Renal Management Principles PDF

Management of Renal Pathologies Dr Wadie Rassam Griffith University MD Lecturer LEARNING OBJECTIVE Outline the basic therapeutic principals (pharmacological and non pharmacological) in the management of common and important conditions of the renal system. RECAP AKI = not a diagnosis itself. Rather a...

Management of Renal Pathologies Dr Wadie Rassam Griffith University MD Lecturer LEARNING OBJECTIVE Outline the basic therapeutic principals (pharmacological and non pharmacological) in the management of common and important conditions of the renal system. RECAP AKI = not a diagnosis itself. Rather a clinical syndrome characterised by renal dysfunction causing an acute drop in eGFR. - actual diagnoses are sepsis, glomerulonephritis, kidney stones etc. CKD = not a diagnosis itself. It just means a kidney abnormality that results in kidney dysfunction for > 3 months. The degree to which this dysfunction should occur to be CKD is when eGFR < 60 - actual diagnoses are diabetic nephropathy, hypertensive nephropathy etc. Overview 1) Lifestyle measures - General lifestyle measures - Dietary modifications - Electrolytes - Hyperkalaemia - Bicarbonate - Nephrotoxics vs renally cleared medications 2) Pharmacological - Anti-hypertensives - Diuretics - Statins - Antimicrobials - Analgaesics - ESAs - Phosphate/Ca/Vit D/PTH 4) Renal replacement therapy - non-operative - Haemodialysis - Peritoneal dialysis 5) Renal replacement therapy - operative - Renal transplant 6) Cases Overview As we go through this lecture, think about the therapies as either: - Preventing further kidney damage - OR - Treating a complication that has resulted from kidney damage Once a kidney is damaged, whilst you can do many things to prevent further damage and treat complications, there are only 3 things you can do that will boost kidney function: - Treat underlying exacerbating factor e.g. IV fluids for dehydration - Dialysis - Transplant LIFESTYLE MEASURES (CKD) - The usuals for cardiovascular disease apply here - - regular exercise - - cardiovascular - - weight-bearing/muscle strengthening – CKD-BMD - - smoking cessation - - alcohol intake reduction - - weight loss DIETARY MODIFICATION - - Fluid - - Drink to satisfy thirst; prevent dehydration - - In hospitalised patients, dehydrated patients will often receive IV fluids - - Fluid restriction may be required in CKD to prevent fluid overload - - High fruit/vegetable/legumes/lean meat; low saturated and trans fats and sugary/sweetened foods - - Protein intake - - aim around 0.75g/kg body weight/day. - - low protein diet = malnutrition risk - - high protein diet = uraemia risk ELECTROLYTES - - - - Sodium - limit salt intake - - In CKD, limit salt intake ( decreased angiotensin II and increased bradykinin - - decreased ATII - - - less vasoconstriction à less TPVR à hypotension - - less aldosterone à less Na/H2O reabsorption à hypotension - - less aldosterone à less K/H excretion à hyperkalaemia (and alkalosis) - - dilation of efferent arteriole à less glomerular filtration - less breakdown bradykinin - - - more bradykinin à vasodilation and cough - also nephroprotective and cardioprotective properties (see coming slide) ACE-I - Indications = HTN, post-ACS, heart failure, CKD. ACE-inhibitors (or ARBs) are first line anti-hypertensive in CKD! - Side effects = AKI, cough, hypotension, hyperkalaemia, teratogenicity - Contraindications = pregnancy, allergy, BL RAS, hyperkalaemia, hypotension - Interactions = ARBs, diuretics, NSAIDs - Monitoring = BP, renal function, potassium ARB - Class = Angiotensin-receptor blockers - Name = ‘sartan’ e.g. candesartan, telmisartan - MOA = inhibits angiotensin II AT1 receptor --> decreased action of angiotensin II - - decreased ATII - - less vasoconstriction à less TPVR à hypotension - - less aldosterone à less Na/H2O reabsorption à hypotension - - less aldosterone à less K/H excretion à hyperkalaemia (and alkalosis) - - dilation of efferent arteriole à less glomerular filtration - - also nephroprotective and cardioprotective properties (see coming slide) - - same, minus bradykinin component ARB - Indications = HTN, post-ACS, heart