Chapter 27 Intrarenal Disorders I Renal Function a Glomerular Function Tests i Creatinine Clearance Test the amount in Bowman s Capsule Collecting Duct the amount of Creatinine in urine 1 Measures glomerular function 2 Clearance plasma volume from which measured amount of substance can be completely eliminated into the urine per unit of time per minute 3 Clearance rate depends on a Substance plasma concentration b Excretory rate of substance ii Creatinine Clearance Rate i Influenced by GFR and renal plasma flow 1 Depends on renal excretion rate of metabolically produced creatinine 2 Creatinine is feely filtered at glomerulus and it is not reabsorbed by the tubules 3 Used to estimate GFR a 24 hours urine collection urinalysis is used for test b Blood sample is drawn during the urine collection period i 1mg dL plasma creatinine ii 1 mg dL means that kidneys are not filtering as much as they 4 Cr Clearance is mL min should be meaning kidney damage 1 73 A UV P x 5 Normal values 90 139 iii Creatinine Clearance Estimations C Cr males 1 140 Age years x Weight Kg 7 2 x serum creatinine mg L 2 C Cr Females C Cr males x 0 85 b Tubular Function Tests less Creatinine overall i Assesses concentrating and diluting ability of kidney 1 Urine Specific Gravity and Urine Osmolality ii Urinalysis a Females have average 15 lower muscle mass than males so they have 1 Macroscopic exam a Appearance b pH c Specific Gravity d Protein e Semiquantation f Glucose g Ketone presence h Dip Sticks do not give you an exact value just if it is low or high 2 Microscopic exam on centrifuged urinary sediment a Cells b Crystals formed by minerals calcium uric acid c Casts protein aggregates that outline the shape of renal tubule where they formed trapped cellular elements for RBC WBC 3 Normal Composition of Urine a Color light yellow to amber b pH Acidic should be 5 5 c Specific Gravity 1 003 1 030 d Red Cells 5 HPF meaning 5 cells per HPF High Power Field i UTI Trauma Glomerulopathy e White Cells 5 HPF f Protein Negative should be 30mg i 30 300mg microalbuminuria Proteinuria g Glucose Negative h Ketones Negative i Nitrates Negative j Casts None k Crystals None c Other Tests i Serum Urine electrolytes 1 Sodium 2 Chloride 3 Potassium ii Anion Gap iii Creatinine Urea and Uric Acid iv Calcium and Phosphorus v Proteins and Enzymes vi Hemoglobin and hematocrit 1 erythropoiesis II Kidney Disease a Diagnosis i Abnormal Urinalysis 1 Concentration of undetermined anions 2 Anion gap a Fine the difference of positive and negative ratio 3 High Anion gap renal failure to sulfate phosphate organic acid anion retention 1 Foundation for differential diagnosis of renal dysfunction 2 Dipstick and microscopic exam 3 Clues to intrarenal pathologies 4 Glycosuria 300 mg dL of glucose 5 Calcium stones 6 Hematuria blood in urine UTI trauma cancer of kidney bladder prostate 7 Chronic Kidney Disease damage to nephron 8 SIADH inserts too many aquaporins 9 Low pH uric acid stones 10 WBCs in Urine UTI a Leukocytes bacterial UTI ecoli 11 High pH bacteria Proteas Klebsiella 12 Yeast Fungus 13 Caoxalate More common urine becomes more acidic ii Other Diagnostic Tests 1 KUB a Kidney Ureter and Bladder X Ray Must drink fluids with contrast b Gross abnormalities related to size position and shape c Renal Calculi 2 Renogram Renal Scan a Renal Vasculature b Contrast injection in blood stream 3 Ultrasonogrpahy 4 CT MRI a Differentiates tissue characteristics pregnancies a Detailed information about vasculature and tissues b Clinical Manifestations i Costovertebral Angle Tenderness 1 Renal capsule damage inflammation 2 T10 L1 Spinal Nerves III Glomerulopathies a Glomular Disorders Blood flow not urinary tubules i After glomerular capillary structure and function b Clinical Manifestations cells proteins escape pore becomes enlarged due to inflammation capillaries thickening decreased blood flow to filter i Hematuria and proteinuria abnormal casts ii Decreased GFR 1 Decreased blood flow to filter iii Edema and hypertension 1 Decreased urine output retaining fluid and sodium 2 Pitting edema starts in the feet c Glomerulonephritis Decreased GFR i Immune response to triggers 1 Primary or secondary etiologies direct to the kidney ii Immune Cells attracted to Inflammation area caused by basement membrane degradation by lysosomes 1 Decreases due to mesangial cell Surrounds the glomerulus contraction causing iii GFR decreased filtration surface area iv Casts indicate glomerular inflammation 1 Leaky excess cells proteins v Acute GN Abrupt sudden and short lived 3 6 weeks 1 Acute Glomerular Inflammation 2 Diagnosis a High BUN and serum creatinine b Low GFR c Proteinuria Foamy urine looks like beer RBC casts d Oliguria decreased or absent urine production e Edema hypertension Due to retaining fluids f Accumulation of nitrogenous wastes Increased BUN and creatinine 3 Triggers of Acute Glomerulonephritis 4 Bacterial Infective Endocarditis a b Pneumococcal Pneumonia c Sepsis blood infections STDs 5 Viral a Hepatitis B b Hepatitis C c Mono 6 Parasitic a Malaria b Toxoplasmosis 7 Primary Disease a Berger Disease IgA nephropathy 8 Multisystem Disease a Systemic Lupus corticosteroids immunosuppressants vi Pathogenesis 1 Initiating trigger primary disease or secondary response 2 3 Leaky membrane decreased GFR diameter reduced 4 Azotemia nitrogenous waste products in the body 5 Buildup of Proteinuria excess protein vii Management 1 Steroids anti inflammatory immunosupressants allows rebuilding repair 2 Plasmapharesis separation of lg s from plasma 3 Supportive diet and fluids a Low Na Low K Low Protein b Restrict fluids without dehydration 4 Manage systemic and renal hypertension viii End Stage Disease ESRD 1 Common outcome of chronic GN 2 Management dialysis renal transplant d Nephrotic Syndrome i Characterized by increased glomerular membrane permeability ii Diagnosis 1 Massive proteinuria 3 3 5 g day 2 Edema hypoalbuminemia 3 Hyperlipidemia lipiduria treat with medicine 4 Hypercoagulability iii Treatment conservative symptomatic treat etiology diet and fluid restriction iv Many cases resolve spontaneously v Can progress to ESRD vi Excess clotting factor strokes clots thrombocies vii Generalised Edema anasarca viii Excess RBCs in urine Nephritic Syndrome not the same as nephrotic IV Tubular Disease a Defects in tubular function of all tubules b Results in i Decreased abnormal molecule secretion or reabsorption ii Impairment in urine concentration and dilution mechanisms c