1 Recommendations

The following guidance is based on the best available evidence. The full guideline gives details of the methods and the evidence used to develop the guidance.

The wording used in the recommendations in this guideline (for example words such as 'offer' and 'consider') denotes the certainty with which the recommendation is made (the strength of the recommendation). See About this guideline for details.

In this guideline the term 'adults' is used to describe people who are aged 18 years or older, and 'children' those who are aged 11 years or younger (excluding neonates less than 1 month old). 'Young people' describes those who are aged 12 to 17 years.

1.1 Assessing risk of acute kidney injury

Identifying acute kidney injury in patients with acute illness

1.1.1 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 [eGFR] less than 60 ml/min/1.73 m2 are at particular risk)

  • heart failure

  • liver disease

  • diabetes

  • history of acute kidney injury

  • oliguria (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 with nephrotoxic potential (such as non‑steroidal anti‑inflammatory drugs [NSAIDs], aminoglycosides, angiotensin‑converting enzyme [ACE] inhibitors, angiotensin II receptor antagonists [ARBs] and diuretics) within the past week, especially if hypovolaemic

  • use of iodinated contrast agents 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.

1.1.2 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

  • oliguria (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 with nephrotoxic potential (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 patients with no obvious acute illness

1.1.3 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.

1.1.4 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, or urological disease

  • new onset or significant worsening of urological symptoms

  • symptoms suggesting complications of acute kidney injury

  • symptoms or signs of a multi‑system 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 iodinated contrast agents

1.1.5 Before offering iodinated contrast agents to adults for non‑emergency imaging, investigate for chronic kidney disease by measuring eGFR or by checking an eGFR result obtained within the past 3 months.

1.1.6 Before offering iodinated contrast agents to adults for emergency or non‑emergency imaging, assess their risk of acute kidney injury. 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 agent.

    Ensure that risk assessment does not delay emergency imaging.

1.1.7 Include the risks of developing acute kidney injury in the routine discussion of risks and benefits of the imaging procedure. Follow the recommendations on shared decision‑making in Patient experience in adult NHS services (NICE clinical guidance 138).

Assessing risk factors in adults having surgery

1.1.8 Assess the risk of acute kidney injury in adults before surgery. Be aware that increased risk is associated with:

  • emergency surgery, especially when the patient 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 with nephrotoxic potential in the perioperative period (in particular, NSAIDs after surgery).

    Use the risk assessment to inform a clinical management plan.

1.1.9 Include the risks of developing acute kidney injury in the routine discussion of risks and benefits of surgery. Follow the recommendations on shared decision‑making in Patient experience in adult NHS services (NICE clinical guidance 138).

1.2 Preventing acute kidney injury

Ongoing assessment of the condition of patients in hospital

1.2.1 Follow the recommendations in Acutely ill patients in hospital (NICE clinical guideline 50) 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.

1.2.2 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.

1.2.3 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.

1.2.4 If using a paediatric early warning score, use one with multiple‑parameter 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, cut‑off points or scores that should trigger a response.

1.2.5 If using a paediatric early warning score, use one with multiple‑parameter or aggregate weighted scoring systems that measure:

  • heart rate

  • respiratory rate

  • systolic blood pressure

  • level of consciousness

  • oxygen saturation

  • temperature

  • capillary refill time.

1.2.6 When children and young people are at risk of acute kidney injury because of risk factors in recommendation 1.1.2:

  • 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 iodinated contrast agents

1.2.7 Offer intravenous volume expansion to adults having iodinated contrast agents if:

  • they are at increased risk of contrast‑induced acute kidney injury because of risk factors in recommendation 1.1.6, or

  • they have an acute illness.

    Offer either isotonic sodium bicarbonate or 0.9% sodium chloride.

1.2.8 Consider temporarily stopping ACE inhibitors and ARBs in adults having iodinated contrast agents if they have chronic kidney disease with an eGFR less than 40 ml/min/1.73 m2.

1.2.9 Discuss care with a nephrology team before offering iodinated contrast agent to adults with contraindications to intravenous fluids if:

  • they are at increased risk of contrast‑induced acute kidney injury, or

  • they have an acute illness, or

  • they are on renal replacement therapy.

Monitoring and preventing deterioration in patients with or at high risk of acute kidney injury

1.2.10 Consider electronic clinical decision support systems (CDSS) to support clinical decision‑making and prescribing, but ensure they do not replace clinical judgement.

1.2.11 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.

1.2.12 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.

1.2.13 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.

1.3 Detecting acute kidney injury

1.3.1 Detect acute kidney injury, in line with the (p)RIFLE[3], AKIN[4] or KDIGO[5] 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

  • 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.

1.3.2 Monitor serum creatinine regularly[6] in all adults, children and young people with or at risk of acute kidney injury.

1.4 Identifying the cause(s) of acute kidney injury

1.4.1 Identify the cause(s) of acute kidney injury and record the details in the patient's notes.

Urinalysis

1.4.2 Perform urine dipstick testing for blood, protein, leucocytes, nitrites and glucose in all patients as soon as acute kidney injury is suspected or detected. Document the results and ensure that appropriate action is taken when results are abnormal.

1.4.3 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

1.4.4 Do not routinely offer ultrasound of the urinary tract when the cause of the acute kidney injury has been identified.

1.4.5 When pyonephrosis (infected and obstructed kidney[s]) 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).

1.4.6 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).

1.5 Managing acute kidney injury

Relieving urological obstruction

1.5.1 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.

1.5.2 When nephrostomy or stenting is used to treat upper tract urological obstruction in adults, children and young people with acute kidney injury, undertake as soon as possible and within 12 hours of diagnosis.

Pharmacological management

1.5.3 Do not routinely offer loop diuretics to treat acute kidney injury.

1.5.4 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.

1.5.5 Do not offer low-dose dopamine to treat acute kidney injury.

Referring for renal replacement therapy

1.5.6 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.

1.5.7 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 on shared decision‑making in Patient experience in adult NHS services (NICE clinical guidance 138).

1.5.8 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.

1.5.9 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.

1.5.10 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 on shared decision‑making in Patient experience in adult NHS services (NICE clinical guidance 138).

Referring to nephrology

1.5.11 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.

1.5.12 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.

1.5.13 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.

1.5.14 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.

1.5.15 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.

1.5.16 Monitor[7] serum creatinine after an episode of acute kidney injury. 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.

1.5.17 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.

1.6 Information and support for patients and carers

1.6.1 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 Patient experience in adult NHS services (NICE clinical guidance 138).

1.6.2 Give information about long‑term treatment options, monitoring, self‑management 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.

1.6.3 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).

1.6.4 Discuss the risk of developing acute kidney injury, particularly the risk associated with conditions leading to dehydration (for example, diarrhoea and vomiting) and drugs with nephrotoxic potential (including over‑the‑counter 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.



[3] Risk, Injury, Failure, Loss, End stage renal disease, (p) refers to the paediatric classification.

[4] Acute Kidney Injury Network.

[5] Kidney Disease: Improving Global Outcomes.

[6] The GDG did not wish to define 'regularly' because this would vary according to clinical need but recognised that daily measurement was typical while in hospital.

[7] The frequency of monitoring should be based on the stability and degree of renal function at the time of discharge.

  • National Institute for Health and Care Excellence (NICE)