Implementing the Kidney Disease: Improving Global Outcomes/acute kidney injury guidelines in ICU patients

Early Laboratory Predictors for Necessity of Renal Replacement Therapy in Patients With Spontaneous Deep-Seated Intracerebral Hemorrhage

Objective: The need for continuous renal replacement therapy (CRRT) in patients with deep-seated intracerebral hemorrhage (ICH) requires sustained intensive care and often postpones further rehabilitation therapy. Therefore, an early identification of patients at risk is essential.

Methods: From 2014 to 2019, all patients with deep-seated ICH who were admitted to intensive care for >3 days were included in the further analysis and retrospectively reviewed for the need for CRRT. All patients underwent CRRT with regional citrate anticoagulation for continuous veno-venous hemodialysis (CVVHD). Outcome was evaluated after 3 months using the modified Rankin scale. A multivariate analysis was performed to identify potential predictors for CRRT in patients with deep-seated ICH.

Results: After applying the inclusion criteria, a total of 87 patients with deep-seated spontaneous ICH were identified and further analyzed. During the first 48 h after admission, 21 of these patients developed early acute kidney injury (AKI; 24%). During treatment course, CRRT became necessary in nine patients suffering from deep-seated ICH (10%). The multivariate analysis revealed “development of AKI during the first 48 h” [p = 0.025, odds ratio (OR) 6.1, 95% confidence interval (CI) 1.3–29.8] and “admission procalcitonin (PCT) value >0.5 μg/l” (p = 0.02, OR 7.7, 95% CI 1.4–43.3) as independent and significant predictors for CRRT in patients with deep-seated ICH.

Conclusions: Elevated serum levels of procalcitonin on admission as well as early development of acute renal injury are independent predictors of the need for renal replacement therapy in patients with deep-seated intracerebral bleeding. Therefore, further research is warranted to identify these vulnerable patients as early as possible to enable adequate treatment.

Progress on the Function and Application of Thymosin β4

Thymosin β4 (Tβ4) is a multifunctional and widely distributed peptide that plays a pivotal role in several physiological and pathological processes in the body, namely, increasing angiogenesis and proliferation and inhibiting apoptosis and inflammation. Moreover, Tβ4 is effectively utilized for several indications in animal experiments or clinical trials, such as myocardial infarction and myocardial ischemia-reperfusion injury, xerophthalmia, liver and renal fibrosis, ulcerative colitis and colon cancer, and skin trauma. Recent studies have reported the potential application of Tβ4 and its underlying mechanisms. The present study reveals the progress regarding functions and applications of Tβ4.

Clinical phenotypes of acute kidney injury are associated with unique outcomes in critically ill septic children

BACKGROUND

Assessment of acute kidney injury (AKI) in septic patients remains imprecise. In adults, the classification of septic patients by clinical AKI phenotypes (severity and timing) demonstrates unique associations with patient outcome vs. broadly defined AKI.

METHODS

In a multinational prospective observational study, AKI diagnosis in critically ill septic children was stratified by duration (transient vs. persistent) and severity (mild vs. severe by creatinine change and urine output). The outcomes of interest were mortality and intensive care unit resource complexity at 28 days.

RESULTS

Seven hundred and fifty-seven septic children were studied (male 52.7%, age 4.6 years (1.5-11.9)). Mortality (overall 12.1%) was different between severe AKI and mild AKI (18.3 vs. 4.4%, p < 0.001) as well as intensive care unit (ICU) complexity (overall 34.5%, 45 vs. 21.7%, p < 0.001). Patients with Persistent AKI had fewer ICU-free days (17 (7, 21) vs. 24 (17, 26), p < 0.001) and higher ICU complexity (52.8 vs. 22.9%, p = 0.002) than transient AKI, even after exclusion of patients with early mortality. AKI phenotypes incorporating temporal and severity data correlate with unique survival (range 4.4-21.6%) and ICU-free days (range of 15-25 days) CONCLUSIONS: The outcome of septic children with AKI changes by clinical phenotype. Our findings underscore the importance of prognostic enrichment in sepsis and AKI for the purpose of trial design and patient management.

IMPACT

Although AKI occurs commonly in patients with sepsis (S-AKI), outcomes for children with S-AKI varies based on the severity and timing of the AKI. Existing S-AKI pediatric data utilize a broad singular definition of kidney injury. Increasing the precision of AKI classification results in a new understanding of how S-AKI associates with patient outcome. A refined classification of S-AKI identifies subgroups of children, making possible a targeted and a personalized medicine approach to S-AKI study and management.

Challenges in the Recognition and Management of Acute Kidney Injury by Hospitals in Resource-Limited Settings

Introduction

Acute kidney injury (AKI) is prevalent in low- and middle-income countries (LMIC) and is associated with significant morbidity and mortality, particularly among hospitalized patients. Successful strategies for the prevention and management of AKI in these countries are dependent on the capacity of primary care centers to provide optimal initial management of patients at risk for this disorder.

Methods

From December 2018 to February 2019, using mixed methods, we assessed hospital capacity and the knowledge of clinicians relevant to the prevention, diagnosis, and management of AKI in Rwanda. A checklist based on Kidney Disease: Improving Global Outcomes (KDIGO) guidelines and clinical vignette-based assessment tool were used to assess hospital capacity and provider knowledge base, respectively. Data were analyzed using stata 13 with findings reported as simple frequencies or means with standard deviation. Multivariate analysis was used to assess factors associated with a higher knowledge score among clinicians.

