Acute renal failure of medical type in an elderly population

Medication Holds in CKD During Acute Volume-Depleting Illnesses: A Randomized Controlled Trial of a "Sick-Day" Protocol

Rationale & Objective

Some drugs prescribed for chronic kidney disease (CKD) may become hazardous on sick days with volume depletion by increasing the risk of acute kidney injury (AKI) and kidney function loss; however, the risks and benefits of their use during intercurrent illness is unknown.

Study Design

6-month pragmatic trial examining a sick-day protocol to determine if withholding prespecified drugs during a volume-depleting illness reduces the incidence AKI or kidney function loss in CKD.

Setting & Participants

315 veterans with stage 3-5 CKD, treated with a renin-angiotensin-aldosterone inhibitor blocker, diuretic, nonsteroidal anti-inflammatory drug, or metformin were randomized into the study with n = 159 and n = 156 in sick-day protocol and usual care groups, respectively.

Intervention

Sick-day protocol administered via interactive voice response system (IVRS) or usual care with 6-month follow-up.

Outcomes

The outcomes of the study are as follows: (1) Change in kidney function, (2) incidence of AKI based on International Classification of Diseases, Tenth Revision codes and ambulatory laboratory testing, (3) urgent service utilizations, and (4) sick days.

Results

The mean age was 70.1 ± 7.4 and 69.2 ± 8.1 years, with a mean baseline glomerular filtration rate (GFR) of 43.1 ± 13.1 and 43.8 ± 13.0 mL/min/1.73 m2, and 112 (70%) and 100 (64%) of participants with diabetes in the sick-day protocol and usual care groups, respectively. The mean change in GFR in the sick-day protocol and usual care groups from baseline to 6-month follow-up, adjusting for baseline GFR, was -0.71 (95% CI, -2.11 to 0.69) and -0.72 (95% CI, -2.12 to 0.68), respectively, with no significant difference, P = 0.99. Hospitalizations in the sick-day protocol and usual care groups were 11.5/100 and 8.4/100 events per person-months, respectively, with the adjusted rate ratio not significantly increased (prevalence ratio, 1.30; 95% CI, 0.96-1.76). Participants interacted with the IVRS in 81% of expected weeks and 19 had one or more qualifying events. In 33 true sick days, participants correctly followed the protocol in only 14.

Limitations

Low incidence of sick days over the 6-month period of the study.

Conclusions

The sick-day protocol was not associated with a significant reduction in AKI episodes or kidney function loss in a high-risk CKD population. Engagement with the IVRS was high, but successful implementation of the sick-day protocol was not optimal.

Trial Registration

ClinicalTrials.gov; NCT03141905.

Clinical Characteristics and Risk Factors for Mortality in Older Patients with Dialysis-Receiving Community-Acquired Acute Kidney Injury

Introduction

Older people in community are susceptible to acute kidney injury (AKI) and hemodialysis is the most important supportive measure used in the management of severe AKI. This study aims to investigate the clinical characteristics, outcomes and risk factors for mortality in older patients with dialysis-receiving-community-acquired AKI (CA-AKI).

Methods

A total of 1953 CA-AKI patients aged 65 years old and above were recruited from 2013 to 2016. Among which, 200 patients received hemodialysis. Clinical characteristics, outcomes, suspected nephrotoxic drug use after CA-AKI and risk factors for mortality in older CA-AKI patients with dialysis were analyzed.

Results

The percentage of CA-AKI patients receiving hemodialysis was 10.2%. Compared with non-dialysis patients, dialysis-receiving patients had more comorbidity, and worse renal function. The types of suspected nephrotoxic drugs used in dialysis patients were more than those in non-dialysis patients. Moreover, dialysis-receiving patients had worse outcomes, including complete recovery of renal function (42.0% vs 71.6%), intensive care unit (ICU) (69.0% vs 15.3%) transfer and in-hospital mortality (50.5% vs 5.6%) (P<0.01). Age, moderate/severe liver disease, beta lactam antibiotics, glycopeptide antibiotics, antifungal agents, drugs for anti-heart failure, category of suspected nephrotoxic drugs, hyperkalemia, increased leucocyte count, ICU transfer, multiple organ dysfunction (MODS), cardiogenic shock and cardio-pulmonary resuscitation (CPR) were risk factors for mortality by univariate logistic regression analysis. After adjusting for confounding factors, the independent risk factors were glycopeptide antibiotics, drugs for anti-heart failure, ICU transfer, MODS and CPR.

Conclusion

The percentage of older CA-AKI patients receiving dialysis was high, and these patients had more comorbidity and worse prognosis. Glycopeptide antibiotics, drugs for anti-heart failure, ICU transfer, MODS and CPR were independent risk factors for mortality.

Is acute kidney injury age-dependent in older adults: an observational study in two centers from North China

Background

Although aging increases susceptibility to acute kidney injury (AKI), whether the AKI risk and the association between AKI and adverse outcomes are age-dependent remain unclear in older adults. The current study aimed to identify whether AKI risk was age-dependent in older adults and to investigate whether the association between AKI and mortality increased with increasing age.

Methods

Medical records from 47,012 adult hospital admissions, including 30,194 older adults aged 60 or older, in two tertiary general hospitals were studied retrospectively. AKI was identified based on changes in blood creatinine levels according to the Kidney Disease: Improving Global Outcomes criteria.

Results

Among the total population and 30,194 older adult patients, the raw incidences of AKI were 8.2 and 8.3%, respectively. The curve of the age-grouped AKI incidence was “U-shaped”, which revealed a positive relationship between the AKI incidence and age among the older adults aged 75 years or older. This trend of the age-AKI relationship was supported by further multivariable analysis. After adjusting for the Charlson Comorbidity Index score, the AKI was associated with in-hospital mortality; however, the associations did not increase with increasing age.

