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

Acute Renal Failure (ARF)

AcuteRabies Hydrophobia Clinical Findings Diagnosis Signs and symptoms with treatment. Read more ... » renalDiabetic Nephropathy and Renal complications of DM (Diabetes Mellitus). Read more ... » failure due to intratubular crystal precipitation can be seen in a variety of clinicalRabies Hydrophobia Clinical Findings Diagnosis Signs and symptoms with treatment. Read more ... » settings, the most common being acute uric acid nephropathyDiabetic Nephropathy and Renal complications of DM (Diabetes Mellitus). Read more ... »

Acute renal failure (ARF) is defined as a sudden decrease of normal kidneyDiabetic Nephropathy and Renal complications of DM (Diabetes Mellitus). Read more ... » function that compromises the normal renal regulation of fluid, electrolyte, and acid–base homeostasis.

ARF (Acute 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 diseaseRabies Hydrophobia Clinical Findings Diagnosis Signs and symptoms with treatment. Read more ... » 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 pressureChronic Long-term Complications Of Diabetes Mellitus. Read more ... » 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 systemRabies Hydrophobia Clinical Findings Diagnosis Signs and symptoms with treatment. Read more ... ».
• Activation of renin angiotensin – aldosteroneAldosteronism Clinical features Causes and Treatment. Read more ... » sys­tem .
• Release of AVPSIADH or Syndrome of inappropriate ADH (AVP). Read more ... » / ADH (arginine vasopressin / antidiuretic hormoneAnterior Pituitary Hormones and Disorders. Read more ... »).
• 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 causes 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 syndromeMetabolic,Insulin Resistance Syndrome X Causes Symptoms. Read more ... ».
• 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 causes of intrinsic ARF

• · Ischemia (Acute tubular necrosis)
• · Nephrotoxins.

Acute tubular necrosis

• Acute tubular necrosis or Ischemic ARF occurs in trauma, haemorrhage, sepsisSepsis (Septic Shock) Definition Diagnosis and Pathophysiology. Read more ... », volume depletion. It can occur on preexisting renal disease.

POST RENAL ARF

• Post renal ARF is usually due to obstructive causes and are fully reversible with surgical treatment .

MAJOR CAUSES OF ARF PRERENAL

• Haemorrhage
• Burns
• Dehydration
• VomitingNausea and Vomiting. Read more ... » and diarrhea
• Diabetes mellitusDiabetes mellitus Types,Causes,Symptoms and Diagnosis. Read more ... » (osmotic diuresis)
•  Pancreatitis Peritonitis
•  Hypoalbuminemia
• Low cardiacPRESENTATIONS OF ischemic heart disease(IHD). Read more ... » output Pulmonary hypertensionThyroid Disorders Examination and Laboratory tests. Read more ... » Sepsis
• Anti hypertensives
• Norepinephrine Epinephrine
• Cirrhosis and ascites (Hepatorenal)
•  ACE inhibitorsHeart Failure Treatment Heart Failure GENERAL PRINCIPLES. Read more ... »
• Multiple meyloma.

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
• Acute tubular necrosis (Ischemia or hypoperfusi6n)
• Toxins
• PPH (Post Partum Haemorrhage) Abruptio placentae
• Drugs  Cyclosporin
•  Antibiotics
• NSAIDs
• Radiocontrast dye
• Interstitial nephritis Infections.
• Calculi CancerUses of Ayurveda for Improvement in Cancer Patients Treatment. Read more ... »
• Clot
•  Stricture Bladder neck obstruction
• Urethral obstruction.

Pathophysiology

• ARF is commonly precipitated by an ischemic or nephrotoxic event.
• Initial vasodilatation is followed by intense vasoconstriction, with blood redistributed from the cortex to the juxtamedullary nephrons
• Intratubular debris and cast formation develop.
• Tubular fluid leaks backward across the injured tubular membrane, which, in addition to tubular obstruction, causes further hemodynamic changes.

FEATURES TO DIFFERENTIATE ACUTE AND CHRONICChronic Hepatitis Classification viral hepatitis Clinical features and Treatment. Read more ... » RENAL FAILURE ARF

• Recent increase in urea and creatinine.
• There is history suggestive of the cause of ARF like diarrhoeaInfections CHOLERA Caused by Vibrio cholerae with diagnosis Treatment Signs and symptoms. Read more ... », 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 AmyloidosisAmyloidosis Symptoms Diagnosis Prognosis and Treatment. Read more ... »
• Polycystic kidney diseaseTubular Diseases of the Kidney Types Clinical Features Diagnosis with Treatment. Read more ... »
• Usually the kidney size is reduced in CRF .

