🔬Pathophysiology
Core Triad
- Airway inflammation — chronic eosinophilic or neutrophilic infiltration of bronchial mucosa
- Airway hyperresponsiveness (AHR) — exaggerated bronchoconstriction to stimuli
- Reversible airflow obstruction — spontaneously or with treatment
Endotypes
T2-High (Eosinophilic)
- Th2 driven: IL-4, IL-5, IL-13, IgE
- Allergic or late-onset eosinophilic
- Responds to ICS, biologics (anti-IL-5, anti-IgE)
T2-Low (Non-eosinophilic)
- Neutrophilic or paucigranulocytic
- Obesity-related, smoking-related
- Poorer ICS response; consider macrolides
📊Diagnosis
PEFR Variability
Diurnal variation >10% on ≥3 days in a week for 2 weeks (home diary). Morning dip is characteristic.
Spirometry Reversibility
Post-bronchodilator FEV1 increase ≥12% AND ≥200 mL from baseline — confirms reversible airflow limitation.
Bronchial Provocation Testing
- Methacholine or mannitol challenge
- Used when spirometry is normal but asthma suspected
- Positive: PC20 <8 mg/mL (methacholine) = AHR confirmed
- High sensitivity; stop if FEV1 falls >20%
Supportive Markers
📋GINA 2023 — Classification by Level of Control
| Control Level | Daytime Symptoms | Night Waking | Reliever Use | Activity Limitation | PEFR/FEV₁ |
|---|---|---|---|---|---|
| Well-Controlled | ≤2 days/week | None | ≤2 days/week | None | ≥80% predicted |
| Partly Controlled | Any 1–2 features present in any week | 60–79% | |||
| Uncontrolled | 3+ features present in any week OR any acute exacerbation | <60% | |||
GINA 2023: Assess control at every visit. Uncontrolled asthma = consider step-up. Review technique and adherence before stepping up.
⚠️Asthma Triggers — VACT
- Viral infections — rhinovirus most common trigger of exacerbations
- Allergens — HDM, pollen, pet dander, mould spores, cockroach
- Cold air / exercise — post-exercise bronchospasm (EIB)
- Tobacco smoke — active and passive; worsens control
- NSAIDs / Aspirin — Samter's triad (asthma + nasal polyps + NSAID sensitivity)
- Beta-blockers — even ophthalmic drops can trigger bronchospasm
- Emotional stress — hyperventilation, vagal response
- Air pollution — PM2.5, ozone, nitrogen dioxide
- Occupational — isocyanates, flour, latex, wood dust
🚨Risk Factors for Fatal/Near-Fatal Attack
- Poor adherence with preventer therapy
- Overuse of SABA — ≥3 canisters/year = danger sign
- No ICS preventer prescribed or taken
- Nocturnal symptoms — circadian cortisol nadir
- Food allergy (especially peanut) + asthma
- Psychosocial factors — depression, denial, low income
- Previous ICU admission / intubation
- Brittle asthma — unpredictable severe attacks
- Smoking, obesity, non-adherence to follow-up
🪜GINA 2023 Stepwise Management
Step up if symptoms uncontrolled for ≥3 months; step down if well-controlled for ≥3 months. Review inhaler technique and adherence at every step change.
1
Step 1 — As-needed low-dose ICS-formoterol (preferred) OR SABA alone
As-needed ICS-formoterol (e.g. budesonide/formoterol) — even if mild intermittent symptoms. Reduces exacerbation risk vs SABA alone. Preferred over SABA-only in adults & adolescents.
2
Step 2 — Regular low-dose ICS daily + as-needed SABA OR as-needed low-dose ICS-formoterol
Daily ICS is cornerstone. Alternatives: LTRA (montelukast) if ICS not tolerated. As-needed ICS-formoterol also effective.
3
Step 3 — Low-dose ICS/LABA combination (preferred) + as-needed SABA or ICS-formoterol
ICS/LABA synergistically reduces exacerbations and improves symptom control. Medium-dose ICS is alternative. Add LTRA as third option.
4
Step 4 — Medium/high-dose ICS/LABA + as-needed reliever
Consider specialist referral. Add tiotropium as third controller (LAMA). Review diagnosis. MART (maintenance and reliever) with ICS-formoterol.