Conclusion

The AKI risk does not increase with age in older adults, except for those aged 75 and above. The association between AKI and in-hospital death did not increase in an age-dependent manner in older adults.

Trial registration

This study was retrospectively registered at clinicaltrials.gov (NCT03054142) on February 13, 2017.

Kidney physiology and pathophysiology during heat stress and the modification by exercise, dehydration, heat acclimation and aging

The kidneys' integrative responses to heat stress aid thermoregulation, cardiovascular control, and water and electrolyte regulation. Recent evidence suggests the kidneys are at increased risk of pathological events during heat stress, namely acute kidney injury (AKI), and that this risk is compounded by dehydration and exercise. This heat stress related AKI is believed to contribute to the epidemic of chronic kidney disease (CKD) occurring in occupational settings. It is estimated that AKI and CKD affect upwards of 45 million individuals in the global workforce. Water and electrolyte disturbances and AKI, both of which are representative of kidney-related pathology, are the two leading causes of hospitalizations during heat waves in older adults. Structural and physiological alterations in aging kidneys likely contribute to this increased risk. With this background, this comprehensive narrative review will provide the first aggregation of research into the integrative physiological response of the kidneys to heat stress. While the focus of this review is on the human kidneys, we will utilize both human and animal data to describe these responses to passive and exercise heat stress, and how they are altered with heat acclimation. Additionally, we will discuss recent studies that indicate an increased risk of AKI due to exercise in the heat. Lastly, we will introduce the emerging public health crisis of older adults during extreme heat events and how the aging kidneys may be more susceptible to injury during heat stress.

Acute Kidney Injury Outcomes of Elderly and Nonelderly Patients in the Medical Intensive Care Unit of a University Hospital in a Developing Country

Background

Aging is associated with a high risk of acute kidney injury (AKI), and the elderly with AKI show a higher mortality rate than those without AKI. In this study, we compared AKI outcomes between elderly and nonelderly patients in a university hospital in a developing country.

Materials and Methods

This retrospective cohort study included patients with AKI who were admitted to the medical intensive care unit (ICU) between January 1, 2012, and December 31, 2017. The patients were divided into the elderly (eAKI; age ≥65 years; n = 158) and nonelderly (nAKI; n = 142) groups. Baseline characteristics, comorbidities, principle diagnosis, renal replacement therapy (RRT) requirement, hospital course, and in-hospital mortality were recorded. The primary outcome was in-hospital mortality.

Results

The eAKI group included more females, patients with higher Acute Physiology and Chronic Health Evaluation II scores, and patients with more comorbidities than the nAKI group. The etiology and staging of AKI were similar between the two groups. There were no significant differences in in-hospital mortality (p=0.338) and RRT requirement (p=0.802) between the two groups. After adjusting for covariates, the 28-day mortality rate was similar between the two groups (p=0.654), but the 28-day RRT requirement was higher in the eAKI group than in the nAKI group (p=0.042).

Conclusion

Elderly and nonelderly ICU patients showed similar survival outcomes of AKI, although the elderly were at a higher risk of requiring RRT.

Preventing acute kidney injury in high-risk patients by temporarily discontinuing medication - an observational study in general practice

BACKGROUND

Elderly, patients with chronic kidney disease (CKD) and patients with heart failure who continue using renin-angiotensin-aldosterone-system (RAAS) inhibitors, diuretics, or non-steroidal-anti-inflammatory drugs (NSAIDs) during times of fluid loss have a high risk of developing complications like acute kidney injury (AKI). The aim of this study was to assess how often advice to discontinue high-risk medication was offered to high-risk patients consulting the general practitioner (GP) with increased fluid loss. Furthermore, we assessed the number and nature of the complications that occurred after GP consultation.

METHODS

We performed a cross-sectional study with patients from seven Dutch general practices participating in the Family Medicine Network between 1 and 6-2013 and 1-7-2018. We included patients who used RAAS-inhibitors, diuretics, or NSAIDs, and had at least one of the following risk factors: age ≥ 70 years, CKD, or heart failure. From this population, we selected patients with a 'dehydration-risk' episode (vomiting, diarrhoea, fever, chills, or gastrointestinal infection). We manually checked their electronic patient files and assessed the percentage of episodes in which advice to discontinue the high-risk medication was offered and whether a complication occurred in 3 months after the 'dehydration-risk' episode.

RESULTS

We included 3607 high-risk patients from a total of 44.675 patients (8.1%). We found that patients were advised to discontinue the high-risk medication in 38 (4.6%) of 816 'dehydration-risk' episodes. In 59 of 816 episodes (7.1%) complications (mainly AKI) occurred.

CONCLUSIONS

Dutch GPs do not frequently advise high-risk patients to discontinue high-risk medication during 'dehydration-risk' episodes. Complications occur frequently. Timely discontinuation of high-risk medication needs attention.

Enhanced renal ischemia-reperfusion injury in aging and diabetes

The incidence and severity of acute kidney injury is increased in patients with diabetes and with aging. However, the mechanisms involved have not been clearly established. The present study examined the effects of aging and diabetes on the severity of renal ischemia-reperfusion (IR) injury in Sprague-Dawley (SD) and type 2 diabetic (T2DN) rats. T2DN rats develop diabetes at 3 mo of age and progressive proteinuria and diabetic nephropathy as they age from 6 to 18 mo. Plasma creatinine levels after bilateral IR were significantly higher (3.4 ± 0.1 mg/dl) in 18-mo-old elderly T2DN rats than in middle-aged (12 mo) T2DN rats with less severe diabetic nephropathy or young (3 mo) and elderly (18 mo) control SD rats (1.5 ± 0.2, 1.8 ± 0.1, and 1.7 ± 0.1 mg/dl, respectively). Elderly T2DN rats exhibited a greater fall in medullary blood flow 2 h following renal IR and a more severe and prolonged decline in glomerular filtration rate than middle-aged T2DN and young or elderly SD rats. The basal expression of the adhesion molecules ICAM-1 and E-selectin and the number of infiltrating immune cells was higher in the kidney of elderly T2DN than age-matched SD rats or young and middle-aged T2DN rats before renal IR. These results indicate that elderly T2DN rats with diabetic nephropathy are more susceptible to renal IR injury than diabetic animals with mild injury or age-matched control animals. This is associated with increased expression of ICAM-1, E-selectin and immune cell infiltration, renal medullary vasocongestion, and more prolonged renal medullary ischemia.

