J18.1 — Community-Acquired Pneumonia
Denied58M · investigation — CT Pulmonary Angiography
Insurer Rationale
Chest X-ray demonstrates right lower lobe consolidation consistent with pneumonia. CTPA is not indicated given confirmed pneumonia diagnosis. Continue antibiotic therapy with reassessment in 48-72 hours.
Clinical Contradiction
Insurer states
“Given the radiographic findings confirming pneumonia, additional cross-sectional imaging is not indicated”
Clinical evidence shows
Elevated D-dimer and pleuritic chest pain mean pulmonary embolism cannot be excluded by chest X-ray alone — CTPA is the only definitive discriminator
Patient risk
Untreated PE has 25-30% mortality if undiagnosed
Reasoning Chain
Patient findings remain shared between pneumonia and pulmonary embolism even after a chest X-ray shows consolidation. The graph distinction shows PE is not excluded by the current work-up. Denying CTPA leaves a potentially fatal competing diagnosis untreated and preserves the wrong management path.
Reasoning Chain
Findings
Breathlessness, Pleuritic chest pain, Pain on inspiration, Tachycardia, Fever
Differential
Community-Acquired Pneumonia (confirmed on cxr) vs Pulmonary Embolism (not excluded)
Shared findings
Breathlessness, Chest pain, Pleuritic pain, Pain on inspiration
Discriminating investigation — DENIED
CTPA
Definitively excludes or confirms pulmonary embolism when pneumonia does not fully explain the presentation
Verdict
Denial is clinically unsafe. A chest X-ray confirming pneumonia does not remove pulmonary embolism from the differential, so the denied CTPA blocks the discriminating step.
Clinical Evidence
NICE Guideline NG158 — Venous thromboembolic diseases
1.3
CTPA is the first-line investigation for suspected PE when clinical probability remains intermediate or high.
BTS Guidelines for Community Acquired Pneumonia in Adults (2023)
Section 3.2
Alternative diagnoses including PE should be reconsidered when pneumonia is not responding as expected.