Drug Therapy for Fluid Volume Excess

anasarca

extreme generalized edema

anuria

no urine output

ascites

fluid volume overload in the abdomen

edema

swelling

kidneys, ureters, bladder, and urethra

what make up the renal system? (4)

regulate volume, composition of urine, regulate pH, eliminating wastes, BP regulation, RBC production, Vitamin D conversion

primary function of kidneys (7)

25%

the kidneys receive ___% of cardiac output

renal capsule

fibrous tissue layer in kidney for protection

cortex, medulla, renal pelvis

regions of the kidney from outer to inner

nephron

functional unit of the kidney

glomerular filtration

passage of components of blood and fluid through glomerulus

tubular secretions

active movement of substances from blood through renal tubule

tubular reabsorption

movement of substances from renal tubule back to vascular system

afferent arteriole

arteriole blood enters glomerulus via ________ _________

70 mg Hg

how much pressure is the glomerulus under?

glomerulus

pushes water, electrolytes, and other solutes out into Bowman’s Capsule

125 ml/min

what is the average glomerular filtration rate?

2 L

approximately how much urine is produced a day?

efferent arteriole

blood leaves the glomerulus via the ______ _______

D

Where is the loop of Henle found?

A. the renal pelvis
B. efferent arterials
C. glomerulus
D. nephron

alterations in renal function, cardiovascular (HTN, CHF), renal, hepatic, burns, trauma, allergies, inflammatory reactions

conditions requiring diuretic agents (8)

increase in capillary permeability, increase in hydrostatic pressure, and decrease in plasma oncotic pressure

what causes edema? (3)

increased capillary permeability

this is a cause of edema that is in response to tissue injury or allergic reaction; it lets fluid flow from blood vessels to extravascular space, leading to swelling

increase in hydrostatic pressure

this is a cause of edema that is seen with fluid overload; an increase in blood volume causes high venous pressure, pushing fluid out of capillary beds

decrease in plasma oncotic pressure

this is a cause of edema that results from low plasma protein as it normally hold onto fluid and keeps it where it should be

edema and alterations in fluid/electrolyte balance

clinical manifestations of fluid overload

kidneys are unable to control volume, composition, and pH of body fluids

why does fluid overload cause alterations in fluid/electrolyte balance?

dependent edema

edema at the lowest point of the body

pulmonary edema

edema in the lungs

anasarca

massive generalized edema

False

True or False: edema occurs only when the heart no longer functions efficiently

diuretics

medication that increases renal secretion of water, sodium, and other electrolytes, increasing urine formation and output

proximal convoluted tubule

carbonic anhydrase inhibitors work where in the nephron?

loop of henle

loop diuretics work where in the nephron?

distal convoluted tubule

thiazide and thiazide like diuretics work where in the nephron?

collecting duct

potassium sparing diuretics work where in the nephron?

patient’s condition

drug selection and dosing depend on the _______ _________

loop diuretic

this is the preferred diuretic when rapid diuretic effect is necessary or when renal impairment is present

loop diuretics

strongest diuretic

furosemide, bumetanide, torsemide

3 loop diuretics

PO, IV, IM

what routes can loop diuretics be given? (3)

loop diuretics

inhibits Na+/Cl- reabsorption in the loop of henle to produce significant fluid loss, also promotes K+ and water excretion

• management of pulmonary edema, CHF, hepatic and renal diseases

• given alone/combination for treatment of HTN

• patients with renal impairment

• patients with hepatic impairment

• critically ill patients

• home care patients

uses of loop diuretics (6)

hyponatremia, hypokalemia, fluid volume deficit, ototoxicity (plasma drug levels > 50 mcg/mL)

adverse effects of loop diuretics (4)

anuria, allergy to sulfonamides

contraindications for loop diuretics (2)

amioglycosides & cephalosporins (increase diuretic effect) and corticosteroids & digoxin (increase risk of hypokalemia)

what are some drug-drug interactions with loop diuretics? (2)

• slow push: 20mg/min (ototoxicity)

• check labs: Na, K, renal function

• baseline weight & daily weight

• I&O

• monitor vitals closely (hypotension)

• give PO in AM

• monitor safety r/t dizziness

what are the nursing implications of loop diuretics (7)

• low sodium diet

• high K diet

• record daily weight

• change position slowly

• take in morning

patient education for loop diuretics

thiazide & thiazide like diuretics

this is the first line treatment for mild-moderate HTN

hydrochlorothiazide

what is an example of a thiazide diuretic

metolazone

what is an example of a thiazide like diuretic?

