Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

CARDIO > W2 > Flashcards

W2 Flashcards

1
Q

what is oxygen therapy?
- including its purpose and uses

A

therapeutic administration of oxygen at a concentration greater then that available to us

purpose = to increase oxygen concentration that gets to alveolar

used to prevent or correct
- hypoxemia - abnormally low oxygenation of arterial blood
- tissue hypoxia - insufficient oxygen available to the tissues to meet metabolic needs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are the acute indications for oxygen therapy?

A
  • cardiac or respiratory arrest
  • to correct acute hyperaemia (PaO2 <80mmHg)
  • acute hypotension
  • to reduce myocardial workload
  • during and post procedure/ general anaesthetic
  • carbon monoxide poisoning
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are the sources of oxygen?

A
  • reticulated system: ‘unlimited’ supply at the bedside. can provide low or high flow
  • portable cylinder: useful when mobilising/moving patients, home oxygen, limited supply depending on size of cylinder. can provide low or high flow oxygen
  • oxygen concentrator: home oxygen, electrical device, entrains room air filters out the nitrogen and delivers approx 95% oxygen at low flows, need back up power supply
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is FiO2 (fraction of inspired oxygen)

  • including what it is on RA and oxygen therapy
A

when we take a deep breath in, breathing atmospheric air - but not all of it is oxygen

percentage of oxygen in the air that your breathing in

room air: 21% oxygen

on oxygen therapy: start at 21% and add 3% for every 1L
- 1L = 24%
- 2L = 27%
- 3L = 30%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is the difference between variable and fixed performance devices for oxygen therapy?

A

Variable performance devices (low flow oxygen)
- Known oxygen flow rate of oxygen to patient, but unknown FiO2 delivered via fine bore tubing
○ Patients inspired FiO2 varies according to peak inspiration flow demands and breathing pattern
- The flow is less than the peak inspiratory flow rate (inspiration of room air will dilute the oxygen delivered) and FiO2 will vary with the rate and volume of breath (don’t supply a reliable FiO2
- e.g. nasal prongs and Hudson mask

Fixed delivery performance devices (most common devices are high flow)
- Known FiO2 delivered to the patient via wide bore tubing
- Provided the total flow is greater than inspiratory flow of the patient
- Example: delivering an FiO2 via a venturi system or AIRVO2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

how do you assess a patients oxygen levels?

A
  • appearance - look (colour of skin), consciousness, distress, WOB, RR
  • SpO2 (via pulse oximeter) -> measures saturation of peripheral oxygen that is bound to haemoglobin
    - normal = above 95%
    - medical team may lower e.g. if COPD 88-92%

-PaO2 - partial pressure of oxygen in arterial blood (via ABGs)
- less then 80mmHg = hypoaxemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what do we need to consider about how much oxygen gets delivered to the tissue?

A

the total amount of arterial oxygen x cardiac output

  • equal to the delivery of oxygen to the tissue
    e.g. -> failing heart = even if give oxygen the heart cant pump so wont increase
    -> low haemoglobin = haemoglobin cant carry oxygen to the tissue
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

how do you monitor someones response to oxygen assessment?
- weaning
- increasing oxygen

A

weaning:
- if vital signs within normal limits, stable,
- turn off O2 and monitor patient -> SpO2, appearance and vital signs

increasing:
MUST RESPOND IMMEDIATELY
- may be required if SpO2 is below target level
- patient experiencing respiratory distress or becoming medically unwell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

NASAL PRONGS:
- flow rate

A

0.25 - 4lpm (no minimum flow rate)
Higher flows cause mucosal dryness and can cause epitaxis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

NASAL PRONGS
- application

A

Turn on oxygen flow
Prongs up each nostril
Tubing over ears
Toggle under chin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

NASAL PRONGS:
- advantages

A

Simple, quick, unobstructive, can be used during meals, visiting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

NASAL PRONGS:
- disadvantages

A
  • Variable oxygen device
    • Only appropriate for relatively low oxygen requirements
    • Mucosal drying and irritation
    • Potential for pressure areas to develop around ears and nose
      • FiO2 can only be estimated
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

FACE MASK:
- flow rate

A
  • Typically 5-10lpm
    • Lower flow rates risk d rebreathing carbon dioxide
      - If flow > 10 lpm or needing oxygen for > 1 day recommend humidified
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

FACE MASK
- application

A
  • Turn on oxygen
    - Apply the face mask, fit over nose then apply elastic strap
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

FACE MASK
- advantages

A
  • Simple to use, quick to set up (e.g. for patients during an arrest)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

FACE MASK:
- disadvantages

A
  • Variable oxygen device
    • Risk of carbon dioxide rebreathing
    • Not humidified (drying of secretions)
    • Potential for pressure areas across nose or with elastic straps
    • Cant eat or comfortably speak
17
Q

what is a venturi?

