Acute Kidney Injury/Urinary Tract Disorders Flashcards
Acute Kidney Injury (AKI)
Characterized by
1) Elevated serum creatinine (up to 1.5x)
2) Decrease in urine ouput
Reversible but mortality is high
CRRT may be required (Continuous renal replacement therapy with one-to-one with a nurse)
Risk for developing AKI
1) Infections
- Sepsis most common cause of AKI (hypotension and antibiotics)
- Widespread vasodilation decreases perfusion
- Antibiotics can be nephrotoxic
2) Hypotension from shock, surgery, HF (less blood flow to the kidneys)
3) Patients exposed to nephrotoxins (medication,radiocontrast)
Pre-renal AKI
Decrease in filtration and perfuison from low blood pressure or flow
Examples
1) Hypovolemia - loss of blood volume from accident, surgery, dehydration, excessive vomiting
2) Altered peripheral resistance (blood vessel smooth muscle lost) = occurs in sepsis, anaphylactic shock, BP meds that relax smooth muscles
3) Cardiac disorders = decreased CO such as heart attack, dysrhythmias
Complication = Intrarenal
Intrarenal AKI
Direct damage to renal tissue, eg. in ATN (acute tubulat necrosis)
Examples
1) Prolonged renal ischemia (prerenal)
2) Nephrotoxic drugs - antibiotics, NSAIDs, radiocontrast
3) Organix solvents like ethylene glycol
4) Acute hemolysis/Rhabdomyolysis
- Release heme that filter through glomerulus and cause less blood to be filtered
Hemolysis can occur from hemolytic transfusion reaction (wrong transfused blood)
Rhabdomyolysis can occur when elder falls and no one finds them for days
5) Acute glomerulonephritis
Postrenal AKI
Mechanical obstruction or urinary outflow
Examples
1) Stones/tumors
2) Enlarged prostate
3) Urethral scarring and infections like STI (narrows urinary tract)
Can cause intrarenal in complication
Mechanisms of AKI
1) Prerenal -
Low perfusion, GFR decreases, PCT/DCT increase retention to raise BP, Aldosterone and ADH released = oliguria/azotemia
2) Intra-renal
Necrosis/apoptosis, inflammation/swelling, epithelial cells die and obstruct filtrate which causes high pressure can form casts that will be excrete in urine, tubular backleck, decreased GFR = Oliguria
3) Post renal
Get rid of obstruction
Clinical course of intrarenal
1) Initiation
- Precipitious event (increased serum creatinine/BUN + oliguria)
- What cause the inury
2) Maintenance
- Drop in GFR
- Urine can be anuria, oliguria or non-oliguria (which is normal urine but unconcentrated) for around 2 weeks
- Fluid retention and metabolic acidosis
- Electrolyte imbalance like CKD - Low sodium/calcium, high phosphate/potassium
- Anemia from erythropioein
- Waste product accumulation
3) Recovery
- Can have diuresis for 1-3 weeks (not concentrated) but risk of hypovolemia, hypotension, low electrolyte, dehydration
Glomerulonephritis
Immune-mediated inflammation of urinary tract that can result in proteinuria, oligura, hematuria
- Effects BOTH KIDNEYS
- Causes - drugs, infection, immune disorder
Types of glomerulonephritis
1) Acute glomerulonephritis - AKI, acute frop in filtration, the oliguria, then recovery (if not advances)
2) Rapidly progressive lomerulonephritis - Kidney failure in weeks to months
3) Chronic glomerulonephritis - Seems like it resolves but damages kidneys slowly until renal failure
4) Nephrotic syndrome
Acute post-streptococcal glomerulonephritis
Immune attack on strep infection causes antigen-antibody complexes that damage the glomerulus
Nephritis appears in 5-21 days after infection
WBC rush to area and inflame (less space for blood to filter)
Some capillaries may rupture causing hematruai
Often in children
Symptoms
Smoky urine (cococola/tea), oliduria, edema especially in periorbial, HTN, Urinalysis show RBC, WBC, protein and erythrocasts in them
Urinary tract infection
Causes can be from urinary statis (as flushing is a defence mechanism to drop the bacterias)
Often form E.coli
Risk factors
i) Females - shorter urethra
ii) Urinary statis - incontinence, obstruction of urine like in BPH, STI causing scar tissue, congenital, impaired blood to bladder, renal calculi, SCI or other nerve damage causing immobility
Cystitis
Lower urinary tract infection
Dysuria - burning while urinating
Frequency - less area for urine to accumulate due to inflammation
Urgency
Suprapubic discomfort
Cloudy/white urine = pus pyuria
= LUTS (Lower urinary tract symptoms)
Pyelonephritis
Upper urinary tract infection (kidneys)
LUTS + Systemic symptoms of infection
Fever, chills, malaise, vomiting, tenderness
Urinylasis will show microscopic hematuria, leukocyte casts
Can become SKD
Renal calculi
Kidney salts when mineral salts become concentrated
Commonly calcium but can also be strubite, uric acid or cystine
Hydronephrosis = kidney becomes edematous because of backup of fluid
Manifestations
Abdominal/flank pain
If in pelvis = pain in the CVA
If in ureters = renal colic pain when stone is being pushed down
Hematuria
Fever/chills/N/V
Polycystic kidney disease
Common genetic disease
Cortex and medulla fill with ccysst that enlarge and destroy surrounding tissues by compression
- Occurs in both kidney
- May experience UTI or HTN
- May require transplant
Symptoms
Abdominal flank pain - enlarged kidneys
Hematuria - Cysts rupture
UTI and HTN
Can leadk to CKD
