This document provides guidelines for the ventilatory management of acute hypercapnic respiratory failure (AHRF) in adults. It aims to highlight currently suboptimal care for AHRF patients in the UK and promote an integrated care pathway involving multiple clinical teams. The guidelines recommend considering non-invasive ventilation when certain criteria are met for conditions like COPD exacerbations. Intubation should not be delayed if non-invasive ventilation is failing. Organizational coordination between intensive care and other clinical areas is also emphasized to improve outcomes for these patients.

1. Better Lung Health for All
BTS/ICS Guidelines for the ventilatory
management of acute hypercapnic
respiratory failure in adults
British Thoracic Society
Intensive Care Society

2. Better Lung Health for All
Introduction
• Acute Hypercapnic Respiratory Failure (AHRF) results
in 50,000 admissions each year in the UK
• Without ventilatory support AHRF is associated with
a high mortality rate and a prolonged inpatient stay
• The incidence of AHRF is similar to upper GI
haemorrhage which is, quite rightly, recognised as a
medical emergency and one in which delay in
instituting treatment and poor coordination between
clinical teams increases mortality

3. Better Lung Health for All
Introduction
• Patients with AHRF are not receiving optimal
therapy:
• BTS NIV audit reports 2011-13
• Acidosis, non-invasive ventilation and mortality in hospitalised
COPD exacerbations. Thorax 2011
• National COPD Audit Programme: secondary care clinical audit
report: “Who Cares Matters 2014” https://www.rcplondon.ac.uk/projects/national-
copd-audit-programme
• “provision of NIV is often poorly performed,
patients not treated until acidosis severe and
some patients inappropriately denied admission
to the ICU”

4. Better Lung Health for All
Aims of Guideline
• Highlight current suboptimal care for individuals
with AHRF in the UK
• Review the evidence base for treatment of AHRF
by invasive and non invasive ventilation
• Promote an integrated AHRF care pathway
involving Emergency Departments, Medical
Admission Units, Respiratory Wards & Critical
Care
• Improve patient outcome and experience

5. Better Lung Health for All
AHRF
• May complicate a number of conditions that
affect lungs and/or impair the function of
respiratory pump
• Airway disease : COPD, asthma, Cystic fibrosis
and non-CF bronchiectasis
• Respiratory pump : neuromuscular disease, chest
wall deformity and morbid obesity
• AHRF may be acute or acute on chronic

6. Better Lung Health for All
Acute exacerbations COPD
• Commonest cause of AHRF : 20% AECOPD
• In COPD signals advanced disease, high risk of
future hospitalisations and limited long term
prognosis
• In COPD mortality 8% without AHRF and up to
30% with AHRF depending on the degree of
acidosis

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In all causes AHRF
Development of AHRF warrants a change in
future care arrangements:
• predicts future life threatening episodes
• indicates need, in some, for domiciliary NIV

8. Better Lung Health for All
Treatment of AHRF
Prior to availability of non-invasive ventilation:
• intubation was required when conventional
treatment failed
• unclear what criteria guided recognition of this
need …...intubation variably offered
internationally……limited availability of intensive
care beds in UK reduced access to this option

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Prognostic indicators
• Mostly investigated in AECOPD, where outcome less good in
those with adverse features, especially when multiple
• Medical staff infrequently use formal severity scoring and
consistently under-estimate survival potential
• Scoring poorly predictive on individual basis and, on its own,
little help in deciding when mechanical ventilation would be
futile
• Important that potentially life-saving treatment, including NIV,
not inappropriately withheld

10. Better Lung Health for All
Recommendations (1):
Prevention AHRF
• Oxygen should be used with care in all individuals at
risk of AHRF
• Use a target oxygen saturation range of 88-92% in
ALL self-ventilating patients at risk of AHRF
• If oxygen indicated, start at 24-28% oxygen via a
Venturi mask

11. Better Lung Health for All
Recommendations (2):
NIV
• Consider starting NIV when pH < 7.35, PCO2 > 6.5
kPa and respiratory rate > 23
• Consider starting NIV in hypercapnic NMD or CWD
patients in the absence acidosis
• NIV should not be used in acute hypercapnic asthma
• Do not delay starting NIV or continue with it when
the patient is deteriorating as both increase
mortality.

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• The use of NIV should not delay escalation to
IMV when this is more appropriate
• Intubation is indicated if NIV is failing (unless it
is not desired by the patient or agreed not in
his/her “best interest”)
• Be aware that clinicians can underestimate
survival potential in AHRF treated by IMV
Recommendations (3):
Invasive Ventilation

13. Better Lung Health for All
Recommendations (4):
NIV in the ICU
• Patients with higher risk of NIV failure can be
predicted and should be considered for direct
admission to ICU
• In many AHRF patients the planned use of NIV post
extubation reduces the need for re-intubation
• In COPD, and in many individuals with NM disease,
NIV-supported extubation should be employed in
preference to inserting a tracheostomy

14. Better Lung Health for All
Recommendations (5):
Organisational aspects
Be aware:
• A care environment with level 2 equivalence
improves the outcome of NIV
• Ward-based NIV risks greater delay in expert
review and/or escalation to IMV
• Coordination of care between the ICU and other
patient areas improves outcome

15. Better Lung Health for All
Recommendations (6):
Governance and risk avoidance
• Care planning is needed between respiratory,
emergency and acute care physicians and the ICU
• A senior clinician should lead in the local production
of a seamless AHRF patient pathway
• Episodes of oxygen toxicity, or unexpected death
whilst on NIV, should be critically reported
• Rolling programmes of staff training and auditing of
performance in AHRF improves outcomes

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Figure 1 Summary for providing acute NIV

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Figure 2 Guide to initial settings and aims with imv

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Figure 3: The three phases of patient management in AHRF

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Further information
The guideline can be found on the BTS website at:
https://www.brit-thoracic.org.uk/guidelines-and-
quality-standards/ventilatory-management-of-
acute-hypercapnic-respiratory-failure-guideline/
Contact: bts@brit-thoracic.org.uk