Renal Pharmacy Beginners Guide - Lecture 5 Acute Kidney Injury Renal Pharmacy Beginners Guide - Lecture 5

Objectives Define AKI Identify risk factors for AKI By the end of this session you should be able to: Define AKI Identify risk factors for AKI Correctly stage an AKI based on creatinine levels or urine output Describe the signs and symptoms associated with AKI Demonstrate the management of AKI Apply safe and appropriate medicines management for patients with an AKI

Definition of AKI A significant deterioration in renal function occurring over hours or days, clinically manifesting as an abrupt and sustained rise in serum urea and creatinine Oxford handbook of Clinical Medicine 8th edition AKI can result in failure to maintain fluid balance, electrolyte levels and acid-base homeostasis AKI now replaces the term acute renal failure (ARF)

Epidemiology Wang et al, 2012 Think Kidneys National AKI Programme

Risk factors for AKI NICE CG169 August 2013 Chronic kidney disease Heart failure Liver disease Diabetes History of acute kidney injury Oliguria Neurological or cognitive impairment or disability, which may limit access to water Surgery Dehydration / hypovolaemia Use of drugs with nephrotoxic potential Use of iodinated contrast agents within the past week Symptoms or history of urological obstruction Sepsis Deteriorating early warning scores Age 65 years or over Oliguria (urine output less than 0.5 ml/kg/hour)

Signs and symptoms of AKI Signs and symptoms will depend on cause, but may include: Reduced urine output or anuria Change to urine appearance Change in urine smell Swelling in legs, ankles and around eyes Fatigue or tiredness Shortness of breath Nausea and vomiting Abdominal pain Dehydration and thirst Seizure or coma in severe cases Chest pain or pressure Confusion and drowsiness AKI may also be asymptomatic and will need a blood test to confirm diagnosis Think Kidneys National Kidney Foundation

Differences between AKI and CKD Acute kidney injury Chronic kidney disease Unwell May seem well for level of function Good colour Hypertensive No skin pigmentation Skin pigmentation Normal haemoglobin Clinically anaemic Normal kidney size Bone disease Normal bone x-rays

Staging of AKI AKI can be staged based on severity. Increasing severity of AKI correlates with higher incidence of poor outcomes1  Staging is based on either Creatinine levels from a blood sample OR Urine output (amount of urine produced in a specified time) Think Kidneys

Staging of AKI KDIGO Criteria (kidney disease: improving global outcomes)

Consequences of AKI Failure to maintain fluid, electrolyte and acid- base homeostasis can lead to: Fluid accumulation Toxin accumulation Hyperkalaemia Altered pH levels – metabolic acidosis Chronic kidney disease End stage kidney disease Multi-organ failure Clinical Knowledge Summaries – AKI

Identify cause of AKI Hypoperfusion/ hypovolaemia Hypotension Obstruction Sepsis Rhabdomyolysis Toxins Medication Acute trauma Liver decompensation Heart failure

Classification of AKI The causes of AKI can be divided into three categories, although more than one cause is often present CPPE – Acute kidney injury

Pre-renal AKI Hypovolaemia/ volume depletion – excessive diuresis, haemorrhage (shock), burns, gastrointestinal losses Reduced cardiac output – congestive cardiac failure, acute MI, sepsis, liver failure Obstruction of renal arteries – renal thrombosis, renal artery stenosis Medication – causing reduction of blood pressure, circulating volume or renal blood flow e.g. ACEi, ARBs, NSAIDs or loop diuretics

Post-renal AKI Obstruction to urine outflow from the collecting ducts in the kidney down to the urethra Deposition of crystals in the tubules e.g. uric acid, sulphonamides, aciclovir, cisplatin Renal stones in the ureter or bladder Tumour, either within the tract or pressing on it from another pelvic organ e.g. prostate hypertrophy, bladder cancer, bowel cancer

Intra-renal/ Intrinsic/ Renal AKI Vascular – vasculitis, thrombosis, emboli, dissection Glomerular – glomerulonephritis Tubular – ischemia, rhabdomyolysis, myeloma, medication with nephrotoxic potential Interstitial – interstitial nephritis, lymphoma

Management of an AKI No specific drug therapy to manage AKI Early identification is key Management is based on identifying and treating potential causes Example Pre-renal AKI (caused by hypotension & hypovolaemia) Restore circulating blood volume with appropriate fluid therapy Monitor electrolyte balance Monitor blood pressure

General principles of AKI management Check blood pressure Check urine output Daily U&Es Assess risk factors for AKI Consider if any risk factors are modifiable Identify cause of AKI Assess hydration status Review medication

Medicines optimisation in AKI NICE 20132 - 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. Patients who are highlighted as having an AKI; either community or hospital acquired, require a review of their medication in order to1: Eliminate the potential cause/ risk/ contributory factor for AKI Avoid inappropriate combinations of medications in the context of AKI Reduce adverse effects Ensure prescribed doses are appropriate for the patient’s renal function Ensure all prescribed medications are clinically appropriate for the patient in view of their AKI and co-morbidities (1) Think Kidneys (2) NICE 2013

Pharmaceutical input for patients with AKI Identify potential drug causes of AKI Review medications and ensure medicines are appropriately withheld/ stopped and suggest suitable alternatives Advise on the use of fluids if required in the management of AKI Clinical Pharmacist, 2012, vol 2, p.103-106

Pharmaceutical input for patients with AKI Provide recommendations around fluid restriction and minimum volumes of drugs used in fluid- overloaded patients Fluid balance chart – paper or electronic Advise prescribers about drug dosing in AKI Counsel patients regarding medication changes Clinical Pharmacist, 2012, vol 2, p.103-106

Medications optimisation Before holding or stopping any medication, review the indication for the medication, review renal function, co-morbidities, blood pressure, other medications for similar indications, discuss with medical team if necessary Is the patient on any medication that should be stopped or avoided? ACE inhibitors ARBs NSAIDs Diuretics Metformin Aminoglycosides Contrast media

Guidelines for medicines optimisation in patients with AKI Click on the Think Kidneys logo to view the document https://www.thinkkidneys.nhs.uk/aki/wp-content/uploads/sites/2/2016/03/Guidelines-for-Medicines-optimisation-in-patients-with-AKI-final.pdf

Think Kidneys resources

Communication to primary care When a patient is identified as having an AKI in secondary care, the following information should be passed to primary care health care professionals Stage of AKI Information regarding medication changes Follow up requirements (which bloods to be done and when, restarting medications that have been stopped)

Summary AKI is serious and can have a detrimental impact on patients. Delayed recognition can result in permanent renal impairment and even death. Awareness of risk factors for AKI and early identification is key. Pharmacists can play an important part in the management of patients with an AKI by reviewing renal function, performing medicines optimisation and raising awareness of AKI amongst patients and other healthcare professionals.

Further reading NICE guidelines https://www.nice.org.uk/guidance/cg169/resources/acute-kidney- injury-prevention-detection-and-management-pdf- 35109700165573 Renal association guidelines www.renal.org Think Kidneys - https://www.thinkkidneys.nhs.uk/

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