Renal safety and survival among acutely ill hospitalized patients treated by blockers of the Renin-Angiotensin axis or loop diuretics: a single-center retrospective analysis.

BACKGROUND: Concern exists regarding the renal safety of blocking the renin-angiotensin system (RAS) during acute illness, especially in the presence of volume depletion and hemodynamic instability. METHODS: We explored the impact of loop diuretics and RAS blockers on the likelihood of developing acute kidney injury (AKI) or acute kidney functional recovery (AKR) among inpatients. Adjusted odds ratio for AKI, AKR and mortality was calculated, using logistic regression models, with subgroup analysis for patients with estimated glomerular filtration rate (eGFR) <30 ml/min/1.73 m2, corrected for blood pressure measurements. RESULTS: 53,289 patients were included. RAS blockade was associated with reduced adjusted odds ratio for both AKI (0.76, CI 0.70-0.83) AKR (0.55, 0.52-0.58), and mortality within 30 days (0.44, 0.41-0.48), whereas loop diuretics were associated with increased risk of AKI (3.75, 3.42-4.12) and mortality (1.71, 1.58-1.85) and reduced AKR (0.71, 0.66-0.75). Comparable impact of RAS blockers and loop diuretics on renal outcomes and death was found among 6,069 patients with eGFR < 30 ml/min/1.73m2. RAS inhibition and diuretics tended to increase the adjusted odds ratios for AKI and to reduce the likelihood of AKR in hypotensive patients. CONCLUSIONS: Reduced blood pressure, RAS blockers and diuretics affect the odds of developing AKI or AKR among inpatients, suggesting possible disruption in renal functional reserve (RFR). As long as blood pressure is maintained, RAS inhibition seems to be safe and renoprotective in this population, irrespective of kidney function upon admission, and is associated with reduced mortality.

Alveolar Hemorrhage Following Positron Emission Tomography/Computed Tomography in 2 Separate Episodes 5 Months Apart.

BACKGROUND Positron emission tomography/computed tomography (PET/CT) has become one of the most prominent modalities worldwide for the diagnosis and surveillance of malignancies. Current clinical imaging guidelines report adverse reactions following PET/CT, especially due to contrast-induced toxicities, such as contrast-induced nephropathy and other rare reactions attributed to a hypersensitivity immune response, such as bronchospasm. Other rare lung toxicities were reported in a few case reports. Herein, we report repeated episodes of alveolar hemorrhage, a novel adverse response to PET/CT, occurring on 2 separate occasions 5 months apart. CASE REPORT A 57 year-old female patient with breast carcinoma managed by mastectomy, adjuvant chemotherapy, irradiation, and hormonal therapy presented with massive alveolar hemorrhage following PET/CT performed for surveillance 13 years after completion of chemotherapy and irradiation. An additional episode of massive alveolar hemorrhage occurred 5 months later following PET/CT, with respiratory failure requiring mechanical ventilation. Fluorine-18 fluorodeoxyglucose ([¹8F] FDG) and iohexol were used for imaging on both occasions. Common causes of alveolar hemorrhage, including malignancy, were excluded. CONCLUSIONS The repeated episodes immediately following PET/CT and the earlier and more intense respiratory failure following the second event raise the possibility of an immune-mediated alveolar hemorrhage in response to either the administration of iodinated radiocontrast agent or to [¹8F] FDG.

Electroencephalography functional connectivity-A biomarker for painful polyneuropathy.

