Asthma Updated Guidelines

Lina Serhan 📝

Dr Nada Abdelrahman

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3/4/2024

Learning objectives

BY THE END OF THIS SESSION, THE STUDENT SHOULD BE ABLE TO

Diagnose different types of asthmatic attack
Manage different types and stages of asthma.

SAMPLE FOOTER TEXT

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Aetiology

Imbalance in the immune response, (type 2 T-helper (Th2) cell-mediated response → increase cytokines (IL)-4, IL-5, and IL-13, IL 25, IL33 promoting eosinophilic inflammation, immunoglobulin E (IgE) production, and airway hyperresponsiveness.

Environmental Factors

Genetic Factors

Immunological Factors

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Environmental exposure to allergen Dermatophagoides pteronyssinus, grass pollen, domestic pets

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Risk factors & associations

Personal or family history of atopy
IgE-mediated atopic
☑ atopic dermatitis (eczema)
☑ allergic rhinitis (hay fever)
Antenatal factors: maternal smoking, viral infection (RSV)
Low birth weight; not being breastfed baby at risk to get asthma.
Air pollution & exposure to allergens
‘hygiene hypothesis’: increased risk of asthma in developed countries → less exposure less Immunity
Sensitive to aspirin. Nasal polyps.

This Photo by Unknown Author is licensed under CC BY-NC

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Pathophysiology of Asthma

Vides

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Investigations for asthma

Guidelines avoid subjective/clinical judgements and advocate objective tests. All patients >= 5 years should have objective tests.
☐ Fractional exhaled nitric oxide (FeNO). 3 types; inducible (iNOS) levels rise in inflammatory cells (eosinophils) & correlate with levels of inflammation. Positive: >= 40 parts per billion (ppb) Confirmatory with other tests
☐ Spirometry and peak flow variability Obstructive: FEV1/FVC ratio <70% obstructive pattern Could be with other diseases like: COPD
☐ Bronchodilator reversibility (BDR) test Positive test : by improvement in FEV1 of 12% or more (increase in volume of ≥200 ml)
☐ Exercise challenge test using histamine or methacholine Positive test : by reduction in FEV1 of >10-15% or more (decrease in volume of ≥200 ml)

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Video

Objectives

The use of basic respiratory function tests:
Spirometry
Peak flow
The interpretation of results.

Steps of investigation

Measure FeNO
DO Spirometry
If obstruction BDR
If negative– monitor Peak Flow variability (2-4 wk if there’s variability → this is asthma) if there’s no go to the next step
If negative– histamine or methacholine challenge test
If 5 unavailable; suspect and treat

Algorithm C Objective tests for asthma in adults aged 17 and over

Interpretation of test results for adults aged 17 and over with symptoms suggestive of asthma

Abbreviations

FeNO, fractional exhaled nitric oxide BDR, bronchodilator reversibility

This algorithm is based on recommendations from NICE’s guideline on asthma, diagnosis, monitoring and chronic asthma management (2017)

Positive test thresholds

Obstructive spirometry: FEV1/FVC ratio less than 70% (or below the lower limit of normal if available) FV50: 40 ppb or more ACR, improvement in FEV1 of 12% or more and increase in volume of 200 ml or more T-1/4 flow variability: variability over 20% Direct bronchial challenge test with histamine or methacholine: FCO: of 8 mg/ml or less

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Diagnosis should be based on objective tests

SAMPLE FOOTER TEXT 10

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Asthma classification

Moderate	Severe	Life-threatening
• PEFR 50-75% best or predicted
• Speech normal
• RR < 25 / min
• Pulse < 110 bpm	• PEFR 33 - 50% best or predicted
• Can’t complete sentences
• RR > 25/min
• Pulse > 110 bpm	• PEFR ≤ 33% best or predicted.
• Oxygen sats < 92%
• ‘Normal’ pCO2 (4.6-6.0 kPa) due to Respiratory Fatigue
• Exhaustion, confusion or coma
• Silent chest, cyanosis or feeble respiratory effort
Bradycardia, dysrhythmia or hypotension.

‘Near-fatal asthma’, is a raised pCO₂ and/or requiring mechanical ventilation with raised inflation pressures.

