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Acut renal failure and treatment Székely Andrea Objectives To define acute renal failure To discuss causes of acute renal failure Diagnosis and Treatment of ARF Introduce Chronic renal failure Methods using case presentations Case 1 24 year old student collapsed after running the Dublin Marathon Had complained of muscle cramps during race and these continued Admitted to A/E after passing a small amount of red urine O/E normal BP and Pulse Urinalysis 2+ Protein, 4+ Blood Light microscopy renal tubular casts Case History continued Urea 20 mmol/L Creatinine 350 micromol/L Sodium 140 Potassium 6.1 Calcium 2.01 mmol/l Phosphate 2.4 mmol/l Urate 500 micromol/l Bicarbonate 17 mmol/l Creatinine Kinase markedly elevated Diagnosis Raised muscle enzymes Assume urinary myoglobin Kidneys normal size and shape on U S Acute renal failure Acute tubular necrosis due to Rhabdomyolysis Acute Renal Failure Treatment Establish the cause of acute renal failure exclude other causes Intrinsic renal disease sepsis obstruction Background chronic renal disease ATN due to Rhabdomyolysis requires aggressive volume expansion (With What ?) with correction of acidosis with close monitoring of urine output blood pressure, pulse, breathing and blood gases and electrolyte and renal function Even if late presentation and established ATN will recover function to normal What does the kidney do? Extracellular Environment maintenance Excretes by-products of metabolism like urea, creatinine, uric acid Individual regulation of salt, water and H+ by changes in tubular reabsorbtion and secretion Hormonal function Ca PO4 via 1,25 cholecalciferol Systemic and Renal haemodynamics Renin angiotensin 2, prostaglandins, bradykinin Red cell production via erythropoiten Potential dysfunction depends on type and extent of renal disease Assessment of Renal Function Blood Urea Serum Creatinine GFR: Used clinically to assess the level of renal function no information on cause GFR is the sum of filtration rates of all nephrons Is the GFR changing or Stable Creatinine is used if monitoring change Creatinine clearance UCr* V(mls) / PCr gives ml/day Chromium EDTA in children MAG 3 isotope scanning Urea and Creatinine as measures of function Urea can be higher in prerenal failure due to volume changes Avid tubular reabsorbtion Blood loss into GI tract Excessive breakdown of Protein Catabolism Creatinine lower in small frame, poor muscle mass Creatinine higher if muscle breakdown Creatinine is freely filtered by the kidney and is not reabsorbed or metabolised 15% is secreted into proximal tubule How does this affect functional assessment??? 3 Categories of Renal Failure Pre-Renal Condition that causes a decrease in blood flow to the kidneys Reduced HP at glomeruli results in poor filtration Post-Renal An obstruction in the outflow of urine Increase HP in Bowman’s capsule results in poor filtration Intra-Renal Direct damage to kidneys, esp. glomeruli Less effective surface area results in poor filtration Post-Renal: Ureteral Stone The material that makes up the stones often consists of calcium deposits, among other things These can cause blockage of urine flow Urine backs up into the kidneys causing nephrons to shut down due to an increase in pressure Analogy In this analogy the ureter acts as a stream Beavers come and build a dam (ureter stones) that block the passage of water down the stream The dam causes a backflow of water that damages the surrounding habitat (kidneys) Pre-Renal: Myocardial Infarction The heart weakens and cannot pump sufficient amounts of blood to the kidneys Glomerular filtration rate decreases (kidney failure ensues) The kidneys may compensate by retaining more salt and water to increase blood volume Analogy In this analogy blood is represented