Renal failureRenal failureDr Chamilka JayasingheDr Chamilka Jayasinghe

Acute Renal FailureAcute Renal Failure• Clinical syndrome in which a sudden

deterioration in renal function results in the inability of the kidneys to maintain fluid & electrolyte homeostasis.

classificationclassification• Pre renal • Intrinsic renal • Post renal

Pre renal failure Pre renal failure • Diminished circulating volume ↓ inadequate renal perfusion ↓ ↓ GFRCommon causes:DehydrationHaemorrhage SepsisCardiac failure*renal function returns to normal once renal

hypoperfusion reversed

Intrinsic renal failureIntrinsic renal failure• Renal parenchymal damageCauses:1. Hypoperfusion/ischaemia2. Post infectious GN3. Lupus nephritis4. HSP nephritis5. Membranoproliferative GN• Acute tubular necrosis:Renal Vein Thrombosis

Post renal failurePost renal failureObstructive causes• PUV• Tumours• Urolithiasis

Differentiation of pre renal Differentiation of pre renal & intrinsic renal failure& intrinsic renal failure

Criteria Pre renal

Intrinsic renal

Specific gravity

>1.020 <1.010

Urine osmolality(mosm/l)

>500 <350

Urine Na(meq/L)

<20 >40

FE Na % <1 >2

BUN/Cr >20 <20

Principles of TreatmentPrinciples of Treatment1. If hypovolaemic intravascular volume expansion

N.Saline 20 ml/kg2. Diuretic therapy Frusemide3. Insensible loss-400ml/m2/24 H fluid restriction4. Mx hyperkalaemia5. Metabolic acidosis6. Hypocalcaemia7. Hyponatraemia8. Hypertension9. Anaemia10.Mx Seizures11.Attention to Nutrition-Na, K, Phosphorus

restriction ,maximize caloric intake

Chronic renal failureChronic renal failure• Definition -Irreversible reduction in GFR• Aetiology1. Congenital2. Acquired -GN3. Inherited-Alport4. Metabolic –

cystinosis,hyperoxaluria,polycystic kidney disease

PathogenesisPathogenesis

• Progressive renal injury despite removal of original insult

• Hyperfiltration injury• Persistent proteinuria• Systemic hypertension• Renal calcium,phosphate deposition• Hyperlipidaemia

Degree of renal dysfunctionDegree of renal dysfunction• Mild chronic renal insufficiency: GFR

50-75 ml/min/1.73 m2

• Moderate chronic renal insufficiency:25-50ml/min/1.73 m2

• CRF 10-25 ml/min/1.73 m2

• End stage renal disease <10 ml/min/1.73 m2

CLINICAL FEATURESCLINICAL FEATURES

• Congenital disorders-renal dysplasia & obstructive uropathy

Presents commonly in neonatal period with FTT, dehydration,UTI

• Acquired conditions- Nephrotic Xd,Glomerular nephritis

Presents in childhood/adolescence with oedema, hypertension,haematuria & proteinuria

Examination Examination • Pallor• Sallow complexion• Short stature• Renal osteodystrophy• Oedema • Hypertension• Pruritis

Investigations Investigations • Blood urea nitrogen↑ • S.creatinine↑• Hyperkalaemia• Hyponatraemia• Acidosis• Hypocalcaemia• Hyperphosphatemia• Uric acid ↑• Hypoalbuminemia• S.cholesterol/TG ↑• UFR-Haematuria,proteinuria

Treatment Treatment • Replacing absent/diminished renal

functions• Slowing the progression of renal

dysfunction

Management Management • Multidisciplinary services –

medical,nursing,social services, nutritionist,psychologist involvement

• Close monitoring clinical& lab studies

• Blood studies –Hb,S.E,BUN,Cr,Ca,PO4,

Alkaline Phosphatase• PTH, X Rays of bone-renal osteodystrophy• Echo –cardiac dysfunction, LVH• Fluid & electrolyte balance

Fluid & electrolyte MxFluid & electrolyte Mx• Polyuric stage-significant sodium losshigh volume ,low caloric feeds with

sodium supplementation• Hypertension/oedema or heart

failure-sodium restriction & diuretic therapy

• Hyperkalaemia-restriction of dietary potassium intake

• Oral alkalinizing agents

Anaemia Anaemia • Inadequate Erythropoetin• Deficiency of iron,folate, vit B12Rx• Human Recombinant Erythropoetin• Vitamin/iron supplementation