5
Step 5 — High-dose ICS/LABA + add-on therapies — specialist centre
Biologics, tiotropium, low-dose OCS. Severe refractory asthma phenotyping required before biologic selection.
💨Reliever Inhalers
SABA — Short-Acting Beta-2 Agonist
- Salbutamol (albuterol) — blue inhaler
- Onset: 5 min; Duration: 4–6 hours
- Rescue only — not regular preventive use
- ≥3 canisters/year = poor control / danger sign
- Terbutaline — alternative SABA
MART — Maintenance And Reliever Therapy
- ICS-formoterol used for BOTH daily maintenance AND rescue
- e.g., Symbicort (budesonide/formoterol) or Fostair
- Reduces exacerbations vs fixed-dose regimens
- Only formoterol-containing ICS combos are MART-approved (rapid onset)
🛡️Controller Inhalers (ICS)
Common ICS Agents
Critical Nursing Points
- Regular daily use is essential — not PRN
- Rinse mouth with water after every ICS dose — prevents oral candidiasis (thrush) and dysphonia
- ICS takes 2–4 weeks for full effect — educate patients
- Use spacer with MDI to improve lung deposition
ICS/LABA Combinations
🧬Biologics for Severe Asthma (Step 5)
| Biologic | Target | Criteria | Route |
|---|---|---|---|
| Omalizumab Xolair |
Anti-IgE | Elevated IgE (30–1500 IU/mL) + sensitised to perennial allergen + ≥6 years | SC every 2–4 weeks |
| Mepolizumab Nucala |
Anti-IL-5 | Blood eosinophils ≥0.3 × 10⁹/L + ≥2 exacerbations/year | SC every 4 weeks |
| Benralizumab Fasenra |
Anti-IL-5Rα | Blood eosinophils ≥0.3 × 10⁹/L | SC; 3 doses monthly then every 8 weeks |
| Dupilumab Dupixent |
Anti-IL-4Rα (blocks IL-4 & IL-13) | Eosinophils ≥0.15 × 10⁹/L or FeNO ≥25 ppb; also for comorbid atopic dermatitis | SC every 2 weeks |
| Tezepelumab Tezspire |
Anti-TSLP (upstream) | Severe uncontrolled regardless of eosinophil count — broadest eligibility | SC every 4 weeks |
All biologics: specialist initiation, 3–4 month trial, continue if ≥50% reduction in exacerbations. Monitor for anaphylaxis post-injection (observe 30 min).
🏥BTS/SIGN Acute Asthma Severity Classification
| Severity | PEFR % Best/Predicted | SpO₂ | Clinical Features |
|---|---|---|---|
| Moderate | 50–75% | ≥92% | Increasing symptoms; able to speak in sentences; no features of severe/life-threatening |
| Severe | 33–50% | ≥92% | Any one of: unable to complete sentences / RR ≥25/min / HR ≥110 bpm / use of accessory muscles |
| Life-Threatening | <33% (or unrecordable) | <92% | Any one of: silent chest / cyanosis / feeble respiratory effort / bradycardia / dysrhythmia / hypotension / exhaustion / confusion / coma |
| Near-Fatal | Absent / unrecordable | <92% | Raised PaCO₂ (>6 kPa) AND/OR requiring mechanical ventilation with raised inflation pressures |
💉Immediate Treatment Protocol
Oxygen
- Target SpO₂: 94–98%
- Use controlled oxygen — avoid hyperoxia
- High-flow if SpO₂ <92%; titrate down once stable
SABA Nebulisers
- Salbutamol 2.5–5 mg nebulised — back-to-back x3 (every 20 min) if severe
- Continuous nebulisation (5–10 mg/h) for life-threatening
- Driven by oxygen nebuliser in acute asthma
Ipratropium Bromide
- 0.5 mg nebulised every 4–6 hours
- Add to SABA for severe/life-threatening asthma
- Synergistic bronchodilation; reduces hospital admissions
Corticosteroids
- Prednisolone 40–50 mg oral for 5 days (preferred)
- IV hydrocortisone 200 mg if unable to swallow
- Oral and IV equally effective — no taper needed for 5-day course
- Start immediately — do not delay for other interventions
🧪Magnesium Sulphate & Escalation
IV Magnesium Sulphate
- 2g IV over 20 minutes — single dose
- Indication: Severe or Life-threatening asthma not responding to initial treatment
- Smooth muscle relaxation via calcium antagonism
- Monitor BP during infusion (vasodilatory)
- May also use nebulised isotonic MgSO₄ (151 mg) in some protocols
ICU Indications — Call Early
- Life-threatening features not improving
- Near-fatal criteria: PaCO₂ >6 kPa rising