Clinical features of ARF

• Thirst
• Orthostatic hypotensionHyperglycemic Hyperosmolar State (HHS) Acute Complication Of DM. Read more ... »
• Systemic hypotension (BP <90 mmHg) -v TachycardiaHyperglycemic Hyperosmolar State (HHS) Acute Complication Of DM. Read more ... » (Pulse rate >100 Imin)
• Tachypnoea
• Raised JVPExamination of arterial pressure pulse with Jugular Venous Pulse (JVP). Read more ... »
• Dry skin and mucous membrane
• Reduced sweating
• History of NSAIDs, ACE-I (ACE inhibitors), ARBs
• (Angiotensin receptor blockersHeart Failure Treatment Heart Failure GENERAL PRINCIPLES. Read more ... ») v Decreased urine output
• Decreased body weig ht
• Hypovolemia
•  Sepsis
•  Hlo Radiocontrast dye
• Flank painChronic pancreatitis Causes Symptoms Diagnosis and Treatment. Read more ... »
• Atheroembolization suggested by Sic nodules, ischemia of fingers, toes
• Glomerulonephritis suggested by oliguria, edema, hypertension, active urine sediment.

 Interstitial nephritis suggested by

• FeverThyrotoxic crisis or Thyroid storm. Read more ... »,
• 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
• · HematuriaDIAGNOSIS and Investigations OF SECONDARY HYPERTENSION. Read more ... »
• · Pyuria.

Acute 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

• Broad granufar casts in urine.
• Eosinophils -in urine – allergic interstitial nephritis. Uric a~id crystal~ in – acute urate nephropathy.

Proteinuria >1g/day suggests gIomerular disease.

Heavy proteinuria> 1 g/day also seen in patients on NSAIDs, ampicillin, rifampicinTuberculosis Treatment Complete DRUGS - ATT (ANTITUBERCULAR TREATMENT)with MDR. Read more ... », 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

• Ultrasonography is useful for post renal ARF to diag­nose causes like – urinary tract obstruction, pelvicalyceal dilatation, retroperitoneal fibrosis, neo­plasia.

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 ANGIOGRAPHYCoronary Angiography -Indications of Coronary Arteriography (Angiography). Read more ... »

RENAL BIOPSY -

• For definitive diagnosisRabies Hydrophobia Clinical Findings Diagnosis Signs and symptoms with treatment. Read more ... ».
• For intrinsic renal ARF e.g. glomerulonephritis, vas­culitis, thrombocytopenic purpura, interstitial nephri­tis.

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 edemaPulmonary Edema Causes Diagnosis with Treatment. Read more ... »
• · Cerebral edema
• · Seizures
• · ArrhythmiasCOMPLICATIONS OF Acute Myocardial Infarction (AMI) AND TREATMENT -2. Read more ... »
• · Metabolic acidosis
• · Lactic acidosis
• · Hemolysis
• · Leucocytosis
• · GI bleeding and bleeding from other sites
• · Infections
• MI
• PericarditisCOMPLICATIONS OF Acute Myocardial Infarction (AMI) AND TREATMENT -2. Read more ... » Pericat”dial effusion Pulmonary embolism Uremic syndrome.

Causes 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 causes Avoid drugs causing ARF
• Low drugRabies Hydrophobia Clinical Findings Diagnosis Signs and symptoms with treatment. Read more ... » dosage of nephrotoxic drugs Maintain fluid balance
• Maintain sodiumRenin and Hypertension Low renin and High Renin essential hypertension with Treatment. Read more ... », potassium, phosphate, calcium levels
• Invasive and noninvasive hemodynamic moni­toring
• Low dose dopamine
• Loop diuretics (frusemide, torsemide) Antihyperte~sives like CCB (Calcium channel blockers) and Alpha-blockers
• Atrial natriuretic peptide
• Prostaglandins
• Antioxidants GlucocorticoidsAdrenal Gland Steroids. Read more ... » 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 dialysisDialysis Indications Complications and Dialysis for Renal Failure. Read more ... » is done
• HemodialysisDialysis Indications Complications and Dialysis for Renal Failure. Read more ... » – in uremic syndrome, refractory hyperkalemia, acidosis
• Continuous renal replacement therapy (CRRT) Continuous arteriovenous hemodiafiltration (CAVHD)
• Continuous venovenous hemodiafiltration (CVVHD).