BACKGROUND AND PURPOSE: Advanced analysis of electroencephalography (EEG) data has become an essential tool in brain research. Based solely on resting state EEG signals, a data-driven, predictive and explanatory approach is presented to discriminate painful from non-painful diabetic polyneuropathy (DPN) patients. METHODS: Three minutes long, 64 electrode resting-state recordings were obtained from 180 DPN patients. The analysis consisted of a mixture of traditional, explanatory and machine learning analyses. First, the 10 functional bivariate connections best differentiating between painful and non-painful patients in each EEG band were identified and the relevant receiver operating characteristic was calculated. Later, those connections were correlated with selected clinical parameters. RESULTS: Predictive analysis indicated that theta and beta bands contain most of the information required for discrimination between painful and non-painful polyneuropathy patients, with area under the receiver operating characteristic curve values of 0.93 for theta and 0.89 for beta bands. Assessing statistical differences between the average magnitude of functional connectivity values and clinical pain parameters revealed that painful DPN patients had significantly higher cortical functional connectivity than non-painful ones (p = 0.008 for theta and p = 0.001 for alpha bands). Moreover, intra-band analysis of individual significant functional connections revealed a positive correlation with average reported pain in the previous 3 months in all frequency bands. CONCLUSIONS: Resting state EEG functional connectivity can serve as a highly accurate biomarker for the presence or absence of pain in DPN patients. This highlights the importance of the brain, in addition to the peripheral lesions, in generating the clinical pain picture. This tool can probably be extended to other pain syndromes.

Changing serum creatinine in the detection of acute renal failure and recovery following radiocontrast studies among acutely ill inpatients: Reviewing insights regarding renal functional reserve gained by large-data analysis.

A rise in serum creatinine (SCr) is widely used for the detection and definition of evolving acute kidney injury (AKI). Yet, it takes time for SCr to re-adjust in response to changes in glomerular filtration rate (GFR), and subtle transient changes in GFR may remain concealed. Additionally, it cannot differentiate altered glomerular hemodynamics and pre-renal failure from true renal tissue injury, necessitating additional clinical and laboratory diagnostic tools. While these features limit the usefulness of SCr and subsequently estimated GFR (eGFR) at a single time point for the individual patient, their overall pattern of changes along time in a large cohort of hospitalized patients may provide a powerful perspective regarding the detection and assessment of shifting kidney function in this population. Herein we review our experience running large data analyses, evaluating patterns of day-to-day changes in SCr among inpatients, occurring around the exposure to iodinated radiocontrast agents. These large data evaluations helped substantiating the existence of contrast-induced nephropathy in patients with advanced renal failure, underscoring the impact of predisposing and confounding factors. It also provides novel insights regarding a phenomenon of "acute kidney functional recovery" (AKR), and illustrate that the incidence of AKI and AKR along the scale of baseline kidney function co-associates and is inversely proportional to kidney function. This can be attributed to renal functional reserve, which serves as a buffer for up-and-down changes in GFR, forming the physiologic explanation for concealed subclinical AKI.

Conditioned pain modulation is more efficient in patients with painful diabetic polyneuropathy than those with nonpainful diabetic polyneuropathy.

ABSTRACT: Endogenous pain modulation, as tested by the conditioned pain modulation (CPM) protocol, is typically less efficient in patients with chronic pain compared with healthy controls. We aimed to assess whether CPM is less efficient in patients with painful diabetic polyneuropathy (DPN) compared with those with nonpainful DPN. Characterization of the differences in central pain processing between these 2 groups might provide a central nervous system explanation to the presence or absence of pain in diabetic neuropathy in addition to the peripheral one. Two hundred seventy-one patients with DPN underwent CPM testing and clinical assessment, including quantitative sensory testing. Two modalities of the test stimuli (heat and pressure) conditioned to cold noxious water were assessed and compared between patients with painful and nonpainful DPN. No significant difference was found between the groups for pressure pain CPM; however, patients with painful DPN demonstrated unexpectedly more efficient CPMHEAT (-7.4 ± 1.0 vs -2.3 ± 1.6; P = 0.008). Efficient CPMHEAT was associated with higher clinical pain experienced in the 24 hours before testing (r = -0.15; P = 0.029) and greater loss of mechanical sensation (r = -0.135; P = 0.042). Moreover, patients who had mechanical hypoesthesia demonstrated more efficient CPMHEAT (P = 0.005). More efficient CPM among patients with painful DPN might result from not only central changes in pain modulation but also from altered sensory messages coming from tested affected body sites. This calls for the use of intact sites for proper assessment of pain modulation in patients with neuropathy.

