Respiratory failure & oxygen therapy

Question 1

Signs of hypoxaemia

Answer 1

Inadequate oxygenation of blood (PaO2 <80mm Hg)

-<60mm Hg= SEVERE hyperaemia

Question 2

Pathological Hypoxaemia

Answer 2

• V/Q mismatch
• Hypoventilation > decreased 02 uptake into blood
• Diffusion abnormality > obstructs diffusion
• decreased F1)2
• Ventilation < headspace ventilation
• Perfusion without ventilation > decreased 02 uptake into blood

Question 3

Signs of Hypoxia

Answer 3

02 delivery to tissues is inadequate to meet metabolic needs

Question 4

Hypoxia results from

Answer 4

1. Hypoxaemia
2. decreased cardiac output
3. decreased haemoglobin
4. Increased metabolic rate

Question 5

Signs of hypercapnia

Answer 5

PaCO2 >/= 50mm Hg (normal=35-45mmHg)

Question 6

Hypercapnia results from

Answer 6

1. Hypoventilation
2. increased V C02
3. Increased dead space as a fraction of V1

Question 7

Sign of respiratory compensation

Answer 7

• increased RR
• increased accessory muscle use
• Nasal faring
• Recession

Question 8

Clinical signs of respiratory distress

Answer 8

Early- RAT
Restlessness
Anxiety
Tachycardia

Is late to- BED
Bradycardia
Extreme Restlessness
Dyspnoea

In paediatrics FINES
Feeding difficulty
Inspiratory stridor
Nasal flares
Expiratory grunting
Sternal Retractions

Question 9

Difference between type 1 and 2 respiratory failure

Answer 9

T1
-Hypoxaemia without hypercapnia (Pa02 <60mm Hg, <8kPa

T2
-Hypoxaemia with hypercapnia (Pa02 <60mmHg, <8kPa or PaC02 >50mm Hg, >6.7kPa)

Question 10

Type 1 Clinical features

Answer 10

• restlessness
• confusion
• aggression
• sweating
• fitting, convulsions
• plucking
• Increased RR, HR, BP
• ECG changes
• Blurrred vision, tunnel vision
• pallor

Question 11

Type 1 Management

Answer 11

• Improve ventilation (breathing exercises, NIV=IPPB or CPAP)
• Mobilise & remove secretions (ACT’s, suction)

Question 12

Type 2 Clinical features

Answer 12

• flushed skin
• drowsiness
• warm peripheries
• bounding pulse
• headache
• convulsions
• coma

Question 13

Type 2 Management

Answer 13

• Oxygen therapy
• NIV = BiPAP or
• intubation= SIMV

Question 14

Aims of Oxygen therapy

Answer 14

• correct hypoxaemia and therefore ain to decrease tissue hypoxia
• decrease WOB
• decrease Myocardial work
• decrease cerebral vasodilation

Question 15

Preventing adverse oxygen therapy effects

Answer 15

1. Hydration
2. Humidification
3. Nebulisation
4. Swedish Nose ( tracheostomy)

Question 16

Indications for humidification

Answer 16

• Fi02 > 0.35
• thick secretions
• consolidation
• major infection
• following surgery
• artificial airways
• diuretic therapy
• dehydrated

Question 17

Nebulisation- Mechanism

Answer 17

Converts solution into fine droplets, suspended in a stream of gas.

-deliver medications or moisten airways

• 6-8L/min, 21% oxygen
• upright sitting, slow, deep breaths (Slow laminar flow), interspersed with TV, mouth breathing.

Question 18

Aerosol therapy

Answer 18

-suspension of fine liquid or solid particle in air