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.

The Effect of Treatment on Short-Term Outcomes in Elderly Patients with Acute Kidney Injury

BACKGROUND

Elderly population (≥ 65) are more prone to develop acute kidney injury (AKI) compared to younger, also elderly with AKI have an increased requirement for dialysis treatment and an elevated risk of short-term and long-term mortality.

AIM

The objectives of this study were to examine the effect of treatment of short-term outcomes and mortality in elderly patients with AKI.

MATERIAL AND METHODS

Seventy elderly AKI patients, that filled one of the criteria of AKI definition and had hospitalization over 24 hours, were enrolled in the study.

RESULTS

The median age of patients was 74.28 ± 6.64, with mean CCI (Charlson Comorbidity Index) score of 6.94 ± 1.94. The majority of patients (70%) were classified at stage 3 of AKIN, 20% of patients were classified at stage 2 and 10% at stage 1. In the groups of patients with death outcome, the chronic cardiomyopathy was more frequently present (p = 0.034). Regarding treatment, 58.6% of the AKI patients underwent hemodialysis while 41.4% received conservative treatment. Mortality rate was 52.8%, out of which 28.6% was in-hospital mortality, while in 24.3% of patients death occurred in the follow-up period of 90 days.

CONCLUSION

In our study, short- term survival is not related to different treatment options. Applied treatment in elderly patients with AKI should be assessed by measuring the long term outcome.

Twist2 Is Upregulated in Early Stages of Repair Following Acute Kidney Injury

The aging kidney is a marked by a number of structural and functional changes, including an increased susceptibility to acute kidney injury (AKI). Previous studies from our laboratory have shown that aging male Fischer 344 rats (24 month) are more susceptible to apoptosis-mediated injury than young counterparts. In the current studies, we examined the initial injury and early recovery phases of mercuric chloride-induced AKI. Interestingly, the aging kidney had decreased serum creatinine compared to young controls 1 day following mercuric chloride injury, but by day 4, serum creatinine was significantly elevated, suggesting that the aging kidney did not recover from injury. This conclusion is supported by the findings that serum creatinine and kidney injury molecule-1 (Kim-1) gene expression remain elevated compared to young controls at 10 days post-injury. To begin to elucidate mechanism(s) underlying dysrepair in the aging kidney, we examined the expression of Twist2, a helix-loop-helix transcription factor that may mediate renal fibrosis. Interestingly, Twist2 gene expression was elevated following injury in both young and aged rats, and Twist2 protein expression is elevated by mercuric chloride in vitro.

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.

Fascin2 regulates cisplatin-induced apoptosis in NRK-52E cells

Previous studies have shown that the aging kidney has a marked loss of α(E)-catenin in proximal tubular epithelium. α-Catenin, a key regulator of the actin cytoskeleton, interacts with a variety of actin-binding proteins. Cisplatin-induced loss of fascin2, an actin bundling protein, was observed in cells with a stable knockdown of α(E)-catenin (C2 cells), as well as in aging (24 mon), but not young (4 mon), kidney. Fascin2 co-localized with α-catenin and the actin cytoskeleton in NRK-52E cells. Knockdown of fascin2 increased the susceptibility of tubular epithelial cells to cisplatin-induced injury. Overexpression of fascin2 in C2 cells restored actin stress fibers and attenuated the increased sensitivity of C2 cells to cisplatin-induced apoptosis. Interestingly, fascin2 overexpression attenuated cisplatin-induced mitochondrial dysfunction and oxidative stress in C2 cells. These data demonstrate that fascin2, a putative target of α(E)-catenin, may play important role in preventing cisplatin-induced acute kidney injury.

[Rehabilitation after hip and knee endoprosthetic treatment in the elderly]

Due to current demographic developments with a continuous increase in average life expectancy and improved medical treatment, the number of elderly patients with joint replacement of the lower extremities also has increased in recent years. Most of these patients have not only one but several chronic diseases requiring treatment and medication. Drug-drug interaction and functional restrictions of the elderly additionally reduce the postoperative psychophysical capacity; therefore, special knowledge in rehabilitative treatment and pain management is necessary. Physiotherapy and exercise should include training of mobility, endurance, strength, coordination and training in activities of daily living. The individual constitution and pain during exercise must always be taken into consideration. Rehabilitative outcome is dependent on a functioning cooperation of an interdisciplinary rehabilitation team and requires an organized, holistic treatment approach in interconnected structures, which aims at rapid postoperative mobilization.

