What’s New in Asthma?

Kirsty ShortECI and St Vincent’s Hospital

Advanced Trainee

But Asthma’s Easy!? • New Australian guidelines released March 2014

• Lack of consensus between international guidelines

• No guidance on management of the crashing asthmatic beyond calling for help

• Lack of engagement of critical care specialties in Australian guideline development

• ECI involvement in Difficult Airway Society (DAS) guidelines 

Comparison of Guidelines

Asthma in ED

• 2.3 million Australians in 2012

• 378 deaths in 2011, mainly in the elderly

• National Bureau of Statistics ‘Snapshots’

.... • .. .a I

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NationaiAsthma Counci !Australia

AUSTRALIAN ASTHMA HiANDBOOK

QUICK REFERENCE GUIDE

asthmahandbook.org.au VERSION 1.0

National Asthma Council Guidelines:2014 Changes

• Emphasis on primary and secondary assessment

• Allocation of asthma severity– Mild/mod grouped together – Severe– Life‐threatening 

Secondary Asthma AssessmentSpeech

Posture

Breathing

Consciousness

Skin colour

Respiratory rate

Heart rate

Chest auscultation

Oxygen saturation (pulse oximetry)

Blood gas analysis (adults. if performed) t

Mild/ Moderate (all of):

Can finish a sentence in one breath

Can walk

Respiratory distress is not severe

Alert

Normal

<25 breaths/min

Adults:< 110 beats/min Children: normal range

Wheeze or Normal lung sounds

>94%

Not indicated

Severe (any of):

Can only speak a few words in one breath

Unable to lie flat due to dyspnoea

Sitting hunched forward

Paradoxical chest wall movement: inward movement on inspiration and outward movement on expiration (chest sucks in when person breathes in)

or Use of accessory muscles of neck or intercostal muscles or 'tracheal tug' during inspiration

or Subcostal recession t abdominal breathing')

t

t

~25 breaths/min

Adults: ~110 beats/min Children: tachycardia

t

90-94%

Not indicated

Life-threatening (any of):

Can't speak

Collapsed or exhausted

Severe respiratory distress or Poor respiratory effort

Drowsy or unconscious

Cyanosis

Bradypnoea (indicates respiratory exhaustion)

Cardiac arrhythmia or Bradycardia (may occur just before respiratory arrest)

Silent chest or Reduced air entry

<90%

or Clinical cyanosis

PaO, <60 mmHg PaC07 >50 mmHg§ PaC0

7within normal range

despite low Pa02

pH <7.35#

Guideline Changes

• More prescriptive O2 saturation targets• Inhaled route of bronchodilation preferred • Steroids for all in first hour • Out: Aminophylline • Revised IV salbutamol dosing regime • NPPV advocated, more studies required

What the Guidelines Don’t Cover

• Use of HFNP

• Approach to NPPV

• Intubating the asthmatic

• Adrenaline in the asthmatic without anaphylaxis

• What to do if there’s no ICU

ASSESS SEVERITY AND START BRONCHODILATOR Table U. Rapid primary assessment of acute asthma in adults and children

Can walk and speak whole sentences in

one breath

Give 4-12 ruffs salbutamo (100 meg per actuation) via pMDI plus spacer

REASSESS SEVERITY

Any of: unable to speak in sentences, visibly breathless, increased work of breathing, oxygen saturation 90-94%

Give 12 puffs salbutamol (100 meg per actuation) via pMDI plus spacer

OR rPrrnrttPnt nebulisation if patient

spacer. Give 5 mg nebuliser with air u

~ Life-threatening

Any of: drowsy, collapsed, exhausted, cyanotic, poor respiratory effort, oxygen saturation less than 90%

Give 2 x 5 mg nebules salbutamol via continuous nebulisation Start oxygen (if oxygen saturation less than 95%)

Table V. Secondary severity assessment of acute asthma in adults and children aged 6 years and over

CONTINUE BRONCHODILATOR Repeat dose every 20-30 mins for f irst hour i f needed (or sooner as needed)

IF POOR RESPONSE, ADD IPRATROPIUM BROMIDE Repeat every 4-6 hours as needed

~---.. CONTINUE BRONCHODILATOR Repeat dose every 20 minutes for first hour (3 doses) or sooner as needed

CONTINUE BRONCHODILATOR Continuous nebulisation until dyspnoea improves.

