Brainscape's Knowledge GenomeTM

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


See full index

Cardiopulmonary Science > Week 2 Hypoventilation / Shunt / Diffusion limitation > Flashcards

Week 2 Hypoventilation / Shunt / Diffusion limitation Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

Invasive and non invasive ways of measuring arterial oxygenation

A

Invasive: Sample of arterial blood PaO2 SaO2

Non invasive: Oximetry SpO2

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

Hypoventilation

Define

A

Amount of fresh gas going to the alveoli (VA)(alveolar ventilation) per unit of time is reduced.

VA= (VT- VD) x f (tidal volume-deadspace)

(VE)(Expired total ventilation) is inadequate for metabolic demand or
(VT)(Tidal volume) is too shallow to clear anatomical dead spaceeffectively

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

List 4 Concequences of hypoventilation

A

Increased PaCo2
Decreased PaO2 (may be increased w o2 therapy)
Increased work of breathing
( to eliminate co2 if normal control of breathing is preserved)
Increased dead space- ( physiological dead space)

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

List 9 Causes of hypoventilation

related to their location in the body.

A
  • Depression of the respiratory centre
  • Trauma haemorrage medulla
  • Spinal injury (C 3,4,5 PHRENIC NERVE)
  • Disease of anterior horn cells (POLIO)
  • Disease of nerves supplying muscles ( eg MS)
  • Diseases at myoneural junction (eg myesthenia gravis)
  • Muscles themselves (Guillan barre,MD)
  • Thoracic cage problems (scoliolis)
  • Upper airway problem
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Sleep disordered breathing

Describe the 2 kinds

A
  • Central sleep apnoea (in brain stem)
    decreased respiratory drive during REM sleep

-Obstructive sleep apnoea(OSA) ( upper airways)
muscle tone around tongue and oropharynx decrease
shape of airway circular to oval
airways close down on expiration
*also close down on inspiration
upper airway-pos pressure
lower airway-neg pressure

Mask ventilation for OSA will blow pos pressure into upper airways to keep them open.

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

Shunt Definition

A

Blood enters arterial system WITHOUT going through ventilated areas of the lung.
Deoxygenated blood mixes with oxygenated reducing PaO2.

Shunts

  • Normal
    • Bronchial circulation
    • Coronary circulation
  • Pathological shunt
    • vascular
    • intrapulmonary
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe the 2 causes for

Pathological shunt

A

Vascular- kids w congenital heart defects vessels are abnormal.(Atrioseptal defect) Blood exits heart w out coming into contact with lungs.

Intrapulmonary- unventilated alveoli due to atalectasis or sputum clogged alveoli. blood passes through.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Normal shunts

A

Bronchial circulation-Blood in bronchial arteries perfuses bronchi, some O2 is extracted and blood moves to pulmonary veins.

Coronoary circulation- Thespian veins return deoxygenated coronary artery blood to left side of the heart

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

Compensatory mechanism for intrapulmonary shunt

such as in chronic hypoxemic lung conditions
eg pneumonia

when does this work?
when doesn’t it?

A

Hypoxic pulmonary vasoconstriciton
corrects the V/Q missmatch V/Q is now zero in that area.

Perfusion redirected to alveoli that are ventilated. Good if only part of the lungs affected

If condition affects all of the lungs eg COPD, cystic fibrosis (Global disease).
All capillaries in both lungs constrict. Increased vascular resistance in capilllaries in lung.
Increased afterload for right side of lung. R sided hypertrophy. R sided heart failure.

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

Impairments to diffusion with result in

A

Decreased Pao2
Normal ish PaCO2

*CO2 diffuses more easily.

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

Rate of diffusion

* edit this

A

Proportional to tissue area

Difference in gas partial pressure

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

Diffusion affected by

A 
1Surface area 
2Time
3O2 vs Co2
4Pressure difference
5Thickness of alveolar membrane / interstitial space
6V/Q ratio
Nature of gas
Contact time b/n blood and gas
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

A-a difference

What is is
How is is calculated
What is it’s value normally?

A

Difference in oxygen partial pressure b/n arteries and alveoli. (PAO2-PaO2)
*ratio is calculated by PaO2/PAO2

Normally PAO2-PaO2 = 5-20 mmHg
due to normal anatomical shunt
V/Q miss matchhing

Difference increases with disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Effect of O2 Therapy

supplemental ventilation

A

Increased PaO2:
Difussion limitation
hypoventilation
V/Q missmatch

No change in PaO2 in:
shunt

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

List some lung diseases that may alter diffusion

A

Abnormal quality/quantity of gas exchange membrane.