[Analgesics in geriatric patients. Adverse side effects and interactions]

Pain is a widespread symptom in clinical practice. Older adults and chronically ill patients are particularly affected. In multimorbid geriatric patients, pharmacological pain treatment is an extension of a previously existing multimedication. Besides the efficacy of pain treatment, drug side effects and drug-drug interactions have to be taken into account to minimize the health risk for these patients. Apart from the number of prescriptions, the age-related pharmacokinetic and pharmacodynamic changes significantly increase the risk among older adults. The use of non-steroidal anti-inflammatory drugs (NSAID) is widespread but NSAIDs have the highest risk of adverse drug reactions and drug interactions. In particular, the gastrointestinal, cardiovascular, renal and coagulation systems are affected. Apart from the known toxic effect on the liver (in high doses), paracetamol (acetaminophen) has similar risks although to a lesser degree. According to current data, metamizol is actually better than its reputation suggests. The risk of potential drug interactions seems to be low. Apart from the risk of sedation in combination with other drugs, tramadol and other opioids can induce the serotonin syndrome. Among older adults, especially in the case of polypharmacy, an individualized approach should be considered instead of sticking to the pain management recommended by the World Health Organization (WHO) in order to minimize drug-drug interactions and adverse drug reactions.

RIFLE classification in geriatric patients with acute kidney injury in the intensive care unit

BACKGROUND

The RIFLE classification is widely used to assess the severity of acute kidney injury (AKI), but its application to geriatric AKI patients complicated by medical problems has not been reported.

METHODS

We investigated 256 geriatric patients (≥65 years old; mean age, 74.4 ± 6.3 years) who developed AKI in the intensive care unit (ICU) according to the RIFLE classification. Etiologic, clinical, and prognostic variables were analyzed.

RESULTS

They were categorized into RIFLE-R (n = 53), RIFLE-I (n = 102), and RIFLE-F (n = 101) groups. The overall in-hospital mortality was 39.8 %. There were no significant differences in RIFLE category between survivors and non-survivors. Survivors had significantly less needs for a ventilator and vasopressor, and lower number of failing organs. Survivors had higher systolic blood pressure, hemoglobin level, and serum albumin levels. We performed a logistic regression analysis to identify the independent predictors of in-hospital mortality. In a univariate analysis, hypertension, chronic kidney disease, RIFLE classification, number of failing organs, need for a ventilator and vasopressor, systolic blood pressure, hemoglobin level, and serum albumin levels were identified as prognostic factors of in-hospital mortality. However, in a multivariate analysis, hypertension, chronic kidney disease, number of failing organs, and serum albumin levels were independent risk factors, with no significant difference for in-hospital mortality with the RIFLE classification.

CONCLUSION

The RIFLE classification might not be associated with mortality in geriatric AKI patients in the ICU. In geriatric patients with AKI, various factors besides severity of AKI should be considered to predict mortality.

Intraoperative hypotension - a neglected causative factor in hospital-acquired acute kidney injury; a Mayo Clinic Health System experience revisited

Acute kidney injury (AKI) is a relatively common complication of cardiothoracic surgery and has both short- and long-term survival implications, even when AKI does not progress to severe renal failure. Given that currently, there are no active effective treatments for AKI, other than renal replacement therapy when indicated, the focus of clinicians ought to be on prevention and risk factor management. In the AKI-surgery literature, there exists this general consensus that intraoperative hypotension (IH) following hypotensive anesthesia (HA) or controlled hypotension (CH) in the operating room has no significant short-term and long-term impacts on renal function. In this review, we examine the basis for this consensus, exposing some of the flaws of the clinical study data upon which this prevailing consensus is based. We then describe our experiences in the last decade at the Mayo Clinic Health System, Eau Claire, in Northwestern Wisconsin, USA, with two selected case presentations to highlight the contribution of IH as a potent yet preventable cause of post-operative AKI. We further highlight the causative although neglected role of IH in precipitating postoperative AKI in chronic kidney disease (CKD) patients. We show additional risk factors associated with this syndrome and further make a strong case for the elimination of IH as an achievable mechanism to reduce overall, the incidence of hospital acquired AKI. We finally posit that as the old saying goes, prevention is indeed better than cure.

The aging kidney: increased susceptibility to nephrotoxicity

Three decades have passed since a series of studies indicated that the aging kidney was characterized by increased susceptibility to nephrotoxic injury. Data from these experimental models is strengthened by clinical data demonstrating that the aging population has an increased incidence and severity of acute kidney injury (AKI). Since then a number of studies have focused on age-dependent alterations in pathways that predispose the kidney to acute insult. This review will focus on the mechanisms that are altered by aging in the kidney that may increase susceptibility to injury, including hemodynamics, oxidative stress, apoptosis, autophagy, inflammation and decreased repair.

Cost effectiveness of a pharmacist-led information technology intervention for reducing rates of clinically important errors in medicines management in general practices (PINCER)

BACKGROUND AND OBJECTIVE

We recently showed that a pharmacist-led information technology-based intervention (PINCER) was significantly more effective in reducing medication errors in general practices than providing simple feedback on errors, with cost per error avoided at £79 (US$131). We aimed to estimate cost effectiveness of the PINCER intervention by combining effectiveness in error reduction and intervention costs with the effect of the individual errors on patient outcomes and healthcare costs, to estimate the effect on costs and QALYs.

METHODS

We developed Markov models for each of six medication errors targeted by PINCER. Clinical event probability, treatment pathway, resource use and costs were extracted from literature and costing tariffs. A composite probabilistic model combined patient-level error models with practice-level error rates and intervention costs from the trial. Cost per extra QALY and cost-effectiveness acceptability curves were generated from the perspective of NHS England, with a 5-year time horizon.

RESULTS

The PINCER intervention generated £2,679 less cost and 0.81 more QALYs per practice [incremental cost-effectiveness ratio (ICER): -£3,037 per QALY] in the deterministic analysis. In the probabilistic analysis, PINCER generated 0.001 extra QALYs per practice compared with simple feedback, at £4.20 less per practice. Despite this extremely small set of differences in costs and outcomes, PINCER dominated simple feedback with a mean ICER of -£3,936 (standard error £2,970). At a ceiling 'willingness-to-pay' of £20,000/QALY, PINCER reaches 59 % probability of being cost effective.