Then consider changing to pMDI plus spacer or intermittent nebuliser (doses as for Severe)

Give 8 puffs (160 meg) via pMDI (21 meg/actuation) every 20 minutes for f irst hour OR

Give 500 meg nebule via nebuliser added to nebulised salbutamol every 20 minutes for f irst hour

1 HOUR

CONSIDER OTHER ADD-ON TREATMENT OPTIONS Table X. Add-on treatment options for acute asthma

START SYSTEMIC CORTICOSTEROIDS

Oral prednisolone 37.5-50 mg then continue 5-10 days

OR, IF ORAL ROUTE NOT POSSIBLE

Hydrocortisone 100 mg IV every 6 hours

REASSESS RESPONSE TO Pertormspirometry(itpatientcapable) TREATMENT (1 HOUR AFTER Repeat pulse oximetry

STARTING BRONCHODILATOR) Check tor dyspnoea while supine

* * Dyspnoea resolved Dyspnoea persists

OBSERVE for more than 1 hour after dyspnoea resolves

PROVIDE POST-ACUTE CARE Ensure person (or carer) is able to monitor and manage asthma at home

Provide oral prednisolone for 5-10 days

Ensure person has regular inhaled preventer Check and coach in correct inhaler technique

Provide spacer if needed Provide interim asthma action plan

Advise/arrange follow-up review

i Persistin~

acute asthma

l • Persistin~

or life-threatenin~ acute asthma

Transfer to ICU or discuss transfer/retrieval with senior medical staff

ASSESS SEVERITY AND START BRONCHODILATOR Table U. Rapid primary assessment of acute asthma in adults and children

Can walk and SJ?eak whole sentences in one breath (Young children:

can move about and speak in phrases)

Give salbutamol (100 meg per actuation) via pMDI plus spacer (plus mask for younger children) 6 y ears and o ver : 4-12 puffs 0 -5 year s: 2-6 puffs

REASSESS SEVERITY

Any of: unable to speak in sentences, visibly breathless, increased work of breathing, oxygen saturation 90-94%

Give salbutamol (100 meg per actuation) via pMDI plus spacer (plus mask for younger children) 6 years and over: 12 puffs 0-5 years: 6 puffs

OR

• life-threatening Any of: drowsy, collapsed, exllausted, cyanotic., poor respiratory effort, oxygen saturation less than 90%

Give salbutamol via continuous nebullsatlon driven by oxygen 6 year s and over: use 2 x 5 mg nebules 0 - 5 years: use 2 x 25 mg nebules Start oxygen If oxygen saturation less than 95% T itrate to tar~et oxygen saturation of at least 95%

Table V. Secondary severity assessm ent of acute asthma in adults and children 6 yea rs and over

Table W . Secondary severity assessm ent of acute a sthma in children 0 -5 years

CONTINUE BRONCHODILATOR Repeat dose every 20- 30 mlns for first hour If needed (or sooner as needed)

• IF POOR RESPONSE, ADD IPRATROPIUM BROMIDE Repeat every 4-6 hours as needed

• -----CONTINUE BRONCHODILATOR Repeat dose every 20 minutes for first hour (3 doses) or sooner as needed

• CONTINUE BRONCHODILATOR Continuous nebullsatlon until breathing difficulty Improves. Then co nsider changing t o pMDI plus spacer or intermittent nebuliser (doses as for Severe)

6 years and over: 8 puffs (160 meg) via pMDI (21 meg/actuation) every 20 mrnutes for first hour 0-5 years: 4 puffs (80 meg) v ia pMDI (21 meg/actuation) every 20 minutes for first hour.

