week 3

Question 1

what is respiratory failure

Answer 1

respiratory failure occurs when the respiratory system fails top oxygenate arterial blood adequately (hypoxaemia) and consequently fails to provide the body with adequate amounts of oxygen (hypoxia) and/or the person fails to ventilate well enough to eliminate carbon dioxide

Question 2

what is hypoxia

Answer 2

inability to provide oxygen to the tissues

Question 3

what is hypoxaemia

Answer 3

lack of oxygen in arterial blood

Question 4

How do we diagnose respiratory failure

Answer 4

take a sample of arterial blood and measure the partial pressure of O2 and CO2

Question 5

what are the two main types of respiratory failure

Answer 5

type 1 and type 2

Question 6

how long does it take for acute respiratory failure to develop

Answer 6

minutes to hours

Question 7

whats an example of an acute respiratory failure

Answer 7

pneumonia

Question 8

how long does chronic respiratory failure take to develop

Answer 8

over days

Question 9

what is an example of chronic respiratory failure

Answer 9

COPD

Question 10

what is type 1 respiratory failure

Answer 10

failure to maintain O2 levels in arterial blood
(hypoxaemia)

Question 11

what is type 2 respiratory failure

Answer 11

failure of respiratory pump to ventilate adequately
(hypoxaemia and hypercapnia)

Question 12

what is ischaemic hypoxaemia due to

Answer 12

inadequate blood flow through the lung

Question 13

What is anaemic hypoxaemia

Answer 13

reduction in the carrying capacity of the blood e.g. anaemia/significant blood loss/sickle cell crisis

Question 14

what is toxic hypoxaemia

Answer 14

difficulty utilising oxygen

Question 15

what are some of the clinical signs of hypoxaemia

Answer 15

central cyanosis
peripheral shut down (cool to touch, cold and clammy)
tachypnoea
tachycardia
low oxygen saturations
confusion or agitation

Question 16

Causes of type 2 respiratory failure

Answer 16

CNS depression/abnormalities with the respiratory drive centres
disorders of the spinal cord
abnormalities of the peripheral nerves
respiratory disease
neuromuscular disease
muscle weakness
loss of integrity of the chest wall/poor ventilatory mechanics

Question 17

what can happen if patients with hypoxic drive are given large and unchecked amounts of additional oxygen

Answer 17

it can remove their drive to breathe

Question 18

what is hypoxic drive

Answer 18

a condition associated with a small number of people with COPd and tends to be associated with more severe cases

Question 19

what does CPAP stand for

Answer 19

continuous positive airway pressure

Question 20

what does CPAP do

Answer 20

delivers the same flow of gas throughout inspiration and expiration
increases functional residual capacity and primarily aimed at improving gas exchange and type 1 respiratory failure
splints open alveoli

Question 21

What does NIV stand for

Answer 21

non-invasive ventilation

Question 22

what does NIV do?

Answer 22

blows air into the lungs, via a nasal mask or a face mask, to ensure that the breathing remains supported and to prevent under-breathing
The NIV machine will recognise that the person using it has started to breathe in and assists with each breath

Question 23

what are the acute effects of NIPPV

Answer 23

reduced PaCO2
increase alveolar ventilation
rest respiratory muscles
decrease load on the respiratory muscles

Question 24

what are the contraindications for NIV

Answer 24

life threatening hypoxaemia
haemodynamic instability
confusion or agitation
upper gastrointestinal surgery or bowel obstruction
barotrauma
inability to protect airway
risk of vomiting
excessive secretions
facial trauma
haemoptysis

Question 25

what are the advantages of NIV

Answer 25

non invasive no sedation can be ward managed low cost easy to withdraw easy to manage at home allows communication, mobility, sleep

Question 26

why is severe hypoxaemia potentially dangerous

Answer 26

because it causes tissue hypoxia with insufficient oxygen available to tissues to meet metabolic needs

Question 27

what does an increase in PaCo2 cause

Answer 27

respiratory acidosis

Question 28

what does a decrease in PaCO2 cause

Answer 28

respiratory alkalosis

Question 29

what are some potential causes of respiratory acidosis

Answer 29

hypoventilation exhaustion drugs cardiac arrest

Question 30

what are some potential causes of a respiratory alkalosis

Answer 30

excess mechanical ventilation acute hyperventilation anxiety/pain stroke anaemia meningitis acute asthma SAH altitude fever

Question 31

what does an increase in HCO3 cause

Answer 31

metabolic alkalosis

Question 32

what does a reduction in HCO3 cause

Answer 32

metabolic acidosis

Question 33

what are some causes of metabolic alkalosis

Answer 33

volume depletion diuretics excess vomiting burns

Question 34

what are the causes of metabolic acidosis

Answer 34

diabetic ketoacidosis diarrhoea renal failure

Question 35

what two organs compensate for one another to maintain a relatively constant pH

Answer 35

lungs and kidneys

Question 36

name some indications for oxygen therapy

Answer 36

hypoxaemia acute care situations in which hypoxaemia is suspected severe trauma acute MI short term therapy (post anaesthesia recovery)

Question 37

name some complications of oxygen therapy

Answer 37

oxygen toxicity depression of ventilation absorption atelectasis fire hazard

Question 38

what is the amount of oxygen delivered dependent on

Answer 38

oxygen flow rate patients inspiratory volume respiratory rate

Question 39

what are the types of oxygen delivery methods?

Answer 39

nasal cannula simple face mask reservoir mask

Question 40

what are the advantages of a nasal cannula

Answer 40

easy to fix keeps hands free not much interference with further airway care low cost compliant

Question 41

what are the disadvantages with nasal cannula

Answer 41

unstable easily dislodges high flow uncomfortable nasal trauma mucosal irritation FiO2 can be inaccurate and inconsistent

Question 42

what are the advantages of a simple face mask

Answer 42

moderate but variable FiO2 good for patients with blocked nasal passages and mouth breathers easy to apply

Question 43

what are the disadvantages of a simple face mask

Answer 43

uncomfortable interfere with further airway care proper fitting is required risk of aspiration in unconscious patient rebreathing

Question 44

name the variable flow devices for prescribing oxygen

Answer 44

nasal cannula face mask reservoir mask/non rebreathe

Question 45

name the fixed flow devices for prescribing oxygen

Answer 45

venturi system via simple face mask or humidified system nasal high flow

Question 46

what is the aim of oxygen therapy

Answer 46

to help manage type 1 respiratory failure