Respiratory Failure

Question 1

Anaemia

Answer 1

condition of reduced red blood all quantity or quality resulting in reduced oxygen carrying capacity

Question 2

Anoxia

Answer 2

absence of oxygen supply in the blood extremely low levels of oxygen

Question 3

Asphyxia

Answer 3

absence of oxygen with carbon dioxide accumulation as a result of interruption to normal breathing

Question 4

Hypoxaemia

Answer 4

refers to a correlation when oxygen in the arterial blood is low as is the partial pressure of oxygen in the arterial blood

Question 5

Hypoxia

Answer 5

the deficiency of oxygen in some specific part of the body

Question 6

HYPOXAEMIA

Answer 6

low oxygen content in arterial blood 
Results from:
low VQ ration 
high VQ ratio 
diffusion impairment 
inadequate FiO2 
Normal - PaO2 80-100 SaO2 >95
Mild Hypoxaemia - PaO2 60-79 SaO2 90-94
Moderate Hypoxaemia - PaO2 SaO2 75-89
Severe Hypoxaemia - PaO2 <40 SaO2 <75

Question 7

HYPOXIA

Answer 7

deficiency of oxygen in some part of the body
Results From:
imbalance between availability of oxygen in the blood and the demands of O2 consumption
oxygen delivery is inadequate to meet cellular respiration/metabolic needs

Causes -

• reduced cardiac output
• low haemoglobin
• increased metabolic rate
• circulatory problems

Question 8

HYPERCAPNIA

Answer 8

excess carbon dioxide in the blood 
Causes - 
VQ mismatch 
alveolar hypoventilation 
ventilatory pump failure 
reduced central drive 
muscle fatigue/weakness
increased pulmonary workload 
increased CO2 production 
increased physiological dead space

Question 9

Signs of Respiratory Distress

Answer 9

Respiratory Compensation

• tachypnoea (increased RR)
• accessory muscle use
• nasal flaring
• recession - increased work of respiratory muscles to increase ventilation causes soft tissues to be sucked into the thoracic cavity as well

Increased Sympathetic Tone

• tachycardia
• hypertension
• sweating

Question 10

Signs of end-organ hypoxia

Answer 10

altered mental status 
fitting/seizures 
ECG changes 
desatruation 
late signs

Question 11

Type 1 Respiratory Failure

Answer 11

hypoxaemic
PaO2 - below 60mmHg
PaCO2 - within or below normal limits

Question 12

Type 2 Respiratory Failure

Answer 12

hypercapnic
PaO2 below 60mmHg
PaCO2 high >55mmHg

Question 13

Acute/Chronic Respiratory Failure

Answer 13

Acute - sudden onset, abnormal pH
Acute on Chronic - acute exacerbation on top of chronic respiratory failure, abnormal pH
Chronic - long term respiratory failure, pH normal due to metabolic alkalosis compensation

Question 14

CAUSES

Answer 14

anything that compromises pulmonary function so that adequate gas exchange can no longer be achieved 
Central 
- trauma 
- infections 
- tumours 
- medications 
- apnoea 
- raised ICP 

Obstructive

• COPD
• asthma
• bronchiectesis
• mucous aspiration
• tumour
• bronchial oedema

Restrictive

• atelectasis
• pulmonary fibrosis
• pleural effusion
• ARDs
• pulmonary oedema

Question 15

Clinical Implications

Answer 15

impaired gas exchange 
dyspnoea 
reduced exercise tolerance 
musculoskeletal dysfunction 
respiratory muscle dysfunction

Question 16

Clinical Features

Answer 16

stridor/wheezing 
tachypnoea 
dyspnoea 
increased WOB 
reduced expansion palpation 
reduced BS auscultation 
reduced SpO2
abnormal ABGs 
tachycardia 
hypertension 
diaphoresis 
cyanosis 
altered mental status

Question 17

Features of Type 1

Answer 17

restlessness 
confusion 
aggression 
sweating 
fitting/seizures
plucking 
ECG changes
increased RR, HR, BP 
blurred vision

Question 18

Features of Type 2

Answer 18

flushed skin 
drowsiness
warm peripheries 
bounding pulse 
coma

Question 19

Medical Management

Answer 19

address underlying causes
O2 therapy
NIV
full invasive mechanical ventilation

Question 20

Physiotherapy Management

Answer 20

position to maximise O2 therapy/VQ matching
ACTs
oxygen therapy optimise