Acute Renal Failure (ARF) Causes Clinical Features TREATMENT of ARF

Acute Renal Failure (ARF)

AcuteCor pulmonale Causes of Cor pulmonale Symptoms of COR PULMONALE and Treatment. Read more ... » renal failure due to intratubular crystal precipitation can be seen in a variety of clinicalPortal Hypertension Clinical Features Symptoms Diagnosis and Treatment. Read more ... » settings, the most common being acuteCor pulmonale Causes of Cor pulmonale Symptoms of COR PULMONALE and Treatment. Read more ... » uric acid nephropathy AcuteCor pulmonale Causes of Cor pulmonale Symptoms of COR PULMONALE and Treatment. Read more ... » renal failure (ARF) is defined as a sudden decrease of normal kidney function that compromises the normal renal regulation of fluid, electrolyte, and acid–base homeostasis.


ARF (AcuteCor pulmonale Causes of Cor pulmonale Symptoms of COR PULMONALE and Treatment. Read more ... » renal failure) is characterized by :

  • · Decrease in GFR (reversible).
  • · Retention of nitrogenous wastes.
  • · Disturbance of balance of fluid volume, electrolytes and acid-base.
  • Oliguria: Urine output <0.5 mL/kg/h in infants or <500 mL/1.73 m2/d in older children
  • Anuria: Total cessation of urinary output
  • Polyuria: Urine output >2 L/m2/d in infants and children or 3 L/d in adults
  • ·Oliguria – i.e. urine output <400 ml/day.
  • Pre-renal and post-renal failure may be reversible by prompt and appropriate treatment.
  • ARF is usually asymptomatic. It is diagnosed by a recent increase in blood urea and creatinine.


ARF may be of 3 types:

  • 1. Prerenal
  • 2. Renal
  • 3. Post renal.
  • Pre-renal
    • There is renal hypoperfusion. Renal pa­renchyma is normal.
  • Renal –
    • Renal parenchymal disease is present.
  • Post renal
    • There is urinary tract obstruction lead­ing to renal failure.
  • ARF is mostly reversible.

PRERENAL ARF

  • It is reversible by proper perfusion of kidneys so that glomerular ultrafiltration pressure becomes normal. Renal parenchymal tissue is normal.
  • If tissue hypoperfusion persists there is damage of renal parenchyma.
  • Due to hypoperfusion there is :
  • Activation of sympathetic nervous system.
  • Activation of renin angiotensin – aldosterone sys­tem .
  • Release of AVP / ADH (arginine vasopressin / antidiuretic hormone).
  • Norepinephrine, angiotensin II and AVP cause vasoconstriction in non-essential areas, inhibit salt loss through sweat glands, stimulate thirst, promote salt and water retention.
  • Prostaglandin E2and prostacyclin cause dilata­tion of afferent arterioles.
  • Angiotensin II causesCor pulmonale Causes of Cor pulmonale Symptoms of COR PULMONALE and Treatment. Read more ... » preferential constriction of efferent arterioles.
  • Thus glomerular filtration pressure is increased and glomerular filtration rate is increased.
  • All these processes help to counter the renal hypoperfusion.
  • GFR (Glomerular filtration rate) is maintained only if systemic pressure is above 80 mmHg.

Hepatorenal syndrome

  • In advanced cirrhosis and other liver diseases there is severe form of ARF, called hepatorenal syndrome.
  • Mortality is very high.

INTRINSIC RENAL ARF

  • This may be due to :
  • 1. Disease of larger renal vessels
  • 2. Disease of glomeruli
  • 3. Ischemic and nephrotoxic ARF
  • 4. Tubulointerstitial disease.

Common causesCor pulmonale Causes of Cor pulmonale Symptoms of COR PULMONALE and Treatment. Read more ... » of intrinsic ARF

Acute tubular necrosis

POST RENAL ARF

MAJOR CAUSESCor pulmonale Causes of Cor pulmonale Symptoms of COR PULMONALE and Treatment. Read more ... » OF ARF PRERENAL

Renal Causes of ARF

  • Renal artery obstruction by thrombus, embolism Renal vein thrombosis
  • Glomerulonephritis
  • Vasculitis
  • Thrombotic thrombocytopeniac purpura Toxaemia of pregnancy
  • DIC (Disseminated intravascular coagulation) SLE (Systemic lupus erythematosus) Scleroderma
  • AcuteCor pulmonale Causes of Cor pulmonale Symptoms of COR PULMONALE and Treatment. Read more ... » tubular necrosis (Ischemia or hypoperfusi6n)
  • Toxins
  • PPH (Post Partum Haemorrhage) Abruptio placentae
  • Drugs  Cyclosporin
  •  Antibiotics
  • NSAIDs
  • Radiocontrast dye
  • Interstitial nephritis Infections.
  • Calculi Cancer
  • Clot
  •  Stricture Bladder neck obstruction
  • Urethral obstruction.


Pathophysiology

FEATURES TO DIFFERENTIATE ACUTE AND CHRONIC RENAL FAILURE ARF

  • Recent increase in urea and creatinine.
  • There is history suggestive of the cause of ARF like diarrhoea, vomiting, burns etc.
  • CRF
  • Anaemia Neuropathy
  • Rena I osteodystrophy Small, scarred kidneys
  • Kidney size may be increased or normal in CRF due to :
  • Diabetic nephropathy Amyloidosis
  • Polycystic kidney disease
  • Usually the kidney size is reduced in CRF .

