TY  - CHAP
M1  - Book, Section
TI  - Diagnostics in Nephrology
A1  - Huppert, Laura A.
A1  - Dyster, Timothy G.
PY  - 2021
T2  - Huppert’s Notes: Pathophysiology and Clinical Pearls for Internal Medicine
AB  - Table  Graphic  Jump  LocationTABLE  6.2*Urinalysis  Tests  and  InterpretationView  Table||Download  (.pdf)TABLE  6.2Urinalysis  Tests  and  InterpretationTestPurposeClinical  SignificanceFalse  negative  results*False  positive  results*LeukocytesDetects  presence  of  pyuriaInfectionBladder  tumorSLEMedication  effectElevated  urine  glucose,  protein,  ketones,  specific  gravityCertain  oxidizing  antibiotics  (e.g.,  cephalexin,  nitrofurantoin)ContaminationNitriteDetects  evidence  of  bacteriuriaBacterial  infectionElevated  specific  gravity,  pH  <6.0,  vitamin  CContaminationUrobilinogenDetects  hepatic  damage  or  obstruction;  aids  in  differentiation  between  obstructive  and  hemolytic  jaundiceLow:  May  suggest  biliary  obstruction  (due  to  less  than  typical  amounts  of  conjugated  bilirubin  reaching  the  intestine  for  conversion  to  urobilinogen)High:  Hemolysis,  hepatobiliary  disease  Elevated  nitrite  levelsPhenazopyridineProteinDetects  glomerular  disease  or  damage.  Urine  dipstick  is  sensitive  for  albumin,  but  has  very  low  sensitivity  for  non-albumin  proteinuria  (e.g.,  tubular  protein,  immunoglobulins)Primary  or  secondary  renal  damageUrine  that  is  acidic  or  diluteDipstick  best  detects  albumin  so  may  miss  non-albumin  protein  (e.g.,  abnormal  antibodies  produced  by  plasma  cells  in  multiple  myeloma)Urine  that  is  alkaline  or  concentratedPhenazopyridinepHAssesses  renal  function  for  excretion  of  acids  and  ability  to  maintain  acid–base  balanceAcid-base  disturbancesRenal  tubular  acidosis  (RTA)  BloodDetects  presence  of  free  hemoglobin,  myoglobin,  or  RBCsHgb:  Extensive/rapid  intravascular  hemolysisMyoglobin:  Skeletal  muscle  trauma  (e.g.,  rhabdomyolysis,  seizure)RBC:  See  “hematuria  below”  or  “Trauma,  infection,  stone,  malignancy  or  GN”Elevated  specific  gravityCaptoprilVitamin  CMenstrual  bleedingIf  assessing  for  blood,  myoglobin  can  cause  a  false  positiveSpecific  gravityAssesses  renal  ability  to  concentrate/dilute  urineLow:  Diabetes  insipidus,  renal  disease,  increased  fluid  intake,  diuresisHigh:  Hypovolemia,  low  effective  circulating  volume  (heart  failure,  cirrhosis,  nephrotic  syndrome),  SIADH,  contrast  dyeAlkaline  urineIV  contrastKetoneAssesses  for  evidence  of  stressors  (which  cause  incomplete  fat  metabolism)FeverStarvationDiabetic  ketoacidosisDelay  in  urine  examinationElevated  specific  gravitySome  medications  (e.g.,  mesna,  levodopa,  phenolphthalein)BilirubinDetects  hepatic  damage  or  obstruction;  aids  in  differentiation  between  obstructive  and  hemolytic  jaundiceHepatobiliary  diseaseHyperthyroidismSepticemiaChlorpromazineSeleniumPhenazopyridineGlucoseDetects  evidence  of  hyperglycemia  (and  therefore,  often,  diabetes)Hyperglycemia  (usually  due  to  diabetes)Proximal  tubule  dysfunction  (Fanconi  syndrome)SGLT2  inhibitorsOf  note,  glucosuria  in  the  setting  of  normal  serum  glucose  may  indicate  Fanconi  syndrome.Elevated  specific  gravityUric  acidVitamin  CKetonesLevodopa*False  positive  results  are  caused  by  false  elevations  in  the  given  parameter.  False  negative  results  are  caused  by  a  false  depression  in  the  parameter.  
SN  - 
PB  - McGraw Hill
CY  - New York, NY
Y2  - 2024/04/20
UR  - accessmedicine.mhmedical.com/content.aspx?aid=1189913235
ER  -