Results

Ten hospitals and 193 health care providers from sites throughout Rwanda participated in the survey. Surveyed hospitals were equipped with basic general medical equipment but were deficient in diagnostic tools and medical supplies that would allow the diagnosis and nondialytic management of AKI. Although 20% of the hospitals could offer hemodialysis services, peritoneal dialysis services were nonexistent. With regard to knowledge base, the health care providers demonstrated significant deficiencies in the diagnosis and management of AKI. The mean knowledge score for all health providers was 6.3 (±1.5) of a maximum of 11, with a mean (±SD) score for doctors, nurses, and midwives of 6.3 ± 2.05, 6.4 ± 1.3, and 6.08 ± 1.2, respectively. On multivariate analysis, the length of clinical experience and age of the respondents were significantly associated with participants’ knowledge score.

Conclusion

This study documents significant barriers to providing optimal management of AKI in primary health care settings in Rwanda, a resource-limited setting. These include lack of specialized medical personnel, significant knowledge gaps among primary health care providers, suboptimal diagnostic capacity, and limited treatment options for detection and management of AKI.

[Extracorporeal renal replacement therapy in acute kidney injury : Recommendations from the renal section of the DGIIN, ÖGIAIN and DIVI]

BACKGROUND

Acute kidney injury (AKI) is a common complication in intensive care unit (ICU) patients. The incidence of AKI in ICU patients exceeds 50% and the associated morbidity and mortality rates increase with severity of AKI. In addition, long-term consequences of AKI are underestimated and several studies show impaired long-term outcome after AKI. In about 5-25% of ICU patients with AKI renal replacement therapy (RRT) is required.

OBJECTIVES

To assist in indication, timing, modality and application of renal replacement therapy of adult patients, current recommendations from the renal sections of the DGIIN (Deutschen Gesellschaft für Internistische Intensivmedizin und Notfallmedizin), ÖGIAIN (Österreichischen Gesellschaft für Internistische und Allgemeine Intensivmedizin und Notfallmedizin) and DIVI (Deutschen Interdisziplinären Vereinigung für Intensiv- und Notfallmedizin) are stated.

MATERIALS AND METHODS

The recommendations stated in this paper are based on the current KDIGO (Kidney Disease: Improving Global Outcomes) guidelines, recommendations from the 17th Acute Disease Quality Initiative (ADQI) Consensus Group, the French Intensive Care Society (SRLF) with the French Society of Anesthesia Intensive Care (SFAR) and the expert knowledge and clinical experience of the authors.

RESULTS

Today, different treatment modalities for RRT are available. Although continuous RRT and intermittent dialysis therapy as well as continuous dialysis therapy have comparable outcomes, differences exist with respect to practical application as well as health-economic aspects. Individualized risk stratification might be helpful to choose the right time to start and the right treatment modality for patients.

DPP-4 enzyme deficiency protects kidney from acute ischemia-reperfusion injury: role for remote intermittent bowel ischemia-reperfusion preconditioning

We analyzed the effects of acute ischemia-reperfusion (KIR) injury on the status of kidney function and architecture in dipeptidyl peptidase4-difficient (DPP4^D) rats and the effect of remote small bowel ischemia-reperfusion (BIR) preconditioning. DPP4-deficient (DPP4^D) and normal Fischer344 (F344) rats were divided into 6 groups: (1) sham-F344, (2) sham-DPP4^D, (3) KIR-F344 (4) KIR-DPP4^D, (5) DPP4^D-KIR-extendin-9-39 and (6) BIR-KIR-F344. Blood creatinine and urea nitrogen levels and the urinary protein-to-creatinine ratio was higher in KIR-F344 rats than BIR-KIR-F344 or KIR-DPP4^D rats 72 h after acute KIR. Conversely, the circulating glucagon-like peptide 1 (GLP-1) levels were higher in BIR-KIR-F344 and KIR-DPP4^D than KIR-F344 rats after acute KIR. KIR-F344 rats showed greater inflammation, oxidative stress, apoptosis, DNA damage and kidney injury than other rat groups. Damage to the kidney architecture in KIR-F344 rats was greater than in BIR-KIR-F344 or KIR-DPP4^D rats. Expression of antioxidant proteins and GLP-1 receptor was higher in kidneys from KIR-DPP4^D and BIR-KIR-F344 than KIR-F344 rats, which suggests better intrinsic responses. We therefore suggest that elevated circulating GLP-1 levels due to DPP4 deficiency and BIR preconditioning protect kidney function and architecture during acute IR injury.

Histopathological Evaluation of Contrast-Induced Acute Kidney Injury Rodent Models

Contrast-induced acute kidney injury (CI-AKI) can occur in 3–25% of patients receiving radiocontrast material (RCM) despite appropriate preventive measures. Often patients with an atherosclerotic vasculature have to receive large doses of RCM. Thus, animal studies to uncover the exact pathomechanism of CI-AKI are needed. Sensitive and specific histologic end-points are lacking; thus in the present review we summarize the histologic appearance of different rodent models of CI-AKI. Single injection of RCM causes overt renal damage only in rabbits. Rats and mice need an additional insult to the kidney to establish a clinically manifest CI-AKI. In this review we demonstrate that the concentrating ability of the kidney may be responsible for species differences in sensitivity to CI-AKI. The most commonly held theory about the pathomechanism of CI-AKI is tubular cell injury due to medullary hypoxia. Thus, the most common additional insult in rats and mice is some kind of ischemia. The histologic appearance is tubular epithelial cell (TEC) damage; however severe TEC damage is only seen if RCM is combined by additional ischemia. TEC vacuolization is the first sign of CI-AKI, as it is a consequence of RCM pinocytosis and lysosomal fusion; however it is not sensitive as it does not correlate with renal function and is not specific as other forms of TEC damage also cause vacuolization. In conclusion, histopathology alone is insufficient and functional parameters and molecular biomarkers are needed to closely monitor CI-AKI in rodent experiments.

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

PURPOSE

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.

PATIENTS AND METHODS

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).

RESULTS

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 %).

CONCLUSIONS

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.