A

fixed performance device - able to deliver known FiO2

Benoulli’s venturi principle:
- Oxygen enters the venturi as a jet
○ Jet of gas generates low lateral pressure as it travels past the entrainment port, which results in drawing in of outside air
○ Total gas from use -> total gas from wall flow meter as well as flow of air being entrained into system from venturi
Constant flow of air entrained through holes

Delivers a mixture of oxygen and room air (RA) to patient:
- Total flow more then peak inspiratory flow (PIF) of patient
○ Normal PIF = 20-30 lpm, shortness of breath (SOB) more then 50lpm
- The amount of room air entrained to dilute the oxygen depends on:
○ Size of port holes and speed of oxygen flow
○ Not always perfect in practice
- The pressure created in the system can reduce the flow of gas to the patient
- If FiO2 equal to or greater then 60% or shortness of breath (SOB) at rest need double system of blender

18
Q

what is the purpose of humidification in oxygen therapy and when would you consider it?

A

Purpose of humidification: mimic typical nasal passage
- Moisten (and warm) inspired air
- Decrease viscosity of secretions
- Reduce airway trauma

Consider humidification if:
- The normal means of humidifying inspired gas has been bypassed or is not functioning effectively e.g. a patient is intubated/ tracheostomy or laryngectomy
- The mucocillary escalator is not functioning correctly
- Thick tenacious secretions
- Infants and children - greater problems heating gases
- Requiring more then 10lpm of oxygen therapy for longer then 1 day

19
Q

what are the 2 types of fixed performance humidification devices (list)

A
  • FISHER AND PAYKEL
  • AIRVO 2
20
Q

explain the fisher and paykel humidification device and how to set up?

A

Has been most common fixed performance device:
- If includes a venturi then it is a fixed performance device (known FiO2)
- If no venturi then it is a variable performance device (known flow rate)
Warm water humidification
Gas is blown over heated sterile water in a disposable water bowl

Set up:
- Flow meter -> narrow bore tubing -> venturi device (some hospitals do not use a venturi device) -> one side of water bowl -> wide bore tubing to exit other side -> patient interface (high flow nasal cannula, face mask, trachea shield)
- IV bag drips in sterile water
- Some models allow dialling up of precise temperature (ICU and tracheostomy patients)
- Dial up oxygen flow according to the venturi (before you apply to the patient)
- May use air oxygen blender or high flow regulator or two oxygen cutlets and two venturi devices

21
Q

explain the AIRVO2 and how to set up

A

Heated humidification and oxygen delivery (fixed performance)
- Air pump 2-60lpm
- Oxygen is attached to the back of the unit. And becomes part of the entrained gas FiO2 21-100%
Patient interface (High flow nasal cannular, face or tracheostomy masks)
Heated pass-over humidification
- Water chamber is heated and vaporises the water molecules (i.e. water molecules are small compared to a bubble through system and nebuliser humidifiers that produce water droplets)
- Gas flows through the chamber and is humidified with the vapour, with humidified gas leaving chamber at 37 degrees

set up:
- slide into place on humidifer until it clicks
- attatch sterile water
- connect breathing tube (Blue end to the top of the AIRVO2)
- plug into the power - turn on
- check disinfection stae (Green light on screen)
- set patient setting - connect wall o2 with the fine bore tubing
- turn on flow rate until FiO2 is displayed on screen
- wait for the ready to use sound
- connect patient interface

22
Q

how can you monitor a patients oxygen therapy?

A

subjective:
- patient comfort
- shortness of breath (BORG, RPE scale)

objective:
- pulse oximetry (SpO2)
- ABGs
- colour (cyanosis)
- distress (SOB, accessory muscle use)
- repiratory rate (RR)

23
Q

what are the hazards of oxygen therapy?

