ABG, PFT, heart sounds Flashcards
List the normal values for the following:
- pH
- pO2
- pCO2
- HCO3
- BE
- saO2
- pH = 7.35-7.45
- pO2 = 80-100 mmHg
- pCO2 = 35-45 mmHg
- HCO3 = 22-26 mEq/L
- BE = -2 - +2 mEq/L
- saO2 = 95-100%
What is step one of interpreting ABG?
Determine if pH value reflects acidemia or alkalemia
- above or below 7.4
What is step two of interpreting ABG?
Classify the pathophysiologic state on the basis of the relationship between pH and PaCO2 values
- inverse relationship = respiratory
- direct relationship = metabolic
What is step three of interpreting ABG?
Determine the adequacy of alveolar ventilation on basis of PaCO2 value.
- < 30 mmHg= Alveolar hyperventilation
- 30-50 mmHg= Adequate alveolar ventilation
- > 50mmHg= Ventilatory failure
What is step four of interpreting ABG?
Determine the Extent of respiratory and metabolic components.
- absolute value of difference between reported PaCO2 and 40; Divide by 100
- Subtract half of this value from 7.4 if reported PCO2 is > 40; Add the entire value to 7.4 if the reported PaCO2 is < than 40.
- Classify problem as “ACUTE” if reported pH is the same as or farther from normal than expected pH; Classify as “CHRONIC” if the reported pH is closer to normal than expected pH
What is step five of interpreting ABG?
Classify if compensated, partially compensated, or uncompensated
- if pH is normal and PaCO2 and HCO3 are BOTH abnormal, then the patient is compensated
- If pH is abnormal and PaCO2 and HCO3– are BOTH abnormal, then the patient is partially compensated
- If pH is abnormal, and either PaCO2 OR HCO3– are abnormal, then the patient is uncompensated
What causes a right shift in the oxygen dissociation curve?
conditions that enhance release of oxygen
- increased CO2
- Increased DPG 2,3
- Increased exercise
- Decreased pH
- Increased altitude
- increased temperature
What causes a left shift in the oxygen dissociation curve?
conditions that keep oxygen tightly attached to Hb
- decreased CO2
- decreased body temp
- increased pH
What are the levels of oxygen that indicate hypoxemia?
60-80 mm Hg: Mild hypoxemia
40-60 mm Hg: Moderate hypoxemia
< 40 mm Hg: Severe hypoxemia
Normal range:
- adults 60-80 mmHg
- infants 40-70 mmHg
What is the first thing to do when evaluating PFTs?
Look at the time volume plot to determine acceptability
- check for variable effort, cough, early glottic closure
- 6s of smooth continuous exhalation and/or a plateau in the volume time curve of at least 1s
- should have normal early peak, no abrupt cessation of flow, no sharp sudden spikes
What are the lung auscultation sites on the R anterior side of the body?
- R upper lobe apical segment
- R upper lobe anterior segment
- R middle lobe medial segment
- R middle lobe lateral segment
- R lower lobe anterior basilar segment
What are the lung auscultation sites on the L anterior side of the body?
- L upper lobe apical segment
- L upper lobe anterior segment
- L lower lobe anterior basilar segment
What are the lung auscultation sites on the L posterior side of the body?
- L upper lobe posterior segment
- L lower lobe superior basilar segment
- L lower lobe posterior basilar segment
- L lower lobe lateral basilar segment
What are the lung auscultation sites on the R posterior side of the body?
- R upper lobe posterior segment
- R lower lobe superior basilar segment
- R lower lobe posterior basilar segment
- R lower lobe lateral basilar segment
- lingular segment under armpitish area
Values for FVC and FEV1 that are over ___ of predicted are defined as within the normal range
80%
The FEV1/FVC ratio is expressed as a percentage, and a normal young individual is able to forcibly expire at least ___ of his/her vital capacity in one second.
A ratio under ___ suggests underlying obstructive physiology; however, the FEV1/FVC ratio declines as a normal sequelae of aging.
80% ; 70%
- reduced ratio is the primary criteria for diagnosing obstructive lung disease
What would the FEV1 values be to indicate normal, mild, moderate, and severe obstruction?
normal = >80% mild = 65-80% moderate = 50-65% severe = <50%
What shape do flow volume curves make when there is an obstruction
there is a rapid peak then curve descends more quickly than normal and takes on a concave shape, reflected by a marked decrease in FEF 25-75
What values are reduced proportionately with restrictive lung disease?
FEV1 and FVC
- note, FEV1/FVC ratio will be normal or even elevated; can’t get air in but can get it out