Diagnostc Tests For Pulmonary Function Flashcards
What do arterial blood gases asses?
Problems related to acid-base balance, alveolar ventilation and oxygenation
Normal pH value and range
Value = 7.40
Range = 7.35-7.45
Normal PCO2 (mmHg) value and range
Value: 40
Range: 35-45
Normal PO2 value and range
Value: 97
Range: >80
Normal HCO3- value and range
Value: 24
Range: 22 - 28
Normal % sat value and range
Value: 97%
Range: >95%
What does PaCO2 directly reflect?
Adequacy of alveolar ventilation
PaCO2 levels for hyperventilation
< 40 mmHg
PaCO2 levels for Hypoventilation
> 40mmHg
PaCO2 value for ventilatory failure
> 50 mmHg
What is ventilatory failure severity determined by?
The extent of acidemia and the repedity of the change of pH
What is acid-base balance an assessment of?
Blood pH - nature and magnitude of respiratory and metabolic disorders
What regulates the acid-base balance?
Lungs and kidneys
How do you determine the nature and severity of the illness with accuracy when it comes to blood gas analysis?
Relationship of arterial pH and arterial CO2 tension is assessed
What does the Henderson-Hasselbalch equation represent?
Carbonic acid to bicarbonate ion relationship
What does the Henderson-Hasselbalch equation permit?
A quick identification of four primary disorders based on pH and CO2
What organ regulates bicarbonate?
Kidneys
Normal human blood pH
7.4
What level of pH is academia?
< 7.4
What does low HCO3 lead to?
Metabolic acidosis
What does high PaCO2 lead to?
Alveolar Hypoventilation and hypercapnia
What is the pH level of alkalemia?
> 7.4
What does high HCO3 cause?
Metabolic alkalosis
What does low PaCO2 cause?
Alveolar hyperventilation, hypocapnia
What does base excess (BE) reflect?
Concentration of bicarbonate in body
What is normal PaO2?
80 to 100 mmHg
What level of PaO2 causes hypoxemia?
< 80 mmHg
What causes respiratory acidosis?
Hypoventilation
Over sedation
Head trauma
NM disorders
Cardiac arrest
Chest trauma
COPD
Pneumonia
Symptoms of respiratory acidosis?
Tachycardia
Confusion
Drowsiness
Dizziness
Minimal if chronic (COPD)
Causes of metabolic alkalosis?
Loss of acid from GI tract or kidney
Increased HCO3- reabsorption or generation
What causes loss of acid from GI tract or kidney?
Vomiting
Laxative abuse
What causes increased HCO3- reabsorption or generation?
Excessive use of antacids
Symptoms of metabolic alkalosis
Tetany
Hypertonic muscles
Numbness
Asymptomatic
What causes metabolic acidosis?
Increased production of acids
Decreased acid excretion by kidneys
Loss of alkali
What causes increased production of acids?
Ketoacidosis
Lactic acidosis
What causes decreased acid excretion by kidneys?
Renal failure
What causes loss of alkali?
Diarrhea
Symptoms of metabolic acidosis
DOE
Deep, rapid breathing
Disorientation
Fatigue
Weakness
Causes of respiratory alkalosis
Hyperventilation
Hypoxemia
CHF
PE
What can cause hyperventilation?
Anxiety/fear/pain
Excessive mechanical ventilation
Symptoms of respiratory alkalosis
Numbness and tingling of lips and extremities
Dizziness
Sinus arrhythmia
What is pulse oximetry an indirect measure measurement of?
O2 saturation
Normal saturation is …?
> /= 95%
Mild hypoxemia PaO2 level
60-80 mmHg
Moderate hypoxia PaO2
40-60 mmHg
Severe hypoxia PaO2
< 40mmHg