Acute Kidney Injury (AKI)

Transcription

1 Acute Kidney Injury (AKI) Epidemilgy f acute kidney injury (AKI) Staging (Kidney Disease Imprving Glbal Outcmes gruping) uses bth serum creatinine and urine utput STAGE SERUM CREATININE URINE OUTPUT times baseline 0.3 mg/dl ( 26.5 mml/l) increase <0.5 ml/kg/h fr 6 12 hurs times baseline <0.5 ml/kg/h fr 12 hurs times baseline Increase in serum creatinine t 4.0 mg/dl ( mml/l) Initiatin f renal replacement therapy, In patients <18 years, decrease in egfr t <35 ml/min per 1.73 m2 <0.3 ml/kg/h fr 24 hurs Anuria fr 12 hurs Grading f AKI directly is prprtinal t mrtality Chertw, Glenn M., et al. "Acute kidney injury, mrtality, length f stay, and csts in hspitalized patients." Jurnal f the American Sciety f Nephrlgy (2005): Csts apprximately 1.2 billin punds per year in the UK, nt including thse wh g n t CRF Causes f acute kidney injury (AKI) AKI is NOT a diagnsis it is a reflectin f an unwell patient Nearly always signifies a systemically unwell patient rather than a primary renal injury- the histry is very imprtant! Classically brken int pre-renal, renal and pst-renal There can ften be a mixture f all aetilgies

2 Pre-renal causes f acute kidney injury (AKI) Renal bld flw is cmprmised causing a reduced glmerular filtratin rate Fluid Hypvlaemia (bleeding, dehydratin, burns, pancreatitis) Hyptensin (e.g. septic shck) Heart failure lw cardiac utput Liver cirrhsis causing lw vlume Vascular Renal artery stensis Impairment f renal bld flw autregulatin Liver disease (hepatrenal syndrme - rare) ACE inhibitrs and NSAIDs Renal causes f acute kidney injury (AKI) Acute tubular necrsis Ischaemia Hypvlaemia, CCF, renal artery stensis, hepatrenal syndrme Basically all the causes f pre-renal failure, hence why intrinsic and pre-renal disease verlap. Nephrtxic Endgenus Haemglbinaemia DIC and ther causes f haemlysis Myglbinuria: Rhabdmylysis (NB have lw ca in these and very high cr>ur) Myelma kidney disease light chain nephrpathy and tubular cast damage Tubular crystal frmatin Exgenus Imaging cntrast Nephrtxic medicatin Drugs Aminglycsides, Amphteracin Cntrast agents NSAIDs, Platinum drugs Acute tubulinterstitial nephritis Drugs: NSAIDS, penicillins, diuretics, antiretrvirals and many mre Infectins: TB, leginella, leptspirsis Autimmune: Sarcid and Sjrgen s Acute glmerulnephritis Vascular Thrmbtic micrangipathies: Haemlytic Uraemic Syndrme, Thrmbtic Trmbcytpaenic Purpura, Pre-eclampsia, Malignant hypertensin Vasculitis

3 Pst-renal causes f acute kidney injury (AKI) These are all sme frm f bstructin either intraluminal, intramural r extrinsic bstructin Intraluminal Nephrlithiasis Tumurs Slughed papilla (pst ATN, DM, sickle, analgesic nephrpathy, amylid and acute pyelnephritis) Clt retentin Intramural Reflux Adynamic urethral segments Neurlgical disrder(ms, spinal crd injury, DM, PD, pst-strke Drugs: Anti-chlinergics and levdpa Tumurs Strictures (wrldwide pst Schistmsmsa haematbium) Extrinsic Gravid uterus Benign and malignant masses Iatrgenic ureteric ligatin Benign prstatic hypertrphy/prstate cancer Retrperitneal pathlgy Retrperitneal fibrsis idipathic, pst inflammatry AAA, drugs (beta blckers and ergts)

