AKI should be considered for individuals with acute illness. Guidance from the National Institute for Health and Care Excellent (NICE) suggests increased awareness of AKI is necessary 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
- 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
- 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 hypovolemic
- use of iodinated contrast agents within the past week
- symptoms or history of urological obstruction, or conditions that may lead to obstruction
- deteriorating early warning scores
AKI is an important medical problem because firstly it is very common. Around 1 in 4 adult hospital admissions are associated with AKI, with 1 in 2 adult critical care admissions being associated with AKI. Approximately a third of patients with AKI in the hospital develop their AKI episode during their stay in the hospital, while two-thirds of patients with AKI in the hospital had AKI at the time of admission.
The second reason why AKI is important is that it’s associated with excess death. Back in 2009, the National Confidential Enquiry into Patient Outcome and Death (NCEPOD) AKI report found that in the UK up to 100,000 deaths each year in hospitals are associated with acute kidney injury and up to 30% could be prevented with the right care and treatment.
The majority of AKI is caused by sepsis, poor hydration and medication but other causes exist including renal tract obstruction and intrinsic renal disease. AKI is associated with high mortality rates; from 8 to 18%, 22–33%, and 32–36% mortality for patients with AKI stages 1, 2, and 3 respectively, whilst in the absence of AKI, mortality runs at 2%. Even in the absence of death, AKI can have short-term and long-term health issues for survivors including heart disease, chronic kidney disease and risk for developing kidney failure.
Since the NCEPOD report, great strides have been made in hospital AKI care, including the introduction of AKI algorithms to detect AKI and national advice on what an AKI bundle should include.
There is greater awareness of clinically recognised risk factors for AKI, both modifiable (e.g., use of iodinated contrast for radiology scans, use of certain medications that can damage the kidneys) and non-modifiable (e.g., age, presence of chronic kidney disease) providing greater opportunity to prevent the development of AKI with appropriate intervention.
For example, staff should be alert to AKI risk in individual patients that may lead to increased clinical monitoring or a change in treatment. Many hospitals now have IT-based AKI alerts that notify clinical teams of the development of AKI from blood tests.