Renal functional recovery among inpatients: A plausible marker of reduced renal functional reserve.

Renal functional reserve (RFR) reflects the ability of the kidney to enhance glomerular filtration rate (GFR) in response to a protein load. Chronic kidney disease (CKD) leads to diminished RFR, since the capacity for whole-body GFR to increase through hyperfiltration of remaining nephrons is limited. Evaluating 41,456 inpatients following computerised tomography we reported many exhibiting acute kidney injury (AKI) but more patients with recovering kidney function (AKR), presumably reflecting resolution of their critical conditions. The incidences of AKI and AKR were closely co-associated and were both inversely correlated with baseline kidney function. We discuss this phenomenon, arguing that AKR among inpatients with an acute illness, like AKI, may often reflect underlying subtle CKD with diminished RFR.

[RADIOCONTRAST NEPHROPATHY: MYTHS OR REALITY? THE VALUE OF PROPENSITY MATCHING APPLIED FOR LARGE DATA RETROSPECTIVE ANALYSES].

INTRODUCTION: Reviewed are three studies we conducted, assessing the risk of contrast nephropathy in hospitalized patients undergoing computerized tomography. These were retrospective large data analyses at a single tertiary care facility, using meticulous and compound propensity score matching and inverse probability of treatment weighting. These studies indicate that overall, the risk of contrast nephropathy is likely negligible, with the exception of patients with grades 4-5 renal failure at baseline (eGFR<30 ml/min/1.73m2), with an odds ratio of 1.51 to develop AKI, associated with increased mortality as compared with patients undergoing non-enhanced imaging. We also assessed the incidence and magnitude of improved kidney function (acute kidney recovery) around imaging, underscoring its potential to mask subclinical AKI. These studies illustrate the strengths of large data analysis with advanced statistical tools.

[INTERNAL MEDICINE: "WHAT MAKES THE DESERT BEAUTIFUL - IS A WELL HIDDEN SOMEWHERE"].

INTRODUCTION: In recent years, the status of Internal Medicine has been constantly wearing down. There has been a dramatic decrease in the number of internal medicine students and residents planning to pursue careers in internal medicine. This is mainly due to a higher workload, as well as physical and professional exhaustion leading to work dissatisfaction and provision of suboptimal patient care. Therefore, an increased tendency towards selecting a career in internal medicine sub-specialties has been noted. In this paper, we will present an open and sincere talk with three young internal medicine specialists, who willingly decided to keep working in internal medicine departments despite the challenging work environment. We will discuss the burnout associated with poor work-life/home balance and disruptive work environment and suggest measurements that may enhance the educational and professional experience and career satisfaction and increase the well-being of internal medicine specialists in the future. We aim to promote awareness to the importance of maintaining high-quality senior physicians working in Internal Medicine departments.

Endothelin-1 levels are decreased in pediatric Type 1 diabetes and negatively correlate with the carotid intima media thickness.

AIMS: Better understanding of the timeline and risk factors for the appearance of complications in pediatric Type-1-diabetes is key for developing prevention strategies. We studied endothelial markers and their determinants in adolescents with Type-1-diabetes at different time points from diagnosis. METHODS: A cross-sectional study of 58 adolescents, mean age 15.0 ± 2.4 years; 20 with recent-onset Type-1-diabetes, 20 with over 7 years of Type-1-diabetes and 18 controls. Clinical and biochemical data were collected. Fingertip arterial reactive hyperemia (EndoPAT) and carotid intima-media-thickness (cIMT) were measured to assess endothelial function and structure. RESULTS: Compared to controls, individuals with prolonged Type-1-diabetes had higher mean cIMT (0.49 ± 0.07 mm vs. 0.43 ± 0.05 mm p = 0.021) and maximal cIMT (0.61 ± 0.08 mm 0.52 ± 0.08 mm, p = 0.025). Endothelin-1 levels were significantly lower in subjects with prolonged Type-1-diabetes (1.2 ± 1.0 pg/ml) compared to controls (3.0 ± 1.7, p = 0.008 pg/ml); they negatively correlated with the mean cIMT (c = - 0.291, p = 0.031) and mean 6 months hemoglobin A1c (c = - 0.301, p = 0.022) and positively correlated with mean c-peptide levels (c = 0.356, p = 0.006) and the weekly exercise time (c = 0.485, p < 0.001). Endothelin-1 levels did not correlate with EndoPAT results. CONCLUSIONS: Our results suggest that the early years after the diagnosis of Type-1-diabetes are an important window for prevention of arterial damage in the pediatric population. The trajectories of relationships of Endothelin-1 with metabolic and vascular measures were opposite from the anticipated, yet consistent. Endothelin-1 related indirectly to adverse measures and directly to favorable measures. Decreased Endothelin-1 levels might reflect early stages in endothelial impairment in Type-1-diabetes, yet its' exact role in the development of complications is yet to be unraveled.

