Safety, Pharmacodynamics, and Efficacy of High- Versus Low-Dose Ascorbic Acid in Severely Burned Adults

2020 ◽  
Vol 41 (4) ◽  
pp. 871-877
Author(s):  
Sarah Sophie Nagel ◽  
Christian Andreas Radu ◽  
Thomas Kremer ◽  
David Meess ◽  
Johannes Horter ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Retrospective Study ◽  
Clinical Outcomes ◽  
Low Dose ◽  
Kidney Injury ◽  
High Dose ◽  
Severe Burns ◽  
Increased Risk ◽  
Before And After ◽  
Resuscitation Fluid

Abstract In sepsis and burns, ascorbic acid (AA) is hypothesized advantageous during volume resuscitation. There is uncertainty regarding its safety and dosing. This study evaluated high dose AA (HDAA: 66 mg/kg/h for 24 hours) versus low dose AA (LDAA: 3.5 g/days) administration during the first 24 hours in severely burned adults. We conducted a retrospective study comparing fluid administration before and after switching from low dose to HDAA in severely burned adults. A total of 38 adults with burns >20% TBSA, who received either HDAA or LDAA were included in this retrospective study. AA serum concentrations were quantified at 0, 24, and 72 hours postburn. HDAA impact on hemodynamics, acid–base homeostasis, acute kidney injury, vasopressor use, resuscitation fluid requirement, urinary output, and the incidence of adverse effects was evaluated; secondary clinical outcomes were analyzed. AA plasma levels were 10-fold elevated in the LDAA and 150-fold elevated in the HDAA group at 24 hours and decreased in both groups afterwards. HDAA was not associated with a significantly increased risk of any complications. A significant reduction in colloid fluid requirements was noted (LDAA: 947 ± 1722 ml/24 hours vs HDAA: 278 ± 667 ml/24 hours, P = 0.029). Other hemodynamic and resuscitation measures, as well as secondary clinical outcomes were comparable between groups. HDAA was associated with higher AA levels and lower volumes of colloids in adults with severe burns. The rate of adverse events was not significantly higher in patients treated with HDAA. Future studies should consider prolonged administration of AA.

Benefit/Risk Profile of Combined Antiplatelet Therapy with Ticlopidine and Aspirin

1991 ◽  
Vol 65 (05) ◽  
pp. 504-510 ◽  
Author(s):  
Raffaele De Caterina ◽  
Rosa Sicari ◽  
Walter Bernini ◽  
Guido Lazzerini ◽  
Giuliana Buti Strata ◽  
...  
Keyword(s):  
Platelet Function ◽  
Low Dose ◽  
Bleeding Time ◽  
Ex Vivo ◽  
Stable Coronary Artery Disease ◽  
High Dose ◽  
Single Drug ◽  
Before And After ◽  
Serum Thromboxane ◽  
Artery Disease

