Exam 1, Deck 2 Flashcards
Potassium levels:
- Intracellularly
- Intravascularly
- Intracellular: As high as 150 m#q
- Intravascular: 3.5-5.2
Four causes of hypokalemia
- Loss from GI tract
- Diet
- Diuretics (except aldactone)
- Enema or laxative abuse
Some sxs of hypokalemia (4)
- Constipation
- ECG changes
- Lower leg weakness
- Paresthesia
A hypokalemic patient as at higher risk of…
why?
Dig toxicity
Because digoxin is positive cardiac inotropic drug
Three types of K+ to administer to a hypoakalemic patient:
- Klor, KDor (PO)
- KCl (IV, if severe)
Notes about administration of K+ (3)
- Never IV push or bolus
- Must be diluted
- No more than 40mEq/L (in 1000mL of fluid)
Three requirements patient must meet in order to recieve K+
- BUN WNL
- Creatinine WNL
- Normal urine output
ECG changes with hypokalemia
Lower T wave
ECG changes with hyperkalemia
Peaked T (almost as high as QRS)
Most common cause of Hyperkalemia
Kidney failure
Three other causes of Hyperkalemia
- Intake of excess K+
- Crush injuries / burns
- Addison’s disease
Electrolyte imbalances of Addison’s (2)
- Hyponatremia
- Hyperkalemia
Physical assessment of Hyperkalemic patient (4)
- HR is slow/weak/absent
- ECG changes
- Irregular heartbeat
- Acidosis
Symptoms of Hyperkalemia (3)
Nausea
Paresthesias
Muscle cramps
How does hyperkalemia lead to acidosis?
As potassium rises, kidneys try to excrete it. In the process, kidneys hold onto H+ levels
Hyperkalemia: Interventions (6)
- Calcium Gluconate
- IV fluids
- IV Na Bicarbonate
- Hemodialysis
- Kayexalate
- Insulin and Glucose IV
Why would you give Calcium Gluconate to a Hyperkalemic patient
It doesn’t change K+ levels, but protects the myocardium and buys time.
Why would you give IV fluids to a hyperkalemic patient
To help the kidneys flush it out
Why would you give Sodium bicarbonate to a hyperkalemic patient
Helps when acidosis is at play: Bicarb makes body alkalotic, convinces body to get rid of potassium
Why would you give Kayexalate to a hyperkalemic patient
Binds to potassium in bowel and brings it out with fecal material (*administered PO or as retention enema)
Why would you give Insulin and glucose IV to a hyperkalemic patient?
SHOVE EVERYTHING INTO THE CLOSET BEFORE THE GUESTS COME
Only administered in the most severe cases (6.8 or above)
Drives potassium into cells
Short term solution
Absorption rate of calcium
30-50% of calcium ingested is absorbed
Functions of calcium (3)
- Needed for muscle contraction
- Essential for blood clotting
- Necessary for electrical conduction of the heart
Three causes of hypocalcemia
- Inadequate intake of calcium / anorexia
- Renal failure
- Lasix
Signs of Hypocalcemia (4)
- Muscle cramping
- Twitching
- Tetany / convulsions
- Cardiac arhytmias
Assessment of hypocalcemia
- Trousseau’s Sign (claw w BP)
- Chvostek’s Sign (cheek flick twitch)
Hypercalcemia - causes (3)
- Increased bone reabsorption
- Cancers (bone and others)
- Immobility
Symptoms of Hypercalcemia (3)
- Lethargy / weakness
- Decreased reflexes
- Constapation
Hypercalcemia interventions (4)
- Decrease intake
- Lasix
- Calcitonin
- Ambulation
“Acidity” is a measure of…
H+ concentration
In acid-base balance, Kidneys control the _______ component.
Metabolic
In acid-base balance, Lungs control the _______ component.
Respiratory
Kidneys: Mechanism for controlling Acid-Bae
Controlling sodium bicarbonate (HCO3)
**Secondary mechanism: Controlling H+
Lungs: Mechanism for controlling acid-base
Controlling carbon dioxide (CO2)
What does CO2 do to acid-base balance?
- High CO2 = ________
- Low CO2 = _________
High CO2 = low ph (acidic)
Low CO2 = high pH (basic)
Mechanism with which CO2 affects pH balance:
CO2 + H20 –> H2CO3 (carbonic acid)
Mechanism with which HCO3 affects pH balance:
H2CO3 (carbonic acid) breaks down into HCO3 and H+
SaO2 def:
Saturation of hemoglobin with O2
PaO2: def
Partial pressure of oxygen dissolved in arterial plasma
What blood gas level would make you start thinking about intubation?
PaO2 of <60
SaO2 of < _____ &
PaO2 of < _____ are considered to be hypotonic
SaO2 < 90%
PaO2 < 60
How would you measure the PaO2? What is the normal value?
