Labs Flashcards
Components of ABG’s
pH
PaCo2 -partial pressure of carbon dioxide
PaO2- partial pressure of oxygen
SO2-oxygen saturation
HCO3- bicarbonate
BE- base excess
Normal range pH &
What does it mean
7.35-7.45
Normal range PaCO2 &
What does it mean
35-45 mm Hg
shows adequacy of gas exchange between alveoli and external environment (alveolar ventilation)
hypoventilation (damaged alveoli, as in COPD) PaCO2 is elevated causing respiratory acidosis
hyperventilation= PaCO2 is decreased, causing respiratory alkalosis
PaO2- Normal range
75-100 mmHg (partial pressure Oxegen)
indicates the amount of O2 present to bind with hemoglobin
SO2
Oxygen Saturation
94-100%
HCO3
Bicarbonate
22-26 mEq/L
Deficit indicates metabolic acidosis
Increased indicates metabolic alkalosis
Intracellular Electrolytes
Cations: K+, Na+, Mg2+
Anions: Cl- HCO3-, PO4 3-
What does Sodium do in the body?
Where sodium goes, fluid flows.
Major cation in the ECF
Maintains blood volume and Blood pressure
regulated by ADH (add da H20)
- aldosterone holds back salt to keep water
Works with K+
Hypernatremia, What is it? What causes it?
-high serum sodium
Caused by:
-inadequate water intake
-excess water loss
-(rarely) Sodium gain
-diarrhea, diabetes related
osmotic diuresis
- increased insensible water loss
fever, heatstroke,
hyperventilation
Sodium is main ECF osmolality, so hypernatremia can cause hyperosmolality
Clinical manifestation and Nursing management of hypernatremia
-water shifts out of cell into ECF due to high osmolarity of ECF
-causes dehydration and shrinking of cells, which can cause dehydration of brain cells, resulting in change in metal status,
Symptoms of decreased ECF volume:
-drowsiness, restlessness, confusion, seizures, coma
- diarrhea
-intense thirst, dry swollen tounge,
postural hypotension
- increased pulse, weakness muscle crams
Symptoms with Normal or increased ECF volume:
-agitations restlessness, twitching, siezures
-edema
-intense thirst
-weight gain, increased BP
Nursing Management:
-if primary water deficit: fluid replacement orally or IV with d5w
-If problem is sodium excess or intravascular depletion: IV fluids like .9% NS,
- or if sodium excess not from water loss, Na excretion through diuretics, and restrict dietary sodium intake
Hyponatremia, causes
low serum sodium
excess sodium loss:
- diarrhea
-vomiting
-primary adrenal insufficiency
-diuretics
-NG suctions
Inadequate sodium intake
- fasting diets
excess water gain:
-misuse of sodium free fluids, hypotonic fluids
water excess in relation to sodium
Signs/symptoms of Hyponatremia
Decreased EFC volume
- apprehension, irritability
-confusion
-cold clammy skin
-postural hypotnesion
-inreased pulse, thready pulse
With normal or increased ECF volume
- apathy headache
-confusion
-muscle spasms, seizures, coma
-nausea vomiting, diarrhea
-weight gain, increased BP
Hyperkalemia causes, Excessive potassium intake
-Excessive or rapid IV administration
-potassium containing drugs
-Renal Failure
-Low aldosterone
-potassium containing slat substitute
hyperkalemia causes, Shift of potassium out of cells
-acidosis
-intense exercise
-tissue catabolism (crush injuries, sepsis, burns, fever)
-tumor lysis syndrome
What does Potassium do?
King Potassium, king of action and contraction. 3.5-5.0
Especially in the heart, keeping cells polarized through Na K+ channel
hyperkalemia causes, failure to eliminate postassium
adrenal insufficiency
meds: Angiotensin II receptor blockers, ACE inhibitors, Heparin, Potassium sparing diuretics, NSAIDS
Renal disease
Hyperkalemia clinical manifestations
Heart:
ECG Tall T waves and ST Elevation
hypotension bradycardia
irregular pulse
GI:
cramping diarrhea, vomiting
Hyperactive bowel sounds
Neuromuscular
increased DTR
paralysis and paesthesia (tingling)
confusion
fatigue irritability
muscle weakness
Causes of hypokalemia
Below 3.0
Fluid/electrolyte loss
D’s
Diarrhea, Diuretics, Diet, DKA, alDosterone
Symptoms of Hypokalemia
Heart
- low and slow pump
- flat T waves, ST depression, presence of U wave
-
Neuromuscular
- Shallow respirations= most deadly!
- Decreased DTR
-cramps and paralysis
GI:
- constipation
- hypoactive bowel sounds
- paralytic illeus= priority because causes risk of small bowel obstruciton
Sodium imbalances values
Hypernatremia: > 145 mEq/L
Hyponatremia <136 mEq/L
hyperkalemia EKG changes
-loss of p waves
- prolong PR interval
ST segment depressions
-Widening QRS
-Tall, peaked T wave
- Vfib
Hypokalemia causes, potassium loss
Dialysis
diaphoresis
GI losses: diarrhea, Vomiting, fistulas, NG suction, ileostomy drainage
renal losses: diuretics, hyperaldosteronism, magnesium depletion
Hypokalemia Shift into cells
-alkalosis
increased epinephrine, up stress
increased insulin release
insulin therapy
hypokalemia from lack of potassium intake
diet low in K+
failure to include potassium in IV fluids if NPO
Starvation