SummaryTiclopidine (T) and aspirin (ASA) are two antiplatelet drugs both capable of prolonging bleeding time (BT), with a different mechanism of action. A synergism in BT prolongation has been reported and is currently considered an argument for not recommending their combination. However, a profound suppression of platelet function might be a desirable counterpart of a marked prolongation of BT, with a possible use in selected clinical situations. We therefore studied ex vivo platelet function (aggregation by ADP 0.5-1-2.5 μM; adrenaline 0.75-2.5 μM; collagen 1.5-150 μg/ml; arachidonic acid 1 mM; PAF 1 μM; adrenaline 0.17 μM + ADP 0.62 μM; serum thromboxane ([TX]B2 generation) and BT (Mielke) in 6 patients with stable coronary artery disease receiving such combination. Patients underwent sequential laboratory evaluations at baseline, after 7 days of T 250 mg b.i.d., before and after the intravenous administration of ASA 500 mg, respectively, and, finally, after a minimum of 7 days of sole ASA oral administration (50 mg/day). The experimental design, therefore, allowed a comparison of T and ASA effects (2nd and 4th evaluation), and an assessment of the combination effect (3rd evaluation). Platelet aggregation in response to all doses of ADP was depressed more by T than by ASA. Conversely, responses to adrenaline, and arachidonate were affected more by ASA than by T. For all other agents, differences were not significant. T + ASA combination was more effective (p <0.05) than either treatment alone in depressing responses to high-dose collagen (% over control, mean ± SEM: T: 95 ± 3; ASA: 96 ± 5; T + ASA: 89 ± 4). Serum TXB2 (basal, ng/ml: 380 ± 54) did not change with T (372 ± 36), dropped to <1 ng/ml on ASA injection and slightly re-increased to 9.1 ± 3.1 ng/ml on oral low-dose ASA. BT (basal 7.4 ± 0.6 min) was affected similarly by T (9.2 ± 0.8) or ASA (9.7 ± 0.9) alone, but increased to 15.0 ± 0.7 min on combination treatment (106% increase over control). Thus, the strong synergism in BT prolongation by ASA-T combination has a counterpart in the inhibition of platelet function in response to strong stimuli such as high-dose collagen, not otherwise affected significantly by single-drug treatment. This effect is a possible rationale for the clinical evaluation of T + ASA combination.

scholarly journals Kidney Injury Caused by Preeclamptic Pregnancy Recovers Postpartum in a Transgenic Rat Model

2021 ◽  
Vol 22 (7) ◽  
pp. 3762
Author(s):  
Sarah M. Kedziora ◽  
Kristin Kräker ◽  
Lajos Markó ◽  
Julia Binder ◽  
Meryam Sugulle ◽  
...  
Keyword(s):  
Rat Model ◽  
Renal Damage ◽  
Kidney Injury ◽  
Tissue Growth ◽  
Female Rats ◽  
Male Rats ◽  
Renal Diseases ◽  
Transgenic Rat ◽  
Increased Risk ◽  
Before And After

Preeclampsia (PE) is characterized by the onset of hypertension (≥140/90 mmHg) and presence of proteinuria (>300 mg/L/24 h urine) or other maternal organ dysfunctions. During human PE, renal injuries have been observed. Some studies suggest that women with PE diagnosis have an increased risk to develop renal diseases later in life. However, in human studies PE as a single cause of this development cannot be investigated. Here, we aimed to investigate the effect of PE on postpartum renal damage in an established transgenic PE rat model. Female rats harboring the human-angiotensinogen gene develop a preeclamptic phenotype after mating with male rats harboring the human-renin gene, but are normotensive before and after pregnancy. During pregnancy PE rats developed mild tubular and glomerular changes assessed by histologic analysis, increased gene expression of renal damage markers such as kidney injury marker 1 and connective-tissue growth factor, and albuminuria compared to female wild-type rats (WT). However, four weeks postpartum, most PE-related renal pathologies were absent, including albuminuria and elevated biomarker expression. Only mild enlargement of the glomerular tuft could be detected. Overall, the glomerular and tubular function were affected during pregnancy in the transgenic PE rat. However, almost all these pathologies observed during PE recovered postpartum.

A New Hafnium-Beryllium System Prioduced by Ion Implantation and Annealing Techniques

1983 ◽  
Vol 27 ◽  
Author(s):  
J.C. Soares ◽  
A.A. Melo ◽  
M.F. DA Silva ◽  
E.J. Alves ◽  
K. Freitag ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Single Crystals ◽  
Room Temperature ◽  
Low Dose ◽  
Correlation Method ◽  
High Dose ◽  
Tetrahedral Sites ◽  
Time Differential ◽  
Before And After ◽  
Beryllium Foil

