RRAPID: B

Question 1

What is a ventilation/ perfusion mismatch?

Answer 1

Imbalance of ventilation + perfusion of alveoli

Causes hypoxaemia

Question 2

Common causes of inadequate pulmonary gas exchange

Answer 2

Obstruction of airflow (upper airway obstruction or bronchoconstriction)
Inadequate alveolar ventilation due to oedema or pneumonia or blood
Hypoventilation due to drugs (alcohol, opioids, benzos) or stroke affecting brainstem
PE = inadequate perfusion of lungs

Question 3

What is the definition of respiratory failure?

Answer 3

Pa02 <8

Question 4

What is the definition of type 1 respiratory failure + what is the common cause?

Answer 4

PaO2 <8 with normal or reduced PaCO2
Usually due to V/Q mismatch:
Pneumonia, pneumothorax
Pulmonary oedema, asthma, PE, pleural effusion

Question 5

What is the definition of type 2 respiratory failure + what are the common causes?

Answer 5

PaO2 <8 + high PaCO2 >6.7 
Usually due to hypoventilation due to opioids or pts with COPD
Causes: 
Severe asthma with exhaustion 
COPD exacerbation 
Reduced GCS 
Opioid toxicity

Question 6

Clinical signs of resp failure

Answer 6

Confusion, agitation, sweating
Reduced GCS 
SOB
Apnoea 
Inability to  talk 
Cyanosis 
Tachypnoea >20 
Tachycardia >100
Use of accessory muscles

Question 7

CXR findings for pneumothorax

Answer 7

Lack of lung markings on affected side

Deviation of trachea away from affected side

Question 8

Management of simple pneumothorax

Answer 8

Needle aspiration or chest tube insertion

Question 9

Management of tension pneumothorax

Answer 9

Needle thoracocentesis using grey/ orange cannula in 2nd IC space, mid clavicular line

Question 10

What is ‘in extremis’?

Answer 10

Severe hypoxia, very low BP or impaired LOC

Indicates thoracocentesis before CXR

Question 11

CXR findings for pleural effusion

Answer 11

Homogenous dense shadowing
Meniscus or fluid level
Loss of costophrenic angle (indicates at least 500ml fluid)

Question 12

CXR findings for pulmonary oedema

Answer 12

Prominent pulmonary hilar 
Perihilar shadowing (Bats wings)
Upper lobe diversion 
Cardiomegaly 
Kerley B lines 
Bilateral pleural effusions

Question 13

CXR findings for PE

Answer 13

Usually normal but may have localised loss of lung markings
Focal interstitial markings
Wedge shaped infarct

Question 14

Patients at risk of respiratory depression

Answer 14

Pre-existing lung conditions 
Increasing age 
Smokers 
Obese pts 
Post op patients 
Immobile pts

Question 15

Recognition in breathing

Answer 15

Look: 
RR 
Depth + symmetry 
Cyanosis 
Accessory muscle use 
Effort of breathing
Obvious chest injury 

Listen for noisy breathing
Percussion
Auscultation

Feel for pulse, tracheal deviation, chest expansion

Question 16

How to interpret ABGs

Answer 16

pH
O2
CO2
Bicarb + BE

ROME: Respiratory goes opposite, metabolic goes equal

Question 17

What are the venturi mask concs?

Answer 17

24%, 28%, 35%, 40%, 60%

Question 18

Causes of breathing problems

Answer 18

CNS depression causing decreased resp drive
Poor resp effort due to muscle weakness/ pain/ restriction
Disorder of lung function (pneumonia, pneumothorax, haemothorax, asthma, COPD, ARDS)

Question 19

How do breathing problems kill?

Answer 19

Hypercapnia + apnoea 
Pulmonary oedema 
Exhaustion 
Hypoxic brain injury 
Secondary cardiac ischaemia