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Acute severe asthma

① ABC ② give oxygen ③ Iv Fluid and Steroid and if very severe and pit is able to swallow give oral prionstone ④ inhaler B agonist (salbutamol)

Management of acute severe asthma

Assess severity of attack

PEF, ability to speak, RR, pulse rate, O₂ sats Warn ICU if severe or life-threatening attack

Immediate treatment¹

Salbutamol 5mg (or terbutaline 10mg) nebulized with O₂ Hydrocortisone 100mg IV or prednisolone 40–50mg PO or both if very ill Start O₂ if saturations <92% (also check ABG), aim sats 94–98%

If life-threatening features present:

Inform ICU and seniors
Give salbutamol nebulizers every 15min, or 10mg continuously per hour. Monitor ECG; watch for arrhythmias
Add in ipratropium 0.5mg to nebulizers
Give single dose of magnesium sulfate (MgSO₄) 1.2–2g IV over 20min

in life-threatening differences clampola traume Dunt

If not improving:

Refer to ICU for consideration of ventilatory support and intensification of medical therapy, eg aminophylline, IV salbutamol if any of the following signs are present:

Deteriorating PEF
Persistent/worsening hypoxia
Hypercapnia
ABG showing low pH or high H’
Exhaustion, feeble respiration
Drowsiness, confusion, altered conscious level
Respiratory arrest

If improving within 15–30 minutes:

Nebulized salbutamol every 4 hours
Prednisolone 40–50mg PO or 5–7 days
Monitor peak flow and O₂ sats, aim 94–98% with supplemental if needed

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When assessing a patient with acute asthma they are classified as being moderate, severe or life-threatening. Which one of the following is a feature of life-threatening asthma?

A Pulse > 110 bpm B RR < 25 / min C Pulse < 110 bpm D Speech normal E RR > 25/min F Oxygen sats < 92%

Case scenario

When assessing a patient with acute asthma they are classified as being moderate, severe or life-threatening. Which one of the following is a feature of moderate asthma?

A Oxygen sats < 92% B Pulse > 110 bpm C RR > 25/min D PEFR 33 - 50% best or predicted E Speech normal F Can’t complete sentences

Case scenario

When assessing a patient with acute asthma they are classified as being moderate, severe or life-threatening. Which one of the following is a feature of moderate asthma?

A RR > 25/min

B Can’t complete sentences

C Pulse > 110 bpm

D PEFR 50-75% best or predicted

E Exhaustion, confusion or coma

F PEFR 33 - 50% best or predicted

Case scenario

SAMPLE FOOTER TEXT 15

When assessing a patient with acute asthma they are classified as being moderate, severe or life-threatening. Which one of the following is a feature of severe asthma?

When assessing a patient with acute asthma they are classified as being moderate, severe or life-threatening. Which one of the following is not a feature of severe asthma?

RR < 25 / min B
PEFR 33 - 50% best or predicted C
Oxygen sats < 92% D
RR > 25/min E
Can’t complete sentences

Case scenario

SAMPLE FOOTER TEXT

When assessing a patient with acute asthma they are classified as being moderate, severe or life-threatening. Which one of the following is a feature of severe asthma?

When assessing a patient with acute asthma they are classified as being moderate, severe or life-threatening. Which one of the following is a feature of life-threatening asthma?

A PEFR 33 - 50% best or predicted B RR < 25 / min C Bradycardia, dysrhythmia or hypotension D Pulse < 110 bpm E Pulse > 110 bpm F Can’t complete sentences

Case scenario

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Management

Admission

All patients with life-threatening
Severe acute asthma admitted if they fail to respond to initial treatment.
other admission criteria include
☑ a previous near-fatal asthma attack
☑ pregnancy
☑ an attack despite already using oral corticosteroid
☑ Presentation at night the incidence at night high

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Management

Oxygen
if patients are hypoxaemic, start supplemental oxygen therapy
if patients are acutely unwell; started on 15 L of supplemental via a non-rebreathe mask, titrated down to a flow rate where they are able to maintain a $SpO_{2}$ 94-98%.

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Management

Bronchodilation with short-acting beta₂-agonists (SABA)
High-dose inhaled SABA e.g. salbutamol, terbutaline.
If no feature of life-threatening or near-fatal asthma; standard pressurised metered-dose inhaler (pMDI) or by an oxygen-driven nebulizer.
Life-threatening exacerbation of asthma; nebulised SABA is recommended

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Management

Corticosteroid

All patients: given 40-50mg of prednisolone orally (PO) daily, continued for at least 5 days or until recovery. If on inhaled steroid: continue
Ipratropium bromide: severe or life-threatening asthma, or if not response to beta₂-agonist and corticosteroid ttt, nebulised ipratropium bromide
IV magnesium sulphate; severe/life-threatening asthma
IV aminophylline; consultation; fail to respond require senior critical care support and should be treated in an appropriate ITU/HDU setting.

