Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

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

Week 2 Hypoventilation / Shunt / Diffusion limitation Flashcards

(41 cards)

Start Studying
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 **

Study These Flashcards
A

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

Common causes

18
Q

Define Epistaxis

19
Q

Haematemesis

Study These Flashcards
A

Vomiting blood

20
Q

What is the difference between wheeze and stridor?

**

Which common respiratory conditions classically present with a wheeze?

Study These Flashcards
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

Study These Flashcards
A

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

22
Q

Define

Dyspneoa

Study These Flashcards
A

Difficulty breathing, shortness of breath.

Feelings of:chest tightness,feeling puffed,suffocating feeling

23
Q

Define Orthopnoea

Study These Flashcards
A

Dyspnoea(SOB) that occurs when lying flat

24
Q

Paroxysmal Nocturnal Dyspnoea (PND)

Study These Flashcards
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
Describe features of a barrel shaped chest
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
Describe and expain Pectus excavum Pectus carinatum
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
Upper chest breathing pattern | occurs in COPD
``` Pursed lip breathing Fixed elevated shoulder girdles Use of accessory muscles Intercostal recession Abdominal paradox ```
28
Explain the concept of intercostal recession
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
Pursed lip breathing
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
Signs of respiratory distress | in neonates with severe respiratory issues
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
Define paradoxical movements
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
Relavence of examining hands of patient with respiratory distress
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
Relavence of examining hands of patient with respiratory distress **** return to cyanosis
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
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.
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
What are the normal adult blood gas values
PaO2= 85-100 mmHg PaCO2= 35-45 mmHg SaO2 =96-100%
36
Central v peripheral cyanosis
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
Clubbing i) Explain, using diagrams, what is meant by clubbing. ii) List conditions whereby clubbing is a recognised feature.
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
# Define hypercapnia List symptoms
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
What is a normal breathing rate?
12-16 breaths per min
40
Sputum
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
Define bronchorrhoea
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.
© 2025 Bold Learning Solutions. Terms and Conditions