Understanding Post-Wildfire Health Impacts on Emergency Departments

The 2025 LA wildfires triggered an emergency-department surge, shifting caseloads toward severe cardiopulmonary presentations and straining acute-care workflows.

Overall emergency department volume during the study window did not rise substantially, but the case mix changed markedly. In a 90-day post-event surveillance period across regional hospitals and health-system EDs, cardiac and pulmonary complaints formed a larger share of visits than in prior years — a pattern that demands heightened triage sensitivity and diagnostic vigilance at first contact.

There was a 46% increase in presentations for myocardial infarction and a 24% rise in pulmonary illness visits; abnormal blood test results more than doubled in the post-event interval, and wildfire smoke exposure was implicated as a proximate environmental trigger. It's important to prioritize early ECG, prompt cardiac-biomarker testing, and thorough pulmonary assessment for symptomatic patients.

Evidence points to mechanisms that extend risk beyond the acute inhalation period: fine particulate matter (PM2.5) can provoke systemic inflammation, promote prothrombotic states, and interact with stress-mediated cardiovascular pathways. The observed rise in abnormal biomarkers supports a sustained biological response and justifies continued clinical surveillance of symptomatic patients after initial exposure.

Key Takeaways:

• What’s new? A post-wildfire case-mix shift shows large relative increases in cardiac and pulmonary ED visits and doubled abnormal blood tests, indicating prolonged physiological impact and a need to review post-discharge follow-up windows.
• Who’s affected? Patients presenting after urban wildfire events—particularly those with cardiopulmonary symptoms or cardiovascular risk factors—have higher short-term morbidity; expand surveillance for these groups.
• What changes next? EDs should adopt surge triage for cardiopulmonary complaints, ensure rapid access to cardiac biomarkers and bronchodilators, and implement extended monitoring and follow-up protocols after wildfires to capture delayed presentations.