Renal Function In High-risk Patients Research Articles

Highest Recorded Serum Creatinine

Serum creatinine is a commonly used laboratory marker to assess kidney function; however, there has not been an established level of serum creatinine to predict mortality. After extensive literature review, we present a case of the highest recorded serum creatinine of 73.8 mg/dL in a 23-year-old male with the history of pediatric deceased donor kidney transplant (DDKT). He initially presented with uremia and signs of acute renal allograft failure after two months of immunosuppressive medication nonadherence, ultimately requiring emergent hemodialysis, which was complicated by new onset seizures. This was the patient's fourth episode of late acute rejection and emphasizes the need for education of immunosuppressant adherence and periodic monitoring of renal function in high-risk patients. Though there is no known creatinine level incompatible with life, this patient appears to have the highest known serum creatinine in a uremic patient on record.

Acute kidney injury and continuous renal replacement therapy in children; what pediatricians need to know

Acute kidney injury (AKI) is characterized by abrupt deterioration of renal function, and its diagnosis relies on creatinine measurements and urine output. AKI is associated with higher morbidity and mortality, and is a risk factor for development of chronic kidney disease. There is no proven medication for AKI. Therefore, prevention and early detection are important. Physicians should be aware of the risk factors for AKI and should monitor renal function in high-risk patients. Management of AKI includes optimization of volume status and renal perfusion, avoidance of nephrotoxic agents, and sufficient nutritional support. Continuous renal replacement therapy is widely available for critically ill children, and this review provides basic information regarding this therapy. Long-term follow-up of patients with AKI for renal function, blood pressure, and proteinuria is recommended.

Early Evaluation of Renal Function in High-Risk Patients after Off-Pump Coronary Artery Bypass Grafting

Background: Cardiopulmonary bypass (CPB) is an unphysiological state and widely regarded as an important contributor to renal failure. Despite improvement in cardiopulmonary bypass technique, anesthesia and intensive care, perioperative renal dysfunction still represents a significant and potentially lethal complication after coronary artery bypass graft surgery (CABG). Renal dysfunction is a serious complication of coronary revascularization with CPB and results in increased morbidity, mortality and prolonged hospital stay. We compared the incidence of perioperative renal dysfunction in patients who underwent CABG, on-pump and off-pump (OPCAB) Methods: A total of 60 high -risk patients with ischaemic heart diseases were included in the study who underwent CABG. Out of the total 60 patients, 30 were in the Off-pump group (Group A) and the rest 30 were in the On-pump group (Group B). They were diagnosed as high-risk patients considering serum creatinine level>1.7mg/dl with age ?60 years, ejection fraction 30-40%. Renal function was evaluated in both groups preoperatively and postoperatively (on 1st, 2nd and 7th postoperative day) and compared between two groups.Results: One patient in the On-pump group died on 6th postoperative day. Preoperative renal parameters were also similar and showed no statistically significant difference. So both groups were comparable. Comparison of renal parameter in OPCAB and on-pump CABG between preoperative and 7th day postoperatively found in this study were blood urea 50.33±6.29, 39.87±4.8 vs 52.67±9.05 , 66.21±6.91 ; S. Creatinine (mg/dl) 1.94±0.19 , 1.28±0.19 vs 2.07±0.31 , 2.82±0.47; Creatinine Clearance Rate(ml/min) 46.61±4.1, 71.51±12.3 vs 46.53±4.6, 34.02±4.49 ; Urine output (ml/24 hrs)1692.7±71.53, 1755.7±82.91 vs 1591.2±78.76, 1492.1±196.29 all are statistically significant(p<0.05). Mean period of mechanical ventilation, ICU stay and total postoperative hospital stay were significantly greater in On-pump group. One patient of Group –B died due to multi organ failure including acute renal failure on 6th postoperative day (3.3%) (p>0.05). Statistically significant difference of renal parameters in different postoperative days showed evidence of well preservation of renal function in OPCAB.Conclusion: Adaptation of OPCAB offers better preservation of renal function as well as better early postoperative outcome specially in high-risk CABG patients.Cardiovasc. j. 2016; 9(1): 23-30

Vitamin D deficiency is a potential risk factor for contrast-induced nephropathy.