Treatment options include:

intubation and ventilation
extracorporeal membrane oxygenation (ECMO)

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Typical results in asthma

FEV1 - significantly reduced
FVC - normal
FEV1% (FEV1/FVC) < 70%

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An asthmatic patient presented with this ABG finding; Comment

pH	7.37	(7.35-7.45)
pO2	10.1 kPa	(>9 kPa)
pCO2	4.9 kPa	(4.7-6.0 kPa) normal
Base excess	1.1	(-2 to 2)
Lactate	1.9 mmol/L	(<2 mmol/L)

life threatening attack

SAMPLE FOOTER TEXT

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Criteria for discharge

☐ Stable on their discharge medication (i.e. no nebulisers or oxygen) for 12–24 hours

Inhaler technique checked and recorded. ☑ PEF >75% of best or predicted

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Drug	Mechanism of action	Notes
Salbutamol	Beta receptor agonist	• Short-acting inhaled bronchodilator. Relaxes bronchial smooth muscle through effects on beta 2 receptors
• Used in asthma and chronic obstructive pulmonary disease (COPD).
• Salmeterol has similar effects but is long-acting
Corticosteroids	Anti-inflammatory	• Inhaled corticosteroids are used as maintenance therapy
• Oral or intravenous corticosteroids are used following an acute exacerbation of asthma or COPD
Ipratropium	Blocks the muscarinic acetylcholine receptors	• Short-acting inhaled bronchodilator. Relaxes bronchial smooth muscle
• Used primarily in COPD
• Tiotropium has similar effects but is long-acting
Methylxanthines (e.g. theophylline)	Non-specific inhibitor of phosphodiesterase resulting in an increase in cAMP	• Given orally or intravenously
• Has a narrow therapeutic index
Monteleukast, zafirlukast	Blocks leukotriene receptors	• Usually taken orally
• Useful in aspirin-induced asthma

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Quick facts

Which beta-2 adrenergic agonist is used to treat acute asthma?
Albuterol
Salbutamol

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Quick facts

What is the MOA of Zileuton ?

Inhibit 5 lipoxygenase and leukotrin

SAMPLE FOOTER TEXT 27

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Quick facts

The muscarinic agonist …methacaline…is used in bronchial provocation challenges to diagnose asthma

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Quick facts

methacdin The muscarinic agonist is used in bronchial provocation challenges to diagnose asthma

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Quick facts

What is the MOA of Ipratropium?

Competitive inhibition of ACh Muscarinic receptors

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Quick facts

… is indicated for the treatment of asthma by preventing IgE from binding mast cells

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Quick facts

Omalizumab is indicated for the treatment of asthma by preventing IgE from binding mast cells

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Quick facts

Tremor and cardiac arrhythmias are side effects of long-acting beta2-adrenergic agonists such as formoterol or salmeterol

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Asthma – suspected		Adult asthma – diagnosed
Diagnosis and assessment	Evaluation: • assess symptoms, measure lung function, check inhaler technique and adherence
• adjust dose • update self-management plan • move up and down as appropriate
Consider monitored initiation of treatment with low-dose ICS	Infrequent, short-lived wheeze	Move down to find and maintain lowest controlling therapy	Move up to improve control as needed	Specialist therapies
		Initial add-on therapy
Add inhaled LABA to low-dose ICS (fixed dose or MART)	Additional controller therapies
Consider:
Increasing ICS to medium dose
or
Adding LTRA
If no response to LABA, consider stopping LABA	Refer patient for specialist care
Short acting β₂ agonists as required (unless using MART) – consider moving up if using three doses a week or more

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Further explanation

Maintenance and reliever therapy (MART)

a form of combined ICS and LABA treatment in which a single inhaler, containing both ICS and a fast-acting LABA, is used for both daily maintenance therapy and the relief of symptoms as required
MART is only available for ICS and LABA combinations in which the LABA has a fast-acting component (e.g, formoterol)

Notes:

Don’t changing treatment in patients who have well-controlled asthma simply to adhere to the latest guidance.

Inhaled corticosteroid doses

⇐ 400 micrograms budesonide or equivalent = low dose
400 micrograms - 800 micrograms budesonide or equivalent = moderate dose
> 800 micrograms budesonide or equivalent = high dose.

