Module 6 Renal & Urologic systems and disorders

patho

Starlings forces

• hydrostatic

• oncotic

The starling equation calculates

• movement of edema fluid

• depends on hydrostatic & oncotic pressure differences between capillaries & interstitium

Glomerular Filtration

• depends on the same opposing forces that produce the exchange of fluids in every capillary in our body

hydrostatic pressure

• force within a fluid compartment

• major force that pushes water out of vascular system at capillary level

Oncotic Pressure

• osmotic pressure exerted by colloids in solution

• Albumin s a major colloid

Fluid movement in capillaries

amount & direction of movement determined by

• capillary hydrostatic pressure

• plasma oncotic pressure

• interstitial hydrostatic pressure

• interstitial oncotic pressure

capillary hydrostatic pressure

• pushed H20 out of capillary

Plasma oncotic pressure

• pulls H20 back into capillary

Interstitial oncotic pressure

• pulls h20 out of capillary into interstitial spaces

filtration

• controls the outward movement of fluid from capillary

reabsorption

• pulls fluid back into capillary

fluid exchange between capillary & tissue

why does fluid exchange between capillary & tissue matter

• low BP = drop in hydrostatic pressure > drop in filtration > acute kidney injury

• low protein state = drop in oncotic pressure > fluid leaking out > edema

Fluid shifts

• plasma to interstitial fluid shift results in edema

• increase in hydrostatic pressure in capillaries

• decrease in plasma oncotic pressure

• increase in interstitial oncotic pressure

Interstital fluid to plasma - fluid shifts

• fluid drawn into plasma space with increase in plasma osmotic or oncotic pressure

  • caused by: hypertonic solutions, osmotic diuretic (mannitol), colloids (albumin, dextran, or FFP)

• compression stockings decrease peripheral edema

  • works by increasing interstitial hydrostatic pressure

A patient with low serum albumin is at risk for which complication related to Starling’s forces in the glomerulus?

• edema

edema causes

Fluid distribution

• intracellular (ICF) = 2/3 of body fluid

• extracellular fluid (ECF) = 1/3 of body fluid

  • intravascular (plasma) - inside blood vessels

  • interstitial - between cells

What is the difference between interstitial fluid & extracellular fluid

• edema - increase interstitial fluid volume

• extracellular = all fluid outside the cells

• interstitial = fluid in the spaces between cells (one part of extracellular fluid)

ICF

• Increase potassium

• moderate magnesium

• decreased sodium, chloride, bicarbonate, phosphorus

• very little calcium

ECF

• increased sodium, chloride

• moderate bicarbonate

• decreased potassium, magnesium, calcium, phosphorus

Isotonic fluid

• used to increase fluid in vascular space

• cells stay the same

• and fluids stay in the intravascular space

Hypotonic fluid - uses hypovolemia w/ hypernatremia and/or dehydration

• cells swell as fluid goes into the cells

• could cause cells to burst

Hypertonic fluid - used for severe hyponatremia or hypoglycemia

A nurse is administering Normal Saline (0.9% sodium chloride) and knows that this fluid type:

• Has the same concentration of solutes as the fluid inside the body’s cells

Renin - Angiotensin - Aldosterone System (RAAS)

What sparks the RAAS to activate

• dehydration

• hyponatremia

• hemorrhage

• decreased cardiac output

• decreased blood volume

• decreased blood pressure

how does RAAS respond to a high salt diet

Antidiuretic hormone

• ADH -also called vasopressin

• helps kidneys control the amount of water your body loses through the urine

• produced in the hypothalamus but released by the pituitary gland

• if too much is produced - syndrome of inappropriate antidiuretic hormone (SIADH)

