EXAM 5 Flashcards
What are the functions and secondary functions of the kidneys?
Maintaining fluid balance
Maintenance of acid-base balance
Excretion of metabolic wastes
Produce Erythropoietin (during hypoxia)
Release Renin (secreted by juxtaglomerular cells) when BP is low, initiates RAAS.
Converting Vit D into Calcitriol (when Ca2+ levels are low)
What are the basic renal processes?
Filtration
Reabsorption (aka resorption)
Secretion
Excretion
What are the classes of diuretics?
Loop diuretics
Thiazide diuretics
Potasium-sparing diuretics
Osmotic diuretics
What is preload
The amount of blood volume that fills the ventricles in the diastole (relaxation) phase of the cardiac cycle (aka filling pressure)
What is afterload?
The pressure the ventricles must work against to open the valves so blood can leave the ventricles (aka peripheral vascular resistance)
Where in nephron do Loop Diuretics work?
Act in ascending limb of Loop of Henle
How do loop diuretics work?
Block reabsorption of Na+ (H20 follows), Cl- (in ascending limb)
Dilate blood vessels
Decrease preload, afterload and BP
What are the indications for loop diuretics?
Manage HTN (not 1st line)
Decrease edema r/t HF, liver, renal disease
What are the adverse effects of loop diuretics?
Hypotension
Na+, K+, and other electrolyte depletion
Possibly hyperglycemia
What is the prototypical Thiazide diuretic?
Hydrochlorothiazide (HCTZ)
Where do thiazide diuretics act?
Distal convoluted tubule
How do thiazide diuretics work?
Block reabsorption of Na+ (H20), Cl-, K+ (in DCT)
Relaxes arterioles
Decreases preload, afterload, and BP
What are the indications for Thiazide diuretics?
First-line tx for HTN
Management of mild to moderate HTN
Adjunct tx for HF, liver disease
What are the adverse effects of Thiazide Diuretics?
Electrolyte imbalance
Hypokalemia
Possibly hyperglycemia
What is aldosterone secreted by?
Adrenal gland
What does aldosterone act on? (which part of the nephron)
Distal CT and collecting duct
What are the effects of aldosterone?
Increased reabsorption of sodium and water
Increased blood pressure
Excretion of potassium
What is the prototypical Potassium-sparing diuretic?
Spironolactone
How do potassium-sparing diuretics work?
Aldosterone-antagonist (blocks reabsorption of Na and water)
Where do potassium-sparing diuretics work?
DCT and collecting ducts
What are the indications for potassium-sparing diuretics?
Management of HTN
Edema r/t HF, liver, renal disease
Counteract K+ loss caused by other diuretics
What are the adverse effects of potassium sparing diuretics?
Hyperkalemia
What drug is the osmotic diuretic?
Mannitol
Where do osmotic diuretics work?
PCT and descending limb
What are the Actions of osmotic diuretics?
Increase osmotic force
Inhibits H2O reabsorption
Produces rapid diuresis
(Degree of diuresis r/t drug conc.)
What are the indications for osmotic diuretics?
Edema
Increased intracranial pressure
What are the adverse effects of osmotic diuretics?
Dehydration
What are the diuretic effects on geriatric patients?
Can cause dizziness, lightheadedness
Risk of orthostatic hypotension
Increase risk of dehydration and constipation
More prone to fluid and electrolyte imbalances
What are two nursing considerations when giving geriatic patients diuretics?
Recommend taking dose in AM
Lower doses if taking other diuretics or anti-HTN
What are the nursing implications for patients on diuretics?
D - diet (potassium intake)
I - I/O monitoring, daily weight
U - unbalanced F&E (electrolytes, BUN, creatinine, hydration)
R - ready for dynamic changes (light-headedness, VS, hearth/breath sounds, cardiac rhythm, etc)
E - no evening doses
T - take in AM
I - increased risk for orthostatic hypotension
C - consider age, other meds that increase risk of F&E imbalances and BP changes
What does Endothelial injury cause? And what are the results?
Vasoconstriction
To reduce blood flow and achieve hemostasis
What are the 3 main steps of hemostasis?
Vasoconstriction
Platelet plug
Clotting cascade
What activates platelet plug formation? What do they then secrete? And what gets triggered by them?
Collagen exposure leads to adhesion of platelets
Activated platelets secrete stimulators (help platelets stick together)
Clotting cascade triggered
What is the role of the clotting cascade?
To cause clotting factors (plasma proteins) to stabilize the fibrin clot and stop bleeding
What do stimulators do platelets secrete and what do they do?
Adenosine diphosphate (ADP) - causes platelets to change shape and aggregate
Thromboxane A2 (TXA2) - induces platelets aggregation
What is the action of aspirin /acetylsalicylic acid (ASA)?
Prevents the formation of TXA2
Prevents platelet aggregation
What are the indications for aspirin?
Stroke and MI prophylaxis
What are the adverse effects of aspirin?
GI bleeding, dyspepsia (heart burn)
What are the drug-drug interactions with aspirin?
May increase risk of bleeding with anti-coagulants and anti-platelet medications
What is the action of clopidogrel?
ADP inhibitor
Alters platelet membrane and prevents signal to aggregate
What is clopidogrel commonly given with? What is the combo effective for?
Aspirin
combo is effective in CVD
What are the indications for clopidogrel?
Prophylaxis of stroke, TIA, MI and post-MI
What are the adverse effects of clopidogrel?