ABSTRACTLow and high dose hafnium imolanted beryllium samoles have been prepared at room temperature by ion implantation of beryllium commercial foils and single crystals. These samples have been studied before and after annealing with the time differential perturbed angular correlation method (TDPAC) and with Rutherford backscattering and channeling techniques. A new metastable system has been discovered in TDPAC-measurements in a low dose hafnium implanted beryllium foil annealed at 500°C. Channeling measurements show that the hafnium atoms after annealing, are in the regular tetrahedral sites but dislocated from the previous position occupied after implantation. The formation of this system is connected with the redistribution of oxygen in a thin layer under the surface. This effect does not take place precisely at the same temperature in foils and in single crystals.

scholarly journals Ripk3 Signaling Regulates Hematopoietic Stem Cell Number and Function during Stress

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3714-3714
Author(s):  
Lei Zhang ◽  
Huacheng Luo ◽  
Jing Li ◽  
Hong-Min Ni ◽  
Mark Sellin ◽  
...  
Keyword(s):  
Inflammatory Cytokines ◽  
Low Dose ◽  
Conflicts Of Interest ◽  
Lymphoblastic Leukemia ◽  
High Dose ◽  
Low Doses ◽  
Hematopoietic Stem ◽  
Increased Risk ◽  
Leukemia Development ◽  
Serial Transplantation

Background: Among all tissues, bone marrow (BM) is the most sensitive tissue to ionizing radiation (IR)-induced acute tissue damage (ATD) and chronic long-term residual damage (LT-RD). BM failure and a significant reduction in blood cells (pancytopenia) often occurs within days after exposure to IR due to the massive death of proliferative hematopoietic progenitor cells (HPCs). However, due to their quiescent cell cycle status and reduced fidelity of DNA repair feature, many hematopoietic stem cells (HSCs) cannot fully eliminate such damage and enter senescence; this results in LT-RD. Abnormal dysplastic hematopoiesis is the most common LT-RD in most victims of IR, followed by an increased risk of leukemia/lymphoma development. Thus IR exposure is an established cause of BM failure and leukemia. A significant increase in the production of inflammatory cytokines is induced by IR which contributes to the pathogenesis of both ATD and LT-RD. Such inflammatory cytokines induce the activation of Ripk3-Mlkl-mediated necroptotic signaling in HSCs. However, the role of Ripk3-Mlkl signaling in IR-induced damage has not studied. Experimental procedures: The self-renewal capacity of HSCs among Ripk3-/-, Mlkl-/- and WT mice were examined and compared by serial transplantation assay. The phenotypes of ATD and LT-RD induced by different dosages of IR were compared among Ripk3-/-, Mlkl-/- and WT mice. The mechanism by which Ripk3 signaling prevents IR-induced leukemia development was studied. Results: Ripk3-Mlkl signaling is not required for hematopoiesis during homeostatic condition. However, during serial transplantation, inactivation of such signaling prevents stress-induced loss of HSCs. Interestingly, Ripk3 signaling also induces an Mlkl-independent ROS-p38-p16-mediated senescence in HSCs. Thus Ripk3-/- HSCs showed better competitive hematopoietic ability compared to Mlkl-/- and WT HSCs during serial transplantation. A sub-lethal dosage of IR (6Gy) induces Ripk3-dependent NF-κB activation and pro-survival gene expression in HSCs, which is necessary for the survival of damaged HSCs. After 6Gy IR, although DNA damage is repaired in most HSCs within 2 days, a proportion of HSCs in WT and Mlkl-/- mice fail to fully repair the damage and undergo p53-p21-dependent senescence. However such cells in Ripk3-/- mice die from apoptosis. Thus the remaining HSCs in Ripk3-/- mice should be functionally normal, while a proportion of the remaining HSCs in Mlkl-/- and WT mice remain damaged but senescent, all as demonstrated by competitive hematopoietic reconstitution assay. Multiple low-doses of IR (1.75Gy once week × 4) induce HSC exhaustion in WT mice but not in Ripk3-/- and Mlkl-/- mice. Interestingly, almost all Ripk3-/- mice develop acute lymphoblastic leukemia within 200 days after such low dose IR, while 45% of WT and 60% of Mlkl-/- mice develop thymomas within 360 days (see Figure). Mechanistically, such low-dose IR stimulates chronic inflammatory cytokine production. Such cytokines induce Ripk3-Mlkl-mediated necroptosis in response to HSC exhaustion observed in WT mice. These cytokines also induce Ripk3-ROS-p38-p16-mediated senescence in response to impaired HSC functioning observed in both WT and Mlkl-/- mice. In Ripk3-/- mice, due to the lack of both necroptotic and senescent signaling, mutant HSCs accumulate and leukemia development is accelerated. Conclusion: Ripk3 signaling plays distinct roles in HSCs in response to different doses of IR. High-dose IR induces Ripk3-dependent NF-κB/survival signaling, which is required for the survival of HSCs which fail to repair the damage. Thus temporal inhibition of Ripk3-NF-κB signaling might help to remove the damaged HSCs thus preventing the occurrence of LT-RD. However multiple low-doses of IR induces Ripk3 activation in HSCs which represses leukemia development by inducing both ROS-p38-p16-mediated senescence and Ripk3-Mlkl-mediated necroptosis. Induced activation of Mlkl-necroptosis might help to repress leukemia development by removing damaged HSCs. Disclosures No relevant conflicts of interest to declare.

