Prognosis of acute renal failure in the elderly

Incidence, predictors and prognosis of acute kidney injury in nonagenarians: an in-hospital cohort study

Background

Given the aging of the population, nephrologists are ever more frequently assisting nonagenarians with acute kidney injury (AKI). The management of these patients presents unique characteristics, including bioethical dilemmas, such as the utilization of renal replacement therapy (RRT) at this extreme age.

Methods

We conducted a retrospective cohort study at a tertiary hospital. Over a 10-year period, 832 nonagenarians were hospitalized for two or more days. A random sample of 461 patients was obtained; 25 subjects were excluded due to lack of essential data. AKI was defined and staged according to the Kidney Disease Improving Global Outcomes (KDIGO) criteria.

Results

We analyzed data from 436 patients, mean age 93.5 ± 3.3 years, 74.3% female; 76.4% required intensive care unit (ICU). The incidence of AKI was 45%. Length of hospital stay, ICU admission, vasopressors, and mechanical ventilation (MV) were independent predictors of AKI. Overall in-hospital mortality was 43.1%. Mortality was higher in the AKI compared to the no AKI group (66.8% vs. 23.8%, p < 0.001). Only 13 patients underwent RRT; all were critically ill, requiring vasopressors and 76.9% in MV. Mortality for this RRT group was 100% but not significantly higher than that observed in 26 non-RRT controls (96.1%, p = 1.0) obtained by proportional random sampling, matched by variables related to illness severity. In multivariable analysis, age, Charlson’s score, vasopressors, MV, and AKI – but not RRT – were independent predictors of mortality.

Conclusions

AKI is common in hospitalized nonagenarians and carries a grave prognosis, especially in those who are critically iil. The use of RRT was not able to change the fatal prognosis of this subgroup of patients. Our data may help guide informed decisions about the utility of RRT in this scenario.

Characteristics of and risk factors for death in elderly patients with acute kidney injury: a multicentre retrospective study in China

Purpose of the study

The incidence of acute kidney injury (AKI) with a poor prognosis in the elderly has been increasing each year. This study aimed to investigate the clinical characteristics of and risk factors for death from AKI in the elderly and help improve prognosis.

Study design

This study was a retrospective cohort study based on data from adult patients (≥18 years old) admitted to 15 hospitals in China between 1 January 2009 and 31 December 2011. The characteristics of AKI in the elderly were compared with those in younger patients.

Results

In elderly patients with AKI, rates of hypertension, cardiovascular disease and multiple organ dysfunction syndrome (MODS) were higher than in younger patients (44.2% vs 31.2%, 16.1% vs 4.6% and 20.9% vs 16.9%, respectively), the length of ICU stay was longer (3.8 days vs 2.7 days, P=0.019) and renal biopsy (1.0% vs 7.13%, P<0.001) and dialysis (9.6% vs 19.2%, P<0.001) were performed less. Hospital-acquired (HA) AKI was more common than community-acquired (CA) AKI (60.3% vs 39.7%), while the most common cause of AKI was pre-renal (53.5%). Multiple logistic regression analysis showed that age (OR 1.041, 95% CI 1.023 to 1.059), cardiovascular disease (OR 1.980, 95% CI 1.402 to 2.797), cancer (OR 2.302, 95% CI 1.654 to 3.203), MODS (OR 3.023, 95% CI 1.627 to 5.620) and mechanical ventilation (OR 2.408, 95% CI 1.187 to 4.887) were significant risk factors for death.

Conclusions

HA-AKI and pre-renal AKI were more common in the elderly. Age, cardiovascular disease, cancer, MODS and mechanical ventilation were independent risk factors for death in the elderly with AKI.

Long-term risk of upper gastrointestinal hemorrhage after advanced AKI

BACKGROUND AND OBJECTIVES

There are few reports on temporary dialysis-requiring AKI as a risk factor for future upper gastrointestinal bleeding (UGIB). This study sought to explore the long-term association between dialysis-requiring AKI and UGIB.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This nationwide cohort study used data from the Taiwan National Health Insurance Research Database. Patients who recovered from dialysis-requiring AKI and matched controls were selected from hospitalized patients age ≥18 years between 1998 and 2006. The cumulative incidences of long-term de novo UGIB were calculated, and the risk factors of UGIB and mortality were identified using time-varying Cox proportional hazard models adjusted for subsequent CKD and ESRD after AKI.

