skip to main content

Acute Severe Asthma Pregnancy — FRCA Final MCQ

Instant feedback + full explanation. One question, done properly.

HardObstetric AnaesthesiaAcute Severe Asthma PregnancyFRCA Final

A 28-year-old woman (ASA I, 65 kg) at 34 weeks gestation presents with acute severe asthma (unable to complete sentences, RR 35, HR 130, SpO2 90% on 15L O2, PEFR 25% predicted). She is not responding to nebulised salbutamol, ipratropium, and IV magnesium. What is the next step?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: C — Helium-oxygen mixture

In acute severe/near-fatal asthma in pregnancy, after failure of nebulised bronchodilators, IV magnesium, and systemic steroids, IV salbutamol (or terbutaline) infusion is the next escalation step before intubation. IV aminophylline is also an option but has a narrower therapeutic window. Intubation is a last resort in severe asthma as it carries extremely high risk (bronchospasm may worsen, high airway pressures, barotrauma, cardiovascular collapse). If intubation becomes necessary: RSI with ketamine (bronchodilator properties), low RR (10-12), prolonged expiratory time (I:E 1:3-4), and permissive hypercapnia.

Reference: BTS/SIGN – 2019 – Asthma guidelines; RCOG – 2019 – Acute asthma in pregnancy