What is the difference between urine osmolarity and urine specific gravity?
Thank you for your help.
Answer:
they are duplicate thing
Hello Nygirl,
I am no expert within this area.
However, I am competent to assess some online medical textbooks
that our library subscribes to...
Here is what I found...
Urine specific gravity reflect the hydration status of the patient and the concentrating qualifications of the kidney. With diminished renal function, the ability of the kidneys to concentrate urine lessen progressively until the specific gravity of urine reaches 1.006–1.010. However, the competency to dilute urine tends to be maintain until renal damage is extreme. Even within uremia, although the concentrating power of the kidneys is limited to a specific gravity of 1.010, dilution power surrounded by the specific gravity range of 1.002–1.004 may still be found. Determination of urine osmolality is undoubtedly a more shrewd measurement of renal function, but determination of specific gravity lend itself to office diagnosis. (From: Schwart's surgery and Lange Urology)
Urine osmolality is a Test which measures renal tubular concentrating talent.
In the hypoosmolar state (serum osmolality <280 mOsm/kg), urine osmolality is used to determine whether water excretion is run of the mill or impaired. A urine osmolality pro of <100 mOsm/kg indicates complete and appropriate suppression of antidiuretic hormone secretion. With average fluid intake, normal disorganized urine osmolality is 100–900 mosm/kg H2O. After 12-hour fluid restriction, normal chaotic urine osmolality is >850 mosm/kg H2O.
(From Diagnostic Tests (McGraw-Hill) )
[Because the density of water is 1 kg/L, the osmolarity (in osmol/L) is roughly equivalent to the osmolality (in osmol/kg) contained by water-based systems with set temperature vacillation, such as the human body; thus, the terms are frequently interchanged surrounded by medical texts. (From: Tintinalli's Emergency Medicine )
Acute Renal Failure
Typical Urinalyis UNa <10 mmol/L SG >1.018
Intrinsic Renal ARF UNa >20 mmol/L SG<1.015
(UNa ->Urine Sodium Concentration; SG-->Specific Gravity)
(Above taken from a table which down 11 causes, individual 2[exogenous toxins and ischemia) listed these urinalysis tests/indicators as factor of the DDx)
(From: Harrison's Internal Medicine > Part 11. Disorders of the Kidney and Urinary Tract > Chapter 260. Acute Renal Failure[ARF] > Clinical Features and Differential Diagnosis > Clinical Assessment >Table 260–2. Useful Clinical Features, Urinary Findings, and Confirmatory Tests in the Differential Diagnosis of Major Causes of ARF)
Chronic Renal Failure
Harrison's Internal Medicine > Part 11. Disorders of the Kidney and Urinary Tract >
Chapter 261. Chronic Renal Failure> Clinical and Laboratory Manifestations of Chronic Renal Failure and Uremia
No table listing lab question paper indicators in this chapter.
However, these excerpt may be adjectives:
"In most patients with stable CRD, the total body contents of Na+ and H2O are increased modestly, although this may not be clinically adjectives. The underlying etiologic disease process may itself disrupt glomerulotubular balance and promote Na+ retention (e.g., glomerulonephitis), or excessive Na+ ingestion may front to cumulative positive Na+ balance and attendant extracellular fluid volume (ECFV) expansion. Such ECFV expansion contributes to hypertension, which surrounded by turn accelerates further the progression of nephron injury."
(In my humble inference, this seems that Chronic Renal Failure recurrently is accompanied
by an increased urine osmolarity)
This also may be supportive:
"Patients with CRD also own impaired renal mechanism for conserving Na+ and H2O (Chap. When an extrarenal cause for fluid loss is present (e.g., vomiting, diarrhea, sweating, fever), these patients are prone to volume depletion. Depletion of ECFV may compromise residual renal function near resulting signs and symptoms of overt uremia. Because of impaired renal Na+ and H2O conservation, the usual indices of prerenal azotemia (oliguria, big urine osmolality, low urinary Na+ concentration, and low fractional excretion of Na+) are not useful. Cautious volume repletion, usually near normal saline, returns ECFV to ordinary and usually restores renal function to prior levels."
Hoping this help some, and that others will jump within to better
clarify!
In the meantime, I am hoping this helps some.
Email me (through god to the left) if you think I could help out out more.
Wishing you the best,
Janice