Category: Emergency Medicine / Acute Internal Medicine / Mental Health
Reading Time: 5 minutes
Introduction: The Diagnostic Tightrope on the Acute Intake
Acute anxiety and panic attacks represent one of the most frequent yet challenging presentations in the emergency department and Acute Assessment Unit (AAU). Presenting with a constellation of rapid physiological surges—chest tightness, palpitations, tachypnoea, paraesthesia, and impending doom—panic attacks routinely mimic life-threatening organic conditions such as Acute Coronary Syndrome (ACS), Pulmonary Embolism (PE), SVT, and anaphylaxis.
At Medicine24, our acute receiving sessions emphasize that while rapid de-escalation is essential, the front-door medic must balance psychological safety with rigorous organic exclusion.
1. The “Safety-First” Organic Exclusion Protocol
Attributing severe physical distress to “anxiety” before completing a structured physiological workup is a well-documented cause of diagnostic bias. Before concluding that a presentation is purely psychogenic, clinicians must systematically rule out critical organic drivers:
Cardiovascular: High-sensitivity troponin deltas and 12-lead ECG monitoring to exclude acute ischemia or tachyarrhythmias (such as paroxysmal SVT).
Respiratory: Point-of-care arterial or venous blood gas analysis to assess $\text{PaO}_2$, $\text{PaCO}_2$, and lactate, ruling out occult hypoxia, severe bronchospasm, or PE.
Endocrine & Metabolic: Blood glucose testing (excluding hypoglycaemia), thyroid function tests (thyrotoxic storm), and serum electrolyte panels.
Toxicology: Screening for stimulant toxicity (e.g., cocaine, amphetamines, synthetic cathinones) or acute withdrawal syndromes (alcohol, benzodiazepines).
Clinical Pearl: Never rely on normal vital signs alone to dismiss a patient’s symptoms as functional or anxiety-driven. Patients experiencing acute PE, early sepsis, or subtle metabolic acidosis frequently report intense anxiety and air hunger as their primary subjective complaint.
2. Managing Hyperventilation: Banning the “Paper Bag”
Severe panic attacks frequently trigger acute hyperventilation, causing hypocapnia ($\text{PaCO}_2 < 4.0\text{ kPa}$), acute respiratory alkalosis, and transient hypocalcaemia. This manifests physically as carpopedal spasms, perioral tingling, and dizziness—which further fuels the cycle of panic.
The Rebreathing Hazard: Modern clinical resuscitation guidelines strictly prohibit the legacy practice of having patients rebreathe into paper bags. In patients whose hyperventilation is secondary to an undiagnosed organic hypoxia (such as PE or asthma), rebreathing paper bags can cause catastrophic hypoxaemia.
The 2026 Protocol: Implement structured verbal grounding and controlled “4-7-8” or square breathing techniques. Guide the patient through slow diaphragmatic breathing while providing clear, calm verbal reassurance.
3. Clinical Differentiation: Acute Panic vs. High-Risk Organic Emergencies
| Clinical Parameter | Acute Panic Attack | Acute Organic Mimic (PE / ACS / Anaphylaxis) |
| Onset Profile | Rapid surge, typically peaking within 10–20 minutes | Variable; often persistent or progressively worsening |
| Blood Gas Pattern | Isolated respiratory alkalosis ($\uparrow \text{pH}, \downarrow \text{PaCO}_2$, normal $\text{PaO}_2$) | Hypoxaemia ($\downarrow \text{PaO}_2$), metabolic acidosis ($\uparrow$ Lactate), or widening A-a gradient |
| ECG Findings | Sinus tachycardia without ischemic ST-T wave dynamics | Ischemic changes, ventricular strain, or dysrhythmias |
| Somatic Signs | Bilateral carpopedal spasm, perioral paraesthesia, lightheadedness | Asymmetric wheeze, stridor, focal neuro deficits, or hemodynamic collapse |
| Response to Grounding | Gradual reduction in heart rate and respiratory frequency | Persistent tachypnoea, desaturation, or hemodynamic instability |
4. Acute Pharmacotherapy and Liaison Psychiatry Referral
When psychological de-escalation alone is insufficient during extreme distress, pharmacological management must be delivered with strict stewardship:
Short-Course Benzodiazepine Stewardship: While short-acting benzodiazepines (e.g., Lorazepam 0.5–1 mg orally) can provide rapid symptom relief in acute crisis, routine prescribing or discharge supplies are discouraged due to risks of tolerance, dependency, and rebound anxiety.
Non-Benzodiazepine Alternatives: Consider short-term use of sedating antihistamines (e.g., Promethazine) or beta-blockers (e.g., Propranolol for autonomic symptoms) where appropriate and non-contraindicated.
Liaison Psychiatry & Crisis Pathways: Ensure every patient presenting with acute psychiatric crisis receives a structured risk assessment and clear signposting to local crisis teams, talking therapies (IAPT / NHS Talking Therapies), or community mental health teams before discharge.
