What is Evidence-Based Practice?
Evidence-based practice (EBP) in EMS means making clinical decisions based on the best available research evidence, combined with clinical expertise and patient preferences. For decades, many EMS practices were based on tradition, anecdote, or theoretical reasoning rather than scientific evidence. The shift toward EBP has led to significant changes in how EMS providers deliver care, and several long-standing practices have been modified or abandoned based on research findings.
Understanding EBP is important for EMS providers at all levels. You may be asked to adopt new protocols based on research findings, and understanding the evidence behind those changes helps you implement them effectively. The NREMT also tests your understanding of current evidence-based practices and may include questions about practices that have changed based on new research.
How EBP Has Changed EMS Practice
Several major shifts in EMS practice illustrate the power of evidence-based medicine:
- Backboard use: For decades, nearly all trauma patients were fully immobilized on long backboards. Research showed that backboards cause pain, pressure ulcers, and respiratory compromise while providing minimal benefit for patients without spinal injuries. Current evidence supports selective spinal motion restriction based on clinical criteria.
- Hyperventilation in head injury: Routine hyperventilation was once standard practice for head-injured patients. Research demonstrated that hyperventilation causes cerebral vasoconstriction, reducing blood flow to an already injured brain and worsening outcomes. Current guidelines recommend normal ventilation rates.
- MAST/PASG trousers: Military anti-shock trousers were widely used for trauma patients in shock. Multiple studies found no benefit and potential harm, leading to their removal from most EMS protocols.
- CPR ratio changes: The compression-to-ventilation ratio has evolved from 5:1 to 15:2 to the current 30:2 based on research showing that minimizing interruptions in chest compressions improves survival from cardiac arrest.
Evaluating Research
Not all studies carry equal weight. The hierarchy of evidence, from strongest to weakest, includes: systematic reviews and meta-analyses, randomized controlled trials, cohort studies, case-control studies, case series, and expert opinion. When evaluating a study, consider the sample size (larger is generally better), whether the study was blinded and randomized, whether the results are statistically significant, and whether the findings are applicable to your patient population and practice setting.
Staying Current
EMS providers can stay current with evidence-based practice through several resources. Peer-reviewed journals such as Prehospital Emergency Care and the Journal of Emergency Medical Services publish EMS-specific research. The Prehospital Evidence-Based Practice (PEP) program through NAEMSP summarizes research on specific EMS topics. Continuing education courses should reflect current evidence. Participate in your agency's quality improvement program, which reviews patient outcomes and compares practice against evidence-based guidelines. Being an evidence-based provider means being willing to change practice when the evidence supports it, even when it contradicts what you were originally taught.