OR Give v ia nebuliser added to nebulised salbutamol 6 years and over: 500 meg nebule 0 -5 year s: 250 meg nebule

1 HOUR

• CONSIDER OTHER ADD-ON TREATMENT OPTIONS Table. Add-on treatment options for acute asthma

START SYSTEMIC CORTICOSTEROIDS

Oral prednisolone 2 mglkg oral (maximum 50 mg) then 1 mglkg on days 2 and 3 OR, if oral ro ute not possib le

Hydrocortisone IV initial dose 8 - 10 mg./kg (max 300 mg). then 4 - 5 rngl\<g/dose every 6 hours on day 1. then every 12 hours on day 2. then once on day 3

OR Methylprednisolone IV initial dose 2 mg/kg (max 60 mg). then 1 mg/kg every 6 hours on day 1, then every 12 hours on day 2, then once on day 3

.& For children 0 - 5 years, a110id systemic corticosteroids if mild/moderate wheezing responds to initial bronchodilator treatment

REASSESS RESPONSE TO TREATMENT (1 HOUR AFTER STARTING BRONCHODILATOR) Pcrtormspiromctrv(itchildcapablcl

I

• No breathing difficulty

OBSERVE for more than 1 hour after dyspnoea resolves

PROVIDE POST-ACUTE CARE Ensure parents are able to monitor and manage asthma at home Provide oral prednisolone for 3-5 days Ensure child has regular Inhaled preventer If Indicated Check and coach In correct Inhaler technique Provide spacer If needed Provide Interim asttlma :><:lion plan Advise/arrange follow-up review

• Breathing difficulty persists

REASSESS

1 No breathing

••••• difficulty for more than one hour

Breathing difficulty persists

L Persisting or

life-threatening acute asthma

Transfer to ICU or discuss transfer/retrieval with senior medical staff

SEVERITY ASSESSED AS LIFE-THREATENING ACUTE ASTHMA

Any of th~e findings:

• drowsy • poor respiratory effort • collapsed • soft/absent breath sounds • exha ust ed • oxygen saturat ion <90" • cyanotic

GIVE SALBUTAMOL VIA CONTINUOUS NEBULISATION

CHILDREN 0 -5 YEARS

Salbutamol2 x 2.5 mg nebules a t a t ime

Use oxycen to drive nebuliser Maintain Sa02 95"or hi&Mr

ADULTS AND ADOLESCENTS

Salbutamo12 x s mg nebules a t a time

Use ajr to drive nebuliser

Give oxvaen v~ wnturi mask and titrate to tarcet SaO, 92-95"

REASSESS IMMEDIATELY AFTER STARTING SALBUTAMOL

M ar ked Improvement Some Improvement

.e Adults and children 6years and over: 500 mcs ipratropium bromide

Children0-5 years: 250 mcs iprotropium bromide

If symptoms do not improve:

Add magnesium sulfate IV - diluted in saline as sina.Je IV infusion over a: 20minutes

Adults: 2 g MgS04

Children 2years and over:O.l-0.2 mmollkg MgS04

• • Symptoms resolved Symptoms not resolved

CONTINUE SALBUTAMOL AND MONITORING

When dyspnoea improves. consider chan,ains salbuumol route of deliv~

p MDI PLUS SPACER

Adults and children6yeorsand over: 12 puffs solbutamol 100 meg/actuation Children0-5 years: 6 puffs salbutamol 100mcg/actwtion

or

INTERMITTENT N EBULISATION

•

Adults and children 6 yeats and over: 5 mg nebule ~ 20 minutes Children0-5 yeors 2.5 mg nebuleevery 20minutes

• CONTINUE SALBUTAMOL BY CONTINUOUS NEBULISATION

CONSIDER THE NEED FOR NPPV OR INTUBATION AND VENTILATION

ARRANGE TRANSFER/RETRIEVAL TO ICU

Salbutamoi iV - initiollooding dose of 5 mcglkg/min lor 1 hour

Then reduce to 1-2 mcglkglmin until breothing stobilises.

.f.\. Monitor blood electrolytes. he~rt r~te Lll and acid/base balance (blood lactate)

The Difficult Airway Society UK

IV vs Nebulised Salbutamol

‘There is no evidence to support the use of IV beta2‐agonists in patients with acute severe asthma.  These drugs should be given by inhalation. No subgroups were identified in which the IV route should be considered.’