A
  • absorption atelectasis
  • hypoxic drive
  • retrolental fibroplasia (retinopathy of prematurity)
  • fire hazard
  • infection
  • bronchoconstriction
24
Q

what are the hazards of humidification:

A
  • over hydration
  • overheating
  • electrical safety
25
Q

what is an ABG and what is it used for?

A

Sample of blood taken from (usually), a peripheral (commonly the radial artery) and analysed in a blood gas analyser
measures: pH, PaCO2, PaO2, HCO3, BE, SaO2

used for:
- presence of hypoxemia (oxygen delivery to the tissue) (PaO2 and SaO2)
- presence or degree of hypocapnia/ hypercapnia (carbon dioxide levels) (PaCO2)
- Acid base balance (pH)

26
Q

what are the normative ranges for ABGs

A

pH 7.35-7.45
low = acidic
high = basic
PaCO2 35-45mmHg
low = basic
high = acidic
PaO2 80-100mmHg
HCO3- 22-26mmol/L
low = acidic
high = basic
BE/BD +-2
Sao2 95-100%
Hb 12-14 (F) (M)

27
Q

what are the types of respiratory failure?

A

type 1: hypoxamia (Pa <60mmHg) wihtout hypercapnia (PaCO2 no higher than 50mmhG)

type 2: hypoxaemia (Pa <60mmHg) with hypercapnia (PaCO2 > 50mmHg)

28
Q

what are the effects of hypoxia

A

death of cells
coma
depressed mental activity

28
Q

what are the effects of hypercapnia

A

death (@100-150mmHg)
coma
depressed mental activity
unbearable dysponea
tremor
headaches
flushed

28
Q

why do a PFT?

A
  • Ascertain severity and type of pulmonary disorder
    • Monitoring pulmonary disorder progression (improvement or deterioration)
    • Monitoring effects of inhaled drugs on the lungs
      ○ Take pre-post bronchodilator readings
    • Pre-op screening to establish anaesthetic risk
      • Can help establish suitability for lung transplantation or lung volume reduction surgery
29
Q

what are the types of PFTs

A
  • DLCO (or TLCO) -> diffusing capacity for lung for carbon monoxide
    • Body plethysmography -> measure FRC and total lung capacity
    • Exercise stress test -> measures VO2 max, changes in vital signs during exercise
    • Spirometry (most common)
      • Peak flow
29
Q

what is spirometry?

A
  • Easy way to measure lung function
    • Can be done using portable device or conducted in a lung function laboratory
    • Subject results are recorded with the subjects:
      ○ Age
      ○ Sex
      ○ Height
      ○ Ethnic origin
    • Results are compared with ‘predicted data’
      Predicted values are the mean values derived from a ‘normal’ population of people that age, height, sex and ethnic origin
29
Q

what instructions do you give to a patient doing a spirometry?

A
  • take in a max deep breath
  • seal lips around mouthpiece
  • blow out through mouthpiece as hard and fast as possible
  • keep blowing out until lungs are ‘empty’
  • min duration =6 seconds
29
Q

what values do we look at in the results of a spirometry?

A
  • vital capacity (VC)
  • forced vital capacity (FVC)
  • forced expiratory volume (FEV1)
  • peak inspiratory flow rate (PEFR)

represented in a volume/time curve or a flow/volume loop

30
Q

how do you interpret spirometry?

A
  1. look at FEV1/FVC
    - normal = 70-85%
    - if less then 70% = obstructive/mixed
    - if more than 70% = restrictive/normal
  2. look at FVC
    - if below 80%= chronic lung disease
    - either obstructive or restrictive
  3. look at FEV1
    - 60-80% = mild disease
    -40-60% = moderate disease
    - <40% = severe disease
31
Q

why would you do a PFT pre and post bronchodilator?
what improvement shows that it has worked?

A
  • helps determine the reversibility of airway obstruction
  • post bronchodilator should show a 12% improvement in FEV1 to confirm
32
Q

how do you measure peak inspiratory flow meter and why?

A
  • measured using PEF meter
  • cheap, portable, rapid, easy
  • measured in L/min and gives good indication of airway calibre
  • often used at home for patients to monitor obstructive lung disorders

quality considerations:
- the test is a maximal and if effort dependent
- perform test in consistent way: position etc

33
Q
A

CARDIO (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions