Acute kidney injury: prevention, detection and management

This guideline covers preventing, detecting and managing acute kidney injury in children, young people and adults. It aims to improve assessment and detection by non-specialists, and specifies when people should be referred to specialist services. This will improve early recognition and treatment, and reduce the risk of complications in people with acute kidney injury.

# Recommendations
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# Assessing risk of acute kidney injury

## Identifying acute kidney injury in people with acute illness
Investigate for acute kidney injury, by measuring serum creatinine and comparing with baseline, in adults with acute illness if any of the following are likely or present:
chronic kidney disease (adults with an estimated glomerular filtration rate  less than 60 ml/min/1.73 m2 are at particular risk)
heart failure
liver disease
diabetes
history of acute kidney injury
-liguria (urine output less than 0.5 ml/kg/hour)
neurological or cognitive impairment or disability, which may mean limited access to fluids because of reliance on a carer
hypovolaemia
use of drugs that can cause or exacerbate kidney injury (such as nonsteroidal antiinflammatory drugs , aminoglycosides, angiotensinconverting enzyme  inhibitors, angiotensin II receptor antagonists  and diuretics) within the past week, especially if hypovolaemic
use of iodine-based contrast media within the past week
symptoms or history of urological obstruction, or conditions that may lead to obstruction
sepsis
deteriorating early warning scores
age 65 years or over. 
Investigate for acute kidney injury, by measuring serum creatinine and comparing with baseline, in children and young people with acute illness if any of the following are likely or present:
chronic kidney disease
heart failure
liver disease
history of acute kidney injury
-liguria (urine output less than 0.5 ml/kg/hour)
young age, neurological or cognitive impairment or disability, which may mean limited access to fluids because of reliance on a parent or carer
hypovolaemia
use of drugs that can cause or exacerbate kidney injury (such as NSAIDs, aminoglycosides, ACE inhibitors, ARBs and diuretics) within the past week, especially if hypovolaemic
symptoms or history of urological obstruction, or conditions that may lead to obstruction
sepsis
a deteriorating paediatric early warning score
severe diarrhoea (children and young people with bloody diarrhoea are at particular risk)
symptoms or signs of nephritis (such as oedema or haematuria)
haematological malignancy
hypotension. 

## Identifying acute kidney injury in people with no obvious acute illness
Be aware that in adults, children and young people with chronic kidney disease and no obvious acute illness, a rise in serum creatinine may indicate acute kidney injury rather than a worsening of their chronic disease. 
Ensure that acute kidney injury is considered when an adult, child or young person presents with an illness with no clear acute component and has any of the following:
chronic kidney disease, especially stage 3B, 4 or 5 as shown in table1, or urological disease
new onset or significant worsening of urological symptoms
symptoms suggesting complications of acute kidney injury
symptoms or signs of a multisystem disease affecting the kidneys and other organ systems (for example, signs or symptoms of acute kidney injury, plus a purpuric rash). 

## Assessing risk factors in adults having iodine-based contrast media
Before offering iodine-based contrast media to adults for nonemergency imaging, investigate for chronic kidney disease by measuring eGFR or by checking an eGFR result obtained within the past 3 months. 
Before offering iodine-based contrast media to adults, assess their risk of acute kidney injury but do not delay emergency imaging. Be aware that increased risk is associated with:
chronic kidney disease (adults with an eGFR less than 40 ml/min/1.73 m2 are at particular risk)
diabetes but only with chronic kidney disease (adults with an eGFR less than 40 ml/min/1.73 m2 are at particular risk)
heart failure
renal transplant
age 75 years or over
hypovolaemia
increasing volume of contrast agent
intra-arterial administration of contrast medium with first-pass renal exposure. 
Include the risks of developing acute kidney injury in the routine discussion of risks and benefits of the imaging procedure. Follow the recommendations in the NICE guideline on shared decision making. 

