USMLE Prep - Medical Reference Library

Pneumothorax — Spontaneous & Secondary (including Tension)

System: Pulmonology • Reviewed: Aug 31, 2025 • Step 1Step 2Step 3

Synopsis:

Tension pneumothorax is a clinical diagnosis requiring immediate decompression; management of stable pneumothorax depends on size and underlying lung disease.

Key Points

  • Stabilize ABCs; begin targeted evaluation without delaying life-saving therapy.
  • Use system-specific risk tools to guide testing and disposition.
  • Order high-yield tests first; escalate imaging when indicated.
  • Start evidence-based initial therapy and reassess frequently.

Algorithm

  1. Primary survey and vitals; IV access and monitors.
  2. Focused history/physical; identify red flags and likely etiologies.
  3. Order system-appropriate labs and imaging (see Investigations).
  4. Initiate guideline-based empiric therapy (see Pharmacology).
  5. Reassess response; arrange consultation and definitive management.

Clinical Synopsis & Reasoning

For Pneumothorax Spontaneous Secondary, frame the differential by acuity and pathophysiology, then align diagnostics to the leading hypotheses. Prioritize stabilization while obtaining high‑yield studies such as CXR (Infection/edema/PTX), ABG/VBG (Oxygenation/ventilation), CT chest (indicated) (PE/other). Incorporate bedside imaging and targeted labs to define severity and identify complications; synthesize results with clinical trajectory to refine the working diagnosis and disposition needs.


Treatment Strategy & Disposition

Initiate disease‑directed therapy alongside supportive care, titrating to objective response. Pharmacologic options commonly include SABA, SAMA, Systemic steroids, Antibiotics (if indicated). Use validated frameworks (e.g., Typical Disposition by Scenario) to guide escalation and site of care. Address precipitating factors, de‑escalate empiric therapies with data, and arrange follow‑up for monitoring and risk‑factor modification; admit patients with instability, high risk of deterioration, or needs for close monitoring.


Epidemiology / Risk Factors

  • Smoking/chronic lung disease; infections or immobility (VTE)

Investigations

TestRole / RationaleTypical FindingsNotes
CXRInfection/edema/PTXConsolidation/effusion/PTX
ABG/VBGOxygenation/ventilationHypoxemia/hypercapnia
CT chest (indicated)PE/otherFindings vary

Typical Disposition by Scenario

ScenarioAction
TensionImmediate decompression and chest tube
Primary small, stableObserve with oxygen and repeat imaging
Primary large or symptomaticAspiration or chest tube
SecondaryChest tube and admit

Pharmacology

MedicationMechanismOnsetRole in TherapyLimitations
High-flow oxygenNitrogen washoutMinutesSmall non-tension PTXO2 toxicity (rare)
Needle decompression/Chest tubeN/AImmediateTension PTX/large PTXInfection/bleeding

Prognosis / Complications

  • Depends on severity/oxygenation; respiratory failure risk

Patient Education / Counseling

  • Explain red flags and when to seek emergent care.
  • Reinforce medication adherence and follow-up plan.

Notes

Avoid positive pressure ventilation until chest tube is in place if pneumothorax is significant. Counsel on smoking cessation to reduce recurrence.


References

  1. British Thoracic Society Pleural Disease Guideline — Link
  2. ACCP Consensus Statement — Link