by water A drought occurs (myocardial infarction) Kidneys act as a dam conserving water (blood), which supplies the people with enough water to survive (i.e. blood supplying tissues) Intra-Renal: Glomerulonephritis A Streptococcus bacterial infection of the throat or skin can lead to acute poststreptococcal glomerulonephritis Strep antigens and antibodies form complexes that attach to the glomerulus The inflammation impairs the kidney’s ability to filter and eliminate waste causing low output of urine Analogy In this analogy a river represents the kidneys An oil spill represents Acute post-strep glomerulonephritis The river cannot filter out or diffuse all the sticky oil Therefore the oil ends up disturbing natural habitat around the river and it cannot function properly What can go wrong (Cause) Acute = Hours Days weeks Blood from renal artery is delivered to glomeruli Perfusion Glomeruli form Ultrafiltrate which flows into tubules Glomerular Diseases Tubules reabsorb and secrete water electrolytes from the ultrafiltrate ATN Urine leaves the kidney and drains into the renal pelvis ureters bladder and urethra Obstruction Prerenal Disease Prerenal Anything which affects the renal perfusion through volume loss hypotension or effective volume depletion What is the hydration status of the patient History and Physical Examination Background History Risk Factors for Acute renal failure If impaired perfusion is prolonged severe and untreated, prerenal failure manifests as Acute Tubular Necrosis Post Renal Failure Causes of renal impairment due to Obstruction of the renal tract Tumours Fibrosis Blood clots Stones Papillae Case 2 76 year old man admitted with urinary symptoms and incontinence found by GP to have abnormal renal function Main complaints were urinary frequency nocturia double micturition and poor stream Past history of MI and TIA O/E Hypertension 180/95 with evidence of volume expansion Raised JVP and cardiomegaly sacral and leg oedema Abdominal examination revealed a large mass arising from the pelvis which was dull to percussion PR no rectal masses but prostate enlarged with smooth nodularity Investigations Urea 20 Creatinine 600 Sodium 136 Potassium 6.0mmol/l Bicarbonate 18 mmol/l Renal Ultrasound Severe bilateral hydronephrosis with dome like bladder expansion Chest Xray Cardiomegaly with upper lobe diversion ECG Twave tenting Treatment Renal Failure Time frame to presentation not clear unwell for weeks ++ Clinical examination suggests obstruction as cause probably due to prostatic hypertrophy Catheter inserted and achieved massive diuresis As bladder reduced in size developed haematuria Urologistsarranged TURP for 4 weeks after presentation Intrinsic renal disease Systemic Disease SLE, Amyloidosis, Wegeners Granulomatosis, Diabetes mellitus Primary renal disease Glomerulonephritis, Acute interstitial nephritis, Acute tubular nephritis Urinalysis and Urinary microscopy 1. Haematuria heavy proteinuria dysmorphic red cells 2. Pyuria with white cell casts no proteinuria 3. Pyuria alone 4. Few cells low grade proteinuria –Bland urinary sediment 5. Haematuria Alone 1. 2. 3. 4. 5. Glomerular disease or vasculitis Tubular or interstitial disease or Obstruction Renal tract infection or TB Prerenal disease renal ischaemia some cases of ATN, tubular interstitial disease IgA or Thin BM will have some proteinuria, Renal tract tumours Renal calculi, sloughed papillae Case 3 A 59 year old man presents with weight loss and night sweats. He had recurrent sinusitis aching joints and a painful left ear. He had shortness of breath for 4 days before and had a small amount of haemoptysis On examinatio . Tender over maxillary sinus and left ear drum was inflamed. He appeared pale he was hypertensive 190/100 he had bilateral fine crepitations in his lungs and his JVP was