CH 22, Renal Disorders

kidneys are responsible for what processes?

• secretion

• acid base balance (so know lab values)

• waste elimination

• glucose homeostasis

what hormones are secreted by the kidneys?

• erythropoetin

• renin

• vitamin D

erythropoetin

• When we become hypoxic, it signals the kidneys to release erythropoetin, which helps produce RBCs

• Renal failure patients generally have low hemoglobin and hematocrit 

renin

Released in response to low BP or low perfusion of blood to kidneys 

how do the kidneys help secrete vitamin D?

it keeps calcium balanced because VD is important for calcium absorption

what waste do kidneys eliminate?

• Urea 

• Uric acid 

• Breaks down drug metabolites

• dysfunction can cause waste buildup

glucose homeostasis in the kidneys

they can produce glucose from amino acids during times of starvation and fasting

neurological consequences of kidney dysfunction

• Confusion

• Stupored mental status; awake but not A&O x3

• High BP due to excess renin 

• Erythropoetin decreased 

• Acid base balance would be off 

• Excess potassium (heart problems)

• low calcium

manifestations of decreased erythropoetin

• Fatigue 

• Weakness

• Run down/no energy

if calcium is low, what assessments should be done?

Chvestoks (cheek) and trusseaus (hand) signs 

uropathy

obstruction of urine flow, which can cause hydronephrosis

• can be caused by kidney stones or BPH

hydronephrosis

build up of urine in the kidneys due to an obstruction that causes back flow

what type of injury can result from nephron damage due to toxins?

ischemic injury

what are the 3 classificatios of renal dysfunction?

pre-renal, intra-renal, and post-renal dysfunctions

pre-renal dysfunction

Anything that causes a ↓ in blood perfusion to the kidneys, that would injure BVs that supply blood to kidneys, or would ↓ BP being supplied to kidneys

intra-renal dysfunction

Direct damage to kidneys from trauma, infection, or nephrotoxic drugs

nephrotoxic drugs include

• Nsaids 

• Ace inhibitors 

• Statins used for high cholesterol 

• Some antibiotics 

post-renal dysfunction

• Obstructive uropathy 

• Hydronephrosis

  • Urine is toxic to nephron cells and breeds bacteria/infection

what questions should the nurse ask when assessing for renal dysfunction?

• Color of urine?

• Pain or burning with urination?

• Frequency of urination?

• Hematuria (blood)?

clinical manifestations of renal dysfunctions

• Could be multisystemic 

• May have abdominal pain

• If toxins aren’t clearing they could be confused

• CVA tenderness (costovertebral angle)

• Hematuria 

• Protein uria 

• Glomerular injury 

• Tea colored urine

what does protein uria look like

looks foamy due to protein spilling into the urine

what types of patients is glomerular injury most commonly seen?

Diabetics and those with high blood pressure

why could the urine be tea colored?

due to bilirubin build up, often seen in liver patients with jaundice

diagnostics for renal dysfunctions

• urinalysis

• BUN

• Urea

• Creatinine

• Renal utlrasound 

• IV pyelogram

• CT/MRI good for diagnosing kidney stones 

why should IV contrast not be used in pts with renal impairment?

because the dye can cause renal failure

what might high glucose in the urine indicate?

ketoacidosis

what might high leukocyte esterase in the urine indicate?

bladder or kidney infection

proper pH of urine

7ish

normal BUN level

5-20

azotemia

BUN level above 20, meaning glomerular filtration rate is decreased

what might cause azotemia?

dehydration, big muscles, high protein diet

should BUN be used as a sole diagnostic test for renal dysfunction?

no because everyone’s baseline is different

normal creatinine level

0.5-1.5

what is creatinine?

a breakdown product of muscle filtered and excreted by kidney that is a reliable indicator of kidney function and GFR

do elders have lower or higher BUN levels?

lower

do more muscular people have lower or higher BUN levels

higher

What does an IV pyelogram do?

allows to see filtration through kidneys with dye

treatments of renal dysfunctions

• Give epotein alpha to stimulate RBC production 

• Give diuretics to rid excess fluids 

• If renal problem can’t be reversed, may need to go on dialysis

what is the main goal of renal dysfunction treatment?

• Maintain fluid/electrolyte balance 

• Monitor RBC production 

Peritoneal dialysis

Uses peritoneum as a filtration system to remove toxins and extra fluids by instilling big bags of dialysate into abdomen by a catheter

Dwell time

the amount of time that the solution sits in peritoneal cavity; typically 4-6 hrs (or as long as provider says it will)

• At the end, the catheter drains out all the peritoneum (usually 30-40 mins to empty)

hemodialysis

When the pts blood is withdrawn from body by an AV fistula; typically all the blood goes through the machine in 15 mins

how long does the person have to wait to use their fistula after having it created?

4-6 weeks

what is important to remember about drawing blood or taking BP in someone with a fistula?

that these things can’t be done in the arm with the fistula