Lecture 10: Examining the urine Flashcards
(21 cards)
When the urine is red what may be causing it to go this colour?
Blood
pathological or menstrual
When the urine is purple what may be causing it to go this colour?
Infection
When the urine is brown what may be causing it to go this colour?
Myoglobulin
When the urine is bubbly what may be causing it to go this way?
Proteins present
What is measured by the semiquantitative urinalysis
i. e. dipstick test
* Protein/Albumin
* Haem (‘blood’)
* pH
* Ketones
* Glucose
* Bilirubin
* Leucocyte
* Nitrites
What does the term visible haematuria
blood can be seen with naked eye in the urine
What does the term non-visible haematuria
dipstick haematuria but blood can only be seen with a microscope
If blood is present, where can the blood be coming from?
Anywhere in the urinary tract
From the glomerulus in the kidneys downwards
If proteins are present in the urine (proteinuria) implies there is a problem where?
Present of proteins implies that there is a problem with the glomerular.
Explain how proteinuria is quantified
Ratio between protein:creatinine in the urine
What biochemistry levels would indicate the kidneys are not working properly
Low eGFR - <60ml/min
Rise in serum creatinine within the eGFR>60mL/min range
Define the term kidney injury/disease
Defined by reduced eGFR and detection and quantification of urine protein +/- blood
What are the two main categories of kidney disease
Acute kidney injury (AKI)
Chronic kidney disease (CKD)
What are the causes of kidney disease?
- Ineffective blood supply (reduced effective plasma volume or narrowed renal arteries)
- Glomerular diseases
- Tubulo-interstitial diseases
- Obstructive uropathy
What does aldosterone do in the nephrons
- Acts on the nuclear mineralocorticoid receptors (MR) within the principal cells of the distal tubule and the collecting duct of the kidney nephron.
- It upregulates and activates the basolateral Na+/K+ pumps, which pumps three sodium ions out of the cell, into the interstitial fluid and two potassium ions into the cell from the interstitial fluid. This creates a concentration gradient which results in reabsorption of sodium (Na+) ions and water (which follows sodium) into the blood, and secreting potassium (K+) ions into the urine (lumen of collecting duct).
Define oliguria
Low urine output
Oliguria is defined as a urine output that is less than 400 mL or 500 mL per 24h in adults - this equals 17 or 21 mL/hour.
What can cause oliguria?
Dehydration. Dehydration is the most common cause of decreased urine output.
Infection or trauma.
Urinary tract obstruction. A urinary tract obstruction or blockage.
Medications e.g. NSAIDs
How does dialysis work?
Blood is pumped into a machine.
The machine contains a semipermeable membrane with diaylsis fluid on the other side. The dialysis fluid is very salty.
Small solutes will moves down the concentration gradient into the dialysis solution e.g. potassium
The blood is pumped back into the patient with the unwanted material removed.
Patients with chronic kidney disease are at risk of what?
- Patients with chronic kidney disease (CKD) are at risk of progressive deterioration in kidney function (and eventually the need for kidney replacement therapy).
- Patients with CKD are at risk of cardiovascular disease
Describe chronic kidney disease
- Defined as the presence of kidney damage or decreased kidney function that persists for at least 3 months.
- CKD is often associated with progressive and irreversible loss of large numbers of functioning nephrons.
- Serious clinical symptoms usually do not occur until the number of functional nephrons falls to at least 70 to 75 percent below normal.
Describe the pathogenesis of chronic kidney disease
An initial insult to the kidney leads to progressive deterioration of kidney function and further loss of nephrons
A slowly progressing vicious cycle that eventually terminates in end stage renal disease