mildly raised. He had moderate leg oedema and all peripheral pulses were present with no femoral or aortic bruits. He had a purpuric rash on his lower limbs with some bullae Investigations Urinalysis showed 3+ Proteinuria and 3+ Blood, microscopy saw some dysmorphic red cells Spot urinary protein 8g/24 hours Hb was low 8.8g/dl Urea 35 mmol/l, Creatinine 480 micromol/l Chest Xray showed interstitial infiltrates Auto antibodies were sent ANCA ANA dsDNA complement Anti GBM antibodies A definitive Test was preformed ANCA related disease Antibodies to neutrophil cytoplasmic antigen are found in 90% of vasculitides C-ANCA diffuse cytoplasmic stippling PAN, now known as anti myeloperoxidase antibody P-ANCA perinuclear staining Wegeners now known as anti proteinase 3 Initially by indirect immunoflourescence now by ELIZA gives more accurate quantification Multisystem disease Wegeners Granulomatosis Active urinary sediment with haematuria and proteinuria glomerular Biopsy Rapidly progressive GN with focal segmental necrotizing GN with crescent formation. Immunofluorescence negative findings or traces only of IgG and C3 Pauciimmune on renal biopsy Systemic disease due to small vessel vasculitis with granuloma causes areas of focal necrosis Treatment Assess organ involvement Exclude other causes Treat Disease process Immunosupression with pulse methylprednisolone and cyclophosphamide has revolutionised outcome from Wegeners RIFLE Global description of ARF R-risk of renal impairment Creatinine >1.5 x Normal UO <0.5 mls/kg/hour for 6 hours I-Injury renal injury Creatinine>2 x Normal UO <0.5 mls/kg/hour for 12 hours F – Failure Creatinine > 3 x Normal or >350 Anuria for 12 hours L –Loss complete loss of renal function for more than 4 weeks (Needing renal replacement) E ESRF complete loss of function needing renal replacement for> 12 weeks Summary Renal Impairment can be acute or chronic Rate of change of function and baseline function is important Prerenal failure is a term to describe reduced renal perfusion Intrinsic renal disease is important as it may be treatable or may be systemic Obstruction is an important cause of renal failure especially in the elderly RIFLE criterion is a new method of describing acute renal failure Questions 1. 2. 3. 4. 5. 6. Does the patient have ARF? Why does the patient have ARF? What is the immediate management? What is the intermediate management? Does the patient need to be transferred? Does the patient need RRT? What is ARF? Acute, usually reversible, decline in GFR ........over days, occasionally weeks ........not necessarily from normal baseline ........usually with a rising plasma urea ........usually with a rising plasma creatinine ........often, but not always with oliguria What is not ARF? Oliguria due to fluid retention .......post-operatively .......as initial response to ECF depletion .......in cardiac failure and other diseases Urinary retention ESRF presenting as uraemic emergency Consequences of ARF Acute metabolic complications Acute cardiovascular complications Prolonged hospitalisation Resource consumption Patient Death Renal Death Common Uncommon ARF in Hospital (Boston Study) 60 50 % of cases developing ARF 50 40 30 25 20 20 20 10 10 10 2 5 5 5 0 Hospital Trauma Elective AAA Open Heart Emergency AAA Incidence of ARF (RA Study) Annual Incidence pmp 2500 2058 2000 1500 872 1000 500 137 0 Creatinine >150 Transiently Severe ARF Causes of Severe ARF 40 (RA Study) 36 % of cases 30 20 14 13 10 10 9 0 Obstruction Surgical Cardiovascular Sepsis ECF Depletion Survival to hospital discharge with ARF ARF alone 90% SCARRF 40-50% (RA/ICS) 100 75 Severe Combined Acute Renal and Respiratory Failure SCARRF +1 5-10% 50 25 All cases of MODS with ARF should have RRT if other therapy continues 0 ARF SCARRF MODS Causes of ARF Pre-Renal Azotemia