respiratory failure

Question 1

how many units of energy do you get from a single carbohydrate molecule in presence of oxygen and without oxygen

Answer 1

• with oxygen= 36 ATP molecules
• without oxygen= 2 ATP molecules

Question 2

how do we inspire (quiet inspiration)

Answer 2

• diaphragm contracts and becomes flat
• external intercostal muscles contract pulling the ribcage upwards and outwards
• contraction of both of the muscles causes the volume of the thoracic cavity to increase which thus decreases pressure (creates this negative pressure- suction effect)
• pressure gradient generated causes air to flow in down pressure gradient

Question 3

what happens during quiet expiration (passive)

Answer 3

• diaphragm relaxes becomes v shaped
• external intercostal muscles relax- ribcage moves downwards and inwards
• thoracic cavity volume decreases and pressure increases (alveolar and intrapulmonary)
• pressure gradient results in air to flow out as well as the recoiling of the elastin fibres in alveoli

Question 4

what happens during active expiration e.g during coughing, exercise

Answer 4

• involves muscle contraction
• diaphragm relaxes as well as external intercostal muscles
• internal intercostal muscles contract further pulling the ribcage downwards and inwards
• accessory muscles (abdominal muscles) contract (pushes diaphragm upwards)
• this results in a decrease in thoracic cavity volume increasing the pressure more than in passive expiration
• greater pressure gradient formed air moves out the lungs

Question 4

what happens during active forced inspiration

Answer 4

• contraction of diaphragm and external intercostal muscles
• abdominal muscles (accessory muscles) also contract
• lung volume increases and thoracic pressure decreases- pressure gradient drives air into the lung
• happens during exercise, respiratory distress such as asthma

Question 4

why do we get a sore throat when breathing through are mouth

Answer 4

• nasal cavity adds moisture to air
• oral cavity does not

Question 5

what are the conducting zones

Answer 5

• trachea
• bronchus
• bronchioles specifically terminating bronchioles
• larynx
• pharynx

Question 6

what are the respiratory zones

Answer 6

• respiratory bronchioles
• alveoli
• alveolar sac

Question 7

what is the upper respiratory region

Answer 7

• nasal cavity
• oral cavity
• pharynx
• larynx

Question 8

what is the lower respiratory region

Answer 8

• trachea
• bronchus
• bronchioles (respiratory and terminal)
• alveolar sac
• alveoli

Question 9

what is tidal volume and what is the anatomical deadspace volume and alveolar volume

Answer 9

• tidal volume 500mls
• anatomical deadspace is 150mls and alveolar volume is 350mls
• anatomical deadspace is fixed and does not change wether you breath fast or slow but alveolar volume can change

Question 10

what noise do you get with upper airway obstruction and when

Answer 10

• during inspiration
• striddle

Question 11

what noise do you get in lower respiratory obstruction and when

Answer 11

• during expiration
• wheezing

Question 11

where is resistance greatest in respiratory system

Answer 11

• resistance is greatest in upper respiratory zone
• flow is turbulent

Question 12

how is breathing controlled

Answer 12

• dual innervated consists of autonomic control (medulla) and somatic control (hyperventilation)

Question 13

how does the body increase breathing rate

Answer 13

• chemoreceptors in carotid body and aortic arch sense changes in carbon dioxide, oxygen levels and ph
• this stimulates sympathetic nervous system (medulla)
• causes to breath faster and harder

Question 14

what happens when sympathetic nervous system fails to work and increase breathing rate

Answer 14

• increased carbon dioxide levels as not cleared
• decrease in ph which can trigger release of nitric oxide
• causes vasodilation
• makes up sleepy

Question 15

what happens when oxygen cannot get in

Answer 15

• hypoxemic hypoxia
• central and peripheral cyanosis
• organ failure of brain, heart, kidneys

Question 16

what is cytotoxic hypoxia

Answer 16

• oxygen not utilised by tissues
• cyanide poisoning
• mitochondria do not work

Question 17

what is respiratory failure and the types

Answer 17

• partial pressure of oxygen <8kPa
• type 1 respiratory failure is when there’s low oxygen but carbon dioxide is also cleared
• type 2 respiratory failure is when there’s both low oxygen and carbon dioxide is not cleared so raised carbon dioxide levels (hypercapnia)

Question 18

how do we measure oxygen levels

Answer 18

• pulse oximeter to measure hb saturation
• arterial blood gas to measure partial pressure of oxygen

Question 19

what is the oxygen cascade

Answer 19

• stepwise decrease in partial pressure of oxygen between the atmospheric air and the mitochondria
• essentially shows the decrease In partial pressure of oxygen as it moves from the atmosphere to the specific areas of our body
• drop in oxygen is fixed
• if this drop is altered suggests somethings wrong
• if measuring oxygen in artery need to know much oxygen initially breathing to calculate drop in oxygen

Question 20

what is the oxygen dissociation curve

Answer 20

• a curve to show hb saturation at different partial pressures of oxygen
• sigmoid shape
• increasing partial pressure increases hb saturation
• positive cooperatively so binding of first oxygen makes it easier for subsequent oxygen to bind
• won’t be able to tell how well lung working of a patient if inspired oxygen very high as there’s mimcl changes in hb saturation when partial pressure Is high

Question 21

what are some causes of respiratory failure

Answer 21

• pneumonia
• asthma
• pulmonary oedema
• COPD
• pneumothorax
• PE
• opioid poisining
• neuromuscular disease

Question 22

what is pneumonia, causes, symptoms, what type of lung disease, what can it cause

Answer 22

- caused by pathogen e.g. streptococcal pneumonia, pneumocystis jiroveci - infection of the lungs specifically alveoli - shunt (poor ventilation but good perfusion) specifically intrapulmonary shunt where alveoli is obstructed with fluid - can cause hypoxemic hypoxia - symptoms include fever, breathlessness, cough - obstructive lung disease

Question 23

what is asthma, what type of lung disease, what it causes and treatment, symptoms

Answer 23

- obstructive lung disease - narrowing of bronchioles (airways) secondary to inflammation - wheezing and mucus plugging - shunt - leads to hypoxemic hypoxia - leads to exhaustion and therefore ventilation - use salbutamol a bronchodilator to dilate airways

Question 24

what is COPD, type of lung disease, causes and mechanism, risk factor

Answer 24

- obstructive - irreversible with bronchodilator - caused by high compliance of lungs and low elastic recoil -associated with emphysema, chronic bronchitis and mucus plugging - smoking is a risk factor

Question 25

what is pneumothorax

Answer 25

- restrictive lung disease - hole in lungs and therefore air enters the intrapulmonary cavity but cannot get out and this causes an increase in pressure which causes lungs to collapse, alveolar compressed - can cause hypoxia

Question 26

what is pulmonary embolism

Answer 26

- blood clot in pulmonary circulation - poor perfusion - dead space- physiological

Question 27

what opioid poisoning

Answer 27

- reduced ventilatory drive so hypoventilation takes place - carbon dioxide increases - drop in oxygen - shunt

Question 28

what is neuromuscular disease in terms of respiratory diseases

Answer 28

- smaller breaths - exhaustion - rising carbon dioxide - oxygen falls

Question 29

what is pulmonary oedema

Answer 29

- swelling of tissues between blood vessels and air spaces due to back pressure from the left ventricle - more difficult for oxygen diffusion - build up of fluid - restrictive - intrapulmonary shunt