Medical Gas Therapy - Egan's Chapter 42 Review

A complete set of vocabulary flashcards covering medical gas therapy principles, oxygen delivery systems, clinical hazards, and calculation thresholds from Egan's Chapter 42 review.

Ventilatory Demand

The work of breathing that can be decreased through properly applied $O_2$ therapy.

Nonrebreather Mask

An oxygen administration device used to deliver high concentrations of $O_2$ ($FiO_2$ approximately $0.60-0.80$) that features one-way valves to prevent rebreathing.

Acute Hypoxemia

A condition defined by low oxygen in the arterial blood, specifically a $PaO_2$ less than $60\,\text{mmHg}$ or an $SaO_2$ less than $90\%$ while breathing room air ($FiO_2\ 0.21$).

Hypercapnia

An abnormal physiological state defined as increased $CO_2$.

Retinopathy of Prematurity (ROP)

A hazard of oxygen therapy in neonates that may result in blindness or visual impairment.

Variable-Performance Systems

$O_2$ delivery systems that provide only part of the patient's inspiratory demand.

Nasal Cannula FiO2 at $4\,\text{L/min}$

Delivers an approximate $FiO_2$ of $0.36$, or $36\%$.

Partial-Rebreather Mask

An oxygen reservoir mask containing $0$ valves that delivers an $FiO_2$ range of $0.40-0.70$ ($40\%-70\%$).

High-Flow Nasal Cannula

An oxygen delivery device that is classified as not being a reservoir device.

Adult Simple Mask Minimum Flow Setting

A flow rate of at least $5\,\text{L/min}$, set to wash out exhaled gases.

True High-Flow $O_2$ Delivery System

An oxygen delivery system that must provide a total flow of at least $60\,\text{L/min}$ to meet or exceed a patient's inspiratory demand and ensure a stable $FiO_2$.

Air-Entrainment System Downstream Obstruction

Back pressure or resistance in the entrainment system causing delivered $O_2$ concentration to increase, total output flow to decrease, and $FiO_2$ to become variable.

Air Entrainment Mask Flowmeter Adjustment

Raising the delivered flow from the flowmeter results in no change in delivered $FiO_2$, but increases total output flow.

Absorption Atelectasis

Alveolar collapse that occurs when high $FiO_2$ washes nitrogen out of the alveoli.

Five Hazards of $O_2$ Therapy

The five primary hazards associated with oxygen administration: $O_2$ toxicity, Retinopathy of Prematurity (ROP), Depression of Ventilation (DOV), fire hazard, and absorption atelectasis.

Vicious Cycle of Oxygen Toxicity

A damaging clinical cycle: $\text{O}_2\text{ toxicity} \rightarrow \text{increased shunting} \rightarrow \text{low } PaO_2 \rightarrow \text{increased } FiO_2 \rightarrow \text{O}_2\text{ toxicity}$.

Bag-Mask Device (BMD / BVM)

A resuscitation device used in an emergency setting to administer close to $100\%$ $O_2$.

Fire Triangle Elements

The three components necessary for a fire to start and continue to burn: oxygen, heat, and fuel.

Emergency Situation $FiO_2$

An oxygen concentration setting of $FiO_2\ 1.0$ ($100\%$).

Determinants of $O_2$ Toxicity Damage

Two primary factors that cause oxygen-induced tissue damage: high concentration ($FiO_2$) and length of exposure.

Organs Susceptible to $O_2$ Toxicity

The two anatomical organs directly vulnerable to oxygen toxicity: the lungs and the central nervous system.

Disadvantages of $O_2$ Masks

Clinical complications associated with masks, including skin irritation, aspiration, and suffocation.

Assessment Methods for Supplemental $O_2$

Three clinical indicators used to determine the need for oxygen therapy: $PaO_2$, $SaO_2\ /\ SpO_2$, and clinical situation.

Clinical Indications for Supplemental $O_2$

Conditions requiring oxygen therapy beyond low blood values, including trauma, myocardial infarction (MI), anesthesia / post-anesthesia recovery, chest pain, hypoxemia, and sickle cell anemia.