Oxygen Therapy - Chapter 14 - Mazzaferro Flashcards
What is the difference between hypoxia and hypoxemia?
Hypoxia is a decrease in the level of oxygen supply to the tissues.
Hypoxemia refers to inadequate oxygenation of arterial blood; defined as PaO2
What is the equation for Oxygen Delivery (DO2)
[CO x the arterial oxygen content]
What is the equation for the arterial oxygen content
[1.34 (mL O2/g) x SaO2 (%) x Hgb (g/dl)] + [PaO2 (mmHg) x 0.003 (mL O2/dl/mmHg)]
What oxygen flow rate can be provided via nasal oxygen lines? and what FiO2 does it provide?
50-150 ml/kg/min can provided 30-70% FiO2
What are the five phases of oxygen toxicity?
(1) Initiation phase - oxygen-derived free radical species (i.e. superoxide anion, peroxide and hydroxyl radicals) cause direct damage to pulmonary epithelial cells as cellular antioxidant stores become depleted. Occurs within 24-72 hrs of exposure to 100% oxygen
(2) Inflammatory phase - Destruction of the pulmonary epithelial lining causes airway inflammation and recruitment of activated inflammatory cells to the site; there is a massive release of inflammatory mediators resulting in increased tissue permeability and development of pulmonary edema.
(3) Destruction phase - severe local destruction occurs and is most commonly associated with patient mortality. I
(4) Proliferation phase - if patient survives phase 3 - type II pneumocytes and monocytes increase during stage of proliferation
(5) Collagen deposition and interstitial fibrosis occurs and can result in permanent lung damage.
An FiO2 or more than ___% should not be administered for longer than ___ to ___ hours.
An FiO2 or more than 50% should not be administered for longer than 24 to 72 hours.
In neonatal patients, oxygen toxicity may cause this type of lesion.
A retinal lesion called retrolental fibroplasia - therefore titrate to the lowest possible concentration in neonates