Clinical features of ARF

 Interstitial nephritis suggested by

  • Fever,
  • arthralgias,
  • pruritic (that itch) red rash.

Urinary obstruction suggested by

  • Colicky pain
  • Suprapubic and flank pain
  • oFlank pain – loin tropain.

Prostate enlargement suggested by

  • Nocturia
  • Frequency
  • Hesitancy.

URINE

  • Oliguria or Anuria.

Prerenal ARF

  • · Urine is acellular
  • · Inactive sediments or hyaline casts present.

Post renal ARF

  • · Inactive sediment
  • · Hematuria
  • · Pyuria.

AcuteCor pulmonale Causes of Cor pulmonale Symptoms of COR PULMONALE and Treatment. Read more ... » tubular necrosis (ATN) i.e. Ischemic ARF, Nephrotoxic ARF

  • · Pigmented, muddy brown granular casts with tubule epithelial cells in urine.
  • · Mild proteinuria « 19/day

Glomerular involvement

  • Tubulointerstitial disease – RBC casts in urine.

Interstitial nephritis

  • · WBC casts in urine.
  • · Nonpigmented granular casts in urine.

Chronic renal disease

Proteinuria >1g/day suggests gIomerular disease. Heavy proteinuria> 1 g/day also seen in patients on NSAIDs, ampicillin, rifampicin, interferon alpha. Bilirubin in urine in hepatorenal syndrome. Fractional excretion of sodium

  • FE Na < 1 % in prerenal ARF
  • FE Na > 1 % in ischemic, nephrotoxic (tubular disease).

BLOOD

  • Serum creatinine: increases progressively in renal failure and is a very good indicator of renal failure.
  • Hyperkalemia
  • Hyperphosphatemia
  • Hypocalcemia
  • Hyperuricemia
  • Anaemia

ULTRASOUND

CT, MRI PLAIN X-RAY ABDOMEN

  • For nephrolithiasis.

PYELOGRAPHY

retrograde, antegrade

  • for lo­calization of site of obstruction.
  • For patency of renal arteries and veins.

MR ANGIOGRAPHY

  • Non-invasive renal vascular study. CONTRAST ANGIOGRAPHY

RENAL BIOPSY

COMPLICATIONS

  • There is impairment of renal excretion of sodiurtl, potassium and water.
  • · Volume overload
  • · Raised JVP
  • · Hyponatrem ia
  • · Hyperkalemia
  • · Hyperphosphatemia
  • · Hypocakemia
  • · Hypermagnesemia
  • · Metabolic acidosis
  • · Uremia
  • · Weight gain
  • · Basal lung rales
  • · Dependent edema
  • · Pulmonary edema
  • · Cerebral edema
  • · Seizures
  • · Arrhythmias
  • · Metabolic acidosis
  • · Lactic acidosis
  • · Hemolysis
  • · Leucocytosis
  • · GI bleeding and bleeding from other sites
  • · Infections
  • MI
  • Pericarditis Pericat”dial effusion Pulmonary embolism Uremic syndrome.

CausesCor pulmonale Causes of Cor pulmonale Symptoms of COR PULMONALE and Treatment. Read more ... » of Hypocalcemia in ARF

  • Metastatic deposition of calcium phosphate when the serum calcium X phosphate in mgjdl is > 70.
  • Tissue resistance to parathyroid hormone. Decreased 1,25 dihydroxyvitamin D.

Effects of hypocalcemia

  • Muscle cramps Seizures Hallucinations Confusion
  • Prolonged QT.

TREATMENT OF ARF

  • Prevention of pre-renal and post-renal causesCor pulmonale Causes of Cor pulmonale Symptoms of COR PULMONALE and Treatment. Read more ... » Avoid drugs causing ARF
  • Low drug dosage of nephrotoxic drugs Maintain fluid balance
  • Maintain sodium, potassium, phosphate, calcium levels
  • Invasive and noninvasive hemodynamic moni­toring
  • Low dose dopamine
  • Loop diureticsHydrochlorothiazide. Read more ... » (frusemide, torsemide) Antihyperte~sives like CCB (Calcium channel blockers) and Alpha-blockers
  • Atrial natriuretic peptide
  • Prostaglandins
  • Antioxidants Glucocorticoids Alkylating agents Plasmapharesis
  • Relief of obstruction of urinary tract
  • Oral or IV sodium bicarbonate if arterial pH <7.2 or serum bicarbonate < 15 meq/L
  • Restriction of dietary phosphate
  • Oral aluminum hydroxide
  • Calcium carbonate
  • Vitamin D
  • Restriction of dietary protein 0.6 g/kg/day Carbohydrate 100 g/day
  • Blood transfusion if required
  • Rarely erythropoietin for anemia
  • Antacids
  • PPI (proton pump inhibitor) and H2blockers Anti biotics
  • Dialysis – if hemodynamically unstable peritoneal dialysis is done
  • Hemodialysis – in uremic syndrome, refractory hyperkalemia, acidosis
  • Continuous renal replacement therapy (CRRT) Continuous arteriovenous hemodiafiltration (CAVHD)
  • Continuous venovenous hemodiafiltration (CVVHD).