Renal Functional Recovery Confounding the Assessment of Contrast Nephropathy: Propensity Score Analysis.

BACKGROUND: Large data analyses confirm the relative safety of contrast-enhanced computed tomography (CT), except for those with advanced renal failure. However, the prevalence of post-contrast acute kidney injury may be masked by acute kidney functional recovery (AKR) in unstable inpatients, irrespective of contrast-enhanced imaging. METHODS: In this work we aimed to assess AKI and AKR along with need for dialysis and mortality, among inpatients undergoing contrast-enhanced or non-enhanced CT. We performed a large-scale retrospective data analysis using propensity score matching (PSM) that compared patients undergoing contrast-enhanced and non-enhanced imaging. We also performed a subgroup analysis of subjects stratified by baseline renal function. RESULTS: A total of 41,456 patients were analyzed. PSM resulted in well-balanced groups. AKR occurred substantially more often than AKI among hospitalized patients following CT imaging, especially among those with low baseline renal function. Yet, in this population, whereas the rate of AKI significantly increased, the rate of AKR significantly decreased following contrast-enhanced studies as compared to patients that underwent non-enhanced CT. A significantly higher proportion of patients with baseline advanced renal failure that underwent contrast-enhanced imaging required dialysis. CONCLUSIONS: The increased incidence of AKI and AKR as seen in patients with lower pre-imaging kidney function possibly suggests that both entities reflect impaired renal functional reserve. Unstable kidney function in inpatients, as demonstrated by rates of AKR and AKI, is an important confounder which requires attention in similar observational studies on the renal effects of contrast media and of various other renal injurious events.

Hyperglycemia on Admission Predicts Acute Kidney Failure and Renal Functional Recovery among Inpatients.

BACKGROUND: Hyperglycemia is associated with adverse outcomes in hospitalized patients. We aimed to assess the impact of glucose levels upon admission on the subsequent deterioration or improvement of kidney function in inpatients with a focus on diabetes or reduced baseline kidney function as possible modifiers of this effect. METHODS: Running a retrospective cohort analysis, we compared patients with normal vs. high glucose levels upon admission. We applied multivariable logistic regression models to study the association between baseline glucose levels with subsequent renal and clinical outcomes. Interaction terms were used to study a possible modifier effect of diabetes. RESULTS: Among 95,556 inpatients (52% males, mean age 61 years), 15,675 (16.5%) had plasma glucose higher than 180 mg/dL, and 72% of them were diabetics. Patients with higher glucose at presentation were older, with a higher proportion of co-morbid conditions. Rates of acute kidney injury (AKI), acute kidney functional recovery (AKR), and mortality were proportional to reduced renal function. AKI, AKR, and mortality were almost doubled in patients with high baseline glucose upon admission. Multivariable analysis with interaction terms demonstrated an increasing adjusted probability of all events as glucose increased, yet this association was observed principally in non-diabetic patients. CONCLUSIONS: Hyperglycemia is associated with AKI, AKR, and mortality in non-diabetic inpatients in proportion to the severity of their acute illness. This association diminishes in diabetic patients, suggesting a possible impact of treatable and easily reversible renal derangement in this population.