failure, CKD. ACE-inhibitors (or ARBs) are first line anti-hypertensive in CKD! - Side effects = AKI, hypotension, hyperkalaemia, teratogenicity - Contraindications = pregnancy, allergy, BL RAS, hyperkalaemia, hypotension - Interactions = ARBs, diuretics, NSAIDs - Monitoring = BP, renal function, potassium ACE-I/ARB Why are ACE-I/ARB first line for HTN in CKD? ACE-I/ARB Nephroprotective properties: ACE-I/ARB Nephroprotective properties: - 1) Treats hypertension – this is nephroprotective in of itself. - 2) Dilation of efferent arteriole à Decreased glomerular hydrostatic pressure decreased glomerular filtration à prevents sclerosis of glomerular basement membrane à nephroprotection, decreased proteinuria ACE-I and ARBs will drop GFR – should you use them in CKD? As long as less than 25% form water and CO2 à make blood more alkaline - Indications = CKD associated metabolic acidosis - Overview 1) Lifestyle measures - General lifestyle measures - Dietary modifications - Electrolytes - Hyperkalaemia - Bicarbonate - Nephrotoxics vs renally cleared medications 2) Pharmacological - Anti-hypertensives - Diuretics - Statins - Antimicrobials - Analgaesics - ESAs - Phosphate/Ca/Vit D/PTH 4) Renal replacement therapy - non-operative - Haemodialysis - Peritoneal dialysis 5) Renal replacement therapy - operative - Renal transplant 6) Cases NEPHROTOXICS VS RENALLY CLEARED NEPHROTOXICS VS RENALLY CLEARED - Nephrotoxic drugs: - aminoglycosides e.g. gentamicin - glycopeptides e.g. vancomycin - less commonly cephalosporins e.g. cefazolin, ceftriaxone, cefepime - - contrast agents e.g. iodine (CT), gadolinium (MRI) - NSAIDs - lithium - ACE-inhibitors, ARBs, mineralocorticoid receptor antagonists, diuretics - - chemotherapy, autoimmune drugs Endogenous nephrotoxins: - myoglobin (rhabdomyolsis) - uric acid (purine breakdown product) - - Bence Jones protein (multiple myeloma) NEPHROTOXICS VS RENALLY CLEARED - With respect to medications that are nephrotoxic vs those who need dose reduction in renal failure, contrast: - 1) metformin - 2) vancomycin - 3) lithium Overview 1) Lifestyle measures - General lifestyle measures - Dietary modifications - Electrolytes - Hyperkalaemia - Bicarbonate - Nephrotoxics vs renally cleared medications 2) Pharmacological - Anti-hypertensives - Diuretics - Statins - Antimicrobials - Analgaesics - ESAs - Phosphate/Ca/Vit D/PTH 4) Renal replacement therapy - non-operative - Haemodialysis - Peritoneal dialysis 5) Renal replacement therapy - operative - Renal transplant 6) Cases DIALYSIS Process of removing excess water, solutes, and toxins from the blood in people whose kidneys can no longer perform these functions naturally. This is either done by haemodialysis or peritoneal dialysis We will contrast them by 1. 1. Process 2. 2. Access 3. 3. Logistics/lifestyle impacts HAEMODIALYSIS - PROCESS 1) 1) Access – either AV fistula, AV graft or central venous catheter 2) 2) blood is pumped into a machine called a dialyser 3) 3) two fluids meet at a membrane in the dialyser – the patient’s blood and the dialysate (fluid we prescribe based of patient’s biochemical markers) 4) 4) blood is cleansed in the dialyser 5) 5) blood is returned to patient HAEMODIALYSIS - ACCESS 1) Haemodialysis requires large bore access. 1) - AV fistulas/grafts are done by vascular surgeons. Planned in advance for CKD. 2) - CVCs can be done by radiologists, nephrologists or critical care doctors. Done for emergency dialysis or inserted temporarily if a fistula needs repair HAEMODIALYSIS - LOGISTICS 1) Occurs generally 3 weekly, with 4 – 6 hour sessions. 