acid base balance Flashcards
buffers - 1st line of defense
Combine with acids or base to prevent pH changes
Act Immediately (within 1 second of abnormal pH)
Primary Regulators
PaCO2 - Partial pressure of CO2 in arterial blood (lungs, and you know the range)
Reflection of depth of pulmonary ventilation
Normal range is 35-45mmHg
PaO2 - THIS IS O2, NOT CO2, Partial pressure of O2 in arterial blood - normal range? (partial o2 in my heart and arteries)
No primary role in acid-base balance regulation if within normal limits
Normal range is 80-100mmHg
Oxygen Saturation - range - just pulse ox
Percentage of hgb saturated by oxygen
Normal value is 95-100%
base excess- what is it, and normal range? (b for base, b for buffer at 2)
Amount of blood buffer that exists
Normal value is +/- 2
Base Excess
Base Deficit
Bicarbonate (my kidneys are bi)
major renal component of acid-base balance. excreted and reproduced by the kidneys to maintain normal acid-base.
2nd line of defense - respiratory
Responds within minutes to hours to changes in acid/base to eliminate or retains CO2.
3rd line of defense - renal system
most adequate - if kidneys are functioning. Responds within hours to days (last line of defense; may take hours or days to restore normal hydrogen ion concentration)
ph
Metabolic and respiratory processes work together to keep H+ levels within a normal range
anion gap
when high- ex. ketones.
Reflection of anions not routinely measured.
Normal: Usually caused by loss of bicarb i.e. diarrhea, diuretics
gap—between the negatively charged and positively charged electrolytes in your blood.
how to obtain arterial blood gases
Heparinized syringe
Blood from an artery
Make sure at least 15-20 minutes have passed after procedures
Apply pressure for 5 minutes
On ice
Prompt delivery to lab
ph and calcium
have inverse relationship - high ph, low calcium, vice versa
crystalloids (krystle goes everywhere)
Solutions with small molecules that flow easily from the bloodstream into cells and tissues
isotonic solutions
to correct volume w/out an net movement. used to treat simple dehydration.
Same concentration of osmotically active particles in ECF
Osmotic pressure is the same inside and outside
Fluid doesn’t shift between extracellular and intracellular areas
blood loss administer what? (need to equalize the blood loss)
isotonic solution to correct imbalance.
isotonic solution (sugar and salt are isotonic)
Examples
Dextrose 5% in water (remember dangers associated with D5W!!)
0.9% Sodium Chloride (Normal Saline) Actually 154mEq Na+
Lactated Ringers -
Plasmalyte
D5 risk
brain cell swelling
hypotonic solution - fluid moves from what to what?
Less concentrated than extracellular fluid
Fluid will move from blood stream into cell
hypertonic solutions
Draws fluid from intracellular space, causing cells to shrink and extracellular space to expand
colloids
Plasma expanders used if blood volume doesn’t improve with crystalloids
Pulls fluid into bloodstream
Needs close monitoring
no lower extremities IV
risk of blood clot