Combination of hyperglycaemia and hyperlipidaemia induces endothelial dysfunction: Role of the endothelin and nitric oxide systems.

Endothelial dysfunction (ED) is a key feature of diabetes and is a major cause of diabetic vasculopathy. Diabetic patients who also exhibit hyperlipidaemia suffer from accelerated vascular complications. While the deleterious effects of high glucose levels (HG) and hyperlipidaemia alone on ED are well established, the effects of combined hyperlipidaemia and HG have not been thoroughly studied. Therefore, the current study examines whether HG and hyperlipidaemia exert synergistic ED, and explores the mechanisms underlying this phenomenon. We applied multi-disciplinary approaches including cultured HUVECs and HMEC-1 as well as knockout mice CByJ.129S7(B6)-Ldlrtm1Her/J (LDLR-/- ) to investigate the mechanisms underlying combined HG and hyperlipidaemia-induced ED. Incremental doses of glucose in the presence or absence of OxLDL were added to HUVECs and HMEC-1. After 5 days, the status of nitric oxide (NO) and endothelin (ET)-1 systems as well as their signal transduction were assessed using Western blot, ELISA and immunoreactive staining. The effects of chronic combination of HG and hyperlipidaemia on endothelial integrity and function as well as alterations in circulatory NO and ET-1 systems were examined in knockout mice LDLR-/- and their wild-type. HUVEC cells exposed to HG and OxLDL displayed enhanced ET-1 production, more than HG or OxLDL when added alone. Overproduction of ET-1 stems from up-regulation of endothelin converting enzyme (ECE)-1 as observed under these conditions. In contrast, combination of HG and OxLDL dramatically decreased both total endothelial NO synthase (eNOS) by 60%, and activated eNOS (peNOS) by 80%. Moreover, NRF2 decreased by 42% and its active form (pNRF2) by 56%, as compared to baseline. Likewise, ETB levels decreased by 64% from baseline on endothelial cells. Furthermore, diabetic LDLR-/- mice displayed a higher blood pressure, plasma triglycerides, cholesterol, ET-1 and NO2/NO3 levels, when compared with normoglycemic LDLR-/- and BALB mice. Combined hyperglycaemia and hyperlipidaemia activates the ET system and attenuates the nitric oxide system with the Nrf2 signalling pathway. These findings suggest that perturbations in these paracrine systems may contribute to ED.

Mortality in Patients with Polymyositis and Dermatomyositis in an Israeli Population.

BACKGROUND: The reported mortality rates of patients with polymyositis and dermatomyositis are highly variable worldwide. The excess mortality of patients with polymyositis/dermatomyositis has not been evaluated in an Israeli population. OBJECTIVES: To investigate the overall mortality in a large and well-established cohort of patients with polymyositis/dermatomyositis as compared to the mortality expected in the matched general population in a tertiary medical center. METHODS: In this retrospective cohort study, the mortality of 166 patients with polymyositis/dermatomyositis was compared to age- and sex-matched control subjects in the general population. All-cause standardized mortality ratios (SMRs) were estimated. RESULTS: Overall, 47 (28.3%) deaths were observed among patients with polymyositis/dermatomyositis during a mean follow-up period of 5.8 ± 4.8 years, which was 7 times higher than in the control group (SMR 7.4, 95% confidence interval [95%CI] 5.5-9.8). The SMRs were comparable in patents with polymyositis (7.7, 95%CI 4.8-12.3) and dermatomyositis (7.2, 95%CI 5.0-10.3). The 1-, 5-, 10-, and 15-year overall survival rates were 90.0%, 82.8%, 51.5%, and 26.1%, respectively, in patients with polymyositis, and 80.3%, 59.6%, 40.0%, and 17.1%, respectively, in patients with dermatomyositis. CONCLUSIONS: The overall mortality among Israeli patients with polymyositis/dermatomyositis is 7.4 times greater than for the general population. Although long-term mortality was comparable between patients with dermatomyositis and polymyositis, patients in the former group died at a notably earlier stage.