2) Requires rigorous attendance to hospital and strict routine 3) Significantly impacts quality of life e.g. difficult to travel long distances PERITONEAL DIALYSIS - PROCESS 1) 1) Access – via a Tenchkoff catheter 2) 2) dialysate is put into the peritoneal cavity via the Tenchkoff catheter 3) 3) two fluids meet at the peritoneum (uses patient’s natural membrane) – blood flowing through the blood vessels in the peritoneum and the dialysate in the peritoneal cavity 4) 4) blood is cleansed in the peritoneal cavity 5) 5) used dialysate is taken out of the Tenchkoff catheter and discarded PERITONEAL DIALYSIS - ACCESS 1) Peritoneal dialysis requires a portal to the peritoneal cavity 1) - Tenchkoff catheters are inserted by general surgeons PERITONEAL DIALYSIS - LOGISTICS 1) Requires bag changing 4+ times a day 2) Can be done from home 3) More freedom to travel 4) Patients should be advised not to swim Overview 1) Lifestyle measures - General lifestyle measures - Dietary modifications - Electrolytes 2) Pharmacological - Anti-hypertensives - Diuretics - Antimicrobials - Analgaesics - CKD specific therapies - Vaccinations - Disease modifying therapies - Nephrotoxics vs renally cleared medications 3) Fluids - Hydration vs fluid restriction 4) Renal replacement therapy/dialysis - Haemodialysis - Peritoneal dialysis 5) Surgical - Renal transplant 6) Cases TRANSPLANT Transplantation of a kidney from a living or cadaveric donor Used in CKD-V, will get people off dialysis Affords greater quality of life once kidney function stabilised Needs rigorous follow up and immunosuppressant compliance. High risk of infection and cancer; transplants usually fail around 14 years RRT - TYPES Acute renal replacement therapy – in a patient whose never had dialysis, done by haemodialysis via an emergently placed central venous catheter Indications for acute dialysis – AEIOU - acidosis - electrolytes e.g. hyperkalaemia - intoxication e.g. methanol, lithium - overload (fluid overload) - uraemia Chronic renal replacement therapy – in a patient with ESRF/CKD-V. done by haemodialysis, peritoneal dialysis or renal transplantation Overview 1) Lifestyle measures - General lifestyle measures - Dietary modifications - Electrolytes 2) Pharmacological - Anti-hypertensives - Diuretics - Antimicrobials - Analgaesics - CKD specific therapies - Vaccinations - Disease modifying therapies - Nephrotoxics vs renally cleared medications 3) Fluids - Hydration vs fluid restriction 4) Renal replacement therapy/dialysis - Haemodialysis - Peritoneal dialysis 5) Surgical - Renal transplant 6) Cases CASE A 63 year old lady, Kidney Spears, presents to ED with her son. He has brought his mum in as she is very confused, has vomited 4 times and appears short of breath. She is unable to give you any history. Her son tells you that she was admitted in hospital for one night and was discharged 5 days ago. She had presented with abdominal pain, and was Investigated with a CT abdomen/pelvis w contrast, which showed no acute abnormality. She was kept in for monitoring, and her pain settled with over the counter pain tablets and was discharged. She has continued these tablets on discharge. PMHx: hypertension, dyslipidaemia, type 2 diabetes mellitus, GORD Meds: ramipril, spironolactone, atorvastatin, metformin, pantoprazole Allergies: nil Her investigations from her admission 5 days ago showed a full blood count within normal limits, UEC showing an eGFR of 64 (similar to previous bloods) and an LFT within normal limits. CASE On examination today: Inspection – working very hard to breathe, confused, grasping at the air Pupils equal and reactive to light, no signs of head injury Vital signs – HR 143, BP 89/53mmHg, RR 30 breaths/min, O2 88% RA, T 39.2C Heart sounds dual without murmurs Chest – decreased air entry and crackles heard in the right lower lung zone. Abdomen soft non-tender No skin rashes, moves all 4 limbs CASE Blood tests: Complete Blood Picture: Reference Range Hb 120 g/L (130-180 g/L) MCV 90 fL (80-100 fl) WCC 21.8 x 10 9/L (4.5-13.5 g/L) Neutrophils 19.9 x 10 9/L (2.0-7.5 g/L) Lymphocytes 1 x 10 9/L (1.5-4.0 g/L) Monocytes 0.5 x 10 9/L (0.2-0.8 g/L) Basophils 0.1 g/L (0 - 0.5 g/L) Eosinophils 0.3 x 10 9/L (0.04-0.4 g/L) Platelets 140 x 109/L (150-400 g/L) CASE Blood tests: GENERAL CHEMISTRY SPECIMEN: SERUM Reference Range Sodium 137 mmol/L (135-145 mmol/L) Calcium 2.59 mmol/L (2.10-2.60 mmol/L) Potassium 6.9 mmol/L (3.5-5.2 mmol/L) Phosphate 1.52 mmol/L (0.75-1.5 mmol/L) Chloride 101 mmol/L (95-110 mmol/L) Protein 74 g/L (60-80 g/L) Bicarb. 13 mmol/L (22-32 mmol/L) Albumin 38 g/L (32-45 g/L) Urea 40mmol/L (3.0-8.0 mmol/L) Alkaline Phosphatase (ALP) 77 U/L (30-110 U/L) Creatinine 322 umol/L (45-90 umol/L) eGFR 4 mL/min/1.73m² (>90mL/min/1.73m²) Bilirubin 15 μmol/L (