RESULTS

A total of 4565 AKI-recovery patients and the same number of matched patients without AKI were analyzed. After a median follow-up time of 2.33 years (interquartile range, 0.97-4.81 years), the incidence rates of UGIB were 50 (by stringent criterion) and 69 (by lenient criterion) per 1000 patient-years in the AKI-recovery group and 31 (by stringent criterion) and 48 (by lenient criterion) per 1000 patient-years in the non-AKI group (both P<0.001). When compared with patients in the non-AKI group, the multivariate hazard ratio (HR) for UGIB was 1.30 (95% confidence interval [95% CI], 1.14 to 1.48) for dialysis-requiring AKI, 1.83 (95% CI, 1.53 to 2.20) for time-varying CKD, and 2.31 (95% CI, 1.92 to 2.79) for time-varying ESRD (all P<0.001). Finally, the risk for long-term mortality increased after UGIB (HR, 1.24; 95% CI, 1.12 to 1.38) and dialysis-requiring AKI (HR, 1.66; 95% CI, 1.54 to 1.78).

CONCLUSIONS

Recovery from dialysis-requiring AKI was associated with future UGIB and mortality.

Acute kidney injury in the elderly

The aging kidney undergoes several important anatomic and physiologic changes that increase the risk of acute kidney injury (formerly acute renal failure) in the elderly. This article reviews these changes and discusses the diagnoses frequently encountered in the elderly patient with acute kidney injury. The incidence, staging, evaluation, management, and prognosis of acute kidney injury are also examined with special focus given to older adults.

Postoperative renal function evaluation, through RIFLE criteria, of elderly patients who underwent femur fracture surgery under spinal anesthesia

INTRODUCTION

The postoperative acute renal failure (ARF) incidence in different kinds of surgery has rarely been studied. Age, cardiac dysfunction, previous renal dysfunction, intraoperative hypoperfusion, and use of nephrotoxic medications are mentioned as risk factors for ARF at the postoperative period. The postoperative ARF definition was based on the creatinine increase by the RIFLE classification (R = risk, I = injury, F = failure, L = loss, E = end stage), which corresponds to a 1.5 creatinine increase, two to three times, respectively, above the basal value. This study aimed to evaluate the postoperative ARF incidence in elderly patients who underwent femur fracture surgery under subarachnoid anesthesia and stratify it by the RIFLE criteria.

METHODS

Ninety patients older than 65 years under spinal anesthesia with fixed dosage of 15 mg of 0.5% isobaric bupivacaine associated with morphine 50 mug were studied. Immediate postoperative creatinine was considered basal and compared with maximal creatinine evaluated at 24, 48, and 72 postoperative hours.

RESULTS

The mean age of the patients was 80.27 years. ARF incidence was 24.44% and stratified this way: R = 21.11% and I = 3.33%.

CONCLUSIONS

In conclusion, the postoperative ARF incidence after femur fracture surgery in patients over 65 years was 24.44%. By analyzing the stratification based on the RIFLE classification, the incidence was categorized as Risk (R) = 21.11% and Injury (I) = 3.33%.