SIADH - syndrome of inappropriate antidiuretic hormone

• kidneys hold onto too much water

• hyponatremic because diluted by excess water

• fluid overload

Hypervolemia

• too much fluid volume typically intravascular but can become interstitial

• Nurses call these patients WET

Common causes of hypervolemia

• heart failure

• kidney disease - chronic or acute renal failure or acute kidney injury

• liver disease - cirrhosis & ascites

• diabetes

Manifestations - hypervolemia

• edema

• bloating

• increase weight

• dyspnea

• hypertension

• crackles

Fluid volume deficit - hypovolemia

• extracellular fluid volume deficit, can’t perfuse the body

• nurses call these patients “dry”

• think hypovolemic shock

Hypovolemia causes

• diarrhea

• hemorrhage (blood loss)

• excessive sweating

hypovolemia manifestations

• dizziness when standing

• dry skin & mucous membranes

• fatigue/weakness

• muscle cramps

• decreased urinary output, increase in urine specific gravity

hypervolemia treatment

• remove fluid without changing electrolyte composition

• give a diuretic

hypovolemia treatment

• replace water and electrolytes with balanced IV solutions

• replace whatever they are missing

Renal calculi: Nephrolithiasis

• kidney stones

• complex etiology

  • increase in stone components in blood and urine

  • anatomic changes

  • metabolic, endocrine & dietary influences

Renal calculi: Nephrolithiasis Risk Factors

• family/personal Hx

• dehydration

• diet high in protein, NA & sugar

• obesity

• digestive diseases/surgery

Types of stones & causes - calcium

• most common

• high doses of vitamin D

• intestinal bypass surgery (d/t metabolic changes)

• metabolic disorders - renal tubular acidosis

Types of stones & causes - struvite

• calcium, magnesium, ammonium & phosphate

• usually caused by a UTI

types of stones and causes - Uric acid

• chronic diarrhea or malabsorption

• high protein diet

• diabetes

• metabolic syndrome

types of stones and causes - Cystine

• amino acid

• hereditary disorder - cystinuria

Nephrolithiasis signs and symptoms

• hematuria

• pain

  • renal colic: acute, intermittent, excruciating pain

  • may radiate down into groin for men

  • nausea/vomiting

Renal Calculi

Treatment for kidney stones

• fluids - oral & IV

• pain management

• medications

  • tamsulosin (flomax)

  • Dutasteride & tamsulosin (Jalyn)

• procedures/surgeries

  • extracorporeal shock wave lithotripsy (ESWL)

  • Percutaneus nephrolithotomy

  • ureteroscopy with or without stent placement

  • parathyroid gland surgery - if hyperparathyroidism caused

A 45-year-old male presents to the emergency department with sudden onset of severe flank pain radiating to the groin, accompanied by nausea and hematuria. A non-contrast CT scan reveals a 6 mm calculus in the left ureter.

Obstruction of urinary flow causing increased intrarenal pressure and ureteral spasm

Urinary Tract Infection risk factors

• infection secondary to pathogens microorganisms

• female anatomy (shorter urethra)

• sexual activity

• Birth control - specifically diaphragms & spermicidal agents

• menopause

• anatomical urinary tract problems

• blockages-kidney stores or enlarged prostate

• suppressed immune system

• catheter use

• recent urinary procedure

Lower UTI

Cystitis Bladder

Prostatitis Prostate

Urethritis Urethra

Upper UTI

Pyelonephritis Kidneys

Interstitial Nephritis Kidney

Renal Abscesses Tubules

UTI S/SX - Kidneys

• back or side pain

• high fever

• shaking & chills

• nausea

• vomiting

UTI S/SX - Bladder

• Pelvic Pressure

• Lower Belly Discomfort

• Frequent, painful urination

• Blood in urine

UTI S/SX - Urethra

• Burning with urination

• dischange

lower urinary tract infection

• #1 Cause: E.Coli

• bacteria gain access to lower urinary tract → evade host defensive mechanism

due to

• Immunosuppression

• Decreased acidity of urine

• Reflux of urine

• decreased mucosal/IgA/prostatic secretions

• damage to lining of system, etc

Urinalysis & urine culture - UTI

• if bacteria found in UA → Pt will need a urine culture & sensitivity (C&S)

UTI Treatments

• antibiotics to treat the cause

Commonly used for simple UTIs:

• Trimethoprim and sulfamethoxazole (Bactrim, Bactrim DS)

• Fosfomycin (Monurol)

• Nitrofurantoin (Macrodantin, Macrobid, Furadantin)

• Cephalexin

• Ceftriaxone

+ Phenazopyridine (Pyridium)- for symptoms

To relieve pain, burning, urgency and frequency

Patient Education: Prevention of UTI

• Drink plenty of liquids, especially water.