PO

what route are thiazide & thiazide like diuretics?

thiazide & thiazide like diuretics

these decrease reabsorption of Na+, H2O, Cl-, HCO3 in distal convoluted tubule

first line treatment of mild-moderate HTN, edema associated with CHF or nephrotic syndrome, patients with renal impairment

what are the uses for thiazide & thiazide like diuretics? (3)

hypotension, weakness, dizziness, diarrhea/constipation, hypokalemia, hyperglycemia

what are the adverse effects of thiazide & thiazide like diuretics? (6)

allergy to fulfonamides, renal failure/anuria

contraindications for thiazide & thiazide like diuretics (2)

• check labs: Na, K, glucose, renal function

• baseline weight and daily weight

• I&O

• monitor vitals closely (hypotension)

• give in AM

• monitor safety r/t dizziness

what are the nursing implications for thiazide & thiazide like diuretics? (6)

low sodium diet, high K diet, record daily weight, change position slowly, take in morning

what is the education for thiazide & thiazide like diuretics? (5)

confusion, weakness, heart palpitations, GI upset, death

signs and symptoms of hypokalemia (5)

low dosing of diuretics, using supplemental potassium, use potassium-sparing along with potassium-losing medication, increase food intake of potassium, restrict dietary sodium intake

prevention and management of potassium imbalances (5)

A

What assessment finding in a patient with HF receiving furosemide would indicate an improvement in fluid volume status?

A. absence of crackles on auscultation of lungs
B. complains of nocturnal dyspnea
C. bounding radial pulse
D. decrease in hematocrit

spironolactone

what is an example of a potassium-sparing diuretic?

slow onset and peak 24-48 hrs, 6 weeks for maximum effect

what are the pharmacokinetics for potassium sparing diuretics? (2)

potassium-sparing diuretics

blocks effects of aldosterone, weak diuretic effect, use in combination with other diuretics

treatment of HF, ascites in liver disease, hyperaldosteronism, hypokalemia, mild-moderate HTN

what are the uses of potassium sparing diuretics? (5)

dizziness, diarrhea, androgen like effects (gynecomastia, irregular periods), increase risk of GI bleed, tumorigenic with chronic toxicity (BBW)

what are the adverse effects of potassium-sparing diuretics? (5)

renal insufficiency, hyperkalemia

what are the contraindications for potassium-sparing diuretics? (2)

ACE-I, ARBs, K+ containing drugs

what drugs interact with potassium-sparing diuretics because they increase the risk of hyperkalemia? (3)

• check labs: K, renal function

• baseline weight and daily weight

• I&O

• monitor safety r/t dizziness

what are the nursing implications for potassium-sparing diuretics? (4)

• avoid salt substitutes

• low K diet

• record daily weight

• monitor abd girth (liver disease)

• change position slowly

• take in AM with food

what are the patient teachings for potassium-sparing diuretics?

muscle crams, ECG changes, hypotension, heart arrythmias, death

what are the signs and symptoms of hyperkalemia? (5)

potassium-sparing along with potassium wasting medications, avoid potassium supplement, avoid salt substitute, maintain urine output

prevention and management of potassium imbalances (4)

mannitol

what is an example of an osmotic diuretic?

IV (glass bottle) given in critical care

what are the pharmacokinetics for osmotic diuretics? (2)

osmotic diuretics

increases solute load (osmotic pressure) of glomerular filtrate, pulls from extravascular into blood, decreases reabsorption of water and electrolytes

reduce intracranial pressure, reduce intraocular pressure, effective in decreased renal circulation and GFR

what are the uses of osmotic diuretics? (3)

hyperosmolar non-ketotic coma, cardiac dysrhythmias, severe dehydration, confusion, H/A, syncope

what are the adverse effects of osmotic diuretics? (6)

severe dehydration, pulmonary edema, abdominal pain, appendicitis, severe cardiac decompensation (HF), older adults

what are the contraindications for osmotic diuretics? (6)

baseline physical exam + neuro + vitals, I&O, closely monitor vitals

what are the nursing implications for osmotic diuretics? (3)

hyaluronidase

what is the antidote for osmotic diuretics?

acetazolamide

what is an example of a carbonic anhydrase inhibitor?

IV (almost never used) & eye drops

what are the 2 methods of delivery for carbonic anhydrase inhibitors?

carbonic anhydrase inhibitors

inhibits carbonic anhydrase to reduce formation of aqueous humor and lower IOP

open-angle glaucoma and secondary glaucoma

uses for carbonic anhydrase inhibitors (2)

metabolic acidosis, Stephen Johnson syndrome, flaccid paralysis, blood dyscrasias

what are the adverse effects of carbonic anhydrase inhibitors? (4)

renal/hepatic disease, addison’s disease, electrolyte imbalance, chronic non-congestive angle-closure glaucoma

what are the contraindications for carbonic anhydrase inhibitors? (4)

baseline vision exam, eye drop admin education

what are the nursing implications for carbonic anhydrase inhibitors? (2)

B

A nurse is instructing a patient on dietary considerations while taking spironolactone. Which of the following statements made by the patient indicates further teaching is necessary?

A. I should not eat foods high in potassium while taking this medication
B. I should use salt substitutes instead of regular salt
C. I should call the NP if I have any adverse effects from my medication
D. I should not take potassium supplements