Acute Tubular Necrosis ischaemic ischaemic toxic Acute Interstitial Nephritis immunological toxic Acute Glomerulonephritis immunological Obstruction / Thrombo-embolic Why does ARF occur? Insult Risk Factors Usually identifiable Usually identifiable Often predictable Sometimes preventable Sometimes correctable W.R.I.S.T. W.. R I S T kers! isk Factors nsults tatus reatment Risk Factors Age Pre-existing renal disease Co-existing cardiac and hepatic disease Generalised vascular disease Conditions interfering with fluid balance (includes dementia & broken legs) ‘Usual medications’ Insults Disturbance of ECF volume status Disturbance of cardiovascular functioning Disturbance of renal haemodynamics Sepsis Operative procedures/anaesthesia Obstruction Prescription of nephrotoxic agents Status Compromised? ECF status Hyperkalaemia Acidosis ‘Uraemia’ Likely to improve? ECF Volume Status Is established on clinical examination Corrected and repeatedly re-assessed with rational/detailed/appropriate fluid therapy Facilitated when appropriate by..... CVP Monitoring PCWP Monitoring Treatment Resuscitate/review Correct other contributors Predict outcome RRT or other investigations as needed Wait……………….. Hyperkalaemia Calcium carbonate/chloride Insulin/Dextrose (1unit:5g) Nebulised Salbutamol 30mins 90mins 6hrs Bicarbonate/Calcium resonium Magic bullets……………. Loop diuretics Mannitol Atrial natriuretic peptide Dopamine 11 3 Kellum JA, M Decker J. Use of dopamine in acute renal failure: a meta-analysis. Crit Care Med 2001; 29:1526-31. 1966-2000 Prevention/Treatment 58 (n=2149) studies 24 (n=1019) outcome 17 (n=854) RCT Mortality 0.44-1.83 ARF 0.55-1.19 RRT 0.55-1.24 Power for >50% effect on ARF/RRT Is it bad for you……? Skin necrosis Tachydysrythmia Ventilatory dysfunction Gut hypoperfusion Ineffective pressor Until proven otherwise.... The patient has not had..... Risk Factors Insults identified identified ECF volume depletion Cardiovascular dysfunction Drug toxicity Obstruction Indication of RRT (renal replacement therapy) Rescuscitated Precipitating event corrected Unlikely to recover quickly MODS Emergent Indications For Initiation of RRT K > 6.5 Volume overload: Refractory to diuretics. Severe Acidosis Uremic complications :Pericarditis Drug Overdose Principles of CRRT Solute removal Diffusion Convection Diffusion Diffusion: The movement of solutes from a higher to a lower solute concentration area. Hemodialysis to waste Dialysate Out Blood In (from patient) Dialysate In Blood Out (to patient) LOW CONC HIGH CONC Convection Convection: The movement of solutes with a water-flow, “solvent drag”, e.g., the movement of membrane-permeable solutes with ultra filtered water. Hemofiltration to waste Blood In (from patient) Replacement. Solution Blood Out (to patient) LOW PRESS HIGH PRESS Hemodiafiltration Diffusive clearance (hemodialysis) + Convective clearance (hemofiltration) Use of dialysate on fluid side of filter and replacement solution on the blood side of the filter. Hemodiafiltration to waste Blood In (from patient) Dialysate Solution Replacement Solution Blood Out (to patient) LOW PRESS LOW CONC HIGH PRESS HIGH CONC Dialysis Access Arterial Venous (AV) Needs 2 catheters one in artery and other in vein No blood pump required: Depends on systemic BP Complications: embolization, bleeding, pseudoaneurysm Not used anymore Dialysis Access Veno-venous (VV) One dialysis catheter in vein Less complications Blood flow more reliable since external blood pump + Technically more complicated. Widely used The M EDUWAY To Care For Patients Types of CRRT SCUF - Slow Continuous Ultra Filtration CVVH - Continuous Veno-Venous Hemofiltration CVVHD - Continuous Veno-Venous HemoDialysis CVVHDF - Continuous Veno-Venous HemoDiaFiltration Types of CRRT CAVH - CAVHD Continuous Arterio-Venous - CAVHDF