Ch.8 Flashcards
Identify the reference ranges for both arterial blood gas and oximetry parameters?
PaO2 80-100 mm Hg (room air)
Hb Males: 14-18 g/dL
Females: 12-15 g/dL
SaO2 >95%
COHb <3% (nonsmokers)
metHb <1.5%
CaO2 16-20 mL/dL
pH 7.35-7.45
PcO2 35-45 mm Hg
НСO3 22-26 mmol/L
BE + or -2 mmol /L
Identify the indications for blood, gas, and oximetry analysis.
Method-Arterial blood gas analysis:
Evaluate ventilation (PCo2), acid-base (pH, PCo2, and HCO3 ), and oxygenation (Po2) status.
Assess the patient’s response to therapy and/or diagnostic tests (eg. O2 therapy, exercise testing)
Monitor the severity and progression of a disease process
Identify the indications for blood, gas, and oximetry analysis.
Method-Hemoximetry (CO-oximetry):
Determine actual blood O, saturation (as opposed to that computed with a simple blood gas analyzer)
Measure abnormal hemoglobin levels (e.g, COHb, metHi
Identify the indications for blood, gas, and oximetry analysis.
Method-Pulse oximetry
Monitor the adequacy of oxyhemoglobin saturation
Quantify the response of oxyhemoglobin saturation to therapeutic intervention or to diagnostic procedure (e.g., bronchoscopy)
Comply with mandated regulations or recommendations by authoritative groups (e.g. anesthesia monitoring)
Screen infants for critical congenital heart diseases
Identify the indications for blood, gas, and oximetry analysis.
Transcutaneous monitoring (PtCo2, Ptcco2,)
Continuously monitor the adequacy of arterial oxygenation and/or ventilation
Continuously monitor for excessive arterial oxygenation (hyperoxemia)
Quantify real-time changes in ventilation and oxygenation due to diagnostic or therapeutic interventions
Screen infants for critical congenital heart diseases
Differentiate between invasive, and I invasive methods for measuring blood gas in oximetry parameters.
*Invasive: Obtained by needle puncture or catheter.
*Non-invasive: Uses external skin sensors.
What are the factors affecting hemoglobin saturation to interruption of oximetry data?
•Presence of COHb
•Presence of metHb
•Vascular dyes
•Dark skin pigmentation
•Nail polish
•Poor local perfusion
•Motion artifact
•Ambient light
How is oxygenation used to assess the cause of severity of hypoxemia.
PaO2
SpO2
SaO2
CaO2
What are the classifications for hypoxemia?
80-100 (Normal)
60-79 (Mild)
40-59 (Moderate)
<40 (Severe)
What are some causes of hypoxemia?
•Hypoventilation
•V/Q mismatch
•Pulmonary shunting
•Diffusion defect
•Low Pio2
How does the Henderson- Hasselbalch equation relate to change the PCO2 and bicarbonate to pH?
The ratio has to stay at 20:1 for normal pH. When pH falls out of this range the bicarbonate and the CO2 will work opposite of each other to help bring pH back to 20:1.
What are the common causes of mixed acid base disorders?
Chronic respiratory acidosis and metabolic alkalosis
-Ventilatory failure and diuretic therapy
-COPD patient treated with steroids or ventilation
Respiratory alkalosis in metabolic acidosis
-salicylate intoxication,
-gram-negative,
-sepsis,
-severe pulmonary edema
Identify the common pre-analytics errors in blood gas analysis.
• Air in sample
• Venous blood admixture
• Excess liquid heparin (dilution)
• Metabolic affects
Identify the common analytic errors in blood gas analysis.
• Calibration
• Verification
• Proficiency testing
Identify the common post-analytic errors in blood gas analysis.
• Incorrect reporting
• Improper interpretation or use of results
What are specific method used to ensure a valid measurement and use of blood gas data?
• Internal validity checks
• External validity checks
How do you interpret arterial blood gas and/or oximetry data?
• O2 assessment
• Acid- base assessment