• Try cranberry juice.

• D mannose

• Wipe from front to back.

• Empty your bladder soon after having sex. Also drink a full glass of water to help flush bacteria.

• Avoid potentially irritating feminine products: deodorant sprays, douches and powders

• Change birth control method

Glomerulonephritis

• Definition: inflammation of glomerular structures

• What happens in the glomerulus? Filtration through the membrane

• Etiology: exact cause unknown but immune reaction causes antibody-antigen complexes (hypersensitivity type III) to get trapped in the basement membrane.

• Now things that shouldn’t get into Bowman’s Capsule do

Types

• Acute, chronic

• Primary – usually due to Group A Beta-hemolytic strep (GABHS)

• Secondary – some other disease triggers – like SLE

Glomerulonephritis s/sx

• Hematuria

• Proteinuria

• Azotemia – waste products stay in blood because nephron isn’t filtering them out

• Fatigue

• Oliguria – dramatic decrease in urine output

• Edema – protein spilled into urine

• Hypertension – kidney isn’t regulating NA-K like normal

• Decreased GFR

• Increased glomerular membrane permeability

Glomerulonephritis treatment acute

• Symptomatic support

• Resolution

Glomerulonephritis treatment Chronic

• Permanent scarring

• Can lead to renal failure

Glomerulonephritis treatment

• ACE inhibitors protect blood flow into the kidneys

• Corticosteroids decrease inflammation less scar tissue

• Diuretics  remove excess fluid

• Diet changes eating less protein, Na, & K

• If renal failure: Dialysis

pyelonephritis

• inflammation of the kidneys (tubules, interstitium, pelvis)

pyelonephritis etiology

Acute: ascending infection (from GU)

• Gram-negative bacteria (E.Coli) most common

Chronic

• Reflux and infection

pyelonephritis s/sx

• Fever, chills, malaise

• Back pain (CVA tenderness = costovertebral angle)

• Cloudy urine, foul odor

• Dysuria, é frequency & urgency

• WBCs & protein in urine

• Elevated WBC in CBC

• Chronic = change in ability to concentrate urine

  • What will specific gravity and urine osmolality look like?

pyelonephritis treatment

Antibiotics:

• Trimethoprim-sulfamethoxazole (TMP-SMX)

• Amoxicillin or Augmentin

• Ceftriaxone or cephalexin

• Ciprofloxacin or levofloxacin

Hydration:

• IVF

Symptom management:

• Pain

• Nausea

Kidney Labs - Creatinine

• Normal range: 0.6-1.2 mg/dL

• Waste product from digestion of protein and normal breakdown of muscle tissue

• Healthy kidneys filter creatinine from blood

Creatinine and BUN ↑ when kidneys are stressed

Kidney Labs - Blood urea nitrogen (BUN)

• Normal range: 8-20 mg/dL

• Liver produces ammonia (contains nitrogen)

• Nitrogen combines with carbon, hydrogen and oxygen = urea

• Healthy kidneys filter urea from blood

• If elevated but creatinine isn’t- usually dehydration

Creatinine and BUN ↑ when kidneys are stressed

Kidney Labs - Glomerular Filtration Rate

• measures kidney function

• decreases with kidney disease & age

Chronic renal failure

• Chronic renal failure is the deterioration & destruction of nephrons with progressive loss of renal function