- Deteriorating despite maximal therapy
- Exhaustion, falling consciousness
- Respiratory arrest / severe hypoxaemia
Intubation Risks in Asthma
- Avoid if possible — high complication rate
- Dynamic hyperinflation / breath stacking
- Pneumothorax, pneumomediastinum
- Post-intubation hypotension
- Difficult extubation due to bronchospasm
🔴Acute Severity Classifier Tool
Acute Asthma Severity Classifier (BTS/SIGN)
🚨Near-Fatal Asthma — Features & Recognition
Defining Features of Near-Fatal Asthma
Gasometric
- PaCO₂ >6 kPa (hypercapnia = respiratory muscle fatigue)
- Severe hypoxaemia PaO₂ <8 kPa
- Respiratory acidosis pH <7.35
Clinical
- Silent chest (no wheeze = no airflow)
- Absent or unrecordable PEFR
- Cyanosis
- Exhaustion — unable to sustain effort
Haemodynamic
- Bradycardia / dysrhythmia
- Hypotension
- Pulsus paradoxus >25 mmHg
- Altered consciousness / coma
Silent Chest Warning — absence of wheeze in severe asthma = near-total airway obstruction = immediately life-threatening. Do NOT be reassured by absence of wheeze.
💊Induction & Intubation in Asthma
Preferred Induction Agent
Ketamine
- Dissociative anaesthetic with bronchodilator properties (catecholamine release → beta-2 agonism)
- Dose: 1–2 mg/kg IV for induction
- Preserves airway reflexes and haemodynamics
- Caution: may increase secretions — have suction ready
Avoid
- Thiopentone — histamine release, may worsen bronchospasm
- Morphine — histamine release
- Suxamethonium — use with caution (hyperkalaemia risk)
Post-Intubation
- RSI (Rapid Sequence Intubation) technique
- Largest ETT possible — reduces resistance
- In-line suction available
- Confirm with ETCO₂ and CXR
🫁Ventilation Strategy for Asthma
Permissive Hypercapnia Strategy
- Accept higher PaCO₂ (up to 8–10 kPa) to avoid barotrauma
- Goal: prevent dynamic hyperinflation
Ventilator Settings
Avoid Breath Stacking
- Maximise expiratory time — gas must fully escape
- Dynamic hyperinflation → intrinsic PEEP (auto-PEEP)
- Air trapping → tension pneumothorax risk
- Hypotension — disconnect circuit to release trapped air if needed
Check for pneumothorax if sudden deterioration on ventilator — urgent needle decompression if tension pneumo.
🧪IV Bronchodilator Therapy (ICU)
Mg
IV Magnesium Sulphate 2g over 20 min
First-line adjunct for severe/life-threatening. May repeat. Monitor deep tendon reflexes (loss = toxicity).
S
IV Salbutamol 5 mcg/min infusion (titrate up to 20 mcg/min)
Use only if nebulised route ineffective. Monitor HR and K⁺ (hypokalaemia risk from SABA).
A
IV Aminophylline (loading 5 mg/kg over 20 min, then infusion)
Narrow therapeutic index — monitor levels (10–20 mg/L). Risk: tachycardia, seizures, arrhythmia. Avoid if on oral theophylline.
Heliox (He-O₂ mixture)
- Helium-oxygen mixture (70:30 or 60:40)
- Lower density → reduces turbulent airflow → improves gas delivery past obstruction
- Use as bridge to other therapies in severe obstruction
- Limits FiO₂ — avoid if SpO₂ <92%
💊Sedation, Paralysis & Recovery
ICU Sedation Strategy
- Propofol — bronchodilatory, preferred infusion
- Midazolam / ketamine — for agitation
- Avoid histamine-releasing agents
- Minimise sedation depth — aim for light/moderate (RASS 0 to -2)
Paralysis (NMB)
- Cisatracurium or vecuronium for ventilator dyssynchrony
- Avoid prolonged use — ICU-acquired weakness risk
- Use with deep sedation only
Post-ICU Recovery
- Wean ventilator as bronchospasm resolves
- Extubate when awake, strong cough, SpO₂ stable on FiO₂ <0.4
- Escalate ICS immediately on discharge from ICU
- Mandatory outpatient follow-up within 2 days
- Psychological assessment — ICU experience, depression screening
- Formal written asthma action plan before discharge
📗Personalised Asthma Action Plan (PAAP)
Based on PEFR % of personal best OR symptom-based. Written and given to every patient. Reviewed at every appointment.