Cochrane meta‐analysis 2003 and 2012

‘3rd line bronchodilator’Australian Asthma Handbook  2014

Really?

• 40 years of research• Cochrane reviewed 15 RCTs (level 1a/1b)• Criticisms:

– Poor case definition– Poorly controlled for age– Non‐equivalent therapies evaluated– No comment on serum salbutamol levels 

AuthorYearLocation

Patient numbersneb: ivAgeWeight

Attack durationbefore treatment

Salbutamolnebulisation

Assumed10 minsalbutamol iv, if 70kg 

Total IVsalbutamolover time

Result Side effects Blood levelssalbutamolng.ml‐1

Lawford 1978Single centre

7:715‐65yrsNo weight

Not stated

10mg in 10ml saline over 45 min

200mcg 900mcg over 45 min IV and nebulised groupsimproved

iv = pulse rise, shaking, ectopics

None

Cheong1982Single centre

34:3716‐69yrsNo weight

½ hr?unclear

5mg at 0, 30 and 120 min. No time of neb duration

125mcg 3000mcgOver 4 hours

IV more effective Tachycardiain iv groupat 3.5hr P<0.001

None

SwedishSociety199013 centres

87:8955 (13)Weightrecordedbut not used for iv

Not stated 5mg over 7min x2 at 0 and 30min delivery by IPPB on inhalation

350mcg 350mcgover 10 min 

Neb betterthan iv

Tachycardiain neb group at 120 minP<0.001

Yes.Pre:postneb  7.1+/‐7:16+/‐9Iv  5.7+/‐6:6.6+/‐6.4   P<0.001

Salmeron19944 centres

22:2539 +/‐13yrsNo weight

14 +/‐ 16 hrs 5mg over 15min x2 during60 min

83 mcg 500mcgover 60 min 

Neb betterNo differenceNS

Yes.Pre:postneb 2.9:7.8iv  3.6:10Non significant

Browne1997Single centre

15:148.4 (3.1)yrs29.2 (10.1)kgChildren

1 hr?unclear

2.5 or 5mg in 4ml saline.No time of nebulisation

1050 mcgFor a 70kg equivalent adult

438 mcgFor average 29.2kg child over 10 min

IV better.9.7hr earlier discharge from ED

Greater tremor in ivP<0.02

None.Assumed to be in the range of 20‐40

• 2002, Westmead Hospital• IV salbutamol/ipratropium neb/both• No side affects or treatment intolerance• Reduction in recovery time with IV salbutamol (p=0.008)

• Less supplemental oxygen required (p=0.0003)• Earlier discharge from hospital (p=0.013)

IV Magnesium Sulphate

‘Magnesium sulphate appears to be safe and beneficial in patients who present with severe acute asthma.’

Cochrane meta‐analysis 2012

‘2nd line bronchodilator’Australian Asthma Handbook  2014

• Are we giving enough? 

• What can we learn from animal models?

• How should we dose effectively?

• Additional benefits?

The Magnesium Debate

• Magnesium and asthma meta‐analyses– Doses and administration times in asthma

• Experience in other clinical scenarios– O & G, cardiology

Author/year PatientsAge yrs

Presentation Co‐morbidity DoseIV MgSO4

Delivery speed

Result Side effects Other drugs Mg level

Iseri/1985 1052‐76

Atrial tachycardia COPDx7, CHF 2g    Infusion

60 sec Ratedown

Not stated Theophyllinein 6

yes

Pritchard/1984 245 Pregnant Eclampsia 4g 4 min then im

One fatality20g iv in error

One blood level

Dicarlo/1986 1054+/‐12

Tests CardiomyopathyX6

6gInfusion

6 min Increase PR, AV refractoryA‐H interval

Warmth, flushing

yes

Wesley/1989 1020‐71

SVT  inducedx5 1x CAD1x SSS

2g 5 sec SlowedSVT

X4 ventric triplet

Verapamil, digoxin, terbutaline,atropine

yes

Viskin/1992Mag vs Adenosine

14 SVT Mitral valve disease. A‐H= Atrial His interval

2g 15 sec Chest pain, flushing, nausea

Hays/1994 767+/‐16

New AF MVDHigh bp

2g 1 min Rate down warmth Digoxin yes

IV magnesium delivery. CAD=Coronary artery disease. SSS= Sick sinus syndrome. MVD= Mitral valve disease

