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الرحمن الله بسمالرحيم

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Acute Versus Chronic Renal Failure

Manal Elshamaa , MD of pediatrics

National Research Centre

Acute Versus Chronic Renal Failure

Manal Elshamaa , MD of pediatrics

National Research Centre

Anatomy

2 Kidneys2 UretersBladderUrethra

Kidney Function

Detoxify bloodIncrease calcium absorption

– calcitriolStimulate RBC production

– erythropoietinRegulate blood pressure and electrolyte

balance – renin

Classifications

Acute versus chronicPre-renal, renal, post-renalAnuric, oliguric, polyuric

Acute Versus Chronic

Acute – sudden onset– rapid reduction in urine output– Usually reversible– Tubular cell death and regeneration

Chronic – Progressive– Not reversible– Nephron loss

75% of function can be lost before its noticeable

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Acute Renal Failure

Definition

Renal function is diminished to the point where body fluid hemostasis can no longer be maintained.

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Prerenal Causes The most common cause of acute renal failure. Hypovolemia Hemorrhage Gastroenteritis Hypoproteinemia Burns Renal or adrenal disease with salt wasting Hypotension Septicemia DIC Hypothermia Congestive heart failure Hypoxia RDS and pneumonia Aortic calmping

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Prerenal Azotemia In severe cases hypovolemic

shock. Oliguria is present in most individuals.

Normal or increased urine output indicates either

Aminogycoside or ATNnephrotoxicity

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Prerenal ARF of Newborns and Infants Causes Peri-natal hemorrhage - Twin-twin

transfusion, complications of amniocentesis, birth trauma

Neonatal hemorrhage - Severe intra-ventricular hemorrhage, adrenal hemorrhage.

Perinatal asphyxia and hyaline membrane disease.

Other causes as NIC &renal vein thrombosis

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Prerenal ARF of Children The most common cause of ARF Prerenal ARF: The most common cause of hypovolemia in

children is gastroenteritis.Congenital and acquired heart diseases

are important causes of ARF in this age group.

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Intrinsic Renal Failure GlomerulonephritisLocalized intravascular coagulation

Acute tubular necrosisAcute interstitial nephritisTumorsDevelopmental abnormalitiesHereditary

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Intrinsic Renal Failure Glomerular diseases: The most

common causes in older children

Nephritic syndrome of hematuria and edema is synonymous with a glomerular etiology of ARF.

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Intrinsic Renal Failure *Localized intravascular coagulation

Acute dehydration HUS

The most common causes of ARF in toddlers

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Acute Tubular Necrosis

Tubular diseases: Acute tubular necrosis(Absence of arterial or glomerular lesions).

There are major histologic changes that take place in ATN:

(1) tubular necrosis with sloughing of the epithelial cells

(2) occlusion of the tubular lumina by casts and by cellular debris

(3)Back leak of filtrate

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Major Causes of Acute Tubular Necrosis

Renal Ischemia:

* Severe pre-renal disease from any cause. Exposure to Nephrotoxins: * Amphotericin B • Aminoglycosides * Heme Pigments * NSAID's

(hemoglobinuria/myoglobinura) • Require a period of dialysis before spontaneous resolution

occurs.

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Intrinsic Renal Failure Interstitial diseases * Acute interstitial nephritis, drug reactions * infiltrative disease (lymphoma) * infectious agents.

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Intrinsic ARF of Children

Hemolytic uremic syndrome (HUS) is the most common cause of ARF in children.

The disease is associated with a diarrheal prodrome caused by Escherichia coli

Children usually present with microangiopathic anemia, thrombocytopenia, colitis, mental status changes, and renal failure.

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Post-renal ARF

Obstructive uropathy

Uretropelvic junction

Uretrocele

Urethral valves

Tumors

Vesicouretral reflux

Acquired Stones

Blood clots

Symptoms of ARF

Decrease urine output (70%) Edema, esp. lower extremity Mental changes Heart failure Nausea, vomiting Pruritus Anemia Tachypenic Cool, pale, moist skin

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Diagnostic Evaluation:

Urinalysis shows proteinuria, hematuria, casts.

