rrd 8 Flashcards
disorders of pulmonary system (214 cards)
purpose of ABGs
to check for efficacy/disruption of gas exchanges and acid/base balance
ABGs measure
- pH
- gas levels (PO2, SO2, PCO2, HCO3) in blood
pH
- indicates level of acidity of blood
- decreased: acidic
- increased: less acidic (basic)
pH norm range, acidosis, alkalosis
- norm: 7.35 to 7.45
- acidosis: < 7.35
- alkalosis: > 7.45
PO2
partial pressure of oxygen in arterial blood (O2 gas dissolved in plasma)
norm PO2 range, hypoxemia
- norm: 80 - 100 mmHG
- hypoxemia: < 80 mmHg
SO2
- oxygen saturation, indicates O2 that is carried by hemoglobin
- how great a percent of each Hgb molecule in the arterial circulation is saturated with O2
cycle of oxygenation
- lungs: O2 conc high, Hgb bind w/ O2 for transport to tissues
- if all 4 O2-binding sites on hemoglobin loaded up w/ O2, Hgb saturated
- shows as o2 saturation percent
PCO2
partial pressure of CO2 gas in the blood (acid)
PCO2 norm
35 - 45 mmHg
when the ____ in a set of ABGs is out of the normal range, it is due to some sort of respiratory problem as long as ____ is normal.
PCO2, HCO3
HCO3
level of bicarbonate in the blood (basic guy)
HCO3 norm
22 - 28 mEg/L
when the ____ in a set of ABGs is out of the normal range, it is due to some sort of metabolic problem as long as ___ is normal.
HCO3, PCO2
steps to analyzing and interpreting ABGs
- analyze pH and decide: acidosis or alkalosis
- analyze pCO2: out of norm, acidosis/alkalosis is RESP origin
- analyze HCO3: out of norm, acidosis/alkalosis is METABOLIC origin
- analyze pO2 and O2 sat: low, hypoxemic
- figure out underlying etiology causing problem and what kind of compensatory changes the body needs to make
ROME
- Respiratory Opposite (PCO2 up, pH down)
- Metabolic Equal (HCO3 up, pH up)
respiratory acidosis
- state of low pH by inhibition of norm breathing pattern
- ex: diminished effectiveness of breathing or decreased RR (hypovent)
- retention + accumulation of CO2 -> more acid in blood
- hypercapnia (high PCO2)
classic patient with resp acidosis
- unconscious and RR decreased from norm to 8 breaths a min -> not breathing out enuf CO2 -> retains CO2 -> blood CO2 high, pH low
body’s compensation for resp acidosis
- lungs are sick
- compensation by kidneys
- to buffer CO2 accumulation: kidneys increase HCO3 production or decrease its excretion
respiratory alkalosis
- state of high pH caused by increase in norm breathing pattern (hyperventilation)
- increased rate of breathing -> blow off more CO2 -> less CO2 in blood -> not enough acid
classic patient with respiratory alkalosis
- states that cause hypervent: anxiety, panic attack, acute asthma, emphysema exacerbations
- RR increases from norm to 28 breaths/min -> breath out too much CO2 -> blood CO2 low, pH high
normal resp rate
12- 20 breaths a min
body’s compensation for resp alkalosis
- sick lungs, compensation by kidneys
- increase CO2 in blood by kidneys decreasing amt of HCO3 made or increase excretion
- can also hang on to acidic substances like H+
metabolic acidosis
- low pH caused by accumulation of acids due to metabolic problems like renal failure + diabetic ketoacidosis
- acid gang accumulation overwhelms alkali guy, HCO3 low