## Assessing risk factors in adults having surgery
Assess the risk of acute kidney injury in adults before surgery. Be aware that increased risk is associated with:
emergency surgery, especially when the person has sepsis or hypovolaemia
intraperitoneal surgery
chronic kidney disease (adults with an eGFR less than 60 ml/min/1.73 m2 are at particular risk)
diabetes
heart failure
age 65 years or over
liver disease
use of drugs that can cause or exacerbate kidney injury in the perioperative period (in particular, NSAIDs after surgery).Use the risk assessment to inform a clinical management plan. 
Include the risks of developing acute kidney injury in the routine discussion of risks and benefits of surgery. Follow the recommendations in the NICE guideline on shared decision making. 

# Preventing acute kidney injury

## Ongoing assessment of the condition of people in hospital
Follow the recommendations in the NICE guideline on acutely ill adults in hospital on the use of track and trigger systems (early warning scores) to identify adults who are at risk of acute kidney injury because their clinical condition is deteriorating or is at risk of deteriorating. 
When adults are at risk of acute kidney injury, ensure that systems are in place to recognise and respond to oliguria (urine output less than 0.5 ml/kg/hour) if the track and trigger system (early warning score) does not monitor urine output. 
Consider using a paediatric early warning score to identify children and young people admitted to hospital who are at risk of acute kidney injury because their clinical condition is deteriorating or is at risk of deteriorating.
Record physiological observations at admission and then according to local protocols for given paediatric early warning scores.
Increase the frequency of observations if abnormal physiology is detected. 
If using a paediatric early warning score, use one with multipleparameter or aggregate weighted scoring systems that allow a graded response and:
define the parameters to be measured and the frequency of observations
include a clear and explicit statement of the parameters, cutoff points or scores that should trigger a response. 
If using a paediatric early warning score, use one with multipleparameter or aggregate weighted scoring systems that measure:
heart rate
respiratory rate
systolic blood pressure
level of consciousness
-xygen saturation
temperature
capillary refill time. 
When children and young people are at risk of acute kidney injury because of risk factors listed in the recommendation in the section on identifying acute kidney injury in people with acute illness:
measure urine output
record weight twice daily to determine fluid balance
measure urea, creatinine and electrolytes
think about measuring lactate, blood glucose and blood gases. 

## Preventing acute kidney injury in adults having iodine-based contrast media
Encourage oral hydration before and after procedures using intravenous iodine-based contrast media in adults at increased risk of contrast-induced acute kidney injury (see the recommendation on increased risk in the section on assessing risk factors in adults having iodine-based contrast media). 
For inpatients having iodine-based contrast media, consider intravenous volume expansion with either isotonic sodium bicarbonate or 0.9% sodium chloride if they are at particularly high risk, for example, if:
they have an eGFR less than 30 ml/min/1.73 m2
they have had a renal transplant
a large volume of contrast medium is being used (for example, higher than the standard diagnostic dose or repeat administration within 24 hours)
intra-arterial administration of contrast medium with first-pass renal exposure is being used.For more information on managing intravenous fluid therapy, see the NICE guideline on intravenous fluid therapy in adults in hospital. 
Consider temporarily stopping ACE inhibitors and ARBs in adults having iodine-based contrast media if they have chronic kidney disease with an eGFR less than 40 ml/min/1.73 m2. 
Discuss the person's care with a nephrology team before offering iodine-based contrast media to adults on renal replacement therapy, including people with a renal transplant, but do not delay emergency imaging for this. 
For a short explanation of why the committee made the 2019 recommendations and how they might affect practice, see the rationale and impact section on preventing acute kidney injury in adults having iodine-based contrast media .
Full details of the evidence and the committee's discussion are in evidence review A: preventing contrast-induced acute kidney injury.
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## Monitoring and preventing deterioration in people with or at high risk of acute kidney injury
Consider electronic clinical decision support systems (CDSS) to support clinical decision making and prescribing, but ensure they do not replace clinical judgement. 
When acquiring any new CDSS or systems for electronic prescribing, ensure that any systems considered:
can interact with laboratory systems
can recommend drug dosing and frequency
can store and update data on patient history and characteristics, including age, weight and renal replacement therapy
can include alerts that are mandatory for the healthcare professional to acknowledge and review. 
Seek advice from a pharmacist about optimising medicines and drug dosing in adults, children and young people with or at risk of acute kidney injury. 
Consider temporarily stopping ACE inhibitors and ARBs in adults, children and young people with diarrhoea, vomiting or sepsis until their clinical condition has improved and stabilised. 