Skin well-being in diabetes: Role of macrophages.

Macrophages are key players in wound healing- along with mediating the acute inflammatory response, macrophages activate cutaneous epithelial cells and promote tissue repair. Diabetes complications, including diabetic chronic wounds, are accompanied by persistent inflammation and macrophage malfunction. Several studies indicate that hyperglycemia induces various alterations that affect macrophage function in wound healing including epigenetic changes, imbalance between pro- and anti-inflammatory modulators, and insensitivity to proliferative stimuli. In this review, we briefly summarize recent studies regarding those alterations and their implications on skin well-being in diabetes.

Biomarker evidence for distal tubular damage but cortical sparing in hospitalized diabetic patients with acute kidney injury (AKI) while on SGLT2 inhibitors.

BACKGROUND: Inhibitors of sodium-glucose co-transporter-2 (SGLT2i) were found to improve renal outcome in diabetic patients in large prospective randomized trials. Yet, SGLT2i may acutely reduce kidney function through volume depletion, altered glomerular hemodynamics or intensified medullary hypoxia leading to acute tubular injury (ATI). The aim or this study was to prospectively assess the pathophysiology of acute kidney injury (AKI) in patients hospitalized while on SGLT2i, differing ATI from pre-renal causes using renal biomarkers. METHODS: Serum and urine Neutrophil Gelatinase-Associated Lipocalin (NGAL) and Kidney Ischemia Molecule (KIM)-1, markers of distal and proximal tubular injury, respectively, were determined in 46 diabetic patients who were on SGLT2i upon hospitalization with an acute illness. RESULTS: Serum and urine NGAL, but not KIM-1, were significantly increased in 21 of the patients who presented with AKI upon admission, as compared with 25 patients that maintained kidney function. Both serum and urinary NGAL correlated with the degree of impaired renal function, which in many cases was likely the result of additional acute renal perturbations, such as sepsis. CONCLUSIONS: Increased urinary and serum NGAL indicates that ATI, principally affecting distal tubular segments, may develop in some of the patients hospitalized with an acute illness and AKI while on SGLT2i. It is suggested that intensified medullary hypoxia by SGLT2i might be detrimental in this injury. By contrast, concomitantly unaltered KIM-1 might reflect improved cortical oxygenation by SGLT2i, and may explain an overall reduced risk of AKI with SGLT1i in large series. The independent potential of SGLT2i to inflict medullary hypoxic damage should be explored further.

Analyzing Medical Research Results Based on Synthetic Data and Their Relation to Real Data Results: Systematic Comparison From Five Observational Studies.

BACKGROUND: Privacy restrictions limit access to protected patient-derived health information for research purposes. Consequently, data anonymization is required to allow researchers data access for initial analysis before granting institutional review board approval. A system installed and activated at our institution enables synthetic data generation that mimics data from real electronic medical records, wherein only fictitious patients are listed. OBJECTIVE: This paper aimed to validate the results obtained when analyzing synthetic structured data for medical research. A comprehensive validation process concerning meaningful clinical questions and various types of data was conducted to assess the accuracy and precision of statistical estimates derived from synthetic patient data. METHODS: A cross-hospital project was conducted to validate results obtained from synthetic data produced for five contemporary studies on various topics. For each study, results derived from synthetic data were compared with those based on real data. In addition, repeatedly generated synthetic datasets were used to estimate the bias and stability of results obtained from synthetic data. RESULTS: This study demonstrated that results derived from synthetic data were predictive of results from real data. When the number of patients was large relative to the number of variables used, highly accurate and strongly consistent results were observed between synthetic and real data. For studies based on smaller populations that accounted for confounders and modifiers by multivariate models, predictions were of moderate accuracy, yet clear trends were correctly observed. CONCLUSIONS: The use of synthetic structured data provides a close estimate to real data results and is thus a powerful tool in shaping research hypotheses and accessing estimated analyses, without risking patient privacy. Synthetic data enable broad access to data (eg, for out-of-organization researchers), and rapid, safe, and repeatable analysis of data in hospitals or other health organizations where patient privacy is a primary value.