Vitamin D deficiency (VDD) is widespread in the general population. Iodinated (IC) or gadolinium-based contrast media (Gd) may decrease renal function in high-risk patients. This study tested the hypothesis that VDD is a predisposing factor for IC- or Gd-induced nephrotoxicity. To this end, male Wistar rats were fed standard (SD) or vitamin D-free diet for 30 days. IC (diatrizoate), Gd (gadoterate meglumine), or 0.9% saline was then administered intravenously and six groups were obtained as the following: SD plus 0.9% saline (Sham-SD), SD plus IC (SD+IC), SD plus Gd (SD+Gd), vitamin D-free diet for 30 days plus 0.9% saline (Sham-VDD30), vitamin D-free diet for 30 days plus IC (VDD30+IC), and vitamin D-free diet for 30 days plus Gd (VDD30+Gd). Renal hemodynamics, redox status, histological, and immunoblot analysis were evaluated 48 h after contrast media (CM) or vehicle infusion. VDD rats showed lower levels of total serum 25-hydroxyvitamin D [25(OH)D], similar plasma calcium and phosphorus concentration, and higher renal renin and angiotensinogen protein expression compared with rats fed SD. IC or Gd infusion did not affect inulin clearance-based estimated glomerular filtration rate (GFR) in rats fed SD but significantly decreased GFR in rats fed vitamin D-free diet. Both CM increased renal angiotensinogen, and the interaction between VDD and CM triggered lower renal endothelial nitric oxide synthase abundance and higher renal thiobarbituric acid reactive substances-to-glutathione ratio (an index of oxidative stress) on VDD30+IC and VDD30+Gd groups. Conversely, worsening of renal function was not accompanied by abnormalities on kidney structure. Additionally, rats on a VDD for 60 days displayed a greater fall in GFR after CM administration. Collectively, our findings suggest that VDD is a potential risk factor for IC- or Gd-induced nephrotoxicity most likely due to imbalance in intrarenal vasoactive substances and oxidative stress.

Glomerular disease: Efficacy of corticosteroids in high-risk IgA nephropathy.

Corticosteroids are frequently used to treat patients with IgA nephropathy (IgAN) despite a paucity of data to support their use in individuals with substantially reduced renal function. A retrospective study provides evidence that these agents may slow the rate of decline in renal function in high-risk patients with IgAN.

Review of tenofovir use in HIV-infected children.

Tenofovir disoproxil fumarate (TDF) is approved by the Food and Drug Administration for use in children ages 2 years and older and is recommended by the World Health Organization for use as a preferred first-line nucleotide reverse transcriptase inhibitor in adults and adolescents ages 10 years and older. The simplicity of once daily dosing, few metabolic side effects and efficacy against hepatitis B virus make TDF suitable for use in a large scale program. Unlike thymidine analoge nucleoside reverse transcriptase inhibitors (NRTIs); tenofovir does not induce multi-NRTI resistance mutations, so more NRTI options are available for future second-line-regimens. Fixed-dose combinations of TDF with other ARVs as a single tablet regimen are now widely available for adults and adolescents, but none are available for young children. Current information on TDF including the pharmacokinetics, safety and tolerability in children and adolescents was reviewed. A dosing regimen according to body-weight-band has been established for pediatric use. Safety concerns of TDF mainly relate to its effects on renal function and bone mineral density. Regular monitoring of renal function in high-risk patients, including those on other nephrotoxic drugs, may be warranted to detect adverse renal effects. Long-term-data on renal and bone outcomes among HIV-infected children is needed. Lessons learned from clinical studies will help clinicians balance the risks and benefits of TDF and design appropriate antiretroviral regimens for children in different circumstances.

Failure of renal biomarkers to predict worsening renal function in high-risk patients presenting with oliguria.

Oliguria is a common symptom in critically ill patients and puts patients in a high risk category for further worsening renal function (WRF). We performed this study to explore the predictive value of biomarkers to predict WRF in oliguric intensive care unit (ICU) patients. Single-center prospective observational study. ICU patients were included when they presented a first episode of oliguria. Plasma and urine biomarkers were measured: plasma and urine neutrophil gelatinase-associated lipocalin (pNGAL and uNGAL), urine α1-microglobulin, urine γ-glutamyl transferase, urine indices of tubular function, cystatin C, C terminal fragment of pro-arginine vasopressin (CT-ProAVP), and proadrenomedullin (MR-ProADM). One hundred eleven patients formed the cohort, of whom 41 [corrected] had worsening renal function. Simplified Acute Physiology Score (SAPS) II was 41 (31-51). WRF was associated with increased mortality (hazard ratio 8.65 [95 % confidence interval (CI) 3.0-24.9], p = 0.0002). pNGAL, MR-ProADM, and cystatin C had the best odds ratio and area under the receiver-operating characteristic curve (AUC-ROC: 0.83 [0.75-0.9], 0.82 [0.71-0.91], and 0.83 [0.74-0.90]), but not different from serum creatinine (Screat, 0.80 [0.70-0.88]). A clinical model that included age, sepsis, SAPS II, and Screat had AUC-ROC of 0.79 [0.69-0.87]; inclusion of pNGAL increased the AUC-ROC to 0.86 (p = 0.03). The category-free net reclassification index improved with pNGAL (total net reclassification index for events to higher risk 61 % and nonevents to lower 82 %). All episodes of oliguria do not carry the same risk. No biomarker further improved prediction of WRF compared with Screat in this selected cohort of patients at increased risk defined by oliguria.