# Detecting acute kidney injury
Detect acute kidney injury, in line with the (p)RIFLE (paediatric Risk, Injury, Failure, Loss, End stage renal disease), AKIN (Acute Kidney Injury Network) or KDIGO (Kidney Disease: Improving Global Outcomes) definitions, by using any of the following criteria:
a rise in serum creatinine of 26 micromol/litre or greater within 48 hours
a 50% or greater rise in serum creatinine known or presumed to have occurred within the past 7 days (see also an algorithm for early identification of acute kidney injury, endorsed by NHS England)
a fall in urine output to less than 0.5 ml/kg/hour for more than 6 hours in adults and more than 8 hours in children and young people
a 25% or greater fall in eGFR in children and young people within the past 7 days. 
Monitor serum creatinine regularly in all adults, children and young people with or at risk of acute kidney injury. Frequency of monitoring should vary according to clinical need, but daily measurement is typical while in hospital. 

# Identifying the cause(s) of acute kidney injury
Identify the cause(s) of acute kidney injury and record the details in the person's notes. 

## Urinalysis
Perform urine dipstick testing for blood, protein, leucocytes, nitrites and glucose in all people as soon as acute kidney injury is suspected or detected. Document the results and ensure that appropriate action is taken when results are abnormal. 
Think about a diagnosis of acute nephritis and referral to the nephrology team when an adult, child or young person with no obvious cause of acute kidney injury has urine dipstick results showing haematuria and proteinuria, without urinary tract infection or trauma due to catheterisation. 

## Ultrasound
Do not routinely offer ultrasound of the urinary tract when the cause of the acute kidney injury has been identified. 
When pyonephrosis (infected and obstructed kidney) is suspected in adults, children and young people with acute kidney injury, offer immediate ultrasound of the urinary tract (to be performed within 6 hours of assessment). 
When adults, children and young people have no identified cause of their acute kidney injury or are at risk of urinary tract obstruction, offer urgent ultrasound of the urinary tract (to be performed within 24 hours of assessment). 

# Managing acute kidney injury

## Relieving urological obstruction
Refer all adults, children and young people with upper tract urological obstruction to a urologist. Refer immediately when one or more of the following is present:
pyonephrosis
an obstructed solitary kidney
bilateral upper urinary tract obstruction
complications of acute kidney injury caused by urological obstruction. 
When nephrostomy or stenting is used to treat upper tract urological obstruction in adults, children and young people with acute kidney injury, carry it out as soon as possible and within 12 hours of diagnosis. 

## Pharmacological management
Do not routinely offer loop diuretics to treat acute kidney injury. 
Consider loop diuretics for treating fluid overload or oedema while:
an adult, child or young person is awaiting renal replacement therapy or
renal function is recovering in an adult, child or young person not receiving renal replacement therapy. 
Do not offer low-dose dopamine to treat acute kidney injury. 

## Referring for renal replacement therapy
Discuss any potential indications for renal replacement therapy with a nephrologist, paediatric nephrologist and/or critical care specialist immediately to ensure that the therapy is started as soon as needed. 
When an adult, child or young person has significant comorbidities, discuss with them and/or their parent or carer and within the multidisciplinary team whether renal replacement therapy would offer benefit. Follow the recommendations in the NICE guideline on shared decision making. 
Refer adults, children and young people immediately for renal replacement therapy if any of the following are not responding to medical management:
hyperkalaemia
metabolic acidosis
symptoms or complications of uraemia (for example, pericarditis or encephalopathy)
fluid overload
pulmonary oedema. 
Base the decision to start renal replacement therapy on the condition of the adult, child or young person as a whole and not on an isolated urea, creatinine or potassium value. 
When there are indications for renal replacement therapy, the nephrologist and/or critical care specialist should discuss the treatment with the adult, child or young person and/or their parent or carer as soon as possible and before starting treatment. Follow the recommendations in the NICE guideline on shared decision making. 