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

The spectrum of acute renal failure (ARF) in the elderly population and the factors predicting poor outcome in these patients are not well defined in literature. Identification of risk factors and poor prognostic markers in these patients can help in planning strategies to prevent ARF and to prioritise the utilization of sparse and expensive therapeutic modalities, especially in a developing country like ours. We retrospectively analyzed data of 454 elderly patients (age >or=60 years), detected having ARF in a tertiary care super-speciality hospital in North India, from April 2000 to March 2004. The mean age of this population was 66.4 years with 70.5% being male. 64% patients had more than one precipitating factors for ARF, with volume depletion being the most common precipitating factor (33% cases). Infection/sepsis (21.6%) and drugs (11.5%) were other important precipitating factors. 31.8% were recorded as having oliguric ARF (urine output <400 ml/day) and 33.5% required renal replacement therapy (RRT). Acute peritoneal dialysis was the most frequent form of RRT given (62.5%). Mortality was 41.2% (187 cases), of whom 56 (29.8%) died inspite of recovery from ARF. Among the survivors, 103 patients (22.7%) had complete renal recovery, 141 (31.1%) had partial renal recovery, while 23 (8.6%), remained dialysis dependent. The factors which were found to be associated with increased mortality were; age >or=70 years, presence of previous chronic illness, ARF precipitated by cardiac failure and infection, need for RRT, oliguria and increasing numbers of failed organs. To conclude, ARF among elderly is a common problem in nephrology practice at our institute and is responsible for 48.9% of nephrology admissions/consultations among elderly patients. Majority of these patients are prone to multiple renal insults. Underlying chronic illness, presence of cardiac failure and sepsis, oliguria, need for RRT and increasing number of organ failure is associated with poor outcome.

Spectrum of renal failure in elderly patients

This prospective study was undertaken to study the spectrum of renal failure and the outcome in elderly patients. Patients included in the study group were elderly (age>60 years) who either attended outpatient renal clinic and or were hospitalized. Renal failure was classified as acute renal failure (ARF), rapidly progressive renal failure (RPRF) and chronic renal failure (CRF). A total of 4255 elderly patients were seen, of these 236 (5.5%) had renal failure. Mean age was 65.1+/-4.2 years (60-86 years). CRF was the commonest, seen in 137 (58.1%) followed by ARF 69 (29.2%) and RPRF in 30 (12.7%) patients. Diabetic nephropathy was the commonest cause of CRF, seen in 58.4% followed by chronic interstitial nephritis in 9.5% and chronic glomerulonephritis in 8.7% of patients. Of 137 patients 53 (38.7%) presented in end stage renal disease (ESRD). Of these 41 (77.3%) were initiated on maintenance hemodialysis and 12 (22.6%) on continuous ambulatory peritoneal dialysis. Only 15 patients were on dialytic support at the end of 1 year. Sepsis contributed to ARF in 75.4% of cases. Forty of 69 patients (57.9%) needed dialytic support. Forty (57.9%) were critically ill, defined as presence of two or more organ system failures (excluding renal failure). Forty two patients (60.9%) died patients. Acute interstitial nephritis (AIN) was the commonest cause of RPRF seen in 10 (33.3%) patients followed by vasculitis in 7 (23.3%). Myeloma cast nephropathy contributed towards RPRF in 20% of patients. Of 30 patients, 10 (33.3%) reached ESRD at end of 3 months of follow up, 4 (13.3%) died due to sepsis. Only 2 showed complete recovery while 14 (46.6%) had partial improvement. AIN patients had a relatively better outcome.

Predictors of mortality in elderly patients with acute renal failure in a developing country

This prospective study was undertaken to systematically analyze the predictors of mortality in the elderly in a developing country. All elderly patients with ARF hospitalized at this tertiary care centre over 1 year were studied. Various predictors analyzed were hospital-acquired ARF, causative factors of ARF, preexisting hypertension and diabetes mellitus, severity of renal failure (initial and peak serum creatinine, need for dialysis), and complications of ARF: infection during the course of illness; serum albumin levels and critical illness defined as presence of two or more organ system failures excluding renal failure. Of 33,301 patients admitted, 4,255 (12.7%) were elderly. Of these 69 (1.6%) had ARF. On analysis of the whole group, both young and elderly, age >60 years had an independent predictor of mortality (odds ratio 5.6, P = 0.001). Forty-two of the 69 (60.9%) elderly ARF patients died. The mortality was significantly increased in those elderly with hospital-acquired ARF (79.2%, P = 0.027), those with sepsis as a cause of ARF (71.2%, P = 0.004), those who required dialysis (72.5%, P = 0.022), those developing an infection during the course of ARF (87.9%, P = 0.000) and in those with a critical illness (90.0%, P = 0.00). On logistic regression analysis of those variables that were significant on univariate analysis, only critical illness (odds ratio 9.97) and infection during course (odds ratio 9.72) were the independent predictors of mortality. To conclude, ARF complicates only 1.6% of hospitalized elderly patients but is associated with a high mortality rate of 61%. Infection during the course of illness and critical illness were the independent predictors of mortality.

Acute renal failure in the elderly: particular characteristics

Elderly individuals comprise the faster growing patient population group and acute renal failure (ARF) is quite common among them, although exact numbers are not known. We reviewed the literature with regards to the characteristics of ARF in elderly patients and describe some useful guidelines. The ageing kidney is characterized by many structural and functional changes, which are mainly due to various chronic disorders, such as hypertension, diabetes and atherosclerosis, which are highly prevalent in these patients. A number of structural and functional changes characteristic of the ageing kidney make elderly people especially prone to renal damage. ARF in the elderly is frequently of multifactorial origin and often with an atypical presentation, like the "intermediate syndrome", which combines characteristics of pre-renal azotemia and acute tubular necrosis. Physical examination and laboratory blood and urine indices may sometimes be misleading occasionally leading to misdiagnosis. Prophylaxis remains the preferred approach to therapy: one should avoid nephrotoxic drugs and poly-pharmacy, adjust drug doses and achieve adequate hydration of the patient as cautiously as possible. Dialysis therapies can be used for treatment of ARF irrespective of age and carry a good prognosis.

Spectrum of renal diseases in the elderly: single center experience from a developing country

From November 1998 to March 2000, two hundred patients over the age of 60 years (Elderly) with clinical renal disease were studied. 144 patients were between ages of 60-69 years, 46 between 70-79 years and 10 were above 80 years. The elderly patients (Male 165; Female 35) with renal disease constituted 11% (200/1816) of the total nephrology consultation during the study period. The clinical presentation included chronic renal failure (42.5%); acute renal failure (28%); nephrotic syndrome (14.5%); acute glomerulonephritis (7.5%); renal vascular disease (5%) and renal cystic disease (2.5%). Diabetic nephropathy, obstructive uropathy and hypertensive nephrosclerosis were the major causes of CRF, accounting for 80% of total CRF in the elderly. Chronic glomerulonephritis and chronic pyelonephritis (CPN) were less common and etiology of CRF was uncertain in 5.9% of cases. However, diabetic nephropathy was the commonest (49.4%) cause of chronic renal failure. We did not see a single case of ischemic nephropathy causing CRF in the present study. Prerenal ARF, obstructive uropathy and sepsis were contributing factors for ARF in 82% of the cases. Volume depletion due to gastrointestinal fluid loss and urinary tract obstruction on account of enlarged prostate were the leading causes of ARF in 20 (35.7%) and 8 (14.3%) cases respectively. Sepsis with or without multiorgan failure was the major (46.7%) cause of mortality in patients with ARF and overall mortality was 26.8%. The commonest (31%) cause of nephrotic syndrome was the idiopathic membranous nephropathy. Diabetic nephropathy related to type-2 diabetes mellitus was the second most common (24.1%) cause of nephrotic syndrome. Diffuse endocapillary proliferative GN of post infectious etiology was the commonest (73.3%) type of acute GN in our elderly patients. Renal cystic diseases were noted in 5 (ADPKD 3; Simple cyst-2) patients. Thus, overall spectrum of renal disease in our elderly patients is similar to that of developed nations except in two ways: (i) Endocapillary proliferative GN of post infectious origin was the commonest type of acute GN and (ii) Rarity or absence of ischemic nephropathy and atherosclerotic renal artery occlusive disease.

Multi-organ renal failure in the elderly

Periodically the question is posed "Why the persistently high mortality in acute renal failure?". By 1986, little progress seemed to have been made in improving outcome and it was stated that once oliguria was resistant to volume replacement and cardiac support, the patient had at best only a 50% chance of surviving. During the period 1960-1985, it can be shown that although outcome was not improving, older and sicker patients were being treated. Reviewing the literature of the past decade, the age and case mix of patients appears stable, but there is no suggestion of improvement in outcome. ARF with sepsis continues to have a mortality of 65 to 80%, and the outcome remains poor in elderly patients with failure of two or more organs. Progress has been slow in Intensive Care Units, and the past 20 years has seen little more than a move away from parenteral towards enteral feeding. Recent advances, however, in ventilatory techniques and the use of supra-physiological doses of glucocorticoids may lead to some improvement in outcome.

Incidence, risk factors, and prognosis of gastrointestinal hemorrhage complicating acute renal failure

BACKGROUND

Few prospective data are currently available on acute gastrointestinal hemorrhage (AGIH) as a complication of acute renal failure (ARF). The aim of the present study was to define incidence, sources, risk factors, and outcome of AGIH in patients with ARF.

METHODS

We performed a prospective study on an inception cohort of 514 patients admitted for ARF to a nephrology intermediate care unit. Data on clinical risk factors for bleeding, frequency of occurrence of AGIH, length of hospital stay, and in-hospital mortality were collected. Independent predictors of AGIH were identified. The relative odds of death and the relative increase in length of hospital stay associated with AGIH were calculated after adjusting for baseline comorbidities.

RESULTS

Sixty-nine patients out of 514 [13.4% (95% CI, 10.6 to 16.7)] had AGIH as a complication of ARF; 59 were upper AGIH. Forty patients had clinically important bleeding. Erosions and/or ulcers accounted for 71% of cases of upper AGIH. Independent baseline predictors of AGIH were represented by severity of illness [odds ratio 1.45 (95% CI, 1.05 to 2.01) for every 10 point increase in APACHE II score], low platelet count [<50,000 mm3; 3.71 (1.70 to 8.11)], noncirrhotic chronic hepatic disease [2.22 (1.09 to 4.55)], liver cirrhosis [3.38 (1.50 to 7.60)], de novo ARF [2.77 (1.30 to 5.90)], and severe ARF [2.07 (1.10 to 3.88)]. In-hospital mortality was 63.8% in patients with AGIH and 34.2% in the other patients; after adjusting for baseline confounders, AGIH remained significantly associated with an increase in both mortality [2.57 (1.30 to 5.09), P = 0.006] and length of hospital stay [37% (1 to 87%), P = 0.047].

CONCLUSIONS

AGIH and clinically important bleeding are frequent complications of ARF. In this clinical condition, AGIH is more often due to upper gastrointestinal bleeding and is associated with a significantly increased risk of death and length of hospital stay. Both renal and extrarenal risk factors are related to the occurrence of AGIH.

Treatment-related acute renal failure in the elderly: a hospital-based prospective study

BACKGROUND

Elderly individuals need a host of diagnostic procedures and therapeutic interventions to take care of ailments. This prospective study was carried out to determine the magnitude of treatment-related acute renal failure (ARF) in the elderly in a hospital setting, to know about pathogenetic factors and to study the factors that could predict an adverse outcome.

METHODS

All elderly patients (>60 years) admitted over a 12-month period were screened prospectively throughout their hospital stay for the development of ARF.

RESULTS

Of 31860 patients admitted, 4176 (13%) were elderly. Of these 59 (1.4%) developed ARF in the hospital. Nephrotoxic drugs contributed towards development of ARF in 39 (66%), sepsis and hypoperfusion in 27 (45.7%) each, contrast medium in 10 (16.9%) and postoperative ARF occurred in 15 (25.4%) patients. These pathogenetic factors were responsible for ARF in different combinations. Amongst these combination of pathogenetic factors, radiocontrast administration (partial chi(2) 28.1, P<0.0001), surgery (partial chi(2) 14.89, P=0.001), and drugs (partial chi(2) 6. 22, P=0.0126) predicted ARF on their own. Nine patients (15.23%) needed dialytic support. Of 59 patients, 15 (25.4%) died, of those who survived, 38 (86.3%) recovered renal function completely and six (13.6%) partially. Mortality in the elderly with ARF was significantly higher than in those without ARF (25.4 vs 12.5%; chi(2) 8.3, P=0.03). Sepsis (odds ratio 43), oliguria (odds ratio 64), and hypotension (odds ratio 15) were independent predictors of poor patient outcome on logistic regression analysis.

CONCLUSION

Incidence of treatment-related ARF in the elderly was 1.4%, with more than one pathogenetic factor playing a role in the development of ARF in the majority. Sepsis, hypotension, and oliguria were the independent predictors of poor patient outcome.