GREEN ZONE — 80–100% PEFR / No Symptoms
- Continue regular controller medication as prescribed
- No need for extra reliever
- Regular exercise and normal activities
- Review triggers and avoid where possible
AMBER ZONE — 50–79% PEFR / Increasing Symptoms
- Take 2–4 puffs salbutamol MDI (or nebuliser 2.5 mg) immediately
- If on MART: take extra ICS-formoterol doses (max 8 puffs/day)
- Start/increase oral prednisolone 40 mg if prescribed in plan
- Repeat salbutamol every 20 minutes up to 3 times
- If not improving within 1 hour → go to RED ZONE / seek emergency care
RED ZONE — <50% PEFR / Severe Symptoms / Not Improving
- Take salbutamol 10 puffs via spacer (1 puff every 30–60 seconds)
- Call ambulance / go to emergency department IMMEDIATELY
- Take prednisolone 40–50 mg (if available)
- Continue salbutamol every 20 minutes while waiting for help
- Do NOT drive yourself — call 999 / 112 / 911
💨Inhaler Technique
MDI (Metered Dose Inhaler) — Correct Technique
- Shake well for 5 seconds; remove cap
- Breathe out slowly and fully
- Place mouthpiece in mouth — seal lips
- Press canister down AND breathe in slowly over 3–5 seconds
- Hold breath for 10 seconds
- Breathe out slowly; wait 30 seconds between puffs
- Rinse mouth after ICS
MDI + Spacer
- Shake MDI; attach to spacer
- Press canister once into spacer
- Breathe in slowly through spacer mouthpiece
- Hold breath 5–10 seconds OR take 5 tidal breaths through spacer
- Wait 30 sec; repeat for next puff
DPI (Dry Powder Inhaler) — e.g. Turbohaler, Accuhaler
- Load the dose (twist/click mechanism)
- Breathe out away from inhaler (not into it)
- Breathe in hard and fast — unlike MDI (no slow breath)
- Hold breath 10 seconds
- DPIs require adequate inspiratory flow — not ideal in acute severe attack
🧼Spacer Maintenance & Adherence
Spacer Cleaning
- Wash weekly with washing-up liquid (dish soap)
- Air dry — do not towel dry (static reduces drug delivery)
- Replace every 6–12 months or if cracked/dirty
- Avoid rinsing with water between uses
Adherence Barriers — Address Proactively
- Denial — "I'm fine, I don't need it every day"
- Side effect fears — "Steroids will harm me" (reassure: ICS are topical, low systemic absorption)
- Cost — explore formulary alternatives, generic options
- Poor technique — regular reassessment at every visit
- Forgetting — tie to daily routine (brushing teeth); phone reminders
- Cultural — religious concerns about inhaler during Ramadan (see Tab 6)
Trigger Avoidance — House Dust Mite
- Allergen-impermeable mattress & pillow covers
- Wash bedding at ≥60°C weekly
- HEPA filter vacuum cleaner; vacuum frequently
- Reduce soft furnishings, carpets in bedroom
- Maintain humidity <50%
🏭Occupational Asthma
- Most important intervention: identify and remove the causative exposure
- Common causes: isocyanates (spray painting), flour dust, latex, wood dust, laboratory animals, soldering flux
- Serial PEFR monitoring at work vs away from work
- Specific inhalation challenge (gold standard)
- Compensation and job change may be necessary
- Even with removal, airway changes may persist — continue ICS
🚭Smoking Cessation & Exercise
Smoking Cessation
- Smoking accelerates lung function decline and worsens asthma control
- Reduces ICS effectiveness significantly
- Offer NRT, varenicline, counselling at every contact
- Passive smoking harmful — advise smoke-free home
Exercise-Induced Bronchospasm (EIB)
- Pre-exercise SABA 15–20 min before activity
- Regular ICS reduces EIB frequency
- LTRA (montelukast) as add-on for EIB
- Warm-up period reduces severity
- Swimming — humid air, less EIB-triggering
