Factors affecting the outcome of acute renal failure among the elderly population in India: a hospital based study

Mortality Analysis in Geriatric Patients With Acute Kidney Injury Admitted in the Intensive Care Unit: A Single-Center Cross-Sectional Study

Introduction Acute kidney injury (AKI) is an abrupt reduction in kidney function that causes nitrogenous waste and other waste products to be retained. Methods This cross-sectional study was conducted from February 2015 to January 2016. The study received approval from the Independent Ethics Committee, which included patients over 60 with AKI. The study duration was 12 consecutive months to ascertain the etiology, severity, and hospital outcomes of AKI. Results The common etiologies of AKI included drug-induced (25%), age-related (21.67%), cardiac (13.33%), respiratory (20%), tropical (15%), and pancreatitis (15%) cases. Another predominant etiology observed was obstructive nephropathy (55%), with the highest (37.5%) mortality rate. The distribution of patients based on KDIGO criteria showed no significant difference in mortality percentages among classes (p=0.177). Conservative management without renal replacement therapy was the most common approach to treat AKI, with a 39% mortality rate. Conclusion Among different causes of AKI in the geriatric age group, drug-induced AKI, and obstructive nephropathy were predominantly associated with hospital mortality.

Follow-up of perfusion index and inferior vena cava collapsibility index in fluid therapy in prerenal acute renal failure

Introduction

Acute renal failure (ARF), which may occur as a result of hypovolemia, is frequently diagnosed in emergency departments. It is essential to determine these patients' volume status and fluid requirement. The aim of this study was to examine the change in the inferior vena cava (IVC) collapsibility index and perfusion index (PI) in order to evaluate fluid deficit, volume status, and response to fluid therapy in patients with prerenal ARF who presented with signs of hypovolemia.

Materials and methods

The study sample included 104 patients diagnosed with prerenal ARF due to hypovolemia in our emergency department. After obtaining informed consent from the patients, intravenous (IV) fluid therapy (20 cc/kg IV infusion of 0.9% sodium chloride solution for 30 min) was initiated. The PI and IVC collapsibility index were measured before and after the treatment.

Results

Of the patients included in this study, 56.7% were women. The mean age was 76.06 years. Of the patients, 46.2% had a history of multiple diseases. Avoidant/restrictive food intake disorder was the most common complaint (28.8%). The mean PI of the patients was 2.20 at admission, which increased to 3.27 after treatment. The mean IVC collapsibility index was 38.39 at admission, which decreased to 29.36 after treatment. There was a significant and negative correlation between the PI and IVC collapsibility index of the patients.

Conclusions

Early diagnosis and treatment of ARF in emergency departments are critical. Serial measurements of the IVC collapsibility index and PI are helpful in monitoring patients' response to fluid therapy.

RRT Selection for AKI Patients With Critical Illness

Acute kidney injury (AKI) is a critical burden on intensive care units in Asia. Renal replacement therapy (RRT) acts as strong supportive care for severe AKI. However, various RRT modalities are used in Asia because of the diversity in ethics, climate, geographic features, and socioeconomic status. Extracorporeal blood purification is used commonly in Asian intensive care units; however, intermittent RRT is preferred in developing countries because of cost and infrastructure issues. Conversely, continuous RRT is preferred in developed countries, indicating the predominance of hospital-acquired AKI patients with complications of hemodynamic instability. Peritoneal dialysis is delivered less frequently, although several studies have suggested promising results for peritoneal dialysis in AKI treatment. Of note, not all RRT modalities are available as a standard procedure in some Asian regions, and it is absolutely necessary to develop a sustainable infrastructure that can deliver optimal care for all AKI patients.