  • Intersitial lung disease
  • rhumatoid lung,scleroderma(connective tissue)

Thickening blood gas barrier
-pulmonary oedema

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Cough

A

Dry-Upper respiratory tract infection
- Early stages acute pneumonia

Moist- chronic bronchitis, bronchiectasis,cystic fibrosis,smokers

Loose or tight-

Weak or strong-

Suppressed short painful cough- pleurisy

Nervous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Define Haemoptysis

List some common causes **

A

Presence blood in sputum due to breakdown of blood vessels adjacent to airway/lung.

Common causes

18
Q

Define Epistaxis

A

Nosebleed

19
Q

Haematemesis

A

Vomiting blood

20
Q

What is the difference between wheeze and stridor?

**

Which common respiratory conditions classically present with a wheeze?

A

WHEEZE - sound produced when air is forced past a point in which airway walls are almost touching. Resulting in vibration of the airway walls. High pitched continous adventitious lung sound.

Heard on expiration. During inspiration the airways are more open and wheeze tends to be less intense

Caused by asthma or airway obstruction. This obstruction may be caused by smooth muscle spasm airway edema, increased secretions, lesions, scarring, tumor foreign bodies.

STRIDOR

Occurs in extrathoracic airways-best heard @mouth or trachea
Heard on inspiration as extrathoracic airways exposed to opposite pressure gradients so diameter decrease on inspiration and increase on expiration

Tracheal or laryngeal obstruction. Croup, laryngeal oedema and tracheal stenosis

21
Q

Define
Tachypnoea
Hyperventilation
Hypernoea

A

Tachypnoea- increased rate of breathing
Hyperventilation-breathing in excess of metabolic needs
Hypernoea-Increased breathing

22
Q

Define

Dyspneoa

A

Difficulty breathing, shortness of breath.

Feelings of:chest tightness,feeling puffed,suffocating feeling

23
Q

Define Orthopnoea

A

Dyspnoea(SOB) that occurs when lying flat

24
Q

Paroxysmal Nocturnal Dyspnoea (PND)

A

Can cause orthopnoea
Occurs in patients with cardiac disease

Hydrostatic shifts in blood volume.Left atrial filling pressure is increased leading to increased pulmonary venous congestion and decreased lung compliance

Gravity causes the spread of basal pulmonary oedema to odema free areas of the lung

25
Q

Describe features of a barrel shaped chest

A

Normal chest is symmetrical.
Ribs descend 45 degrees from the spine.
AP diameter is less than the transverse diameter

BARREL SHAPED CHEST
ribs more horizontal
Intercostal muscles decreased mechanical advantage
No bucket handle action

26
Q

Describe and expain
Pectus excavum
Pectus carinatum

A

Pectus excavum-funnel chest
Most common
Congenital defect several ribs and the sternum grow abnormally inwards, producing a concave, or caved-in, appearance in the anterior chest wall.

Pectus Carinatum-Pigeon chest
Protrusion of the sternum that occurs as a result of an abnormal and unequal growth of the costal cartilage connecting the ribs to the sternum. costal cartilages grow outward pushing the sternum forward.

Although the shape of the chest wall is distorted, it does not usually affect the internal organs. 4x more likely in males

27
Q

Upper chest breathing pattern

occurs in COPD

A 
Pursed lip breathing
Fixed elevated shoulder girdles
Use of accessory muscles
Intercostal recession
Abdominal paradox
28
Q

Explain the concept of intercostal recession

A

Drawing in of inspaces ( intercostal spaces)
Seen first in floating ribs
Sucked inwards on inspiration because acessory muscles working so hard due to resistance to airflow that they generate EXCESSIVE negative.

Occurs in patients with COPD

It’s a form of paradoxical movement

29
Q

Pursed lip breathing

A

Raises interbronchial pressure by expiratory apposition thereby increasing resistance to expiration.

Generates intrinsic PEEP(positive end expiratory pressure) to keep airways open during expiration for longer.