• Renal function lost cannot be regained

• Function well below our anatomic reserve

• Most common causes of CRF = long term uncontrolled DM & HTN

Chronic Renal Failure - stages

• Renal insufficiency (stages 3-4)

• Renal failure (stage 5)

• End stage renal disease (ESRD)

Stage 1 Chronic Renal Failure

• possible kidney damage (e.g. protein in the urine) with normal kidney function

• eGFR 90 or above

• kidney function 90-100%

Stage 2 Chronic renal failure

• kidney damage with mild loss of kidney function

• eGFR 60-89

• kidney function 60-89%

Stage 3a Chronic renal failure

• mild to moderate loss of kidney function

• eGFR 45-59

• kidney function 45-59%

stage 3b chronic renal failure

• moderate to severe loss of kidney function

• eGFR 30-44

• kidney function 30-44%

stage 4 chronic renal failure

• severe loss of kidney function

• eGFR 15-29

• kidney function: 15-29%

stage 5 chronic renal failure

• kidney failure

• eGFR less than 15

• less than 15%

what is uremic frost

• a rare sign of severe kidney failure in which white, powdery crystals form on the skin because waste products build up in the blood.

chronic renal failure: altered homeostasis

Problems associated with CRF reflect inability of the kidneys to perform necessary functions

• Waste excretion

• Fluid & electrolyte balance

• Acid-base regulation

• Vit D synthesis

• Erythropoietin synthesis

• Regulation of BP

Chronic renal failure complication

1) Accumulation of nitrogenous wastes (urea, creatinine, uric acid)

Azotemia

2) Declining ability to produce urine

Oliguria, anuria, uremia

3) Electrolyte imbalances

Hyperkalemia

4) Fluid imbalance

HTN, Increase risk of HF

6) Decreased erythropoietin production

Anemia

7) Acid-base imbalance

Acidosis

8) Decreased activation of vitamin D

Hypocalcemia

Increased phosphorous

Renal Diet

• limit proteins to high biologic value proteins

• may need a fluid restriction as well

Renal Diet Avoided

• foods higher in potassium

  • oranges, bananas, potatoes, tomatoes, brown rice

• foods higher in phosphorus

  • processed meat, dairy, soft drinks

• deep fried foods

• foods higher in saturated & trans fat

• large amounts of meat & poultry

• prepared or packaged foods

  • typically higher in sodium

renal diet recommendation

• fresh fruits & veggies

  • apples, peaches, carrots, green beans

• low potassium & phosphorus

  • white bread, pasta, rice, wheat cereals, rice milk

• moderate amounts of protein

  • plant based options

    • ex tofu nut butter, soy yogurt

renal diet moderation

• foods high in potassium

  • bran cereals, oatmeal, beans, lentils & nuts

• alcohol

  • no more than 1-2 drinks/day

when does a patient get put on dialysis

• usually when GFR is 15% or less + s/s

renal dosing across the lifespan - why does it matter

• kidneys remove many drugs from the Body

• impaired kidney function → drug build up → toxicity

• dosing must be adjusted to patients age, renal function, clinical condition

renal dosing across the lifespan - how do we keep patients safe

• size dose to kidney function + age (pharmacy and provider will do this, but you need to report the information in front of you)

• age extremes (neonates/elderly) = most risk

• follow levels + labs

• evaluate + be ready to adjust often

neonates & infants

• kidneys immature at birth → decreased clearance

• drug half-life prolonged

• require smaller doses or longer intervals (eg antibiotics)

• by 1 year renal function approaches adult levels

children

• after infancy renal clearance may be faster than adults

• often require weight based or body surface area dosing

• careful monitoring essential

adults

• typically stable renal function if health

• adjust dosing if kidney disease or acute illness (eg. dehydration, sepsis)

older adults

• normal aging → decrease GFR & renal blood flow

• BEERS criteria

• “normal” creatinine can be misleading (low muscle mass)

• higher risk of accumulation (digoxin, aminoglycosides, lithium)

• start low, go slow