Urinary Neutrophil Gelatinase-Associated Lipocalin Is Excellent Predictor of Acute Kidney Injury in Septic Elderly Patients

Elderly is the main age group affected by acute kidney injury (AKI). There are no studies that investigated the predictive properties of urinary (u) NGAL as an AKI marker in septic elderly population. This study aimed to evaluate the efficacy of uNGAL as predictor of AKI diagnosis and prognosis in elderly septic patients admitted to ICUs. We prospectively studied elderly patients with sepsis admitted to ICUs from October 2014 to November 2015. Assessment of renal function was performed daily by serum creatinine and urine output. The level of uNGAL was performed within the first 48 hours of the diagnosis of sepsis (NGAL1) and between 48 and 96 hours (NGAL2). The results were presented using descriptive statistics and area under the receiver operating characteristic curve (AUC-ROC) and p value was 5%. Seventy-five patients were included, 47 (62.7%) developed AKI. At logistic regression, chronic kidney disease and low mean blood pressure at admission were identified as factors associated with AKI (OR=0.05, CI=0.01-0.60, p=0.045 and OR=0.81, CI=0,13-0.47; p=0.047). The uNGAL was excellent predictor of AKI diagnosis (AUC-ROC >0.95, and sensitivity and specificity>0.89), anticipating the AKI diagnosis in 2.1±0.3 days. Factors associated with mortality in the logistic regression were presence of AKI (OR=2.14, CI=1.42-3.98, p=0.04), chronic obstructive pulmonary disease (OR = 9.37, CI =1.79-49.1, p=0.008) and vasoactive drugs (OR=2.06, CI=0.98-1.02, p=0.04). The accuracy of NGALu 1 and 2 as predictors of death was intermediate, with AUC-ROC of 0.61 and 0.62; sensitivity between 0.65 and 0.77 and specificity lower than 0.6. The uNGAL was excellent predictor of AKI in septic elderly patients in ICUs and can anticipate the diagnosis of AKI in 2.1 days.

Drug-Induced Kidney Injury in the Elderly

The incidence of acute kidney injury in the elderly has grown over the past decade. One of the primary drivers is drug-induced nephrotoxicity, which is the result of a combination of the unique susceptibilities to kidney injury and the increased use of medications in the elderly population. Specific drug classes are associated with increased rates of kidney injury including agents that block the renin angiotensin system, antimicrobials, and chemotherapeutic agents. Mechanistically, injury may be due to hemodynamic effects, tubular or glomerular toxicity, and interstitial nephritis. Early recognition of nephrotoxicity is critical, as are preventative steps when applicable. Unfortunately, treatment for established drug-induced kidney injury is limited and supportive care is required. Limiting exposure to nephrotoxic drugs is critical in decreasing the incidence of acute kidney injury in the elderly patient.

Acute kidney injury in elderly intensive care patients from a developing country: clinical features and outcome

AIM

The elderly are at high risk of acute kidney injury (AKI) because of structural and functional degeneration over time and with the aging of the population, the demand for intensive care unit (ICU) admission for older patients has risen recently. However, data from developing countries are scarce. This study aimed to describe the incidence of AKI in elderly patients admitted to ICU from a developing country, to determine the most frequent etiologies for renal impairment and identify its risk factors and outcome.

METHODS

All patients admitted to the ICU at a Brazilian teaching hospital for 12 consecutive months were followed prospectively from the time of admission until ICU discharge. Elderly was defined as aged >60 years and AKI was defined according to the Kidney Disease Improving Global Outcomes 2012 criteria. Multivariable logistic regression was used to adjust confounding and selection bias.

RESULTS

Two hundred elderly patients were included in the study. AKI incidence was 27% and the main etiology was sepsis (48.1%). At logistic regression, baseline creatinine (odds ratio [OR]=5.17, p<0.0001), Acute Physiology and Chronic Health Evaluation (APACHE) II (OR=1.20, p<0.0001), sepsis (OR=2.96, p<0.0001), and longer ICU stay (OR=1.68, p<0.0001) were associated with AKI in elderly patients. Baseline creatinine (OR=1.97, p=0.018), APACHE II (OR=1.29, p<0.0001), sepsis (OR=1.87, p<0.0001), and AKI severity (OR=2.57, p=0.027) were identified as predictors of death.

CONCLUSION

AKI was frequent in elderly patients admitted to ICU from a developing country, and it was identified as a risk factor for death. Sepsis was an important risk factor for both AKI and mortality, similar to developed countries and in younger populations.