P18 Plasma-lyte 148 vs 0.9% saline for fluid resuscition in children: electrolytic and clinical outcomes

2018 ◽  
Vol 103 (2) ◽  
pp. e1.22-e1 ◽  
Author(s):  
Wignell Andrew ◽  
Davies Patrick
Keyword(s):  
Clinical Outcomes ◽  
Kidney Injury ◽  
Fluid Volume ◽  
Lower Percentage ◽  
Clinical Effects ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
Significant Difference ◽  
Resuscitation Fluid ◽  
Plasma Chloride

AimsCrystalloid fluid boluses are a mainstay of treatment in unwell children, with the traditional fluid of choice being 0.9% saline (NS). However, the use of NS has been associated with an increase in plasma chloride levels and acidosis, leading to kidney injury and other detrimental clinical effects. Plasma-Lyte 148 (PLA) is a balanced, physiological, crystalloid intravenous fluid, which is both calcium-free and isotonic. Its use in place of NS for fluid resuscitation may circumvent hyperchloraemic metabolic acidosis. In May 2015 our hospital altered its standard resuscitation fluid from NS to PLA. We aimed to compare the effect of fluid boluses of NS to those of PLA in children.MethodsAll patients admitted in the 18 month periods before and after the change from NS to PLA, and receiving a fluid bolus in the first 24 hours of admission, were included. Post-surgical patients and those who had undergone haemofiltration were excluded. Arterial blood gas and creatinine values for up to 5 days after bolus fluid administration were examined. Patients were stratified according to the total resuscitation volume (ml/kg), then split into categories determined by the balance of PLA vs. NS.The primary outcome was plasma chloride. Secondary outcomes included blood pH and percentage change in creatinine. Clinical outcomes were length of ventilation and length of PICU stay.Results126 patients were included in the analysis. Patients receiving NS boluses tended to have a higher maximum chloride, higher average chloride, lower pH and higher percentage creatinine increase than those given PLA. Subgroup analysis showed a statistically significant difference in average serum chloride for the 61–90 ml/kg group {PLA 105.59±1.29 vs NS 111.29±2.1 mmol/L; difference: −6.21 [95% confidence interval (CI)−9.55,–2.87]}. Patients who received PLA tended to have a higher pH than those receiving NS. A statistically significant difference was seen in the 10–30 ml/kg group [PLA 7.42±0.49 vs NS 7.33±0.65; difference: 0.0913 (95% CI: −0.18 to −0.02)].Significant differences were not seen in the clinical outcomes of length of stay or ventilationConclusionPLA as a resuscitation fluid is significantly associated with a more physiological plasma chloride and pH across several resuscitation fluid volume categories, when compared to NS. The trends in the other fluid volume categories are in line with these findings, but are not statistically significant. There was also a trend towards patients receiving PLA having a lower percentage rise in creatinine than those who received saline. These results were consistent over all weight and age categories.