## Referring to nephrology
Refer adults, children and young people with acute kidney injury to a nephrologist, paediatric nephrologist or critical care specialist immediately if they meet criteria for renal replacement therapy in recommendation 1.5.8. 
Do not refer adults, children or young people to a nephrologist or paediatric nephrologist when there is a clear cause for acute kidney injury and the condition is responding promptly to medical management, unless they have a renal transplant. 
Consider discussing management with a nephrologist or paediatric nephrologist when an adult, child or young person with severe illness might benefit from treatment, but there is uncertainty as to whether they are nearing the end of their life. 
Refer adults, children and young people in intensive care to a nephrology team when there is uncertainty about the cause of acute kidney injury or when specialist management of kidney injury might be needed. 
Discuss the management of acute kidney injury with a nephrologist or paediatric nephrologist as soon as possible and within 24 hours of detection when one or more of the following is present:
a possible diagnosis that may need specialist treatment (for example, vasculitis, glomerulonephritis, tubulointerstitial nephritis or myeloma)
acute kidney injury with no clear cause
inadequate response to treatment
complications associated with acute kidney injury
stage 3 acute kidney injury (according to (p)RIFLE, AKIN or KDIGO criteria)
a renal transplant
chronic kidney disease stage 4 or 5 as shown in table 1. 
Monitor serum creatinine after an episode of acute kidney injury. Base the frequency of monitoring on the stability and degree of renal function at the time of discharge. Consider referral to a nephrologist or paediatric nephrologist when eGFR is 30 ml/min/1.73 m2 or less in adults, children and young people who have recovered from an acute kidney injury. 
Consider referral to a paediatric nephrologist for children and young people who have recovered from an episode of acute kidney injury but have hypertension, impaired renal function or 1+ or greater proteinuria on dipstick testing of an early morning urine sample. 

# Information and support for patients and carers
Discuss immediate treatment options, monitoring, prognosis and support options as soon as possible with people with acute kidney injury and/or, if appropriate, their parent or carer. Follow the recommendations on patient views and preferences and shared decision making in the NICE guidelines on patient experience in adult NHS services and shared decision making. 
Give information about longterm treatment options, monitoring, selfmanagement and support to people who have had acute kidney injury (and/or their parent or carer, if appropriate) in collaboration with a multidisciplinary team appropriate to the person's individual needs. 
Give information about future care to people needing renal replacement therapy after discharge following acute kidney injury. This should include information about the frequency and length of dialysis sessions and the preparation needed (such as having a fistula or peritoneal catheter). 
Discuss the risk of developing acute kidney injury, particularly the risk associated with conditions leading to dehydration (for example, diarrhoea and vomiting) and drugs that can cause or exacerbate kidney injury (including overthecounter NSAIDs), with people who are at risk of acute kidney injury, particularly those who have:
chronic kidney disease with an eGFR less than 60 ml/min/1.73 m2
neurological or cognitive impairment or disability, which may mean limited access to fluids because of reliance on a carer.Involve parents and carers in the discussion if appropriate. 

# Terms used in this guideline
This section defines terms that have been used in a particular way for this guideline. For other definitions see the NICE glossary.

## First-pass renal exposure
First-pass renal exposure is when the contrast medium reaches the renal arteries in a relatively undiluted form, for example, through injection into the left heart, thoracic and suprarenal abdominal aorta, or the renal arteries.

## Stages of chronic kidney disease
Stage
eGFR (ml/min/1.73 m2)
Description
Qualifier
Kidney damage, normal or increased GFR
Kidney damage (presence of structural abnormalities and/or persistent haematuria, proteinuria or microalbuminuria) for 3 months
Kidney damage, mildly reduced GFR
Kidney damage (presence of structural abnormalities and/or persistent haematuria, proteinuria or microalbuminuria) for 3 months
A
Moderately reduced GFR  other evidence of kidney damage
GFR <60 ml/min for 3 months  kidney damage
B
Moderately reduced GFR  other evidence of kidney damage
GFR <60 ml/min for 3 months  kidney damage
Severely reduced GFR  other evidence of kidney damage
GFR <60 ml/min for 3 months  kidney damage
Established kidney failure
GFR <60 ml/min for 3 months  kidney damage# Recommendations for research
As part of the 2019 update, the guideline committee made 2 new research recommendations (marked ). Research recommendations retained from the 2013 guideline are labelled .

