Oxygen Therapy

Question 1

What is Hypoxemia

Answer 1

-it is the abnormal low oxygenation of aryerial blood
-caused by hypoventilation, diffusion abnormalities, reduced FiO2 and Hb deficiencies
-it is determined by ABG
-can progress to hypoxia that is reduced oxygen at tissue level

Question 2

What is Oxygen therapy

Answer 2

-it is the therapeutic application of oxygen at a higher cncertration that room air
-increases alveolae oxygen concerntration
-prevents or treats hypoxemia
-utilized in acute conditions (pneumonia), trauma,myocardial infarction, after surgery and chronic conditions (chronic heart failure and COPD)
-medically prescibed
-PT indicates the device, flow rate, O2% and saturation
-effects should be closely monitored

Question 3

Complications of O2 Therapy

Answer 3

-impaired respiratory drive in hypercapnia COPD
-O2 toxicity
-blindness in children
-absorption atelectasis
-drying of mucous membranes
-pt dependency
-fire hazard

Question 4

How to deliver O2 therapy

Answer 4

-O2 source
-flow meter
-O2 delivery device

Question 5

O2 delivering systems

Answer 5

-variable performance device
-fixed performance device
-enclosure systems

Question 6

Variable performance devices

Answer 6

-delivers O2 at low flow rates
-sensitive to pt’s ventilation pattern and RR
-cannot predict FiO2
-FiO2 increases by 4% for every 1 L/min increase in flow

Question 7

Three types of variable performance device

Answer 7

-nasal cannula
-simple O2 masks
-resevoir masks

Question 8

Nasal cannula

Answer 8

-two soft prongs inserted in anterior nares and connected to O2 source via tubing
-nasopharynx acts as resevoir
-flow rate= 0.23-6 L/min
-flow rate greater than 4 L/min result in dryness therefore humidification needed

Question 9

Simple oxygen mask

Answer 9

-plastic mask that covers mouth and nose with exhalation ports on the sides of mask
-base has air inlet that has a tubing connected to source
-room air flow through mask and the ports with the oxygen hence increasing total flow
-mask is the resevoir
-flow rate= 5-10 L/min
-provides +/- 40-60% O2

Question 10

Resevoir masks

Answer 10

-similar to simple O2 mask but has 1L resevoir bag that increases resevoir volume and FiO2
-has two types- partial and non-rebreathing mask

Question 11

Partial rebreathing

Answer 11

-during exhalation, O2 and 1/3 expired air enters bag
-last 2/3 of expired air goes through exhalation ports
-O2 flow should be suffienct to not deflate the bag
-produce 40-70% O2

Question 12

Non-rebreathing mask

Answer 12

-theres is a one-way valve between the reservoir bag and mask
-prevents exhaled air from entering the bag
-port valves close during inhalation and the reservoir valve open to deliver O2
-vice versa for exhalation
-provides 60-90% O2

Question 13

Fixed performance devices

Answer 13

-delivers relatively high O2 rate to equal/exceed peak respiratory flow
-the FiO2 is known/fixed
-example is venturi mask that has large exhalation ports
-delivers 20-60% O2
-no humidification if flow less the 4 L/min
-used for hypercapnia COPD

Question 14

Enclosure systems

Answer 14

-used for infants and children
-examples include O2 tents, hoods and incubators

Question 15

Domiciliary Oxygen therapy

Answer 15

• when pt requires O2 therapy at home
  -delivered using a nasal cannula

Question 16

Types of domiciliary oxygen therapy

Answer 16

-long-term oxygen therapy (LTOT) is O2 deliver over 18hrs a day, flow rate maintain PaO2 and SpO2
-nocturnal oxygen therapy (NOT) for pts who requires therapy for more that 1/3 of the night
-Ambulatory oxygen therapy (AOT) for pts on LTOT that req it during ambulation

Question 17

Domiciliary Oxygen therapy delivering systems

Answer 17

-oxygen concerntrator is an electric device that use a molecular sieve to separate O2 from nitrogen in room air
-compressed gas cylinder is most common, cylinder is in trolley and requires regular delivery and changing
-liquid oxygen system consists of a large stationary unit where small canisters are filled with liquid oxygen, very costly and requires regular deliveries

Question 18

Assessment for Home Oxygen

Answer 18

-pulse oximetry less 92% req home therapy
-ABG analyzed to assess LTOT eligibility

Question 19

Contraindications for home oxygen therapy

Answer 19

-severe cardiopulmonary disease with dypnoea but PaO2>60
-pts who continue to smoke
-no adequate therapy for underlying conditions that caused hypoxaemia
-not motivated to be disciplined to use for the prescribed hours of the day

Question 20

General PT considerations of O2 therapy

Answer 20

-treat at bedside if pt needs continuous O2
-document, device and flows during treatment
-ensure device fits correctly
-monitor skin or provide appropriate padding
-observe mask for sputum, clear or change if needed