Ten-year experience of percutaneous image-guided radiofrequency ablation of malignant renal tumours in high-risk patients

To evaluate survival and outcomes after percutaneous radiofrequency ablation (RFA) of malignant renal tumours in high-risk patients with long-term follow-up. Between 2002 and 2009, 62 patients (71 tumours), with a median age of 73.5 years (20-87), consecutively treated with RFA under ultrasound or computed tomography guidance for malignant renal tumours were retrospectively selected and prospectively followed until 2012, including 25 patients (40.3 %) with solitary kidney and 7 cystic cancers. Maximal tumour diameters were between 8 and 46 mm (median: 23 mm). Radiofrequency ablation was technically possible for all patients. Mean follow-up was 38.8 months (range: 18-78 months). Primary and secondary technique effectiveness was 95.2 % and 98.4 % per patient respectively. The rates of local tumour progression and metastatic evolution were 3.2 % and 9.7 % per patient and were associated with tumour size >4 cm (P = 0.005). The disease-free survival rates were 88.3 % and 61.9 % at 3 and 5 years. No significant difference in glomerular filtration rates before and after the procedure was observed (P = 0.107). The major complications rate was 5.9 % per session with an increased risk in the case of central locations (P = 0.006). Percutaneous renal RFA appears to be safe and effective with useful nephron-sparing results. • Radiofrequency ablation (RFA) is a well-tolerated technique according to mid-term results. • RFA for malignant renal tumours preserved renal function in high-risk patients. • Mid-term efficacy of RFA was close to that of formal conservative surgery. • Tumour size and central location limit the efficacy and safety of RFA.

Urinary Metabolomic Analysis for the Identification of Renal Injury in Patients With Acute Heart Failure

Worsening renal function in patients admitted with heart failure is associated with increased morbidity. These changes are not usually apparent initially and often take up to 48 hours to be detected. Using the novel technique of metabolomic analysis, this study aims to determine if markers of renal injury are identifiable at presentation that are associated with the development of worsening renal function in high-risk patients with heart failure. A prospective exploratory study enrolled a convenience sample of patients with suspected heart failure. Eligible patients had to be older than 18 years, have a B-type natriuretic peptide (BNP) level over 100 pg/mL, have a history of diabetes or hypertension, meet Boston criteria for heart failure (>8), and require hospital admission as judged by the treating physician. Patients receiving no more than one dose of diuretic prior to enrollment were excluded. Urine was collected during the emergency department (ED) stay. Initial creatinine and the peak value between 24 to 48 hours were used to determine worsening renal function as defined by a change of >0.3 mg/dL or absolute 25% increase. Urine samples underwent gas chromatography/mass spectrometry (GC/MS) profiling. Peak metabolite values were measured and data were log-transformed. Partial least squares-discriminant analysis (PLS-DA) was used to identify metabolites associated with worsening renal function. Specific urinary metabolites were ranked based on their regression coefficients. The 24 enrolled subjects had a median age of 58 years (interquartile range [IQR] = 49.5 to 67.5 years) with 58% being male. Worsening renal function occurred in 10 subjects (41.7%). A total of 156 metabolites were identified. The optimal number of metabolites for class discrimination as determined by PLS-DA was three, with a classification accuracy of 78%. These metabolites were taurine, sulfuric acid, and talose. Urinary metabolites found at the time of presentation may be markers of early renal injury. It is therefore possible that the process of renal injury is initiated prior to ED arrival in patients with suspected heart failure, and these may be used to identify a high-risk patient population.

N-Acetylcysteine does not prevent renal dysfunction after off-pump coronary artery bypass surgery

Coronary artery bypass graft surgery in high-risk patients may be associated with postoperative renal dysfunction. N-Acetylcysteine is a powerful antioxidant and has been used to prevent contrast-induced renal dysfunction. The efficacy of N-acetylcysteine in preventing postoperative renal dysfunction following off-pump coronary artery bypass graft surgery was studied. A prospective, randomized, controlled study was conducted in patients undergoing off-pump coronary artery bypass graft. The study group (37 patients) received N-acetylcysteine in the perioperative period, whereas the control group (37 patients) did not. The data obtained were analysed using the independent sample t-test (Student's t-test) and χ-test. There was no significant difference in the incidence of renal dysfunction between the two groups. Three patients (8.6%) in the N-acetylcysteine group and four (11.4%) in the control group developed renal dysfunction (P value was 1.00). N-Acetylcysteine does not have any beneficial effect on renal function in high-risk patients undergoing off-pump coronary artery bypass graft.