# Key recommendations for research

## Risk stratification for contrast-induced acute kidney injury
Can risk of contrast-induced acute kidney injury be stratified by eGFR thresholds? 
For a short explanation of why the committee made the recommendation for research, see the rationale on preventing acute kidney injury in adults having iodine-based contrast media .
Full details of the evidence and the committee's discussion are in evidence review A: preventing contrast-induced acute kidney injury.
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## Different oral fluids and oral fluid regimens
What is the relative effectiveness and cost effectiveness of different oral fluids and different oral fluid regimens, both with and without oral N-acetylcysteine, at preventing contrast-induced acute kidney injury? 
For a short explanation of why the committee made the recommendation for research, see the rationale on preventing acute kidney injury in adults having iodine-based contrast media .
Full details of the evidence and the committee's discussion are in evidence review A: preventing contrast-induced acute kidney injury.
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## Long-term outcomes of acute kidney injury
What are the long-term outcomes of acute kidney injury in adults, children and young people? 

## Rapid referral to nephrology services for moderate to severe acute kidney injury
What is the clinical and cost effectiveness of rapid referral (within 12 hours) to nephrology services for adults with moderate to severe (stage 2 to 3) acute kidney injury not needing critical care? 

## Definition of acute kidney injury  system for staging and detection
Can a simplified definition and staging system, based on Systeme International (SI) units, be used to predict short- to medium-term outcomes in acute kidney injury? 

## Introducing renal replacement therapy
What is the clinical and cost effectiveness of early versus later introduction of renal replacement therapy in patients with acute kidney injury stages 2 and 3, when there is no urgent need for therapy? 

## Preventing deterioration
What is the clinical and cost effectiveness of continuing ACE inhibitor or ARB treatment, versus stopping treatment 24 hours before cardiac surgery and resuming 24 hours after, in people with chronic kidney disease and an eGFR of less than 30 ml/min/1.73m2? # Rationale and impact
This section briefly explains why the committee made the recommendations and how they might affect practice. It links to details of the evidence and a full description of the committee's discussion.

# Preventing acute kidney injury in adults having iodine-based contrast media
Recommendations 1.2.7, 1.2.8 and to 1.2.10

## Why the committee made the recommendations
For adults undergoing procedures with intravenous iodine-based contrast media, the evidence showed that oral fluids were as good as intravenous fluids at preventing contrast-induced acute kidney injury. The evidence did not show that any particular type of oral or intravenous fluids is most effective.
The committee agreed that intravenous fluids are not necessary for outpatients who are usually at a lower risk of contrast-induced acute kidney injury. It also agreed that only inpatients at particularly high risk needed intravenous fluids. Most of the risk factors were taken from recommendation 1.1.6 (developed as part of the 2013 guideline) apart from the level of eGFR which was based on the committee's clinical knowledge and experience. The committee also agreed that, based on their experience and expertise, the risk for intra-arterial administration depends on the site of the injection, and is particularly high with first-pass renal exposure because the contrast medium passes into the kidneys relatively undiluted.
For inpatients at particularly high risk of contrast-induced acute kidney injury, economic modelling showed that intravenous volume expansion with a regimen containing intravenous sodium chloride 0.9% and/or intravenous sodium bicarbonate provides best value.
Based on the evidence, the committee decided that intravenous volume expansion should be used only for inpatients at particularly high risk and that oral hydration should be encouraged in all other adults at increased risk of contrast-induced acute kidney injury.
The committee agreed that more research on estimating the risk of contrast-induced acute kidney injury would help to inform future guidance, so made a research recommendation on the use of eGFR thresholds to stratify risk.
Although the committee agreed that oral hydration regimens were non-inferior to intravenous hydration regimens at preventing contrast-induced acute kidney injury, there was not enough comparative data to enable them to be clear about which oral fluid (if any) was most effective. There was some limited evidence that N-acetylcysteine was not beneficial. However, the committee agreed that, in the absence of evidence of harm, this was not sufficient to make a recommendation to restrict its use. Therefore, it made a research recommendation on different oral fluids and different oral fluid regimens, with and without N-acetylcysteine.
The committee did not consider it necessary for all patients being offered iodine-based contrast media to be routinely discussed with a nephrology team, but concluded that this was important for adults on renal replacement therapy, including people with a kidney transplant. The radiology team responsible for administering the contrast medium or the healthcare professional offering the procedure, such as a cardiologist, would usually do this. For people with other contraindications to intravenous fluids, the committee agreed that the decision to give iodine-based contrast media was better made by individual healthcare professionals.