CONCLUSIONS

PINCER produced marginal health gain at slightly reduced overall cost. Results are uncertain due to the poor quality of data to inform the effect of avoiding errors.

The ethics of offering dialysis for AKI to the older patient: time to re-evaluate?

Older patients are more susceptible to AKI. In the elderly, AKI has been associated with increased morbidity and mortality, and it is a significant risk factor for CKD and dialysis-dependent ESRD. There are now accumulating data that the start of dialysis for some older patients is associated with poor outcomes, such as high treatment intensity, suffering, and limited life prolongation, which occur at the expense of dignity and quality of life. The biomedicalization of aging is a relatively recent field of ethical inquiry with two directly relevant features to decisions about starting dialysis for older patients with AKI: (1) the routinization of geriatric clinical interventions, such as dialysis, which results in the overshadowing of patient choice, and (2) the transformation of the technological imperative into the moral imperative. A major consequence of the biomedicalization of aging is that societal expectations about standard medical care have resulted in the relatively unquestioned provision of dialysis for AKI to older patients. This paper calls for nephrologists to re-examine the data and their attitudes to offering dialysis to older patients with AKI, especially those patients with underlying CKD and significant comorbidities. Shared decision-making and the reinforcement of the right of the patient to make a choice need to slow down the otherwise ineluctable routinization of starting old and very sick patients on dialysis. In the process of shared decision-making, nephrologists should not automatically recommend dialysis for older patients; in those patients who can be predicted to do poorly, recommending against dialysis upholds the Hippocratic maxim to be of benefit and do no harm. This paper challenges the automatic transformation of the technological imperative into the moral imperative for older patients with AKI and points to the need for a re-evaluation of dialysis ethics in this population.

α(E)-catenin regulates BMP-7 expression and migration in renal epithelial cells

BACKGROUND

The aging kidney has a decreased ability to repair following injury. We have shown a loss in expression of α-catenin in the aging rat kidney and hypothesize that decreased α-catenin expression in tubular epithelial cells results in diminished repair capacity.

METHODS

In an effort to elucidate alterations due to the loss of α-catenin, we generated NRK-52E cell lines with stable knockdown of α(E)-catenin.

RESULTS

α(E)-catenin knockdown resulted in decreased wound repair due to alterations in cell migration. Analysis of gene expression in the α(E)-catenin knockdown cells demonstrated almost a complete loss of bone morphogenetic protein-7 (BMP-7) expression that was associated with decreased phospho-Smad1/5/8 staining. However, addition of exogenous BMP-7 increased phospho-Smad1/5/8, suggesting that the BMP-7 pathway remained intact in C2 cells. Given the potential role of BMP-7 in repair, we investigated its role in wound repair. Inhibition of BMP-7 decreased repair in non-targeted control cells; conversely, exogenous BMP-7 restored repair in α(E)-catenin knockdown cells to control levels.

CONCLUSIONS

Taken together, the data suggests that the loss of α(E)-catenin expression and subsequent downregulation of BMP-7 is a mechanism underlying the altered migration of tubular epithelial cells that contributes to the inability of the aging kidney to repair following injury.

Diclofenac induced acute renal failure in a decompensated elderly patient

Non-steroidal anti-inflammatory drugs (NSAIDs) are one of the most commonly prescribed drugs in post-operative period worldwide. Their nephrotoxic effects are documented and accounts for around 15.5% of all cases of drug induced renal failure. Acute renal failure following NSAIDs usage are reported in volume depleted patients which is further precipitated by co-morbid conditions like hypertension and various drug interactions that increase plasma level of NSAIDs and worsens the condition. This highlights the importance of hydration in post-operative period as well as assessment of co-morbid conditions before administration of NSAIDs to prevent acute renal failure.

Acute kidney injury, sodium disorders, and hypercalcemia in the aging kidney: diagnostic and therapeutic management strategies in emergency medicine

This article summarizes the current literature regarding the structural and functional changes of the aging kidney and describes how these changes make the older patient more susceptible to acute kidney injury and fluid and electrolyte disorders. It discusses the clinical manifestations, evaluation, and management of hyponatremia and shows how the management of hypernatremia in geriatric patients involves addressing the underlying cause and safely correcting the hypernatremia. The current literature regarding evaluation and management of hypercalcemia in older patients is summarized. The management of severe hypercalcemia is discussed in detail. The evaluation and management of acute kidney injury is described.

Concurrent use of diuretics, angiotensin converting enzyme inhibitors, and angiotensin receptor blockers with non-steroidal anti-inflammatory drugs and risk of acute kidney injury: nested case-control study

OBJECTIVES

To assess whether a double therapy combination consisting of diuretics, angiotensin converting enzyme inhibitors, or angiotensin receptor blockers with addition of non-steroidal anti-inflammatory drugs (NSAIDs) and the triple therapy combination of two of the aforementioned antihypertensive drugs to which NSAIDs are added are associated with an increased risk of acute kidney injury.

DESIGN

Retrospective cohort study using nested case-control analysis.

SETTING

General practices contributing data to the UK Clinical Practice Research Datalink linked to the Hospital Episodes Statistics database.

PARTICIPANTS

A cohort of 487,372 users of antihypertensive drugs.

MAIN OUTCOME MEASURES

Rate ratios with 95% confidence intervals of acute kidney injury associated with current use of double and triple therapy combinations of antihypertensive drugs with NSAIDs.

RESULTS

During a mean follow-up of 5.9 (SD 3.4) years, 2215 cases of acute kidney injury were identified (incidence rate 7/10,000 person years). Overall, current use of a double therapy combination containing either diuretics or angiotensin converting enzyme inhibitors or angiotensin receptor blockers with NSAIDs was not associated with an increased rate of acute kidney injury. In contrast, current use of a triple therapy combination was associated with an increased rate of acute kidney injury (rate ratio 1.31, 95% confidence interval 1.12 to 1.53). In secondary analyses, the highest risk was observed in the first 30 days of use (rate ratio 1.82, 1.35 to 2.46).