The Magnesium Debate

• Magnesium and asthma meta‐analyses• Experience in other clinical scenarios• Cardiovascular safety profile• Magnesium levels• Pharmacological principles• Attenuation of catecholamine effects • Role for a rapid loading dose and infusion

Your 70kg Patient

National Asthma Council 2014 DAS Draft recommendations 2014

IV SalbutamolFirst 10 minsNext 50minsNext 1 hrTotal over 2 hr

3.5 mg17.5 mg4.2 mg25.2 mg

1.05 mg17.5 mg21.0 mg39.6 mg

IV Magnesium 2g over 20 minutes 2.8g over 4 minutes

ECI Clinical Tool on Asthma

• Importance of highlighting ongoing work and controversies

• Structured approach to the crashing asthmatic based on Australian experience

• Emphasis on collaboration and feedback

Procedure Pearls: the crashing patient with life threatening asthma 10 Mar 2014

• Keep sat up and on BIPAP until RSI drugs given, then lie down and apply BVM

• Place nasal prongs 15Umin for apnoeic oxygenation providing that placement of this does not

break your BVM seal 1 Preparation for intubation 11 Mar 2014 Avoid vigorously bagg --------------------------------

• hyperinflation, increas Airway and breathing: • Administer post-intubc; • Asthmatic patients are 'SOAP-ME'

permissive hypercapn • Suction

• Suggested settings: • Oxygen - BVM attached to oxygen Fi02 1.0, ongoing BIPAP • Airways (ETI, LMI

• SIMV- volume c• • Positioning- sit up Managing the deteriorating ventilated asthmatic 10Mar2014

• Fi02 1.0 • Monitoring and Me

• TV 8mUkg (ideal ! • Inspiratory flow ra

• PEEP 0-3cm H2C

• I:E ratio 1:4 ide all

• Plateau airway pr

Useful resources

'Dominating the Vent Par

• Continuous pu • Medications:

• Ketamine stability)

• Suxamett • If ketamin • Rocuronit • Sedative i

• End tidal C02

• Calibrate moni

Circulation:

• 2x large bore IV ca • IVF on pump set al

other cannula free • Give a fluid bolus ~

repeated.

ACI NSW Agency for Clinical Innovation

1. Immediately take off ventilator and allow patient to expire (can use both hands to press on chest to mechanically assist expiration)

2. Attach bag and 15Umin oxygen and gently ventilate assessing lung compliance 3. Assess 'MASH'

• Movement of the chest during ventilation

• Arterial saturation (Sa02) and Pa02 • Skin colour of the patient (are they turning blue or pinking up?) • Hemodynamic stability

4. Look for the cause of dl Pitta II~:

• Displacement of the ET Obstruction of the ETI

• Patient factors- inade• • Equipment- ventilator

• 'Stacked breaths' - AI<

5. Address the causes for 6. If you run into trouble v1

ventilator whilst awaitin,

ventilator.

• Not involving the most experienced airway doctor available

• Not involving your critical care colleagues

• Not appreciating or preparing for rapid patient deterioration:

Hypoxia and respiratory arrest

Hypotension and cardiovascular collapse - reduced preload with positive pressure

ventilation (these patients are pre-load dependant)

• Taking patient off BIPAP and lying patient flat pre delivery of RSI drugs

• Using conventional ventilation strategies

• Not adequately sedating and paralysing patient post intubation

• Failure to deliver nebulisers via the ventilation circuit

~ Emergency ~ Care Tnstitute

Where to from now?

High dose MgNIPPV

HFNP Trial ‐ RPA

World Asthma Day May 6th 2014

Thanks to

• Dr Sally McCarthy and Dr John Mackenzie (ECI)• Dr Willie Sellers and Dr Imran Ahmad (DAS)• Professor Mike James (anaesthetist, UCT)

References available on request