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Acute Kidney Injury . Dr Andrew Lewington Consultant Renal Physician/Honorary Clinical Associate Professor Leeds Teaching Hospitals. What is AKI?. Functions of the Kidney. maintenance of body composition osmolality, electrolyte content, acidity excretion of metabolic end products
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Acute Kidney Injury Dr Andrew Lewington Consultant Renal Physician/Honorary Clinical Associate Professor Leeds Teaching Hospitals
Functions of the Kidney maintenance of body composition osmolality, electrolyte content, acidity excretion of metabolic end products urea, drugs secretion of erythropoietin maturation of erythrocytes secretion of activated form of vitamin D3 calcium and phosphate balance renin secretion angiotensinogen→angiotensin I
Stage 1 eGFR ≥ 90 • Kidney damage, normal or increased GFR • Stage 2 eGFR 60-89 • Kidney damage, mildly reduced GFR • Stage 3A eGFR 45-59 • Moderately reduced GFR ± other evidence of kidney damage • GFR < 60 ml/min for ≥ 3 months ± kidney damage • Stage 3B eGFR30-44 • Stage 4 eGFR 15-29 • Severely reduced GFR ± other evidence of kidney damage • Stage 5 eGFR< 15 • Established kidney failure • Kidney damage (presence of structural abnormalities and/or persistent haematuria, proteinuria or microalbuminuria) for ≥ 3 months Stages of CKD
Acute Kidney Injury Term encompasses all forms of AKI rapid reduction in kidney function occurs over hours to days no specific symptoms exception – stones failure to regulate fluid and electrolyte balance acid/base balance failure to excrete some drugs
Acute Kidney Injury • Most commonly associated with acute illness (hypoperfusion) • recovery usual if patient recovers from primary cause • severe AKI may progress to chronic kidney disease • Rarer forms • require rapid recognition for specific therapy
Increased mortality associated with changes inserumcreatinine Chertow et al: JASN 2005
Definition of AKI – Kidney Disease Improving Global Outcomes • Serum creatinine rise ≥26 µmol/L within 48 hours or • Serum creatinine rise ≥1.5 fold from the baseline value, which is known or presumed to have occurred within one week or • Urine output is <0.5 mL/kg/hr for >6 consecutive hours
Epidemiology • based on old definitions • 5% of hospital admissions • 30% of ICU admissions • based on new definitions • 18% of hospital admissions • 30-80% of ICU admissions
Aetiology • essential to establish aetiology • aetiology determines treatment • not all AKI is secondary to ischaemia /reperfusion injury • important to identify rarer causes
AKI is a Syndrome Pre-renal AKI • Sepsis • Hypovolemia Intrinsic AKI • Acute tubular injury • Tubulointerstitial injury • Glomerulonephritis • Vasculitis Post-renal AKI • Kidney stones • Prostatic hypertrophy • Retroperitoneal fibrosis
Clinical Presentation of AKI • Risk factors for AKI (some) • chronic kidney disease • cardiac failure • peripheral vascular disease • diabetes mellitus (with proteinuria) • liver disease • myeloma
Clinical Presentation • poor fluid intake • nausea, vomiting • ↓ functional capacity • excessive fluid losses • fever • diuretics • diarrhoea • high stoma output • haemorrhage • burns
Clinical Presentation • drug history • nephrotoxic drugs • radiocontrast media • urinary tract symptoms • prostatic disease • renal calculi
Clinical Presentation • volume status • core temperature • heart rate • JVP • postural hypotension • cardiovascular status • peripheral perfusion • BP • heart rate and rhythm
Clinical Presentation • palpable bladder • prostatic hypertrophy • carcinoma of cervix • bruits/absent pulses • renovascular disease • rash • vasculitis • interstitial nephritis
Complications of AKI • metabolic • hyperkalaemia • cardiovascular • pulmonary oedema, arrhythmias, pericarditis • gastrointestinal • nausea, vomiting, gastritis, ulceration, malnutrition
Complications of AKI • neurological • seizures, mental status changes • infectious • haematological • anaemia, bleeding
Investigations • Full Blood Count and clotting • U&Es and bicarbonate (previous renal function) • Liver Function Tests and bone • urinalysis (prior to urinary catheter) • immunological screen – if vasculitis suspected
Investigations • ultrasound of renal tract within 24hrs if • obstruction suspected • isoteric cause suspected requiring a kidney biopsy • consider blood film, LDH • (if ↓ Hb and ↓ Pl) • consider creatine kinase • (rhabdomyolysis)
Prevention of AKI is Essential • Risk of complications • increased length of stay • increased mortality • chronic kidney disease • Cost • £1.2 Billion
Prevention • identify risk factors • > 75 years • pre-existing chronic kidney disease • vascular disease • diabetes mellitus (with proteinuria) • cardiac failure • hypovolaemia • sepsis • nephrotoxins • drugs • contrast media
Prevention • treat sepsis promptly • optomise volume status • stop/avoid • nephrotoxic medications • minimise volume of contrast
Treatment of AKI dependent upon the cause • supportive therapy • stabilise haemodynamics • treat complications • renal replacement therapy - dialysis • avoid further renal insults • nephrotoxins • Hypotension • Hold antihypertensives/diuretics
Treatment of AKI • specific therapy • e.g. vasculitis – • Immunosuppression • If suspected – refer immediately
June 11, 2009 Royal Society of Medicine London
Key findings < 50% of AKI care considered good poorassessment of risk factors 43% of post-admission AKI - unacceptable delay in recognition
Patients with c-AKI sustain more severe AKI than h-AKI • Patients with c-AKI have better short term and long term outcomes than h-AKI
The Context:Addressing vulnerability & Transforming Urgent Care • Provide better support for people to self-care Self-treatment options & care plan to know what to do and who to contact when deterioration • Help people with urgent care needs get right advice in right place, first time • Highly responsive urgent care services outside hospital • People with serious and life threatening emergency care needs receive treatment in centres with facilities and expertise • Connect all urgent and emergency care services
Acute kidney injury: prevention, detection and management up to the point of renal replacement therapy (CG169) • Guidance from the National Institute for Health and Care Excellence • August 2013 • Dr Andy Lewington • Leeds Teaching Hospitals
NICE AKI Guideline • 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 patients with AKI in a variety of settings • in view of its frequency and mortality rate, prevention or amelioration of just 20% of cases of AKI would prevent a large number of deaths and substantially reduce complications and their associated costs
NICE AKI Guidelines Rajib Pal (expert adviser) GP Principal, Hall Green Health, West Midlands