Contrast-induced Nephropathy—Choice of Contrast Agents to Reduce Renal Risk

Contrast-induced nephropathy (CIN) represents an increasing healthcare burden and challenge as the frequency of diagnostic imaging and interventional procedures increases, particularly among patients at risk for developing CIN. Universally accepted strategies to reduce the risk for CIN include careful patient screening and selection, adequate patient hydration, limiting the volume of contrast medium administered, and choosing a safe, non-ionic, low-osmolar contrast agent. For both intra-arterial and intravenous use, all ionic and non-ionic iodinated contrast agents may further impair renal function in high-risk patients. Based on comparisons of contrast media in proximal renal tubular cell culture and in recent robust head-to-head prospective clinical trials in high-risk patients, however, iso-osmolar iodixanol and low-osmolar iopamidol are comparable and appear to be the contrast agents of choice to reduce renal risk for CIN.

Pulsatile Flow Improves Renal Function in High-Risk Cardiac Operations

The effects of pulsatile perfusion on microcirculation and renal function in high-risk patients were evaluated in this study. Pulsatile roller pumps with a pulsatile control module and membrane oxygenator were used in a clinical setting. 40 patients undergoing elective cardiac surgery with a high risk of either having chronically obstructive pulmonary disease or chronic renal failure were randomly included in the study to be perfused using pulsatile or continuous flows. Blood samples were collected at induction of anesthesia, at the time of aortic clamping and declamping and 1 and 24 h following cessation of the bypass. Urea and creatinine concentrations in blood were measured and systemic vascular resistance was calculated. Urine output, crystalloid and colloid infusions were recorded. We observed that pulsatile roller pump perfusion and the extracorporeal circuit used in the clinical study improved microcirculation and renal function in high-risk patients undergoing cardiopulmonary bypass.

Perioperative N-acetylcysteine to Prevent Renal Dysfunction in High-Risk Patients Undergoing CABG Surgery

Renal dysfunction is a complication of coronary artery bypass graft (CABG) surgery performed with cardiopulmonary bypass (CPB) that is associated with increased morbidity and mortality. N-acetylcysteine, an antioxidant and vasodilator, counteracts renal ischemia and hypoxia. To determine whether perioperative intravenous (IV) N-acetylcysteine preserves renal function in high-risk patients undergoing CABG surgery with CPB compared with placebo. Randomized, quadruple blind, placebo-controlled trial (October 2003-September 2004) in operating rooms and general intensive care units (ICUs) of 2 Ontario tertiary care centers. The 295 patients required elective or urgent CABG and had at least 1 of the following: preexisting renal dysfunction, at least 70 years old, diabetes mellitus, impaired left ventricular function, or undergoing concomitant valve or redo surgery. Patients received 4 (2 intraoperative and 2 postoperative) doses of IV N-acetylcysteine (600 mg) (n = 148) or placebo (n = 147) over 24 hours. The primary outcome was the proportion of patients developing postoperative renal dysfunction, defined by an increase in serum creatinine level greater than 0.5 mg/dL (44 micromol/L) or a 25% increase from baseline within the first 5 postoperative days. Secondary outcomes included postoperative interventions and complications, the requirement for renal replacement therapy (RRT), adverse events, hospital mortality, and ICU and hospital length of stay. There was no difference in the proportion of patients with postoperative renal dysfunction (29.7% vs 29.0%, P = .89; relative risk [RR], 1.03 [95% confidence interval {CI}, 0.72-1.46]) in the N-acetylcysteine and placebo groups, respectively. We noted nonsignificant differences in postoperative interventions and complications, the need for RRT (0.7% vs 2.1%; P = .37), total (6.1% vs 9.6%; P = .26) and serious adverse events, hospital mortality (3.4% vs 2.7%; P>.99), and ICU and hospital length of stay between the N-acetylcysteine and placebo groups. A post hoc subgroup analysis of patients (baseline creatinine level >1.4 mg/dL [120 micromol/L]) showed a nonsignificant trend toward fewer patients experiencing postoperative renal dysfunction in the N-acetylcysteine group compared with the placebo group (25.0% vs 37.1%; P = .29). N-acetylcysteine did not prevent postoperative renal dysfunction, interventions, complications, or mortality in high-risk patients undergoing CABG surgery with CPB. Further research is required to identify CABG patients at risk for postoperative renal events, valid markers of renal dysfunction, and to establish renal thresholds associated with important clinical outcomes.

Review: Low-osmolality contrast media is associated with less deterioration in renal function in high-risk patients

Source Citation Barrett BJ, Carlisle EJ. Meta-analysis of the relative nephrotoxicity of high- and low-osmolality iodinated contrast media. Radiology. 1993 Jul;188:171-8