Approach to type 2

Respiratory Failure

Changing Nature of NIV

• Not longer just the traditional COPD

patients

• Increasingly

– Obesity

– Neuromuscular

– Pneumonias

• 3 fold increase in patients with Ph 7.25

and below

Impact

• Changing guidelines

• Increased complexity

• Increased number of patients

• Decreased threshold for initiation

• Lower capacity for ITU to help

• Higher demands on nursing staff

Resp Failure

• Type 1 Failure of Oxygenation

• Type 2 Failure of Ventilation

• Hypoventilation

• Po2 <8

• Pco2 >6

• PH low or bicarbonate high

Ventilation

• Adequate Ventilation

– Breathe in deeply enough to hit a certain

volume

– Breathe out leaving a reasonable residual

volume

– Breath quick enough

– Tidal volume and minute ventilation

Response to demand

• Increase depth of respiration

• Use Reserve volume

• Increase rate of breathing

• General increase in minute ventilation

• More gas exchange

Failure to match demand

• Hypoventilation

• Multifactorial

• Can't breathe to a high enough volume

• Can't breath quick enough

• Pco2 rises

• Po2 falls

Those at risk

• COPD

• Thoracic restriction

• Central

• Neuromuscular

• Acute aspects

– Over oxygenation

– Pulmonary oedema

Exhaustion

• Complicates all forms of resp failure

• Type one will become type two

• Needs urgent action

• Excessive demand

• Unable to keep up

• Resp muscle hypoxia

Exhaustion

• Muscles weaken

• Depth of inspiration drops

• Residual volume drops

• Work to breath becomes harder

• Spiral of exhaustion

• Pco2 rises, Po2 drops

Type 2 Respiratory Failure

Management

Identifying Those at Risk

• Pre-existing conditions

• Acute factors

– Bronchoconstriction/Pulmonary oedema

– Hypoxia

• Superimposed problems

– Metabolic acidosis

– Low cardiac output

Recognising the problem

• Pick them up early- plan escalation

• Confusion

• Flap

• Signs of exhaustion • Agitation,

• High HR,

• High BP

• Sweaty

Why are they in type two?

• Don’t assume

• Multifactorial

• Examination- wheeze, opiods, oedema

• EARLY x-ray- Pneumothorax

• ECG- Myocardial infarction

• Bloods- Metabolic, BM, TSH

Simple Measures

• Reduce work of breathing

• Sit them up- 45 degree angle

• Good sputum clearance

• Enough oxygen- 88-92%? hypoxia will kill

you first

• Avoid resp depressants

• Max cardiac output

Treat underlying cause

• Bronchospasm

– Reduces air trapping and V/Q mismatch

– Lots of nebs, magnesium, aminophyline

• Pleural disease

– drain pneumothorax/effusions

• Cardiac output

– fluids/inotropes

Non Invasive Ventilation

• Augmenting patients breathing without an

ET tube

• Maximises Inspiratory volume (maintains

tidal volume)

• Stops airway collapse

• Can control rate of breathing

• Reduces the work of breathing

NIV

• Bilevel positive pressure ventilation

• Maintaining the volume in the lungs

between two ideal levels

• Applies pressure at maximum ventilation

(ipap)

• Applies pressure at maximum expiration to

splint airways (epap)

NIV- Does it work

• Up to 70% reduction in work of breathing

• Improved mortality over invasive

ventilation

• Reduced

– Invasive ventilation

– Hospital mortality

– Length of stay

• Mortality static over 10 years

• Effective in the elderly

Role of NIV

• Support tiring patient at early stage

• Treat type two resp failure to avoid

invasive ventilation

• Ceiling of treatment when invasive

ventilation is inappropriate

• Palliation

Timing of NIV

• Is the PH <7.35

• Is the Pco2 >6.5

(i.e. do they have a respiratory acidosis)

• Is their oxygen appropriate for the patient?

• Have you treated the correctable factors

for 30-60mins?

• If so consider starting NIV

Timing of NIV

• Maximise for an hour?

– Mild to Moderate Acidosis

– COPD

– 20% will improve

• Delay of more than hour is harmful

• Delay in other patient groups

– Poorer outcomes

Timing of NIV

• Maximise one hour if

– Simple copd exacerbation

– Ph 7.25 or above

– Capacity for review in one hour

– Capacity for immediate initiation of NIV

– No signs of exhaustion

Contra indications to NIV

• Very few

– No longer

• Low ph

• Low GCS

• Mainly indications for Invasive ventilation

• Facial injuries

• Poor upper airway

• Uncontrolled bowel obstruction- NG tube

Who should be invasively

ventilated

• 1) Reversible pathology

• 2) Remains active

• 3) Reasonable muscle bulk

And don’t forget

• 4) Patients wishes

• Contact early!!

Decision Time

• Is this patient more appropriate for

consideration for immediate invasive

ventilation? • Poor upper airway

• very hypoxic

• severe sepsis

• bowel obstruction

• Not PH or decreased GCS

Decision Time

• Is the patient suitable for NIV but should

be considered for ITU if fails NIV?

– Protect respiratory muscles

– Prevent VAP

– Protect against muscle wasting

– Protect against ITU Psychosis

– Patients do better on NIV

NIV as a Trial

• Best done in ITU

– Ph < 7.15

– Decreased GCS

– Confusion

– Pneumonia

• Delayed intubation = increased mortality

• Make decisions early and be proactive

Special Circumstances

• Pulmonary Oedema

– Works

– May not keep them alive long term

• Asthma

– Just don't

• Pneumonia

– If not for ITU

Where to NIV?

• Initiation shouldn’t be delayed

• Specialist Unit

• Appropriate staffing

– Trained Nurses

– Capacity to do regular obs

– 2-1 nursing

– Level 2-3

Setting up

• Mode

– Bilevel/bipap/pressure support

• Ipap

– High pressure used to fill the lung

• Epap

– Low pressure use to keep lungs open

• Difference Ipap and Epap = Tidal volume

IPAP Vs EPAP

• IPAP controls depth of ventilation

• Bigger gap between ipap and epap =

deeper ventilation

• Therefore IPAP controls PCO2

• EPAP overcomes stiff and noncompliant

lungs and airways

• EPAP and help oxygenation

Rule of thumb

• Initial settings

• Start IPAP -15

EPAP – 3

• Review patient clinically.

Is their chest rising? Is their heart rate and BP

improving? Are they working less hard to

breath?

• If not titrate up IPAP in 2cm increments

Rule of thumb

• Are their sats low?

• Is their chest barely moving?

• Is the apnoea alarm buzzing at you?

• If any of yes to any of these increase both

the EPAP and IPAP by 2 increments.

• Once your happy repeat ABG in 1 hour

Oxygen

• Continue to aim 88-92%

• Supply oxygen through mask or tubing

• Difficult to predict how much they need

• Machine looses a lot of oxygen

• Patient is ventilating better

• Start high and titrate down

Failing on NIV

• High respiratory rate,

• High BP

• High pulse

• Agitation

• Working hard to breath with accessory

muscles

• Sweating

Pco2 not coming down

• Inadequate ventilation

• Assess airway

• Sit patient up

• Treat underlying cause

• Increase IPAP

• Repeat ABG

Po2 Poor

• Maximise ventilation

• Increased inspired Oxygen

• Increase EPAP and IPAP until chest rising

• Treat underlying cause

• Reassess for pneumothorax/mucus

plugging

Conclusion

• Changing nature of patients

• Reduce work of breathing

• Early planning- ?ITU

• Early initiation- ?wait until acidotic

• Very few contraindications