CONCLUSIONS

A triple therapy combination consisting of diuretics with angiotensin converting enzyme inhibitors or angiotensin receptor blockers and NSAIDs was associated with an increased risk of acute kidney injury. The risk was greatest at the start of treatment. Although antihypertensive drugs have cardiovascular benefits, vigilance may be warranted when they are used concurrently with NSAIDs.

Advanced age affects the outcome-predictive power of RIFLE classification in geriatric patients with acute kidney injury

The RIFLE (risk, injury, failure, loss, and end-stage) classification is widely used to gauge the severity of acute kidney injury, but its efficacy has not been formally tested in geriatric patients. To correct this we conducted a prospective observational study in a multicenter cohort of 3931 elderly patients (65 years of age or older) who developed acute kidney injury in accordance with the RIFLE creatinine criteria after major surgery. We studied the predictive power of the RIFLE classification for in-hospital mortality and investigated the potential interaction between age and RIFLE classification. In general, the survivors were significantly younger than the nonsurvivors and more likely to have hypertension. In patients 76 years of age and younger, RIFLE-R, -I, or -F classifications were significantly associated with increased hospital mortality in a stepwise manner. There was no significant difference, however, in hospital mortality in those over 76 years of age between patients with RIFLE-R and RIFLE-I, although RIFLE-F patients had significantly higher mortality than both groups. Thus, the less severe categorizations of acute kidney injury per RIFLE classification may not truly reflect the adverse impact on elderly patients.

Neutrophil gelatinase-associated lipocalin in acute kidney injury

Acute kidney injury (AKI) is recognized as an independent risk factor for morbidity and mortality. Unfortunately, this syndrome was historically underdiagnosed due to inconsistent definition of AKI as well as insensitive and nonspecific diagnostic tools. Recent advances in defining AKI, understanding its pathophysiology, and improving its diagnostic accuracy have an impact in disease management and clinical outcome. Prompt recognition and treatment of AKI still remains the cornerstone of clinical management of this syndrome. This chapter focuses on the recent advances in diagnosis of AKI using novel serum and urine biomarkers. The role of neutrophil gelatinase-associated lipocalin (NGAL) in pathophysiology and diagnosis of AKI is presented. A detailed analysis of the biology of NGAL and presentation of laboratory methods of measurement is also provided. The role of NGAL as biomarker beyond the boundaries of nephrology is also presented.

Renin-angiotensin-aldosterone system blockade effects on the kidney in the elderly: benefits and limitations

The proportion of the population that is elderly (age>or=65 years) is growing across the world. The increasing longevity of humans results in a higher number of elderly patients' presenting with multiple chronic diseases such as hypertension, diabetes, and chronic kidney disease (CKD). These problems increase morbidity and mortality in the elderly. Overactivity of the renin-angiotensin-aldosterone system (RAAS) is associated with the development of hypertension, cardiovascular events, and CKD, so targeting the RAAS is a logical therapeutic approach. Elderly patients present special concerns regarding the benefits versus risks of using RAAS blockers. Plasma renin activity declines with age, which has been attributed to the effect of age-associated nephrosclerosis. Plasma aldosterone is also reduced with age, resulting in a greater risk for hyperkalemia in older individuals, especially when coupled with the age-associated decline in GFR. Moreover, the elderly have a higher frequency of concurrent conditions and are on many medications, which may further increase the risk for adverse effects of RAAS blocking agents. Unfortunately, there is a paucity of literature that is specifically aimed at studying elderly using the RAAS blockers. We present in our in-depth review data regarding benefits and limitations of the use of the RAAS blockades on the various sites along the RAAS pathway for elderly patients. Specific attention was given to the role of combination RAAS blockade therapy and higher monotherapy dosing in the treatment of hypertension in the elderly.

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.

Nephrotoxicity as a cause of acute kidney injury in children

Many different drugs and agents may cause nephrotoxic acute kidney injury (AKI) in children. Predisposing factors such as age, pharmacogenetics, underlying disease, the dosage of the toxin, and concomitant medication determine and influence the severity of nephrotoxic insult. In childhood AKI, incidence, prevalence, and etiology are not well defined. Pediatric retrospective studies have reported incidences of AKI in pediatric intensive care units (PICU) of between 8% and 30%. It is widely recognized that neonates have higher rates of AKI, especially following cardiac surgery, severe asphyxia, or premature birth. The only two prospective studies in children found incidence rates of 4.5% and 2.5% of AKI in children admitted to PICU, respectively. Nephrotoxic drugs account for about 16% of all AKIs most commonly associated with AKI in older children and adolescents. Nonsteroidal anti-inflammatory drugs (NSAIDs), antibiotics, amphotericin B, antiviral agents, angiotensin-converting enzyme (ACE) inhibitors, calcineurin inhibitors, radiocontrast media, and cytostatics are the most important drugs to indicate AKI as significant risk factor in children. Direct pathophysiological mechanisms of nephrotoxicity include constriction of intrarenal vessels, acute tubular necrosis, acute interstitial nephritis, and-more infrequently-tubular obstruction. Furthermore, AKI may also be caused indirectly by rhabdomyolysis. Frequent therapeutic measures consist of avoiding dehydration and concomitant nephrotoxic medication, especially in children with preexisting impaired renal function.