CIRP Secretion during Cardiopulmonary Bypass Is Associated with Increased Risk of Postoperative Acute Kidney Injury

2021 ◽  
Author(s):  
Wenyan Liu ◽  
Yang Yan ◽  
Dan Han ◽  
Yongxin Li ◽  
Qian Wang ◽  
...  
Keyword(s):  
Acute Kidney Injury ◽  
Cardiac Surgery ◽  
Cardiopulmonary Bypass ◽  
Rna Binding ◽  
Multivariable Analysis ◽  
Kidney Injury ◽  
Proinflammatory Response ◽  
Increased Risk ◽  
Before And After ◽  
The Difference

Abstract Background Systemic inflammation contributes to cardiac surgery–associated acute kidney injury (AKI). Cardiomyocytes and other organs experience hypothermia and hypoxia during cardiopulmonary bypass (CPB), which induces the secretion of cold-inducible RNA-binding protein (CIRP). Extracellular CIRP may induce a proinflammatory response. Materials and Methods The serum CIRP levels in 76 patients before and after cardiac surgery were determined to analyze the correlation between CIRP levels and CPB time. The risk factors for AKI after cardiac surgery and the in-hospital outcomes were also analyzed. Results The difference in the levels of CIRP (ΔCIRP) after and before surgery in patients who experienced cardioplegic arrest (CA) was 26-fold higher than those who did not, and 2.7-fold of those who experienced CPB without CA. The ΔCIRP levels were positively correlated with CPB time (r = 0.574, p < 0.001) and cross-clamp time (r = 0.54, p < 0.001). Multivariable analysis indicated that ΔCIRP (odds ratio: 1.003; 95% confidence interval: 1.000–1.006; p = 0.027) was an independent risk factor for postoperative AKI. Patients who underwent aortic dissection surgery had higher levels of CIRP and higher incidence of AKI than other patients. The incidence of AKI and duration of mechanical ventilation in patients whose serum CIRP levels more than 405 pg/mL were significantly higher than those less than 405 pg/mL (65.8 vs. 42.1%, p = 0.038; 23.1 ± 18.2 vs. 13.8 ± 9.2 hours, p = 0.007). Conclusion A large amount of CIRP was released during cardiac surgery. The secreted CIRP was associated with the increased risk of AKI after cardiac surgery.

scholarly journals Concentration of meropenem in patients with sepsis and acute kidney injury before and after initiation of continuous renal replacement therapy: a prospective observational trial

2020 ◽  
Vol 72 (1) ◽  
pp. 147-155 ◽  
Author(s):  
Ilona Nowak-Kózka ◽  
Kamil J. Polok ◽  
Jacek Górka ◽  
Jakub Fronczek ◽  
Anna Gielicz ◽  
...  
Keyword(s):  
Acute Kidney Injury ◽  
Renal Replacement Therapy ◽  
Replacement Therapy ◽  
Kidney Injury ◽  
Regional Citrate Anticoagulation ◽  
High Dose ◽  
Prolonged Infusion ◽  
Time Points ◽  
Drug Concentrations ◽  
Before And After

