ABG, Oximetry, & Spirometry Flashcards
What information is obtained from an ABG?
- acid base status
- oxygenation
- CO2 elimination (aka ventilation)
- COHb & methemoglobin level
What are the indications for ABG?
- assess the ventilatory status, oxygenation, & acid base status (CO2, O2, & pH, respectively)
- assess the response to an intervention
What are the contraindications for ABG?
- bleeding diathesis
- AV fistula
- severe peripheral vascular disease, absence of an arterial pulse (arteriolosclerosis)
- infection over the site
What are the differences between ABG and pulse ox?
- pulse ox is non-invasive & provides immediate, continuous data
- pulse ox does not assess ventilation (CO2) or pH
- pulse ox unreliable when pO2<70-80%
- pulse ox cannot interpret methemoglobin or COHb
T/F: Pulse oximetry can assess the patients ventilation (CO2).
- FALSE!
Which artery is used in ABG?
- *radial artery
- femoral, dorsal pedis, brachial
What will the ABG values be for a patient in respiratory acidosis?
- low pH
- high pCO2
What will the ABG values be for a patient in metabolic acidosis?
- low pH
- low HCO3
What will the ABG values be for a patient in respiratory alkalosis?
- high pH
- low pCO2
What will the ABG values be for a patient in metabolic alkalosis?
- high pH
- high HCO3
What is the disorder of a patient with ABG values of low pH and high pCO2?
- respiratory acidoisis
What is the disorder of a patient with ABG values of high pH and low pCO2
- respiratory alkalosis
What is the disorder of a patient with ABG values of low pH and low HCO3?
- metabolic acidosis
What is the disorder of a patient with ABG values of high pH and high HCO3?
- metabolic alkalosis
What are the causes of respiratory alkalosis?
- hyperventilation
What are the causes of respiratory acidosis?
- hypoventilation
What does VBG assess?
- pH
- CO2
What should spirometry be used to diagnosis?
- asthma
- COPD
What S&S would lead to a dx of asthma?
- wheezing
- hx: cough worse @ pm, recurrent wheeze, difficulty breathing, & chest tightness
- ‘wheeze with a squeeze’
What are indications for spirometry?
- persistent cough
- chronic sputum production
- breathlessness on exertion
- decreased activity
- occupational exposures
- (+) family hx
T/F: Spirometry is NOT recommended for screening of COPD.
- True
When should spirometry be used?
- initial assessment
- s/p tx (i.e. pharmacologic)
- loss of control of asthma
- q 1-2y
- demonstrate to the pt the tx that they cannot feel is actually working
What age group does not get spirometry?
- 0-4y
What are contraindications for spirometry?
- anything that has increased pressure
What does a low spirometry FEV1/FVC ratio indicate?
- obstructive dz
What does a non-low spirometry FEV1/FVC ratio and low FVC value indicate?
- restrictive dz
