controls, significantly higher sNGAL, uCysC, and uNGAL values were observed in the asphyxia-AKI and asphyxia–no AKI subgroups. Regarding uKIM-1, only the absolute values were significantly higher in asphyxiated neonates (DOL 10). sNGAL, uCyst, and uNGAL had a significant diagnostic performance as predictors AKI on DOL 1.

Conclusions

sNGAL, uCysC, and uNGAL are sensitive, early AKI biomarkers, increasing significantly in asphyxiated neonates even in those not fulfilling AKI criteria. Their measurement on DOL 1 is predictive of post-asphyxia-AKI.     

���Է����ˡ����Ժ��������ۺ��������ƽ�չ

急性肺损伤(acute lung injury，ALI)、急性呼吸窘迫综合征(acute respiratory distress syndrome，ARDS)是指由非静水压原因所导致的肺部一系列病理生理改变继而引起急性、进行性缺氧性呼吸衰竭。ALI和ARDS不是孤立、相互分割的疾病，它们是严重损伤引起机体全身免疫炎征反应失控过程中的不同阶段。从损伤→全身炎症反应综合征     

Optimal ventilator settings in acute lung injury and acute respiratory distress syndrome

Despite recent advances in intensive care medicine, acute lung injury and its more severe form, acute respiratory distress syndrome pose major therapeutic problems. While mechanical ventilation is integral to the care of these patients, its adverse consequences including ventilator-induced lung injury are determinants of disease progression and prognosis. Among several important ventilator parameters, the use of low tidal volumes is probably the most important feature of lung-protective mechanical ventilation. Intensivists should be trained to recognize acute lung injury and acute respiratory distress syndrome and encouraged to use low-tidal-volume ventilation in clinical practice. Alternative modes of ventilation such as high-frequency ventilation and prone position should be reserved for selected patients in whom conventional lung-protective ventilation strategies have failed.     

Right ventricular failure in acute lung injury and acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is a clinical entity involving not only alveolar lesions but also capillary lesions, both of which have deleterious effects on the pulmonary circulation, leading to constant pulmonary hypertension and to acute cor pulmonale (ACP) in 20-25% of patients ventilated with a limited plateau pressure (Pplat). Considering the poor prognosis of patients suffering from such acute right ventricular (RV) dysfunction, RV protection by appropriate ventilatory settings has become a crucial issue in ARDS management. The goal of this review is to emphasize the importance of analyzing RV function in ARDS, using echocardiography, in order to limit RV afterload. Any observed acute RV dysfunction should lead physicians to consider a strategy for RV protection, including strict limitation of Pplat, diminution of positive end-expiratory pressure (PEEP) and control of hypercapnia, all goals achieved by prone positioning.     

急性肺损伤/急性呼吸窘迫综合征液体治疗策略

背景 高通透性肺水肿是急性肺损伤/急性呼吸窘迫综合征(acute lung injury/acute respiratory distress syndrome,ALI/ARDS)的基本病理生理特征,其程度与ALI/ARDS的预后密切相关.目的 对ALI/ARDS患者合理的液体管理,有助于改善ALI/ARDS患者的肺水肿,降低该病病死率.内容 回顾了ALI/ARDS液体治疗策略探索过程中存在争议的问题(如限制性或开放性的液体治疗策略及治疗液体种类的选择),总结了该领域近年来的研究进展(如ALI/ARDS病程不同阶段的差异化治疗及液体治疗的监测指标).趋向 今后将进一步探索该病在不同的病理生理状态下特异性的液体治疗方法,寻求高效敏感的监测指标,指导液体治疗策略的选择和调整.     

High-frequency oscillatory ventilation in adults with traumatic brain injury and acute respiratory distress syndrome

BACKGROUND: This study observed adverse events of rescue treatment with high-frequency oscillatory ventilation (HFOV) in head-injured patients with acute respiratory distress syndrome (ARDS). METHODS: Data of five male patients with ARDS and traumatic brain injury, median age 28 years, who failed to respond to conventional pressure-controlled ventilation (PCV) were analyzed retrospectively during HFOV. Adjusted mean airway pressure at initiation of HFOV was set to 5 cm H2O above the last measured mean airway pressure during PCV. Frequency of pulmonary air leak, mucus obstruction, tracheal injury, and need of HFOV termination due to increased intracranial pressure, decreased cerebral perfusion pressure, or deterioration in P(a)CO2 were analyzed. RESULTS: During HFOV we found no complications. We recorded 390 datasets of intracranial pressure, cerebral perfusion pressure and P(a)CO2 simultaneously. Intracranial pressure increased (>25 mmHg) in 11 of 390 datasets, cerebral perfusion pressure was reduced (<70 mmHg) in 66 of 390 datasets, and P(a)CO2 variations (<4.7 kPa; >6.0 kPa) were observed in eight of 390 datasets after initiation of HFOV. All these alterations were responsive to treatment. P(a)O2/F(I)O2-ratio improved in four patients during HFOV. Conclusion: High-frequency oscillatory ventilation appears to be a promising alternative rescue treatment in head-injured patients with ARDS if continuous monitoring of intracranial pressure, cerebral perfusion pressure and P(a)CO2 are provided, in particular during initiation of HFOV.     