The Frequency and Outcome of Acute Kidney Injury in a Tertiary Hospital: Which Factors Affect Mortality?

Acute kidney injury (AKI) is a major cause of mortality and morbidity in hospitalized patients. Incidence and mortality rates vary from country to country, and according to different in-hospital monitoring units and definitions of AKI. The aim of this study was to determine factors affecting frequency of AKI and mortality in our hospital. We retrospectively evaluated data for 1550 patients diagnosed with AKI and 788 patients meeting the Kidney Disease: Improving Global Outcomes (KDIGO) guideline AKI criteria out of a total of 174 852 patients hospitalized in our institution between January 1, 2007 and December 31, 2012. Staging was performed based on KDIGO Clinical Practice for Acute Kidney Injury and RIFLE (Risk, Injury, Failure, Loss of kidney function and End-stage renal failure). Demographic and biochemical data were recorded and correlations with mortality were assessed. The frequency of AKI in our hospital was 0.9%, with an in-hospital mortality rate of 34.6%. At multivariate analysis, diastolic blood pressure (OR 0.89, 95% CI 0.87-0.92; P < 0.001), monitoring in the intensive care unit (OR 0.18, 95% CI 0.09-0.38; P < 0.001), urine output (OR 4.00, 95% CI 2.03-7.89; P < 0.001), duration of oliguria (OR 1.51, 95% CI 1.34-1.69; P < 0.001), length of hospitalization (OR 0.83, 95% CI 0.79-0.88; P < 0.001), dialysis requirement (OR 2.30, 95% CI 1.12-4.71; P < 0.05), APACHE II score (OR 1.16, 95% CI 1.09-1.24; P < 0.001), and albumin level (OR 0.32, 95% CI 0.21-0.50; P < 0.001) were identified as independent determinants affecting mortality. Frequency of AKI and associated mortality rates in our regional reference hospital were compatible with those in the literature. This study shows that KDIGO criteria are more sensitive in determining AKI. Mortality was not correlated with staging based on RIFLE or KDIGO. Nonetheless, our identification of urine output as one of the independent determinants of mortality suggests that this parameter should be used in assessing the correlation between staging and mortality.

Use of peritoneal dialysis in AKI: a systematic review

BACKGROUND AND OBJECTIVES

The role of peritoneal dialysis in the management of AKI is not well defined, although it remains frequently used, especially in low-resource settings. A systematic review was performed to describe outcomes in AKI treated with peritoneal dialysis and compare peritoneal dialysis with extracorporeal blood purification, such as continuous or intermittent hemodialysis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

MEDLINE, CINAHL, and Central Register of Controlled Trials were searched in July of 2012. Eligible studies selected were observational cohort or randomized adult population studies on peritoneal dialysis in the setting of AKI. The primary outcome of interest was all-cause mortality. Summary estimates of odds ratio were obtained using a random effects model.

RESULTS

Of 982 citations, 24 studies (n=1556 patients) were identified. The overall methodological quality was low. Thirteen studies described patients (n=597) treated with peritoneal dialysis only; pooled mortality was 39.3%. In 11 studies (7 cohort studies and 4 randomized trials), patients received peritoneal dialysis (n=392, pooled mortality=58.0%) or extracorporeal blood purification (n=567, pooled mortality=56.1%). In the cohort studies, there was no difference in mortality between peritoneal dialysis and extracorporeal blood purification (odds ratio, 0.96; 95% confidence interval, 0.53 to 1.71). In four randomized trials, there was also no difference in mortality (odds ratio, 1.50; 95% confidence interval, 0.46 to 4.86); however, heterogeneity was significant (I(2)=73%, P=0.03).

CONCLUSIONS

There is currently no evidence to suggest significant differences in mortality between peritoneal dialysis and extracorporeal blood purification in AKI. There is a need for good-quality evidence in this important area.

Elderly patients with acute kidney injury (AKI): clinical features and risk factors for mortality

PURPOSE

Elderly patients with AKI are associated with considerable mortality. The clinical features and risk factors predicting poor outcomes of these patients are not known. The aim of this study is to investigate the clinical features and risk factors affecting mortality in elderly patients with AKI.

