Respiratory failure and Intubation (1B)

Question 1

Why would somebody go to ICU?

Answer 1

• Haemodynamic/respiratory/neurological monitoring
• Support of normal body functions (Intubation and mechanical ventilation. Cardiovascular support eg inotropes)
• Stabilisation of life threatening injuries
• Treatment of multi organ failure

Question 2

What is the definition of respiratory failure?

Answer 2

When the patient loses the ability to ventilate adequately (CO2) or to provide sufficient oxygen to the blood and systemic organs

Question 3

What is hypoxaemic respiratory failure?

Answer 3

Long, o2 gas movement, regional ventilation)
PaO2 < 60 mm Hg
PaCO2 < 42 mm Hg

• Lung disease is severe enough to interfere with O2 exchange

Question 4

What is hypercapnic respiratory failure?

Answer 4

Pump, CO2 gas movement, effective minute ventilation, overall ventilation

PaCO2 > 50 mm Hg

The respiratory system pump is inadequate and cannot maintain ventilation to eliminate the CO2 produced by metabolism

Question 5

What is acute respiratory failure?

Answer 5

Rapid onset, short course and pronounced symptoms

Question 6

What is chronic respiratory failure?

Answer 6

Long duration of poor ABG values with (metabolic) compensation

Question 7

VE =

Answer 7

minute ventilation

RR x VT (tidal volume)

Question 8

Vd =

Answer 8

dead space (non gas exchange area -> upper airways)

Question 9

VD=

Answer 9

dead space ventilation

= RR x Vd

Question 10

VA=

Answer 10

alveolar ventilation

= (VT - Vd) x rr
= VE- VD

Question 11

Normal male
Vd =
VT =
RR
VE =
VA=
CO2 =

Answer 11

Vd = 100mL
VT =500 mL
RR = 12
VE = 61/min
VA= 4.81/min
CO2 = normal

Question 12

Post abdominal surgery
Vd =
VT =
RR
VE =
VA=
CO2 =

Answer 12

Vd = 100 mL
VT = 250 mL
RR = 24
VE = 61/min
VA= 3.61/min
CO2 = increased

Question 13

DBE with physiotherapist
Vd =
VT =
RR=
VE =
VA=
CO2 =

Answer 13

Vd = 100 mL
VT = 750 mL
RR= 8
VE = 61/min
VA= 5.21/min
CO2 = decreased.

Question 14

PE 2 weeks post discharge
Vd =
VT =
RR=
VE =
VA=
CO2 =

Answer 14

Vd = 200 mL
VT = 500 mL
RR= 12
VE = 61/min
VA= 3.61/min
CO2 = increase

Question 15

Mechanisms & causes

• Hypoxaemic respiratory failure

Answer 15

– Reduced gas going to areas with perfusion
• Low lung volume (O2 movement problem)
– No gas going to areas with perfusion
• Acute lobar collapse (O2 movement problem)
– Diffusion impairment

Question 16

Mechanisms & causes

• Hypercapnic respiratory failure

Answer 16

Mechanisms & causes
• Hypercapnic respiratory failure
(CO2 movement problem)
– Depressed drive
• Opiate overdose
– Impaired neuromuscular function
• Cervical spinal cord injury
• Guillain Barré syndrome
• Respiratory muscle dysfunction
– Weakness
– Fatigue

Question 17

Mechanisms & causes

– Increased respiratory load

Answer 17

– Increased respiratory load
• Increased airway resistance
– asthma
• altered chest wall compliance
– kyphoscoliosis
– # ribs
• Decreased lung compliance

Question 18

Clinical manifestations

• Hypoxaemia

Answer 18

– Decreased mental acuity (PaO2 < 40‐50 mm Hg)
– Agitation followed by somnolence
– Dyspnoea
– Increased RR, change in pattern of breathing
– (Organ failure – renal failure, brain injury)

Question 19

Clinical manifestations

• Hypercapnia

Answer 19

– Depends on rate of rise of CO2 and metabolic
compensation
– Dyspnoea
– Increased RR, change in pattern of breathing
• COPD – accessory muscle use, paradoxical breathing,
intercostal space or rib indrawing, pursed lips breathing
– Agitation, tremor
– Confusion to coma
– Increased ICP, headache

Question 20

Implications respiratory failure for physiotherapy

Answer 20

• Watch for signs & symptoms of respiratory
failure
• Review medical assessment & management
• Determine type of respiratory failure
– hypoxaemic, hypercapnic
• Determine cause of respiratory failure
– problem list in terms of impairments
• Choose appropriate treatment interventions

Question 21

Reasons for intubation

Answer 21

• Maintain patent upper airway
• (suffocation)
• Protect lower respiratory tract
• (aspiration)
• Enable adequate tracheobronchial toilet
• (suctioning)
• Allow ventilatory support
– Mechanical ventilation
• during paralysis & sedation
• rest respiratory muscles
– Oxygen therapy/CPAP/PEEP

Question 22

What is a Tracheostomy?

Answer 22

• A tracheostomy is an artificial airway that is shorter
than an endotracheal tube
• Inserted surgically or percutaneously through the
neck into the trachea between 2nd and 3rd tracheal
rings
• Bypasses the upper airway and all air intake occurs
via the tracheostomy tube when cuff is inflated
• Can be temporary or permanent

Question 23

Why is an ETT not done long term?

Answer 23

unstable, pressure on tracheal wall

Question 24

Indications for Tracheostomy

Answer 24

• The same as for endotracheal intubation but……
• When intubation will be required for a longer period
– As the ETT passes through the vocal cords these can be
damaged
• Voice problems
• Swallowing problems (aspiration)
• Prolonged mechanical ventilation (> 10‐14 days)
• To facilitate weaning from mechanical ventilation
• Tracheomalacia, tracheal stenosis

Question 25

• Compared to an ETT a tracheostomy:

Answer 25

– reduces dead space compared to an ETT, easier to wean
from mechanical ventilation
– allows reduction in level of sedation as it is more
comfortable (less gag stimulation)
– patient can communicate more easily ‐ mouth words, or
specialised tubes may allow use of a speaking valve

Question 26

Tracheostomy management

Answer 26

• Will vary between facilities
• Multidisciplinary teams
• Physiotherapist
– Checking patency
– Tube changes
– Decannulation (removal)