The use of prone ventilation in acute lung injury and acute respiratory distress syndrome

Prone positioning has been suggested since 1974 as a ventilatory strategy to improve oxygenation and pulmonary mechanics in patients with acute lung injury and acute respiratory distress syndrome. Although this mode of ventilation can improve gas exchange, the optimal role of the prone position is uncertain. The aim of this article is to examine the evidence in support of this mode of ventilation in adult patients with acute lung injury and acute respiratory distress syndrome. Limitations of the currently available evidence upon which the recommendations are made must be recognized. With these limitations in mind, however, the available evidence has been considered and conclusions presented. Considerable clinical experience confirms that prone ventilation can improve oxygenation in the majority of patients. It is difficult to predict which patients will respond. There are few contraindications and with experienced staff it can be achieved safely. Most patients should therefore be considered for a trial of prone positioning. Prolonged and repeated prone ventilation may be more effective. Whether the improvement in physiological parameters translates into improved clinical outcomes is less certain and well-designed randomized controlled trials will be required to address this issue.     

Lung injury and acute respiratory distress syndrome after cardiopulmonary bypass.

Cardiopulmonary bypass is often followed by pulmonary dysfunction as assessed by measuring the alveolar-arterial oxygenation gradient, intrapulmonary shunt, degree of pulmonary edema, pulmonary compliance, and pulmonary vascular resistance. It is also regarded as a risk factor for development of acute respiratory distress syndrome. On the other hand, cardiopulmonary bypass is associated with a whole body inflammatory response, which involves activation of complement, leukocytes, and endothelial cells with secretion of cytokines, proteases, arachidonic acid metabolites, and oxygen free radicals. Leukocyte adhesion to microvascular endothelium, leukocyte extravasation, and tissue damage are the final steps. Although the inflammatory response to cardiopulmonary bypass often remains at subclinical levels, it can also lead to major organ dysfunction and multiple organ failure. This review article summarizes the recent literature on the molecular and cellular mechanisms involved in the phenomenon of pulmonary dysfunction after cardiopulmonary bypass. It also summarizes reports on the prevalence and mortality of acute respiratory distress syndrome after cardiac surgery.     

Acute lung injury and acute respiratory distress syndrome after pulmonary resection

BACKGROUND: In this study we investigate the frequency and mortality of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) after pulmonary resection. METHODS: Patients that underwent pulmonary resection at the Royal Brompton Hospital between 1991 and 1997 were included. The case notes of all patients developing postoperative complications were retrospectively reviewed. RESULTS: The overall combined frequency of ALI and ARDS was 3.9%. The frequency was higher in patients over 60 years of age, males and those undergoing resection for lung cancer. ALI/ARDS caused 72.5% of the total mortality after resection in this series. CONCLUSIONS: In our experience ALI and ARDS are major causes of mortality after lung resection.     

Acute lung injury and acute respiratory distress syndrome after pulmonary resection

The occurrence of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) after thoracic surgery are perplexing and persistent problems. Variously described as postpneumonectomy pulmonary edema, noncardiogenic pulmonary edema, and postlung resection pulmonary edema, ALI and ARDS may be considered a single entity, with ALI being the less severe form of ARDS. It is characterized by the acute onset of hypoxemia with radiographic infiltrates consistent with pulmonary edema, without elevations in the pulmonary capillary wedge pressure. Although this syndrome does not occur frequently and is usually without identifiable cause, the mortality is high. However, the phenomenon has not been rigorously studied owing to the low incidence, with primarily retrospective case series reported. Thus, the nomenclature, risks, and pathogenesis are not well defined. Interest in this syndrome has recently been renewed as the rate of other perioperative complications has declined. ALI/ARDS is reviewed with a focus on potential etiologies and the spectrum of available interventions.