Bleeding
What is a consideration with clopidogrel?
It is highly bound to protein (albumin)
Its duration of action is 5 days - may interfere with surgery due to increased risk of bleeding
What is the normal range of platelet count?
150,000 - 400,000 platelets per microliter (mcL)
What’s the term for platelet count under 150,000?
Thrombocytopenia
What are considerations when pts are on antiplatlet drugs?
Avoid IM injections
Discontinue 5-7 days before surgical procedures
Abrupt discontinuation may increase risk of CV events (educate pt on this)
Assess CBC (H/h, platelet count)
What are important things to teach patients on antiplatelet drugs?
Use electric razors, soft toothbrush
Prevent injury
Report signs of bleeding (hematuria, black tarry stools, bruising, increased bleeding from small cuts, nose bleeds)
Food/Herbal interactions: chamomile, feverfew, garlic, ginger, ginkgo (increase risk of bleeding)
What are the actions of rivaroxaban and apixaban?
Oral factor Xa inhibitor
Prevents new clots from forming
No effect on already-formed clots
Prophylactic treatment of clots
What is the indication for rivaroxaban and apixaban?
Increased risk or history of thrombotic events
What are the adverse effects of rivaroxaban and apixaban?
Bleeding (however no routine monitoring required)
What is the black box warning for rivaroxaban and apixaban?
Increased risk of clots if discontinued abruptly
What is the antidote for rivaroxaban and apixaban?
Andexxa (binds to and negates drug effect)
What are the drug-drug interactions for rivaroxaban and apixaban?
Other anticoagulants, antiplatelets, aspirin
What are the actions of warfarin (coumarin)?
Inhibits action of multiple clotting factors
Inactivates vitamin K dependent-clotting factors (II, VII, IX, X)
No effect on a formed clots
Prevents clot enlargement
What are the indications for warfarin?
Prophylaxis and treatment of thromboembolic events
What are the considerations with warfarin?
Onset of action 36-72 hours (b/c highly (98%) bound to protein)
3-5 days to reach therapeutic range
“Bridge therapy” needed (usually a heparin)
Return of normal coagulation levels takes 3-4 days (also b/c protein bound)
What are the drug-drug interactions of warfarin?
Heparin, NSAIDs, anti-platelet drugs
What is the black box warning/ adverse effects of warfarin?
Bleeding
What is the antidote for warfarin?
Vitamin K
What are important labs to monitor for a patient on warfarin?
PT/INR
What does prothrombin time measure?
Time it takes for a clot to form
How is the PT therapeutic range changed for patients on warfarin?
1.5-2 times baseline (and may be increased in other conditions)
What are the normal and therapeutic ranges of INR?
Normal: 0.8-1.2 (1)
Therapeutic range: greater than 2-3.5 (dependent on condition)
What herbal/ foods are antagonists to warfarin?
Vitamin K supplements and foods high in vitamin K
Foods - asparagus, broccoli, cabbage, cauliflower, kale
Supplements - green tea, gingko, garlic, ginger, cranberry (juice), chamomile, & licorice
Increase risk of bleeding
What are the nursing implications for someone on warfarin?
Avoid IM injections
Assess CBC PT/INR
Observe for s/sx of bleeding
Routine time
High-alert medication
Use of NSAIDs, anti-platelets increase risk of bleeding
What patient teachings are important for someone on warfarin?
Soft toothbrush/ no flossing
Electric shaver
Assistive devices
Report s/sx of bleeding
Prevent injury
Routine lab tests
Herbal/food interactions
What receptors do opioids bind to in CNS?
Mu and kappa receptors
What risks do mu-opioid receptor agonists cause?
Respiratory depression and constipation
How do Mu-opioid receptor agonists work?
Alter perception of pain
What is morphine prescribed for?
Acute and chronic pain
What is morphine (ER) prescribed for?
Chronic pain management
Which type of morphine is given for breakthrough pain?
Short-acting
What is hydromorphone prescribed for?
Severe acute and chronic pain
Does dilaudid cause more or less nausea than morphine?
Less
What are the increased risks of hydromorphone over morphine?
Orthostatic hypotension, urinary retention, and respiratory depression
What is codeine prescribed for?
Mild to moderate pain
What is fentanyl prescribed for?
perioperative anesthesia
Who is fentanyl ordered for?
Opioid-tolerant pts
Management of breakthrough cancer pain
Chronic persistent pain
How much stronger is fentanyl than morphine?
100 times stronger
What is oxycodone prescribed for?
Moderate to severe pain
What is methadone prescribed for?
Moderate to severe pain in opioid-tolerant; ATC long-term tx
Used in tx to reduce or quit heroin/opiates (higher doses)
What are the adverse effects of opioids?
Central Nervous System
- Sedation, confusion, drowsiness, dizziness, floating
feeling, and possible euphoria
Respiratory
- Respiratory depression
Cardiovascular
- Hypotension, bradycardia
Gastrointestinal
- Constipation, nausea, vomiting
Genitourinary
- Urinary retention
Miscellaneous
- Tolerance, physical and psychological dependence
When do you consider holding opiates?
If RR is less than 12 breaths/min
What are signs of over-sedation?
Respiratory depression less than 10/min
Unresponsive to verbal cues
Require painful stimuli (sternal rub)
What is the opioid antagonist?
Naloxone
What does naloxone do?
Reverses opioid-induced CNS and respiratory depression
Reverses analgesia effects