METHODS

A prospective study on the elderly patients with AKI (age ≥65 years old) was conducted. A consecutive sample of 99 elderly patients with AKI was evaluated. These patients were divided into survivor group and non-survivor group according their outcomes. Factors including clinical characteristics and laboratory features were compared between these two groups. Analysis of correlations between death and categorized risk factors was done by means of Pearson's chi-squared test (or Fisher's exact test). Multivariate logistic regression was performed to analyze the possible risk factors for death.

RESULTS

The main causes of the elderly patients with AKI were ischemia (53.34%), surgery (33.33%), sepsis/infection (10.10%), nephrotoxic drug (3.03%). The mortality rate of the elderly patients with AKI was 42%. Significant differences were found between the survival group and non-survival group of the elderly patients in concomitant disease, complicated with multiple organ dysfunction syndrome (MODS), albumin, etc. Concomitant disease and MODS were found to be the independent risk factors for death of the elderly patients with AKI after adjusting for age, sex, pre-albumin, sepsis/infection, and serum creatinine (SCr).

CONCLUSION

This study found that concomitant disease and MODS were the independent risk factors for the death of elderly patients with AKI.

Is angiotensin-converting enzyme inhibitor a contraindication for contrast-induced nephropathy prophylaxis? A review about its paradox

Contrast-induced nephropathy (CIN) is reported to be the third leading cause of acute renal failure. The role of angiotensin-converting enzyme (ACE) inhibitors in CIN is controversial. Some studies pointed out that it was effective in the prevention of CIN, while some concluded that it was associated with increased risk of CIN, especially for patients with preexisting renal impairment. Nevertheless, it is a common practice in many centers to prescribe ACE inhibitors before coronary angiography. The most likely mechanisms leading to CIN are medullary hypoxia due to decreased renal blood flow (RBF) secondary to renal artery vasoconstriction and direct tubular toxicity by contrast medium (CM). Furthermore, experimental data suggest that an activated renin-angiotensin-aldosterone system, increased endothelin-1, and reactive oxygen species play a role in the pathogenesis of CIN and these can be inhibited by using ACE inhibitors. In this context, we review the medical literatures and discuss the pathogenesis, the role of renin-angiotensin-aldosterone system on the development of CIN and ACE inhibitors' effect on CIN.

Acute kidney injury in the elderly population

The elderly population is more prone to acute kidney injury (AKI) than younger populations. Older patients have less renal reserve because of reduced glomerular filtration rates due to anatomic/functional changes, and concomitant diseases such as hypertension, diabetes, atherosclerosis, heart failure, ischemic renal disease, and obstructive uropathy. The risk of AKI may also increase as a result of aggressive diagnostic and therapeutic procedures, which include medical agents, radiology, and surgical intervention. AKI in the elderly has a multifactorial physiopathology due to different etiologies. Studies that have specifically compared prognosis of AKI in elderly versus young over the recent years suggest that age is a predictor of long-term outcome. In most cases, the treatment of AKI is similar for all age groups. The majority of critically ill patients with AKI will eventually need renal replacement therapy (RRT). The influence of RRT on renal outcome remains a subject of intense investigation and debate. Avoiding situations that could damage the kidney is an important strategy to prevent AKI development in the elderly, besides medical and interventional therapeutics.

Inhibition of the renin-angiotensin system and chronic kidney disease

Chronic kidney disease (CKD), a major worldwide public-health problem which affects about 10% of the population, has an increased annual incidence rate of about 5-8%. This increased incidence is mainly due to type 2 diabetes and hypertension and the increasing incidence of elderly patients with CKD. Although the progression to end-stage renal failure (ESRF) is mainly based upon the underlying disease, comorbid conditions such as an initial low renal function, severe proteinuria, and high levels of blood pressure also play important roles in the development of ESRF. Since experimental and clinical evidence suggest that angiotensin II plays a central role in the progression of CKD, pharmacological inhibition of the renin-angiotensin-aldosteron system (RAAS) with angiotensin converting enzyme inhibitors or angiotensin II receptor antagonists has been suggested as first-line treatment for hypertension and prevention of ESRF in these patients. Aliskiren, a novel renin inhibitor is also a promising medical intervention. However, independently of the category of the drugs used, low target blood pressure levels seem to be equally or more important for the delay or prevention of CKD. In this review the results of studies with pharmacological inhibition of the RAAS in patients with diabetic and nondiabetic nephropathy is discussed.