4 Treatment f acute kidney injury (AKI) Avidance f AKI Identify high risk patients: Elderly, CKD, cardia failure, liver disease, diabetes, vascular disease, n nephrtxic medicatins Mnitr patients apprpriately: fluid balance, blds tests Maintain circulatin: Hydratin, resuscitatin and xygenatin Minimise renal insult: nephrtxics, cntrast hspital acquired infectin Manage acute illness Optimise vlume status BP, CRT, pulse, edema, sats, urine utput Shuld have iv fluid prtcl If fluid deplete: Crystallid (500ml) stat blus THEN REASSESS Maintenance: Hartmanns Need 25-30ml/kg water, 1mml salt and g glucse per day Evidence f crystallid r cllid Vlume needed t resuscitate smene is cmparable between crystallid and cllid - SAFE study (2007) shwed nly 1.3x mre crystallid than cllid needed N evidence frm RCTs that cllid is better at all and may cause harm. They are als mre expensive. NB. CRISTAL study actually fund that cllids (inc HES) imprved mrtality at 90 days pst-itu admissin relative t crystallid. S a cnfusing area. Saline r Hartmanns Plasma-lyte better utcmes than saline Stp nephrtxics ACE-I, diuretics, metfrmin, allpurinl etc. Als cnsider stpping antihypertensives Avid cntrast if pssible Dialysis r haemfiltratin Renal ward Further treatment Treat sepsis antibitics shuld be given within 1 hur f suspicin f sepsis Sterids (in AIN) Cyclphsphamide (vasculitis) Plasma exchange (HUS/TTP)

5 Cmplicatins f acute kidney injury (AKI) Hyperkalaemia Calcium glucnate 10mls f 10% if ECG changes Insulin and dextrse 10units f actarapid in 50ml f 50% dextrse ver 15 minutes (if ptassium >6.5 mml/l r ECG changes) Salbutaml 5mg nebulised (cautin in tachycardia r heart disease) Insulin and salbutaml wrk fr rughly 4 hurs r less Fursemide is useful if the patient is passing gd vlumes f urine but ONLY IF THE PATIENT IS FLUID OVERLOADED Catin exchange resins are verused mderate effect with high rates f cnstipatin which might paradxically make the situatin wrse rectal rute is preferable if must be used. Renal replacement therapy if refractry Lnger term review diet, avid ptassium sparing diuretics/ace-i, ARBS, NSAIDs. Be wary f the ptassium lad in bld transfusins Pulmnary edema Sit patient up High-flw xygen unless cntraindicated cnsider CPAP Opiates e.g. IV diamrphine mg r mrphine 2.5mg-5mg as bth an anxilytic and a vendilatr dn t give t ften due t accumulatin in renal failure If haemdynamically stable give 80mg fursemide IV and cnsider further bluses r infusin f 10mg/hur If haemdynamically stable GTN infusin titrating up frm 1mg/hur as tlerated by bld pressure (systlic abve 100mmHg) If unstable will need transfer t high dependency setting fr urgent filtering If hyperkalaemic with bicarbnate <22mml/L and nt fluid verladed then can cnsider 1.26% sdium bicarbnate ver 1 hur (can be given via peripheral cannula but avid in cannula that calcium glucnate was given thrugh) Acidsis Bicarbnate use shuld be reserved fr hyperkalaemia pending specialist help ph<7.15 will need immediate critical care input fr filtratin Uraemic encephalpathy Acute setting presents as cma Chrnically: fatigue, weakness, anrexia, nausea, metallic taste, pruritis, imptence Will need emergency renal replacement therapy in the acute setting Uraemic pericarditis Will need RRT Hypertensin (mre f a prblem in CRF but acute renal failure can present with hypertensive emergency and needs aggressive treatment, e.g. nitrprusside, beta blckers, ACE-I slwly ver 24-48h) Sepsis avid r adjust dses f nephrtxic drugs (e.g. vanc and gent) Electrlyte derangement fluid, sdium and ptassium restrictin, and RRT if it is still there.

6 Questins cncerning acute kidney injury (AKI) A 50 year ld alchlic male presents with sepsis secndary t klebsiella pneumnia. His backgrund includes IHD, previus pneumnia, hyperchlesterlaemia and hypertensin. Medicatins include: fursemide, enalapril, aspirin, clpidgrel, c-amxiclav (current) and simvastatin He is treated with IV antibitics and is managed n an ITU setting fr 1 week On step dwn t a medical ward rutine blds reveal: Sdium 132 Ptassium 5.0 Urea 24 (frm 8) Creatinine 390 (frm 60) Clinically he is mildly dry, with a BP 135/83, HR 90, he is catheterised with a U/O 35ml/hr His management plan shuld include which f the fllwing? 1. Switch t high dse IV fursemide, stp enalapril, give IV fluids t maintain urine utput, daily blds 2. Stp fursemide, stp enalapril, add in dpamine and maintain adequate hydratin t maintain urine utput, daily blds 3. Stp fursemide, stp enalapril, adequate fluids t maintain urine utput, daily blds 4. Cntinue fursemide, stp enalapril, high dse crticsterids and cntinue adequate fluids t maintain urine utput, daily blds 5. Nne f the abve Answer 3