SAMPLE FOOTER TEXT

Asthma: management in adults

Step	Notes
1 Newly-diagnosed asthma	Short-acting beta agonist (SABA)
2 Not controlled on previous step OR
Newly-diagnosed A with symptoms

= 3 / week or night-time waking | SABA + low-dose inhaled corticosteroid (ICS) | | 3 | SABA + low-dose ICS + leukotriene receptor antagonist (LTRA) ext with Kan | | 4 | SABA + low-dose ICS + long-acting beta agonist (LABA) Continue LTRA depending on patient’s response to LTRA | | 5 | SABA +/- LTRA we can stop it & no response Switch ICS/LABA for a maintenance and reliever therapy (MART), that includes a low-dose ICS ext with sABA + ICS | | 6 | SABA +/- LTRA + medium-dose ICS MART OR consider changing back to a fixed-dose of a moderate-dose ICS and a separate LABA 400 - 800 | | 7 | SABA +/- LTRA + one of the following options: • increase ICS to high-dose (only as part of a fixed-dose regime, not as a MART) 800 • a trial of an additional drug (for example, a long-acting muscarinic receptor antagonist or theophylline) • seeking Expert advice |

What is the most appropriate next step in the following scenario: newly diagnosed adult with asthma (symptoms < 3 times/weeks)?

A Switch to either a MART regime with a moderate-dose ICS or to separate moderate-dose ICS and LABA inhalers

B Add a low-dose ICS

C Stop LABA + increase ICS to medium-dose

D Add a SABA

E Switch ICS/LABA for a MART regime with a low-dose ICS

F Add a LABA

Case scenario

SAMPLE FOOTER TEXT 37

What is the most appropriate next step in the following scenario: adult with asthma not controlled by a SABA + low-dose ICS?

A Add a leukotriene receptor antagonist B Add a LABA C Stop LABA + increase ICS to medium-dose D Trial of either high-dose ICS as part of fixed-dose regime, additional drug (e.g. LAMA or theophylline) or referral E Switch to either a MART regime with a moderate-dose ICS or to separate moderate-dose ICS and LABA inhalers F Add a SABA

Case scenario

SAMPLE FOOTER TEXT 38

What is the most appropriate next step in the following scenario: adult with asthma not controlled by a SABA + low-dose ICS +/- leukotriene receptor antagonist + LABA?

SAMPLE FOOTER TEXT 39

A	Add daily oral prednisolone
B	Add a LABA
C	Switch to either a MART regime with a moderate-dose ICS or to separate moderate-dose ICS and LABA inhalers
D	Stop LABA + increase ICS to medium-dose
E	Switch ICS/LABA for a MART regime with a low-dose ICS
F	Trial of either high-dose ICS as part of fixed-dose regime, additional drug (e.g. LAMA or theophylline) or referral

Case scenario

What is the most appropriate next step in the following scenario: adult with asthma not controlled by a SABA +/- leukotriene receptor antagonist + MART regime with a low-dose ICS?

SAMPLE FOOTER TEXT 40

A	Trial of either high-dose ICS as part of fixed-dose regime, additional drug (e.g. LAMA or theophylline) or referral
B	Add a low-dose ICS
C	Add a LABA
D	Switch to either a MART regime with a moderate-dose ICS or to separate moderate-dose ICS and LABA inhalers
E	Stop LABA + increase ICS to medium-dose
F	Add a leukotriene receptor antagonist

Case scenario

What is the most appropriate next step in the following scenario: adult with asthma not controlled by a SABA + low-dose ICS + leukotriene receptor antagonist?

A Switch to either a MART regime with a moderate-dose ICS or to separate moderate-dose ICS and LABA inhalers

B Add a LABA

C Stop LABA + increase ICS to medium-dose

D Trial of either high-dose ICS as part of fixed-dose regime, additional drug (e.g. LAMA or theophylline) or referral

E Add daily oral prednisolone

F Add a low-dose ICS

SAMPLE FOOTER TEXT 41

What is the most appropriate next step in the following scenario: adult with asthma not controlled by a SABA?

A Add daily oral prednisolone B Add a LABA C Add a SABA D Add a low-dose ICS E Add a leukotriene receptor antagonist F Switch ICS/LABA for a MART regime with a low-dose ICS

Case scenario

SAMPLE FOOTER TEXT 42

What is the most appropriate next step in the following scenario: adult with asthma not controlled by a SABA +/- leukotriene receptor antagonist + MART regime with a moderate-dose ICS?

