Renal Flashcards
(32 cards)
Roles of the kidneys:
- Maintaining homeostasis
- Excretion
- Acid-base balance (reabsorbing H+/HCO3-
- Water balance
- Electrolyte balance
- Removing toxins and waste (urea, creatinine, uric acid, bilirubin)
- Controlling BP
- Hormone secretion (eg. Renin)
What waste product is used as an indicator of GFR and why?
Creatinine as it is not reabsorbed or secreted during filtration
Hormones that increase water reabsorption:
- Aldosterone: acts on distal tubule to increase H2O absorption
- Vasopressin (ADH): released from posterior pituitary and acts on collecting ducts to increase H2O absorption
UTI risk factors (for females)
- short, straight urethra
- pregnancy
- use of diaphragm and spermicidal compounds for birth control
- proximity of urinary meatus to vagina and anus
- sexual intercourse
Urinary risk factors (for males)
- prostatic hypertrophy
- uncircumcised
- anal intercourse
UTI risk factors (general)
- ageing
- catheterisation
- genetic factors
- urinary tract obstruction
- Neurogenic bladder dysfunction
- vesicoureteral reflux
Cystitis
Inflammation of the bladder (most common)
Pyelonephritis
Inflammation of renal pelvis and parenchyma (ascending to the kidneys)
Common bacterial agents causing UTI
- E. Coli (most common)
- proteus mirabilis
- enterbacter
- klebsiella spp.
- enterococcus spp.
- pseudomonas aeruginosa
Clinical manifestations of UTI
- frequency/urgency
- dysuria
- cloudy/smelly
- unilateral flank pain or groin pain
- fever/chills
Diagnosis of renal calculi (kidney stones)
UA
cystoscopy
Renal stone analysis
X-ray
Serum: calcium, oxalate, uric acid
Kidney stones risk factors:
- infection
- genetic predisposition
- urinary stasis
- immobility
- hypercalcaemia
- increased uric acid
- increased urinary oxalate level
UTI treatment
- antibiotics
- agents that sterilise the urinary tract
- drugs:
- block spasms of the urinary tract muscles
- decrease urinary tract pain
- protect the cells of the bladder from irritation
- treat enlargement of the prostate gland in men
Prerenal causes of acute kidney injury:
- hypovolaemia (dehydration, haemorrhage, excessive diuretics)
- decreased CO (arrhythmias, HF, MI)
- decreased PVR (anaphylaxis, neurological injury, septic shock)
- decreased renovascular blood flow (renal vein/artery thrombosis, embolism)
Intrarenal causes of acute kidney injury:
- nephrotoxic injury (medications, contrast media, crush injury, chemical exposure, haemolytic blood transfusion reaction)
- interstitial nephritis (allergies, infections)
- thrombotic disorders
- malignant hypertension
- SLE
- prolonged prerenal ischarmoa
Post-renal causes of acute kidney injury
- benign prostatic hyperplasia
- bladder cancer
- calculi formation
- prostate cancer
- spinal cord disease
- strictures
- trauma (back, pelvis, perineum)
Functional and structural characteristics of acute renal failure
Functional:
- decreased GFR
- decreased urine output
- increased nitrogenous waste in blood (urea and creatinine)
Structural:
- cell death (apoptosis and necrosis)
- loss of adhesion in intrinsic renal cells (obstruction)
Dialysis
- movement of fluid and molecules across semipermeable membrane from one compartment to another
- haemodialysis or peritoneal dialysis
Indications for diuretics:
- oedema associated with CHF
- acute pulmonary oedema
- liver disease
- renal disease
- hypertension
- conditions that cause hyperkalaemia
Phases of acute kidney injury
- Onset phase: kidney injury occurs
- Oliguric phase: urine output decreases from renal tubule damage
- Diuretic phase: kidneys try to heal and urine output increases, but tubule scarring and damage occur
- Recovery phase: tubular oedema resolves and renal function improves
Clinical manifestations of acute kidney injury
- decreased urine output
- fluid retention and peripheral oedema
- SOB
- fatigue
- confusion
- nausea
- weakness
- irregular heartbeat
Clinical signs in the oliguric phase of acute kidney injury
- urine output <400ml/day
- increases in blood urea nitrogen and creatinine levels
- electrolyte disturbances - hyperkalaemia, hyperphosphataemia
- acidosis
- fluid overload
- distended neck veins
- hypertension
- pulmonary oedema
Important nursing assessments for acute kidney injury
- monitor urine output, assess fluid balance
- monitor vital signs (particularly BP and HR), auscultate heart sounds
- assess urine (dipstick), assess for blood, infection or pain
Indications for haemodialysis in acute kidney injury:
- volume expansion that cannot be managed with diuretics
- hyperkalaemia refractory to medical therapy
- correction of severe acid-base disturbances that are refractory to medical therapy
- severe azotemia (BUN>80-100)
- uraemia