Management of acute renal failure in the elderly patient: a clinician's guide

Numerous anatomical and functional changes occurring in the aging kidney lead to reduced glomerular filtration rate, lower renal blood flow and impaired renal autoregulation. The elderly are especially vulnerable to the development of renal dysfunction and in this population acute renal failure (ARF) is a common problem. ARF is often iatrogenic and multifactorial; common iatrogenic combinations include pre-existing renal dysfunction and exposure to nephrotoxins such as radiocontrast agents or aminoglycosides, use of NSAIDs in patients with congestive cardiac failure and use of ACE inhibitors and diuretics in patients with underlying atherosclerotic renal artery stenosis. The aetiology of ARF is classically grouped into three categories: prerenal, intrinsic and postrenal. Prerenal ARF is the second most common cause of ARF in the elderly, accounting for nearly one-third of all hospitalized cases. Common causes can be grouped into true volume depletion (e.g. decreased fluid intake), decreased effective blood volume (e.g. systemic vasodilation) and haemodynamic (e.g. renal artery stenosis, NSAID use). Acute tubular necrosis (ATN) is the most common cause of intrinsic ARF and is responsible for over 50% of ARF in hospitalized patients, and up to 76% of cases in patients in intensive care units. ATN usually occurs after an acute ischaemic or toxic event. The pathogenesis of ATN involves an interplay of processes that include endothelial injury, microvascular flow disruption, tubular hypoxia, dysfunction and apoptosis, tubular obstruction and trans-tubular back-leak. Vasculitis causing ARF should not be missed as this condition is potentially life threatening. The likelihood of a postrenal cause for ARF increases with age. Benign prostatic hypertrophy, prostatic carcinoma and pelvic malignancies are all important causes. Early identification of ARF secondary to obstruction with renal imaging is essential, and complete or partial renal recovery usually ensues following relief of the obstruction.A comprehensive medical and drug history and physical examination are all invaluable. Particular attention should be paid to the fluid status of the patient (skin turgor, jugular venous pressure, lying and standing blood pressure, urine output). Urinalysis should be performed to detect evidence of proteinuria and haematuria, which will aid diagnosis. Fractional excretion of sodium and urine osmolality may be measured but the widespread use of diuretics in the elderly gives rise to unreliable results. Renal imaging, usually ultrasound scanning, is routinely performed for assessment of renal size and to exclude urinary obstruction. In some cases, renal biopsy is necessary to provide specific diagnostic information. The general principles of managing ARF include treatment of life-threatening features such as shock, respiratory failure, hyperkalaemia, pulmonary oedema, metabolic acidosis and sepsis; stopping and avoiding administration of nephrotoxins; optimization of haemodynamic and fluid status; adjustment of drug dosage appropriate to glomerular filtration rate; early nutritional support; and early referral to nephrologists for diagnosis of ARF cause, timely initiation of dialysis and initiation of specific treatment. The treatment of prerenal and ATN ARF is largely supportive with little evidence of benefit from current pharmacological therapies. Despite advances in critical care medicine and renal replacement therapy, the mortality of ARF has not changed significantly over the last 40 years, with current mortality rates being up to 75%.

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%.

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.

Are antibiotic drugs well prescribed in case of renal insufficiency? A retrospective study

Renal insufficiency (RI) is a major complication in hospitalized patients. We aim to determinate if the severity of RI is considered for antibiotic prescriptions. A 10-month retrospective study including all in-patients of an orthopedic surgery department, based on the analysis of antibiotic prescriptions of patients with RI, was set up as follows: identification of patients with RI estimated with Cockcroft formula, classification by severity stage, and analysis of antibiotic prescriptions to be adapted to RI. About 10% of patients had RI. Among them, 54 (32%) received antibiotics (on average, 1.75 drugs per patient). Sixteen (17%) of antibiotic prescriptions required either dose adaptation or therapeutic drug monitoring. In all, only four prescriptions were adapted to renal function. In other cases, antibiotics were prescribed according to protocols for patients with normal renal function. Moreover, therapeutic drug monitoring was only performed for half of required cases and then showed values > ULN three times out of four. Creatinine clearance (CrCl) has been calculated for half of patients with RI. In practice, dosage adjustment of antibiotics is done only for patients with severe RI. Within the framework of the introduction of an electronic prescribing technology and medication order pharmaceutical review procedures, CrCl is now systematically calculated and then taken into account by both prescribers and clinical pharmacists.

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.

Transcriptional analysis of the molecular basis of human kidney aging using cDNA microarray profiling

BACKGROUND

The molecular basis of renal aging is not completely understood.

METHODS

We used global gene expression monitoring by cDNA microarrays to identify age associated genes in human kidney samples. Our samples included young (8 weeks-8 years, N= 4), adult (31-46 years, N= 7), and old kidneys (71-88 years, N= 9).

RESULTS

Old kidneys had more glomerulosclerosis, tubular atrophy, interstitial fibrosis, and fibrous intimal thickening in small arteries. We identified approximately 500 genes that were differentially expressed among the three age groups. Old kidneys appeared to have increased extracellular matrix turnover and a nonspecific inflammatory response, combined with a reduction in processes dependent on energy metabolism and mitochondrial function. Quantitative supervised bioinformatics analyses of adult and old kidney expression data correlated the expression of 255 gene profiles with renal pathology scores. Microarray class prediction analysis (PAM) identified 50 unique genes that segregated old kidneys into two distinct clusters: those more similar within age class (OO, N= 5) versus old kidneys more similar to adult kidneys (OA, N= 4). The expression of six functionally significant genes was further validated by quantitative reverse transcription-polymerase chain reaction (RT-PCR) (FN1, MMP7, TNC, SERPIN3A, BPHL, CSPG2) in the experiment group and, subsequently, confirmed independently in 17 additional old and adult age-stratified test kidney samples. The p53 inducible gene, CSPG2, performed best in separating OO kidneys from adults and OA samples in this analysis.

CONCLUSION

The method described in this study using independent validation samples can be envisioned to test utility of the identified genes in assessing age-related changes that contribute to decline in renal function.