SAMPLE FOOTER TEXT 43

A Add daily oral prednisolone

B Stop LABA + increase ICS to medium-dose

C Add a LABA

D Switch ICS/LABA for a MART regime with a low-dose ICS

E Trial of either high-dose ICS as part of fixed-dose regime, additional drug (e.g. LAMA or theophylline) or referral

F Switch to either a MART regime with a moderate-dose ICS or to separate moderate-dose ICS and LABA inhalers

A 50-year-old man with late-onset asthma presents with malaise and weight loss. He also complains of recurrent bouts of sinusitis. Bloods show a marked eosinophilia is a stereotypical history of:

signs of upper Reip track

A Churg-Strauss syndrome

B Buerger’s disease

C Polyarteritis nodosa

D Takayasu’s arteritis

E Granulomatosis with polyangiitis

F Temporal arteritis

Case scenario

SAMPLE FOOTER TEXT 44

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An 18-year-old man is admitted to the emergency department with an episode of acute asthma. He is unable to complete sentences, tachycardic (118 beats per minute) and tachypnoeic (respiratory rate 30). He has received salbutamol, ipratropium bromide nebulisers and intravenous hydrocortisone through a large bore cannula in the right antecubital fossa. Despite another salbutamol nebuliser, there is no improvement in his condition. What medication would be most appropriate to add?

A. Beclamethasone B. Magnesium sulphate C. Amoxicillin D. Nifedipine E. Adrenaline

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Remember asthma is not only asthma, always consider other possible diagnosis

SAMPLE FOOTER TEXT 46

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Occupational Asthma

SAMPLE FOOTER TEXT 47

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Asthma: occupational

Exposure to the following chemicals is associated with occupational asthma:

isocyanates - the most common cause
Spray painting and foam moulding using adhesives
platinum salts
soldering flux resin
glutaraldehyde
flour
epoxy resins
proteolytic enzymes

Investigations

~~Serial measurements~~ of peak expiratory flow are recommended at work and away from work. home

Referral ; respiratory specialist for suspected patients

Patients concerns: chemicals at work are worsening their asthma Doctor; history that symptoms seem better at weekends / when away from work.

SAMPLE FOOTER TEXT 49

Which one of the following is the best investigation for occupational asthma?

A Spirometry

B Serum IgE

C Schirmer’s test

D Serial peak flows at home and at work

E Overnight dexamethasone suppression test

F Serum tryptase

Case scenario

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Case scenario

A 45-year-old man presents with a three-month history of wheezing and dyspnoea whilst at work. His symptoms improve significantly when at home and at weekends.
What is the likely causative agent?

A. Simple coal worker’s lung B. Silica C. Cotton dust D. Asbestos E. Isocyanates

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Asthma & Pregnancy

Reassure
Guidelines: Good control of asthma during pregnancy.
Drugs safe during pregnancy and breastfeeding’.
‘inhaled drugs, beclometasone and salmeterol
Theophylline
prednisolone

SAMPLE FOOTER TEXT 51

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A 28-year-old woman is attending her annual asthma review. She is currently prescribed a salbutamol inhaler 100μg and budesonide 400μg. Her asthma is well controlled and she hasn’t needed to use her ‘blue inhaler’ over the past year. She is currently trying for a baby and is concerned about taking her asthma medications during pregnancy.

What is the most appropriate change to her medications?

A. Add leukotriene receptor antagonist B. Reduce budesonide dose C. Reduce salbutamol dose D. Stop budesonide E. Stop salbutamol

In the step-down : aim for a reduction of 25-50% in the dose of inhaled corticosteroids

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Asthma Updated Guidelines

Learning objectives

Aetiology

Environmental Factors

Genetic Factors

Immunological Factors

Risk factors & associations

Pathophysiology of Asthma

Investigations for asthma

Objectives

Steps of investigation

Abbreviations

Positive test thresholds

Diagnosis should be based on objective tests

Asthma classification

Acute severe asthma

Management of acute severe asthma

Assess severity of attack

Immediate treatment¹

If life-threatening features present:

If not improving:

If improving within 15–30 minutes:

When assessing a patient with acute asthma they are classified as being moderate, severe or life-threatening. Which one of the following is not a feature of severe asthma?

Case scenario

When assessing a patient with acute asthma they are classified as being moderate, severe or life-threatening. Which one of the following is a feature of life-threatening asthma?

Management

Admission

Management

Management

Management

Corticosteroid

Typical results in asthma

An asthmatic patient presented with this ABG finding; Comment

Criteria for discharge

Quick facts

Quick facts

Quick facts

Quick facts

Quick facts

Quick facts

Quick facts

Quick facts

Further explanation

Maintenance and reliever therapy (MART)

Notes:

Inhaled corticosteroid doses

Remember asthma is not only asthma, always consider other possible diagnosis

Occupational Asthma

Asthma: occupational

Investigations

Case scenario

Asthma & Pregnancy

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