Hemofiltration Continuous Arterio-Venous HemoDialysis – Continuous Arterio-Venous HemoDiaFiltration SCUF Primary therapeutic goal: • Safe management of fluid removal UF rate ranges up to 2 L/Hr No dialysate No replacement fluids Large fluid removal via ultrafiltration Blood Flow rates = 10-180 ml/min CVVH Primary therapeutic goal • Convective solute removal • Safe fluid management UF rate ranges 12-20 L/24 hours (>500 ml/hr) Requires replacement solution to drive convection No dialysate CVVHD Primary therapeutic goal • Solute removal by diffusion • Safe fluid volume management Requires dialysate solution UF rate ranges 2-7 L/24 hours (~300 ml/hr) Dialysate Flow rate = 15-45 ml/min (~1-3 L/hr) Blood Flow rate = 10-180 ml/min No replacement solution Solute removal determined by Dialysate Flow CVVHDF Primary therapeutic goal: • Solute removal by diffusion and convection • Safe fluid management Combines CVVH and CVVHD therapies UF rate ranges 12-20L/24hr Uses dialysate solution Uses replacement solution Blood Flow rate = 10-180ml/min Dialysate Flow rate = 15-45 ml/min Summary Access Access Return Return Dialysate Access SCUF Effluent CVVH Access Return Return Replacement Replacement (pre or post dilution) Effluent Dialysate (pre or post dilution) I Effluent CVVHD Effluent CVVHDF Complication: Vascular access Monitor for complications Subclavian or jugular vein Respiratory distress Hematoma/bleeding at site Infection Cardiac arrhythmia during placement Tubing disconnection Hemorrhage/air embolism Potential patient problem Air embolism Hypothermia Blood leak Ekg interference Peritoneal Dialysis (PD) Use of the peritoneal membrane for ultrafiltration and diffusion Acute PD -temporary catheter -2 days Chronic PD- permanent catheter Continuous ambulatory peritoneal dialysisCAPD 4 exchanges/day Ultrafiltration- osmotic pressure 1.5-4.25 % glucose Peritoneal dialysis - advantages Dependency on medical staff Restriction of fluid and food intake Continued dialysis-stable hemodynamic and metabolic conditions eritoneal dialysis- disadvantages Hypoalbuminemia and malnutrition Exacerbation of DM Exacerbation of respiratory disturbances Efficiency -“BIG”patients,low residual function Less efficient for emergent fluid and K removal Peritonitis, sclerosing peritonitis Burnout COMPLICATIONS OF PERMANENT DIALYSIS CARDIOVASCULAR Accelerated Atherosclerosis Coronary calcification Ischemic heart disease Peripheral vascular disease Left ventricular hypertrophy- HTN, Anemia Valvular calcification Heart failure BONE and JOINTS disease secunder hyperparathyroidism b 2 microglobuline amyloidosis Renal Transplantation Cadaveric renal transplantation (CRT) Living related renal transplantation (LRD) Living unrelated renal transplantation Kidney and pancreas transplantation IMMUNOSUPPRESSION Steroids Calcineurin Inhibitors- cyclosporine, FK506 Azothioprine, Mycophenolate mofetil ATG, OKT3 Rapamycin Anti IL2 antibodies Renal Transplantation Common Complications Ischemia-ATN Rejection Infections- Bacterial CMV Opportunistic infections Renal Transplantation Late Complications Rejection Cyclosporine toxicity Recurrence of primary disease- FGS Renal artery stenosis Chronic allograft dysfunction Atherosclerosis, osteoporosis Advantages of transplantation Freedom from dialysis Improvement in nutritional state Improvement in Fertility and sexual function Less restriction of food and fluid intake Improved QOL and survival Limitations of transplantation Early Medication - need for compliance Immunosupression and infections Exacerbation of diabetes Hyperkalemia and volume overloadpossible Procedures during follow up- biopsies etc Limitations of transplantation Late Chronic allograft dysfunction-T1/2=7 years Atherosclerosis, osteoporosis Exacerbation of hepatitis B and C Malignancy-frequency and severity