Renal Physical Diagnostic Skills - Prunuske Flashcards
(28 cards)
How do you assess a patient’s hydration status using urine specific gravity?
- Specific gravity correlates with urine osmolality
- gives important insight into the patient’s hydration status
- Normal = 1.003 to 1.030
- Relative hydration: <1.010
- Relative dehydration: >1.020
- gives important insight into the patient’s hydration status
What are the causes of false positive urinalysis results for Bilirubin?
- Bilirubin → Phenazopyridine (Pyridium)
What are the causes of false positive urinalysis results for blood?
- Blood → Dehydration, exercise, hemoglobinuria, menstrual bleeding, myoglobinuria, beets
What are the causes of false positives for glucose in urinalysis results?
- Glucose → Ketones, Levadopa
What are the causes of false positive Ketones on urinalysis?
- Ketones → Acidic urine, elevated specific gravity, mesna, phenolphthalein
What are the causes of false positive Leukocyte esterase on urinalysis?
- Leukocyte esterase → contamination
What are the causes of false positive Nitrites on urinalysis?
- Nitrites → contamination, exposure of dipstick to air, phenazopyridine
What are the causes of false positive Protein on urinalysis?
- Protein → alkaline/concentrated urine, phenazopyridine, quaternary ammonia products
What are the causes of false positive elevation Specific gravity on urinalysis?
- Specific gravity → dextran solutions, IV radiopaque dyes, proteinuria
What are the causes of false positive Urobilinogen on urinalysis?
- Urobilinogen → elevated nitrite levels, phenazopyridine
What are the causes of false negative Bilirubin on urinalysis?
- Chlorpromazine (Thorazine)
- selenium
What are the causes of false negative Blood on urinalysis?
- Captopril (Capoten)
- elevated specific gravity
- pH < 5.1
- proteinuria
- vitamin C
What are the causes of false negative Glucose on urinalysis?
- Elevated specific gravity
- uric acid
- vitamin C
What are the causes of false negative Ketones on urinalysis?
Delay in examination of urine
What are the cause of false negative Leukocyte esterase on urinalysis?
- Elevated specific gravity
- glycosuria
- ketonuria
- proteinuria
- some oxidizing drugs:
- cephalexin [Keflex]
- nitrofurantoin [Furadantin]
- tetracycline
- gentamicin
- vitamin C
What are the cause of false negative Nitrites on urinalysis?
- Elevated specific gravity
- elevated urobilinogen levels
- nitrate reductase-negative bacteria
- pH < 6.0
- vitamin C
What are the causes of false negative Protein on urinalysis?
- Acidic or dilute urine
- primary protein is not albumin
What are the causes of false negative depression of Specific gravity on urinalysis?
Alkaline urine
What is the impact of sensitivity and specificity of urinalysis in the diagnosis of proteinuria?
- Results: ≥ 3+ protein
- Sensitivity: 96%
- Specificity: 87%
What is the impact of sensitivity and specificity of urinalysis in the diagnosis of hematuria?
- Microscopic hemature results: ≥ 1+ blood
- Sensitivity: 91 to 100%
- Specificity: 65 to 99%
What is the impact of sensitivity and specificity of urinalysis in the diagnosis of UTI?
- Sensitivity: 94 to 100%
- Specificity: 14 to 26%
What are 3 common causes of hematuria?
- Definition: presence of 3+ red blood cells (RBCs) per high-powered field (HPF) in two of three urine samples
- Causes:
- tumors
- renal calculi
- infections
What are 3 common causes of proteinuria?
- Definition: urinary protein excretion of more than 150 mg per day (10 to 20 mg per dL)
- Causes:
- Diabetes mellitus
- exercise (transient)
- Minimal change disease
What is normal urine pH on urinalysis?
Urinary pH can range from 4.5 to 8 but normally is slightly acidic (i.e., 5.5 to 6.5) because of metabolic activity.