Acute Kidney Injury After Radiocontrast-Enhanced Computerized Tomography in Hospitalized Patients With Advanced Renal Failure: A Propensity-Score-Matching Analysis.

BACKGROUND: The overall risk of postcontrast acute kidney injury (PC-AKI) after computerized tomography (CT) is negligible, likely because of the small volume of injected iodinated contrast media required. However, the safety of contrast media-enhanced CT in patients with advanced renal functional impairment, an established major risk factor for PC-AKI, is unknown. MATERIALS AND METHODS: This is a retrospective study using large data analysis of hospitalized patients at a single center. Adults undergoing CT or magnetic resonance imaging were included in the study and were stratified by estimated glomerular filtration rate (eGFR) (≤30 or >30 mL/min/1.73 m) and by either contrast-enhanced or nonenhanced imaging. Only patients with serial determination of creatinine before and after imaging were included. Demographic, clinical, and laboratory data between groups were analyzed and compared using univariate analysis, propensity score matching, and multivariate logistic regression analysis. RESULTS: A total of 22,319 imaging studies were included. Patients with an eGFR of 30 mL/min/1.73 m or lower undergoing contrast-enhanced CT (n = 403) had an increased risk to develop PC-AKI than did similar patients undergoing enhanced or nonenhanced magnetic resonance imaging (n = 96) or nonenhanced CT (n = 1576) or patients undergoing contrast-enhanced CT with a preprocedural eGFR higher than 30 mL/min/1.73 m (n = 9173). These findings remained robust after propensity matching for demographic, procedural, and clinical parameters. Multivariate regression analysis of all patients undergoing CT with preimaging eGFR of 30 mL/min or lower (n = 1979) revealed that iodine-based contrast enhancement increased the likelihood of post-CT AKI by 51% (confidence interval, 1.23-2.05). CONCLUSION: Although radiocontrast-enhanced CT is considered safe in most hospitalized patients and in ambulatory settings, the risk of PC-AKI remains significant among inpatients with substantial preimaging renal functional impairment. Caution is warranted using iodine-based enhanced CT in hospitalized patients with an eGFR of 30 mL/min/1.73 m or lower.

Near-drowning: new perspectives for human hypoxic acute kidney injury.

Concepts regarding hypoxic acute kidney injury (AKI) are derived from widely used warm ischemia-reflow (WIR) models, characterized by extensive proximal tubular injury and associated with profound inflammation. However, there is ample clinical and experimental data indicating that hypoxic AKI may develop without total cessation of renal blood flow, with a different injury pattern that principally affects medullary thick limbs in the outer medulla. This injury pattern likely reflects an imbalance between blood and oxygen supply and oxygen expenditure, principally for tubular transport. Experimental models of hypoxic AKI other than WIR are based on mismatched oxygen delivery and consumption, particularly within the physiologically hypoxic outer medulla. However, evidence for such circumstances in human AKI is lacking. Recent analysis of the clinical course and laboratory findings of patients following near-drowning (ND) provides a rare glimpse into such a scenario. This observation supports the role of renal hypoxia in the evolution of AKI, as renal impairment could be predicted by the degree of whole-body hypoxia (reflected by lactic acidosis). Furthermore, there was a close association of renal functional impairment with indices of reduced oxygen delivery (respiratory failure and features of intense sympathetic activity) and of enhanced oxygen consumption for active tubular transport (extrapolated from the calculated volume of consumed hypertonic seawater). This unique study in humans supports the concept of renal oxygenation imbalance in hypoxic AKI. The drowning scenario, particularly in seawater, may serve as an archetype of this disorder, resulting from reduced oxygen delivery, combined with intensified oxygen consumption for tubular transport.