Arterial stick
Normal = 80-100
Abnormal ABG profile of respiratory acidosis:
pH: Low
PaCO3: High
Abnormal ABG profile of metabolic acidosis:
pH: Low
HCO3: Low
Abnormal ABG profile of respiratory alkalosis:
pH: High
PaCO2: Low
Abnormal ABG profile of metabolic alkalosis:
pH: High
H2CO3: High
Interpreting ABG’s:
4 steps
1) Look at the number
2) Look at the pH
3) Is the problem respiratory or metabolic?
4) Determine compensation (absent / partial complete)
Function of Allen test
Test that must be positive to proceed with testing ABGs
Allen test: Steps (4)
1) Patient forms tight fist
2) Apply pressure at wrist (ulnar and radial)
3) Patient opens wrist. Palm should be pale.
4) Release ulnar
What does a positive Allen test look like? Why is this important?
Palm turns pink within 15 seconds of releasing Ulnar (then you know that it is safe to use radial)
What precautions do you take with the blood drawn from ABGs? (2) Why?
Precautions:
- Heparinize the container so it doesn’t clot
- Put it on ice to decrease BMR
IT IS LIVING TISSUE
After taking an ABG, what do you do and why?
Pressure for 10-15 minutes
To prevent bleeding / hematoma
How do you know if the problem with the ABG is respiratory or metabolic?
If the PaCO2 has the same acid/base status as the pH, it’s respiratory.
If the HCO3 has the same acid/base status as the pH, it’s metabolic,
Common causes of respiratory acidosis (2)
- Depression of the respiratory center
- Decreasing aerating surface of hte lung
Four things that could depress the respiratory center
- Opioids
- Barbituates / Benzos
- Anesthesia
- Head trauma
Four problems that would decrease the aerating surface of hte lung
- COPD
- Pneumonia
- Airway obstruction
- Chest wall trauma
Nursing assessment of a patient with respiratory acidosis (4)
- Ashen color
- Change in mental status due to hypoxia
- pH <7.35
- Change in respiratory rate
How does respiratory rate change with acidosis? Why? (2)
- If due to a CNS problem: Slow and shallow
- If due to decreased lung surface area: Quicker RR
Respiration assistance for pt in respiratory acidosis
- If severe
- If mild
- Other note
- Intubation if severe, cannula if mild
- COPD: LOW FLOW O2
Why do you give low flow CO2 to a COPD patient
Because of the Haldene effect
What is the Haldene effect
Increased levels of O2 will actually bump up PaCO2 levels, and COPD patients can’t compensate.
Respiratory acidosis: Nursing interventions for…
- Opioids (2)
- Benzos
- Assess RR before administering opioids
- Opioid antidote = narcan
- Benzo antidote = Romazicon
Common causes of respiratory alkalosis (3)
Hyperventilation
Pain
Head trauma (medulla)
Respiratory Alkalosis: Nursing assessment (3)
Lightheadedness / dizziness
Tetany
Why does respiratory alkalosis cause tetany?
Because alkalosis can interfere with calcium utilization, so tetany can develop. Claw-like hands.
Nursing intervention for respiratory alkalosis
Rebreather mask (paper bag) – allows patient to rebreathe CO2
How does DKA occur?
- Glucose is not being metabolized because of lack of insulin
- so body breaks down fatty acids, which yield ketones (acidic)
hence KETOACIDOSIS
Common causes of metabolic acidosis (6)
- Diabetes mellitus (DKA)
- Starvation
- ASA overdose
- Renal failure
- Severe diarrhea
- Tissue anoxia
Why does tissue anoxia occur and what does it do to acid/base balance?
Tissue anoxia occurs if the patient is not breathing – body switches to anaerobic metabolism, which produces acid.
Nursing assessment of metabolic acidosis (3)
- Lethargy –> coma
- High serum K+
- Kussmaul breathing to compensate
What is Kussmaul breathing?
Deep, rapid respirations to compensate for acidosis
Nursing interventions for metabolic acidosis (3)
- Amp of sodium bicarb
- Check potassium (may be high)
- Treat the cause (insulin, food, lavage)
Common causes of metabolic alkalosis (3)
- Loss of HCl (due to gastric loss)
- Excessive intake of sodium bicarb
- Fluid and electrolyte loss
Explain how fluid loss can lead to alkalosis
Body compensates by saving sodium and water, subsequently wastes H+ (result: alkalosis)
Two sources of HCl loss
- Vomiting
- Gastric suction
Nursing assessment of metabolic alkalosis (2)
- Low serum potassium
- Shallow slow respirations
Why would you see low serum potassium in metabolic acidosis?
Because cells take in potassium to compensate for alkalinity (release H+)
Nursing interventions for metabolic alkalosis (2)
- KCl
- Fluid (NS, LR)
