Hyperventilation Syndrome
😮💨 Hyperventilation Syndrome is often a functional disorder linked to anxiety and panic attacks.
✅ Always exclude organic causes (e.g., asthma, PE, LVF) before diagnosis to avoid unnecessary treatments.
🧠 Education and reassurance are the cornerstones of management.
📖 About Hyperventilation Syndrome
Hyperventilation Syndrome is characterised by increased rate and depth of breathing, leading to excessive loss of carbon dioxide (CO₂).
This causes respiratory alkalosis → reduced cerebral blood flow + neuromuscular irritability.
It commonly occurs in anxiety, panic, or stressful events, but always consider organic pathology.
- ⚠️ Diagnosis of exclusion – rule out cardiac, pulmonary, or metabolic causes first.
- 🩺 Can coexist with somatisation or panic disorder.
🩺 Clinical Presentation
- Triggers: Stress, panic, receiving bad news.
- Respiratory: Rapid deep breathing, air hunger, sense of “can’t get a deep breath.”
- Neuromuscular:
- ✋ Perioral & digital paraesthesia.
- ✊ Carpopedal spasm (due to ↓ ionised calcium).
- 🦵 Muscle cramps, weakness.
- Autonomic / psychological: Palpitations, sweating, dizziness, sense of impending doom.
- Other: Near-syncope, faintness, visual blurring.
🧾 Differentials to Exclude
- 🌬️ Asthma – wheeze, diurnal variation.
- ❤️ LVF – orthopnoea, basal crackles, abnormal echo/BNP.
- 🫁 Pulmonary embolism – pleuritic chest pain, risk factors, CT-PA or V/Q scan.
- 🦠 Lymphangitis carcinomatosa – progressive breathlessness, CT changes.
- 🌫️ Interstitial lung disease – fine inspiratory crackles, HRCT findings.
- ⚡ Metabolic acidosis – Kussmaul breathing, low HCO₃⁻ on VBG/ABG.
- 💪 Neuromuscular weakness – poor effort on spirometry, weak cough.
🔎 Investigations
- 🧾 History & exam: Key to diagnosis – look for context of stress/anxiety.
- 🫁 CXR / CT chest: Should be normal in hyperventilation.
- 📊 Pulmonary function: Normal FEV₁ / FVC if good effort.
- 🩸 ABG: Respiratory alkalosis (↑pH, ↓pCO₂, normal or slightly ↓HCO₃⁻).
- ❤️ ECG / bloods: To rule out cardiac or metabolic pathology.
💊 Management
- 🧘♀️ Reassurance: Calm explanation reduces anxiety-driven hyperventilation.
- 😮💨 Breathing retraining: Slow diaphragmatic breathing; pursed-lip breathing.
– Paper bag rebreathing is rarely recommended now due to risk of hypoxia, but may help acutely if supervised.
- 🧠 Psychological support: CBT, relaxation training, stress management.
- 💊 Medication:
- Short-term benzodiazepines may help in severe panic states (use cautiously).
- SSRIs in underlying anxiety/panic disorder.
- 🏃 Lifestyle: Exercise, sleep hygiene, avoiding caffeine/alcohol excess.
📈 Prognosis
- 🟢 Usually benign and self-limiting once anxiety controlled.
- 🟡 Chronic hyperventilation may persist in panic disorder or somatisation.
- 🔴 Misdiagnosis risks → unnecessary anticoagulation, CT scans, or invasive procedures.
📝 Key Exam Tips
- ABG in panic hyperventilation = low pCO₂, high pH.
- Reproducing symptoms with a voluntary “hyperventilation test” can support diagnosis.
- Never forget to exclude PE, asthma, or LVF in acute breathlessness.
📚 References