The effect of withdrawal of ACE inhibitors or angiotensin receptor blockers prior to coronary angiography on the incidence of contrast-induced nephropathy

BACKGROUND

The effect of continuing or discontinuing chronic angiotensin-converting enzyme inhibitor (ACEI) or angiotensin receptor blocker (ARB) therapy prior to coronary angiography on the incidence of contrast-induced nephropathy (CIN) is not clear. We undertook a randomized trial to evaluate the effect of withdrawing ACEIs or ARBs 24 h prior to coronary angiography on the incidence of CIN associated with coronary angiography.

METHODS

A total of 220 patients with chronic kidney disease (CKD) stages 3-4 (glomerular filtration rate 15-60 ml/min/1.73 m2) on ACEI or ARB therapy were randomized before angiography to either ACEI/ARB continuation group or discontinuation group. A third group of patients with CKD stages 3-4 but not on angiotensin blockade therapy were also followed. The primary outcome measure was the incidence of CIN defined by a rise in serum creatinine by 25% or 0.5 mg/dl (44 micromol/l) from baseline.

RESULTS

There was no statistically significant difference in the incidence of CIN between the three groups (P=0.66). The incidences were 6.2%, 3.7%, and 6.3% for the continuation, discontinuation, and angiotensin blockade naïve group, respectively. There was also no significant difference found between the groups in mean serum creatinine and glomerular filtration rate values at baseline and post contrast administration.

CONCLUSION

Withholding ACEIs and ARBs 24 h before coronary angiography does not appear to influence the incidence of CIN in stable patients with CKD stages 3-4.

Comparison between early and delayed acute kidney injury secondary to infectious disease in the intensive care unit

BACKGROUND

Results from a number of studies suggest that the delayed manifestation of acute kidney injury (AKI) is associated with higher in-hospital mortality, while other studies were unable to demonstrate any difference among early and delayed AKI in terms of in-hospital mortality.

OBJECTIVE

The aim of this study was to investigate differences in outcome among patients with AKI upon admission to an intensive care unit (ICU) and those who develop AKI post-admission.

METHODS

We studied patients with AKI secondary to infectious diseases admitted to the ICU. We retrospectively compared data on patients admitted with AKI (early AKI) with data on those who developed AKI 24 h after admission (delayed AKI).

RESULTS

Acute kidney injury occurred in 147 of 829 (17.7%) patients admitted to the ICU. Of these, 96 (65%) had early AKI and 51 (35%) had delayed AKI. Renal failure was classified according to RIFLE criteria-an AKI-specific severity score that is used to place patients into one of five categories: risk, injury, failure, loss or end-stage renal disease. Based on these criteria, 6% of the early AKI and 4% of the delayed AKI patients were in risk category, 18% of the early AKI and 27% of the delayed AKI patients were in the injury category and 76% of the early AKI and 69% of the delayed AKI patients were in the failure category. We found no significant association between RIFLE and death. On admission, patients with early AKI had statistically significantly higher serum urea and creatinine levels than delayed AKI patients (P<0.0001). Arterial bicarbonate was lower in early AKI (P=0.02). Sepsis, hypotension and use of mechanical ventilation were more frequent in delayed AKI (P<0.05). The APACHE II score was higher in early AKI (P=0.05) patients. In total, 98 (66.7%) patients died, with a tendency towards higher mortality in patients with delayed AKI (61.5 vs. 76.5%, P=0.07).

CONCLUSION

Mortality among patients with infectious diseases-associated AKI admitted to the ICU is high, with a trend to be higher in those who developed delayed AKI.