What is the OPQRST (Onset, Provocation/Palliation, Quality, Radiation, Severity, Time) history‑taking process for EMS providers?

OPQRST History-Taking Process in EMS

OPQRST is a systematic mnemonic used by EMS providers to obtain a focused history of the present illness, particularly for patients with pain or acute symptoms, and should be performed early in the patient assessment after stabilizing ABCs (airway, breathing, circulation). 1

Components of OPQRST

O - Onset

• Determine the exact time when symptoms began - this is the single most critical piece of historical information, particularly for time-sensitive conditions like stroke and acute coronary syndrome 1
• For patients who cannot provide this information or who awaken with symptoms, establish when the patient was last known to be at baseline or "normal" 1
• Use creative questioning to establish time anchors: check cell phone call timestamps, television programming times, or when the patient was last ambulatory to bathroom/kitchen 1
• Document whether onset was sudden, gradual, or associated with specific activity 1
• For stroke patients, if onset time cannot be determined, use standardized time parameters: morning (6:00 AM-11:59 AM), afternoon (noon-5:59 PM), evening (6:00 PM-11:59 PM), overnight (midnight-5:59 AM) 1

P - Provocation/Palliation

• Identify what makes the symptoms better or worse 1
• For chest pain: determine if symptoms occur with exertion, rest, or specific positions 1
• Ask about prior similar episodes and what relieved them (e.g., nitroglycerin, rest) 1
• Document any interventions already attempted by the patient or bystanders 1

Q - Quality

• Have the patient describe the symptom in their own words 1
• For chest discomfort: crushing, pressure, squeezing, sharp, burning, or tearing 1
• For neurological symptoms: weakness, numbness, difficulty speaking, vision changes 1
• Avoid leading questions - let the patient characterize the sensation 1

R - Radiation/Region

• Identify the primary location of symptoms 1
• Determine if symptoms spread to other areas (e.g., chest pain radiating to jaw, arm, back) 1
• For stroke: document specific neurological deficits and their distribution (facial droop, arm weakness, speech abnormalities) 1
• Map the anatomical distribution precisely 1

S - Severity

• Use a standardized scale (typically 0-10, with 10 being worst imaginable) 1
• For stroke patients, use validated assessment tools like the Cincinnati Prehospital Stroke Scale (CPSS) or Los Angeles Prehospital Stroke Screen (LAPSS) rather than subjective severity scales 1
• Document whether severity is changing (improving, worsening, or stable) 1
• Compare to previous similar episodes if applicable 1

T - Time/Timing

• Reconfirm the exact onset time - this cannot be overemphasized for time-sensitive emergencies 1
• Determine duration of symptoms (continuous vs. intermittent) 1
• For chest pain: symptoms lasting >15 minutes suggest acute myocardial infarction rather than angina 1
• Document any pattern or progression of symptoms over time 1
• If symptoms previously resolved and then recurred, the therapeutic clock resets to when current symptoms began 1

Integration into EMS Assessment

Timing in Patient Evaluation

OPQRST should be obtained after initial ABCs are stabilized but before or concurrent with other interventions 1. The traditional sequence has been: (1) assess ABCs and vital signs, (2) obtain focused history including OPQRST, (3) assess cardiac rhythm, (4) initiate treatment 1. However, for time-sensitive conditions like STEMI, the 12-lead ECG should be prioritized and performed as early as possible at the scene, potentially before completing the full OPQRST 1.

Critical Additional Elements

• Always bring witnesses, family members, or caregivers with the patient to verify onset time and provide collateral history 1
• Document circumstances surrounding symptom development 1
• Obtain relevant past medical history: prior similar events, cardiac disease, stroke, diabetes, hypertension, seizures, drug abuse 1
• Check blood glucose to rule out hypoglycemia as a stroke mimic 1
• For chest pain: specifically ask about aspirin allergy, recent gastrointestinal bleeding, and use of phosphodiesterase-5 inhibitors within 24-48 hours 1

Common Pitfalls and Caveats

Atypical Presentations

Atypical symptoms are more common in elderly patients, women, and diabetics, but any patient may present atypically 1. For acute coronary syndrome, atypical presentations may include isolated shortness of breath, nausea, sweating, or lightheadedness without classic chest pain 1.

Time Documentation Errors

The most critical error is failing to establish or incorrectly documenting onset time 1. If family cannot accompany the patient, EMS must document family contact information and provide it to the receiving physician 1.

Delaying Critical Interventions

Do not allow completion of OPQRST to delay time-sensitive interventions 1. For suspected STEMI, obtain 12-lead ECG at the scene as the priority, then complete history while preparing for transport 1.

Overlooking Stroke Mimics

Hypoglycemia, seizures, and other conditions can mimic stroke 1. Always check blood glucose in the field if equipment is available 1.