🌍GCC-Specific Asthma Context
Prevalence & Epidemiology
- GCC has some of the highest asthma prevalence globally
- Saudi Arabia: up to 25% prevalence in some surveys
- UAE, Qatar, Kuwait: 15–20% prevalence reported
- Rapidly urbanising environment accelerating atopic disease
Environmental Triggers Unique to GCC
- Sandstorms (Haboob / Khamsin) — PM10 particles trigger acute severe asthma; emergency visits spike during storm events
- Dust & desert aerosols — year-round low-level particulate exposure
- Air conditioning paradox — AC systems harbour mould, dust mite, indoor allergens; poor maintenance is risk factor
- Coastal high humidity (UAE, Bahrain, Qatar) — promotes mould growth and HDM proliferation
- Extreme heat — outdoor exercise-induced asthma; heat accelerates ozone formation
Cultural & Social Factors
- Waterpipe / Shisha smoking — widely prevalent in GCC; causes airway inflammation and can trigger/worsen asthma; educate as clearly as cigarette smoking
- Occupational asthma in construction — cement dust, silica, paint fumes; large migrant workforce at risk
- Traditional remedies — may delay seeking care; encourage evidence-based treatment
- Family clustering — atopic family history; opportunistic screening of siblings
Ramadan Fasting & Inhalers
Key Teaching Point
- Scholarly consensus: Inhalers do NOT break the fast — medication goes to lungs (respiratory tract), not GI tract
- Patients should continue preventer and reliever inhalers throughout Ramadan without hesitation
- Some patients may prefer nebuliser — religiously acceptable and clinically effective
- Advise timing of doses (pre-Suhoor / post-Iftar) for twice-daily medications
- Monitor for potential dehydration (dry airway mucosa)
🏛️DHA / DOH / SCFHS Regulatory & Formulary Context
DHA (Dubai Health Authority)
- DHA Essential Medicines List includes: salbutamol, ipratropium, ICS (beclometasone, fluticasone, budesonide), ICS/LABA (seretide, symbicort), prednisolone, IV magnesium sulphate
- Biologics (omalizumab, mepolizumab, dupilumab) on DHA formulary with specialist justification
- DHA Asthma Management Protocol aligned with GINA 2023
- Nurses may perform nebuliser therapy under DHA standing orders
- Asthma nurse specialist role recognised by DHA
DOH (Abu Dhabi Department of Health)
- DOH asthma clinical pathway mandates written PAAP for all asthma patients
- Annual asthma review with spirometry recommended
- Biologics require Prior Authorization from DOH
SCFHS (Saudi Commission)
- SCFHS nursing exams test BTS/SIGN classification, acute management, and GINA stepwise therapy
- Saudi MoH guidelines aligned with GINA 2023
- Prometric exam: acute severe criteria, magnesium dose, oxygen targets commonly tested
📝GCC / SCFHS / DHA Exam High-Yield Summary
BTS Severity — Must Know Numbers
- Moderate: PEFR 50–75%
- Severe: PEFR 33–50% + any clinical feature
- Life-threatening: PEFR <33% or SpO₂ <92% or silent chest
- Near-fatal: PaCO₂ >6 kPa / IPPV needed
- O₂ target: 94–98%
Magnesium Sulphate
- Dose: 2g IV over 20 minutes
- Indication: severe or life-threatening not responding
- Mechanism: smooth muscle relaxation (Ca²⁺ antagonism)
Action Plan Zones (Exam Favourite)
- Green: 80–100% PEFR — continue as normal
- Amber: 50–79% — increase reliever, consider OCS
- Red: <50% — emergency / call ambulance
ICS Key Nursing Points
- Rinse mouth after ICS — prevent candidiasis
- Regular daily use — not PRN
- Takes 2–4 weeks for full effect
Ventilation in Asthma ICU
- Permissive hypercapnia strategy
- Low RR (10–12), low PEEP, long expiratory time
- Avoid breath stacking → pneumothorax