## How the recommendations might affect practice
The recommendations may result in lower resource use for outpatient procedures because people will not need to be admitted to hospital to be given intravenous fluids for volume expansion before they are given a contrast medium.
The recommendation on intravenous volume expansion reflects current practice so there should be no change in practice for inpatients who are at particularly high risk of contrast-induced acute kidney injury. There may be reduced resource use for lower risk inpatients who will not need intravenous fluids.
Full details of the evidence and the committee's discussion are in evidence review A: preventing contrast-induced acute kidney injury.
Return to recommendations# Context
Acute kidney injury, previously known as acute renal failure, encompasses a wide spectrum of injury to the kidneys, not just kidney failure. The definition of acute kidney injury has changed in recent years, and detection is now mostly based on monitoring creatinine levels, with or without urine output. Acute kidney injury is increasingly being seen in primary care in people without any acute illness, and awareness of the condition needs to be raised among primary care health professionals.
Acute kidney injury is seen in 13% to 18% of all people admitted to hospital, with older adults being particularly affected. These people are usually under the care of healthcare professionals practising in specialties other than nephrology, who may not always be familiar with the optimum care of people with acute kidney injury. The number of inpatients affected by acute kidney injury means that it has a major impact on healthcare resources. The costs to the NHS of acute kidney injury (excluding costs in the community) are estimated to be between 434 million and 620 million per year, which is more than the costs associated with breast cancer, or lung and skin cancer combined.
There have been concerns that suboptimal care may contribute to the development of acute kidney injury. In 2009, the National Confidential Enquiry into Patient Outcome and Death (NCEPOD) reported the results of an enquiry into the deaths of a large group of adults with acute kidney injury. This described systemic deficiencies in the care of people who died from acute kidney injury: only 50% of these had received 'good' care. Other deficiencies in the care of people who died of acute kidney injury included failures in acute kidney injury prevention, recognition, therapy and timely access to specialist services. This report led to the Department of Health's request for NICE to develop its first guideline on acute kidney injury in adults and also, importantly, in children and young people.
This guideline emphasises early intervention and stresses the importance of risk assessment and prevention, early recognition and treatment. It is primarily aimed at the non-specialist clinician, who will care for most people with acute kidney injury in a variety of settings. The recommendations aim to address known and unacceptable variations in recognition, assessment, initial treatment and referral for renal replacement therapy. The inpatient mortality of acute kidney injury varies considerably, depending on its severity, setting (intensive care or not), and many other patient-related factors, but in the UK might typically be 25% to 30% or more. In view of its frequency and mortality rate, prevention or amelioration of just 20% of cases of acute kidney injury would prevent a large number of deaths and substantially reduce complications and their associated costs.
New evidence was identified by the NICE surveillance team on preventing contrast-induced acute kidney injury. Topic experts, including those who helped to develop the 2013 guideline, agreed that a significant new study could have an impact on the recommendations. This evidence has been reviewed and the recommendations in this area updated.# Finding more information and resources
You can see everything NICE says on this topic in the NICE Pathway on acute kidney injury.
To find out what NICE has said on topics related to this guideline, see our web page on acute kidney injury.
For full details of the evidence and the guideline committee's discussions, see the evidence reviews. You can also find information about how the guideline was developed, including details of the committee.
NICE has produced tools and resources to help you put this guideline into practice. For general help and advice on putting NICE guidelines into practice, see resources to help you put guidance into practice.