Serum creatinine and BUN levels are elevated; arterial blood gas levels, serum electrolytes may be abnormal.

Renal untrasonography rules out treatable obstructive uropathy.

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Laboratory Findings in the Differential

Diagnosis of Acute Renal Failure:

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FeNa

Calculation of fractional excretion of sodium (FeNa)

FeNa = (urine Na/plasma Na)/(urine creatinine/plasma creatinine)

FeNa <1 % = prerenal ARF FeNa >1% = ATN

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Therapeutic and Pharmacologic Interventions:

Surgical relief of obstruction .Correction and control of biochemical imbalances.Restoration and maintenance of blood pressure Low protein diet with supplemental amino acids

and vitamins.Initiation of dialysis, or continuous renal

replacement therapy for patients with progressive azotemia .

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Continuous Hemofiltration (HF)It is useful in patients with ARF.

Continuous AVHF Continuous VV HF

Blood is pumped By a pump

through fillter

by patient heart

ARF: Life Threatening Conditions

HyperkalemiaVolume overloadVascular access

Hyperkalemia Symptoms

WeaknessLethargyMuscle crampsParesthesiasDysrhythmias

Hyperkalemia & EKG K > 5.5 -6 Tall, peaked T’s Wide QRS Prolong PR Diminished P Prolonged QT

Hyperkalemia Treatment

KayexalateCalcium gluconate (carbonate)Sodium BicarbonateInsulin/glucoseLasix AlbuterolHemodialysis

Chronic Renal Failure

150–200 cases per million people = new cases each year

Chronic renal failure and ESRD affect more than 2 out of 1,000 people in the U.S

Mortality = 20%

Chronic Renal Failure Causes

Glomerular diseases 40% (after 5 yrs old)Anatomic abnormalities 20% (under 5 yrs

old)Hereditary renal diseases 15% (after 5 yrs

old)Pylonephritis with reflux nephropathy 15%Miscellaneous10%: Vascular, HUS, JDM,

wilms tumor.

CRF Symptoms

Growth failureWeaknessFatigueNeuropathyCHFAnorexiaNauseaVomiting

SeizureConstipationPeptic ulcerationDiverticulosisAnemiaPruritusJaundiceAbnormal hemostasis

Problems Related to ESRD

Metabolic – K/CaVolume overloadAnemia, platelet disorder, GI bleed PericarditisPeripheral neuropathy, dialysis dementiaAbnormal immune function

Dialysis

½ of patients with CRF eventually require dialysis

Diffuse harmful waste out of bodyControl BPKeep safe level of chemicals in body2 types

– Hemodialysis– Peritoneal dialysis

Hemodialysis

3-4 times a weekTakes 2-4 hours Machine filters

blood and

returns it to

body

Types of Access

Temporary site AV fistula

– Surgeon constructs by combining an artery and a vein– 3 to 6 months to mature

AV graft– Man-made tube inserted by a surgeon to connect artery

and vein– 2 to 6 weeks to mature

Temporary Catheter

AV Fistula & Graft

What This Means For You

No BP on same arm as fistulaProtect arm from injuryControl obvious hemorrhage

– Bleeding will be arterial– Maintain direct pressure

No IV on same arm as fistulaA thrill will be felt – this is normal

Access Problems

AV graft thrombosis AV fistula or graft bleedingAV graft infectionSteal Phenomenon

– Early post-op– Ischemic distally– Apply small amount of pressure to reverse

symptoms

Peritoneal Dialysis

Abdominal lining filters blood3 types

– Continuous ambulatory– Continuous cyclical– Intermittent

Dialysis Related Problems

Lightheaded –give fluidsHypotensionDysrhythmiasDisequilibration Syndrome

– At end of early sessions– Confusion, tremor, seizure– Due to decrease concentration of blood versus

brain leading to cerebral edema

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Thank you