Prolongs expiration and alters the I:E ratio (normally 1:2 now it’s 1:3) Trying to eliminate CO2 and reduce hyperinflation. Prevents passive airway collapse
Allows patient to take more air in on next inspiration

*Grunting in infants is similar expiration starts with a closed glottis resulting in explosive release of airway pressure. Prevents airway collapse

30
Q

Signs of respiratory distress

in neonates with severe respiratory issues

A

Dilation of nostrils- to decrease airway resistance
Grunting- Similar to pursed lip breathing

Sternal recession- Ribcage is very compliant and is associated with increased negative intraplural pressure during inspiration.

See-saw effect- In severe respiratory distress the ribcage will move inward as the abdoment distends outwards during inspiration

31
Q

Define paradoxical movements

A

Intercostal recession

Abdominal paradoxical movements
-Abdomen is sucked in on inspiration as an innefective diaphragm is pulled up by negative pressure generated within the chest.

due to paralysed diaphragm , increased inspiratory load or weak muscles

32
Q

Relavence of examining hands of patient with respiratory distress

A

Temp:
cold = poor perfusion
hot& sweaty= high CO2 causes vasodialation

Colour:
Blue=cyanosis due to hypoxemia or inadequate perfusion
Nicotine=smoker

Finger clubbing= chronic hypoxemia(low blood oxygen)

Flapping tremor= (asterixis) due to high CO2

33
Q

Relavence of examining hands of patient with respiratory distress

** return to cyanosis

A

Temp:
cold = poor perfusion
hot& sweaty= high CO2 causes vasodialation

Colour:
Blue=cyanosis due to hypoxemia or inadequate perfusion
Nicotine=smoker

Finger clubbing= chronic hypoxemia(low blood oxygen)

Flapping tremor= (asterixis) due to high CO2

34
Q

Cyanosis
Draw the oxyhaemoglobin dissociation curve and label the axes.
ii) Briefly describe the four factors that shift the curve to the right and left.

A

Bluish discoloration of skin and mucous membranes

Pathological causes of cyanosis:
Low PaO2(hypoxemia)
Cardiac disease 
Abnormal haemaglobin pigments
Decreased regional blood flow . low CO
35
Q

What are the normal adult blood gas values

A

PaO2= 85-100 mmHg
PaCO2= 35-45 mmHg
SaO2 =96-100%

36
Q

Central v peripheral cyanosis

A

CENTRAL
Bluish tinge of areas not usually prone to local circulatory changes such as the tongue.

Due to desaturation of arterial blood.Central cyanosis is caused by diseases of the heart or lungs, or abnormal haemoglobin. Will have peripheral cyanosis as well.

PERIPHERAL
Bluish tinge of
Peripheral cyanosis is caused by decreased local circulation and increased extraction of oxygen in the peripheral tissues

37
Q

Clubbing

i) Explain, using diagrams, what is meant by clubbing.
ii) List conditions whereby clubbing is a recognised feature.

A

Swelling of the soft tissue of tip of finger with loss of the normal angle between the nail and the nail bed leading to an abnormal rounded appearance.
Downward curving nail.

Softening nail beds which makes nails seem to float instead of being attached.

Primary digital clubbing
pachydermoperiostosis (young males)

Idiopathic pulmonary fibrosis,
Cystic fibrosis (thick mucus in throat and digestive tract),
Lung cancer
Tuberculosis
COPD,
bronchiectasis (destruction of the large airways)

Crohn disease
ulcerative colitis

Congenital heart diseases

38
Q

Define hypercapnia

List symptoms

A

Hypercapnia: a condition of abnormally elevated CO2 levels in the blood

PaCO2 of 45mmHg +

Symptoms
Headaches especially on walking
Confusion, drowsiness, decreased concentration
Warm moist skin
Full bounding pulse(very strong)
Flapping hand tremor (asterixis)
39
Q

What is a normal breathing rate?

A

12-16 breaths per min

40
Q

Sputum

A

Normal amount 100ml/24 h

Mucoid- clear or white mucous
Purulent- pus cells infection (yellow, green brown)
Rusty- sign of inflammation old red blood cells
Blood stained- haemoptysis
Plugs or casts- impaced mucous shape of airway
Yellow- asthma due to presence of eosinophils
Green- from bacterial infection
Brown- altered blood eg fungal infection
Frothy pink- severe pulmonary oedema
Brown/ black- carbon particles

foul smelling- presence of anaerobic organisms (lung abcess,bronchiectasis)

41
Q

Define bronchorrhoea

A

Production of large volumes of clear watery sputum. Sometimes occurs in patients with alveolar cell carcinoma.

Cardiopulmonary Science (6 decks)

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