Selecting nonprescription analgesics

Worldwide, there has been an emerging patient demand for access to efficient drugs without consulting a doctor and obtaining a prescription. As a result, there has been an expanding movement of prescription-only drugs to over-the-counter (OTC) status. An increasing number of drugs are becoming available OTC, empowering patients to treat themselves. Where the principle of empowering individuals to treat themselves can fail is when consumers lack the knowledge to do so safely. This potentially applies to the self-selection of analgesic drugs by consumers. When used inappropriately, these drugs pose significant risks. The nonsteroidal antiinflammatory drugs (NSAIDs) are associated with many adverse reactions, interactions, and contraindications in a number of patient groups, even at OTC doses. In particular, in the elderly, the high incidence of cardiovascular and gastrointestinal disease, coupled with age-related decline in renal function and multiple medication use, all warrant extra caution with the use of NSAIDs and make paracetamol the simple analgesic drug of first choice. Despite the possibility of hepatotoxicity in overdose, paracetamol represents a better all-round option for most patients requiring OTC analgesic therapy.

La chirurgie digestive lourde après 80 ans

OBJECTIVE

The interest in geriatric surgery is on the increase because of the ageing of the population. Our study reviewed the results of a non- specialised unit. Method 54 octogenarians underwent digestive surgery including visceral resection. Cancer predominated the indications (80%).

RESULTS

The patients exhibited cardiovascular (87%), endocrine (18.5%) or neuropsychiatric (29.6%) disorders with 75% scoring ASA III or IV. Morbidity was of 81.5% with 20% of specifically surgical complications and a 40.2% rate of cardiovascular complications. Post-surgical mortality was of 7.4% and the survival rate at 2 years was of 44.4%. The treating physicians judged that in 65% of patients the intervention had improved the initial status of the patient and had stabilised the disease in 35% of cases. The percentage of patients living at home declined from 83.3% before the intervention to 64.8% after the intervention. Only 2 out of the 9 patients having undergone stomy of the colon following colectomy continued to improve.

CONCLUSION

This study underlines the interest of major surgery in octogenarians, including in units non-specialised in geriatric surgery.

Effects of NSAIDs on the incidence of hospitalisations for renal dysfunction in users of ACE inhibitors

INTRODUCTION

Although relatively safe, both NSAIDs and ACE inhibitors can cause renal dysfunction in patients with compromised renal function. Case reports indicate that the combined use of ACE inhibitors and NSAIDs increases the risk of renal dysfunction. It is not known how often and when renal dysfunction occurs in patients using a combination of ACE inhibitors and NSAIDs.

OBJECTIVE

The objective of the study was to investigate the effects of NSAIDs on the incidence of hospitalisations due to renal dysfunction in patients treated with ACE inhibitors.

STUDY DESIGN

Case-control study nested within a cohort of users of ACE inhibitors.

PARTICIPANTS

All participants had at least two consecutive prescriptions for an ACE inhibitor. One hundred and forty-four cases were admitted to hospital for renal insufficiency during use of ACE inhibitors. There were 1189 randomly sampled control patients who did not have any hospital admission for renal dysfunction during use of ACE inhibitors.

MAIN OUTCOME MEASURES

The risk for hospitalisation for renal dysfunction associated with exposure to NSAIDs in patients receiving ACE inhibitors was expressed as odds ratios (OR).

RESULTS

Of 144 cases, a total of 32 (22.2%) received NSAIDs in the 90 days before hospital admission for renal dysfunction. Recent start (<90 days) of an NSAID was associated with an increased risk of admission for renal dysfunction (adjusted OR 2.2; 95% CI 1.1-4.5). The increased risk was most pronounced in patients aged >70 years (adjusted OR 2.7; 95% CI 1.0-7.2). For patients who started NSAIDs and were dispensed at least three prescriptions in the 90 days preceding hospitalisation an adjusted OR of 7.1 (95% CI 1.8-28.7) was observed.

CONCLUSIONS

This study strongly suggests an increased risk for hospitalisation for renal insufficiency in patients receiving ACE inhibitors who start using NSAIDs. Elderly patients receiving several prescriptions for NSAIDs in a short period of time are particularly at risk. Renal function should be closely monitored in these patients.

Diarrhoea, vomiting and ACE inhibitors:--an important cause of acute renal failure

The occurrence of severe acute renal failure in 3 patients who developed diarrhoea while taking angiotensin converting enzyme (ACE) inhibitors led us to undertake a retrospective cohort survey to determine the frequency with which diarrhoea and vomiting are associated with acute renal failure in patients taking this class of drug. Serum creatinine was measured as part of the diagnostic workup of 2398 consecutive admissions to an acute medical receiving unit in a district general hospital. Outcome measures were the presence of diarrhoea and/or vomiting, and whether taking an ACE inhibitor, NSAID or diuretic at the time of admission, also previous, initial and follow up serum creatinine concentrations. Peak serum creatinine in the 3 cases was 1159, 989 and 765 micromol/l. None of the 3 required dialysis and all recovered renal function completely after receiving large volumes of intravenous fluid. In the cohort study, 89 of 2398(3.7%) admissions had serum creatinine >/=200 micromol/l. Nine were regular dialysis patients. Of the remaining patients, 30 (37.5%) were taking an ACE inhibitor. Six of 30 (20%) gave a history of diarrhoea and/or vomiting. Median creatinine concentration in this group was 135 (range 111-209) micromol/l before admission, 292 (216-724) micromol/l when first seen in hospital, and 134 (94-219) micromol/l following the withdrawal of drug therapy and fluid replacement. In conclusion, volume depletion causing acute renal failure in patients taking ACE inhibitors is not uncommon. Such patients and their general practitioners should be aware that reversible renal impairment may occur during intercurrent illnesses, particularly if characterised by diarrhoea and/or vomiting.