Hypertension Hypertension • Related to volume overload or

excessive Renin production related to glomerular disease

• Salt restricted diet• Frusemide, ACEI, CaCB, Beta

Blockers

Immunization Immunization • Withhold live vaccines while on

immunosuppressive therapy

• Adjust drug dosage as many drugs are excreted by kidney

Aim to slow progression of Aim to slow progression of renal dysfunctionrenal dysfunction

• Optimal control of hypertension• Maintain s.phosphate within normal

range to minimize renal Ca & PO4 deposition

• Prompt treatment of infectious complications & episodes of dehydration

• Correct anaemia• Avoid NSAIDS

NUTRITION & GROWTHNUTRITION & GROWTH• Restriction of phosphate, potassium,sodium

accordingly• Fluid balance• Recommended daily caloric intake for age• Protein 2.5 g/Kg/24 Hours• High biological value- egg,milk,meat• Help of dietician• Enhance caloric intake by-supplementing with

modular components of CHO, fat(MCT), Protein • Enteral tube feedings• Water soluble vitamins• Zinc, iron supplements

Growth Growth • Apparent growth hormone resistant

state

• Rx Recombinant Human Growth Hormone

Renal osteodystrophyRenal osteodystrophy• GFR<50% ↓1 alpha hydoxylase↓ ↓1,25 (OH)2D3 ↓

↓Intestinal calcium absorption↓ ↓PTH activity↑ ↓Bone resorption↑

GFR <20%GFR <20%• Compensatory mechanisms

inadequate• Hyperphosphatemia• Hypocalcaemia• PTH secretion↑ results in increasing

bone resorption and osteitis fibrosa cystica

Clinical features of renal Clinical features of renal osteodystrophyosteodystrophy

• Muscle weakness• Bone pain• Fractures with minor trauma• Rachitic changes• Varus, valgus deformities of long

bones

Investigations Investigations • S.calcium ↓• S.Phosphorus ↑• Alkaline phosphatase ↑

• X Rays-widened metaphysis with subperiosteal resorption

End stage renal diseaseEnd stage renal disease• The state at which renal dysfunction

has progressed to the point at which homeostasis & survival can no longer be sustained with native kidney function & maximum medical management

ComplicationsComplications

• Electrolyte abnormallities- dilutional hyponatraemia,hyperkalaemia*,hypocalcemia,hypermagnesemia

Seizures,arrhythmias,tetany,weakness,acidosis• Pericarditis /effusions,tamponade• Myocardial ischaemia• Mental state changes• Peritonitis/ pancreatitis• Infection at catheter exit sites• Vascular access problems- ischaemia of limbs

Renal replacement therapyRenal replacement therapy• Dialysis –peritoneal/ haemodialysis• Renal transplantation

Dialysis initiated whenDialysis initiated when• GFR <10-15 ml/min/1.73 m2

• Refractory fluid overload• Electrolyte imbalance• Acidosis• Growth failure• Uraemic symptoms-fatigue, nausea,

impaired school performance

Peritoneal dialysisPeritoneal dialysis• Peritoneal membrane is the dialyser• Excess body water is removed by

osmotic gradient created by high dextrose [ ] in dialysate

• Waste is removed by diffusion from peritoneal capillaries into dialysate

• Must be performed daily

HaemodialysisHaemodialysis• In hospital setting• 3-4 hour sessions/week• Fluid & solute wastes are removed

via indwelling subclavian, internal jugular catheter

Advantages of peritoneal Advantages of peritoneal dialysisdialysis

• Can be done at home• Technically easier• Freedom to attend school & other

activities• Less restrictive diet• Less expensive than haemodialysis

DisadvantagesDisadvantages• Catheter malfunction• Catheter related infections-

peritonitis,exit site infection• Impaired appetite• Negative body image• Caregiver “burn out”

Renal transplantation Renal transplantation • To provide the most normal lifestyle

& possibility for rehabilitation for the child & family

• Optimal treatment for ESRD is early renal transplant from a living related donor

Renal transplant pre & post Renal transplant pre & post managementmanagement

• Donor evaluation• Recipient evaluation• Looking out for post transplant

complications- rejection reaction, technical defects, recurrence of original disease, drug toxicity ,infection(CMV,HIV,HSV,PCP),

bleeding, bowel obstruction

END