Chapter 42 Egan Medical Gas Therapy (Exam 2)

What 2 things are the overall goal of O2 therapy?

maintain adequate tissue oxygenation and minimizing cardiopulmonary work

What 3 things are clinical objectives for O2 therapy?

correct documented or suspected acute hypoxemia, decrease symptoms associated with chronic hypoxemia, decrease the workload hypoxemia imposes on the cardiopulmonary system

What are the PaO2 and SaO2 levels for documented hypoxemia?

PaO2 < 60 mmHg and SaO2 < 90%

What are the four main complications with oxygen therapy?

Oxygen Toxicity, Depression of Ventilation, Retinopathy of Prematurity (ROP), Absorption Atelectasis (N2 washout)

What are the 3 basic designs for oxygen delivery systems?

low-flow, high-flow, and reservoir systems

When would a Nasal Catheter be used?

bronchoscopy

What is the FiO2 and LPM range of nasal catheter?

0.25-5 LPM and 22-45%

What is the LPM and FiO2 for a Transtracheal Catheter?

.25 - 4 LPM and 22-35%

What is the main complication with Transtracheal Catheter?

infection

At what flow is the problem of inaccuracy flow greatest?

less than or equal to 3 LPM

What are the two Reservoir Canula systems and what is main purpose of use for them?

nasal reservoir and pendant reservoir; designed to conserve oxygen

What are 3 most common of reservoir masks?

simple mask, partial rebreathing mask, nonrebreathing mask

When is most common situation for a simple mask?

short-term oxygen use for post-op patients

What happens with mask volume when simple mask is set less than 5 LPM?

acts as dead space and causes CO2 rebreathing

What is design difference between nonrebreather and partial rebreather?

a nonrebreather prevents rebreathing with one-way valves

What is rule of thumb for high-flow systems with flow?

to qualify as high-flow device, a system should provide at least 60 LPM of total flow

How does given O2 concentration of high-flow system relate to patients peak inspiratory flow?

the flow must equal or exceed the patient's peak inspiratory flow rate

What is main benefit of using a high-flow device?

can ensure fixed FiO2

What 2 key variables do FiO2 provided by air-entrainment devices depend on?

air-to-O2 ratio (total flow of device) and amount of flow resistance downstream from mixing site

What are the 3 main features of a High-Flow Nasal Cannula?

delivers a high FiO2, meets or exceeds the patient’s minute ventilation and therefore acts as a fixed oxygen delivery device, generates a distending positive airway pressure

When are Blending Systems typically used?

when air-entrainment devices cannot provide a high enough O2 concentration or flow

What is the benefit of using a blender?

allows precise control over both FiO2 and total flow output by separating pressurized air and O2 and mixing

How does an oxygen blender work?

air and O2 enter the blender and pass through dual pressure regulators that exactly match the two pressures allowing the gas to flow to a precision proportioning valve

What are the 3 Ps for selecting a Delivery Approach?

purpose, patient, and performance

What is the general purpose when selecting a delivery system?

to increase FiO2 sufficiently to correct arterial hypoxemia

What does an order for O2 therapy via protocol permit?

permits O2 therapy to be initiated, modified, or discontinued by the RT without needing a physician order each time

What is purpose of Nitric Oxide Therapy?

vasodilates improving blood flow to lungs, improving oxygenation, and decreasing pulmonary vascular resistance

What is the value of Helium as a therapeutic gas use?

based solely on its low density

How is the general way that Heliox improves patients breathing?

less dense gas mixture creating a laminar flow instead of turbulent flow reducing work of breathing

What 3 things would CO2 - O2 (Carbogen) therapy be used?

hiccups, carbon monoxide poisoning, preventing complete washout of CO2 during cardiopulmonary bypass

What are the available mixtures for Carbogen?

5:95% and 7:93%