Abstract Background The effect of renal replacement therapy on drug concentrations in patients with sepsis has not been fully elucidated because the pharmacokinetic properties of many antimicrobials are influenced by both pathophysiological and treatment-related factors. The aim of this study was to determine meropenem concentrations in patients with sepsis before and after the initiation of continuous venovenous hemodialysis with regional citrate anticoagulation (RCA-CVVHD). Methods The study included 15 critically ill patients undergoing RCA-CVVHD due to sepsis-induced acute kidney injury. All participants received 2 g of meropenem every 8 h in a prolonged infusion lasting 3 h. Meropenem concentrations were measured in blood plasma using high-performance liquid chromatography coupled with tandem mass spectrometry. Blood samples were obtained at six-time points prior to and at six-time points after introducing RCA-CVVHD. Results The median APACHE IV and SOFA scores on admission were 118 points (interquartile range [IQR] 97–134 points) and 19.5 points (IQR 18–21 points), respectively. There were no significant differences in the plasma concentrations of meropenem measured directly before RCA-CVVHD and during the first 450 min of the procedure. The drug concentration reached its peak 2 h after initiating the infusion and then steadily declined. Conclusions The concentration of high-dose meropenem (2 g every 8 h) administered in a prolonged infusion was similar before and after the introduction of RCA-CVVHD in patients with sepsis who developed acute kidney injury.

scholarly journals P179 Glucocorticoid exposure and link to serious adverse events in patients with ANCA-associated vasculitis

Rheumatology ◽  
2020 ◽  
Vol 59 (Supplement_2) ◽  
Author(s):  
Philip Spearpoint ◽  
Cormac Sammon ◽  
Antonio Ramirez de ◽  
Arellano Serna ◽  
Peter Rutherford
Keyword(s):  
Cardiovascular Disease ◽  
Adverse Events ◽  
Renal Disease ◽  
Real World ◽  
Low Dose ◽  
Remission Induction ◽  
High Dose ◽  
Anca Associated Vasculitis ◽  
Increased Risk ◽  
New Onset

Abstract Background Remission induction in ANCA-associated vasculitis (AAV) is with high dose glucocorticoids (GC) and immunosuppressants. Patients are exposed to high GC dose and/or prolonged low dose. EULAR/EDTA guidelines target 7.5-10mg at 3 months but acknowledge this is often achieved later. This study used UK real world practice data to examine the scale of GC exposure and associated clinical risks in AAV. Methods The study utilised the Clinical Practice Research Datalink (CPRD) - Hospital Episode Statistics (HES) linked database. AAV patients were identified using specific READ and ICD codes and followed between 01/01/1997 and 01/01/2018. GP prescriptions were used to describe periods of continuous GC use, stop and restart and when high dose (&gt; 30mg/day) and low dose (&lt;30mg/day) was prescribed. Diagnostic codes indicative of infections and adverse events linked to GCs were used to estimate rates in the AAV population using a generalized linear model with a Poisson distribution. Results 450 AAV patients with at least one GC prescription were analysed. The median dose decreased to 9.3 mg (IQR 5.0 - 17.0) at 6 months and 5.1 mg (0.00 - 10.0) at 12 months,50% patients were taking &gt; 10mg at 5 months and 25% were still &gt; 10mg at 12 months. However, within 6 months of achieving 10mg/day, 50% relapse to needing dose &gt;10mg, 75% within 2 years and 90% within 6 years. In adjusted Poisson model (age, gender, year of diagnosis before/after 2013) the rate of infection in AAV patients taking high dose was 2.59 times (CI95 1.95, 3.45) that of those on low dose and lower in those not taking GCs (IRR 0.27 (0.22-0.34)). Increased risk of new onset cardiovascular disease (IRR 2.55 (0.92, 7.04)) and new onset renal disease (IRR 3.4 (1.29-8.96)) were higher in patients receiving high dose. Conclusion AAV patients have significant exposure to high dose GCs and in real world practice, GC dose remains higher than recommended in current clinical guidelines. High dose GCs are associated with high risk of infection and new cardiovascular disease and renal disease. This creates a significant patient burden and has implications for healthcare resource use. Disclosures P. Spearpoint: Corporate appointments; Employee of Vifor Pharma. C. Sammon: Corporate appointments; Employee of PHMR. A. Ramirez de Arellano Serna: Corporate appointments; Employee of Vifor Pharma. P. Rutherford: Corporate appointments; Employee of Vifor Pharma. Shareholder/stock ownership; Vifor Pharma.

Sign in / Sign up

Export Citation Format

Share Document