Acute kidney injury (AKI), previously called acute renal failure, has chiefly been described as a syndrome since World War 2. Traditionally ‘a(chǎn)cute renal failure’ was regarded as a less common organ failure, with patients typically requiring dialysis and managed by nephrologists. This view has now been overturned. AKI encompasses a wide spectrum of injury to the kidneys, not just ‘kidney failure’.It is a common problem amongst hospitalised patients, in particular the elderly population whose numbers are increasing as people live longer. Such patients are usually under the care of doctors practicing in specialties other than nephrology. For normal function the kidneys require a competent circulation. Conversely, it is known that renal function is vulnerable to even relative or quite modest hypotension or hypovolaemia. Hence AKI is a feature of many severe illnesses. Although these illnesses may affect many organs, the simple process of monitoring urine output and/or creatinine permits detection of AKI.

The definition of AKI has been evolving in recent years. There is a need for a standardised definition of AKI that can be applied in a pragmatic fashion in routine clinical practice, research, audit and healthcare education. With current technology most AKI diagnosis is based on monitoring of serum or plasma creatinine levels, with or without urine output measurement. These methods are imperfect, and there is no ‘gold standard’ for the diagnosis of AKI. Work on AKI has been hampered by multiple definitions. In 2004 the Acute Dialysis Quality Initiative (ADQI) group14 published their consensus definition of AKI, known as the RIFLE definition. More recently small rises in creatinine have been recognised as being independently associated with increased mortality. In 2007, the AKI Network (AKIN)84 published their AKI definition, an evolution of the RIFLE definition. The recent International Kidney Disease: Improving Global Outcomes (KDIGO) guidelines67 proposed a merger of RIFLE and AKIN, with some simplification.

In developed countries AKI is seen in 13-18% of all people admitted to hospital.64,97,122 The frequency of AKI amongst inpatients means that it has a major patient and economic impact. According to NHS Kidney Care, the costs of AKI to the NHS (excluding AKI in the community) are estimated to be between ￡434 million - ￡620 million per year which is more than expenditure on breast cancer, or lung and skin cancer combined. It also remains the case that AKI is seen increasingly in primary care in the absence of any acute illness and there is a need to ensure that awareness of the condition is raised amongst primary care health professionals and that any identified cases of AKI are managed or referred appropriately.?

There have long been concerns that clinicians may inadvertently contribute to the development of AKI, by their use of drugs that are harmful to the kidneys.However, in spite of its wider adoption in the UK from the 1970’s,audit was not fully applied to AKI until the turn of the millennium.A seminal moment was the confidential enquiry into the deaths of a large group of adult patients with AKI, published by the National Confidential Enquiry into Patient Outcome and Death (NCEPOD) in 2009.This described systemic deficiencies in the care of patients who died of AKI including failures in AKI prevention, recognition, therapy and timely access to specialist services. Only 50% of these sick patients received ‘good’ care.91 It was clear that many adult specialties needed to greatly improve their recognition and management of AKI and redesign their services. There are also known and unacceptable variations in the recognition, assessment, initial treatment and usage of renal replacement therapy in AKI. Some 20-30% of cases of AKI are regarded partially or fully preventable.Even if only 20% of cases can be prevented or ameliorated, successful preventive measures would produce a large reduction in deaths, complications and costs due to AKI.

The NCEPOD report informed a referral from the Department of Health for NICE to develop its first guideline on AKI.?

The guideline development process is defined by its scope, published after stakeholder consultation. Therefore, the guideline does not cover all aspects of AKI, only addressing areas within the scope. guide.medlive.cn Acute kidney injury Introduction

Final draft Methods, evidence and recommendations Importantly these guidelines include paediatric acute kidney injury. The scope of the guideline focuses on identifying clinical and cost effective practice that might improve care and outcomes in intervention in the earlier parts of the disease process, including risk assessment and prevention, early recognition and treatment. It does not include evidence regarding aspects of dialysis beyond the decision on its initiation. NICE guidance does not aim to provide a ‘textbook’ of care for the area under consideration. Thus it is beyond the scope of the guideline to give detailed discussion of the more basic management of AKI causes such as hypovolaemia, sepsis, and nephrotoxins. Instead it

aims to distil relevant evidence and use this to provide a set of recommendations. It is primarily aimed at generalist clinicians, who will care for the large majority of patients with AKI in a nonspecialist hospital or primary care setting