Patient Assessment: History, Vital Signs, and Clinical Status

Why Patient Assessment Comes Before Every Exposure

Before you position a patient or make a single exposure, you must know who you are imaging and whether it is safe to proceed. A thorough pre-procedure assessment protects the patient from harm, protects you from liability, and gives the radiologist clinical context for interpreting the images. The two pillars of pre-procedure assessment are the patient history and vital signs.

Collecting the Pre-Procedure Patient History

A focused history does not require you to be a nurse or physician—it requires you to ask the right questions, listen carefully, and document accurately.

Standard history elements for radiologic procedures include:

• Chief complaint and reason for exam — confirms you have the correct study ordered for the correct clinical question.
• Allergies — particularly contrast media allergies if IV contrast is anticipated; note the type of reaction (rash vs. anaphylaxis matters).
• Current medications — anticoagulants, metformin, and kidney-affecting drugs are clinically relevant for contrast studies.
• Pregnancy status — for any patient of childbearing potential, ask the last menstrual period and whether pregnancy is possible. Elective imaging is generally deferred or shielding is applied when pregnancy cannot be ruled out.
• Relevant medical history — renal disease, diabetes, cardiac conditions, or prior surgeries near the area of interest.
• Implants and metal objects — pacemakers, joint replacements, aneurysm clips (critical for MRI; relevant to positioning in plain radiography as well).
• Ability to cooperate — can the patient hold still, follow breathing instructions, or stand?

Document responses on the facility's pre-procedure history form exactly as the patient states them. If a concern is identified—such as a reported contrast allergy, possible pregnancy, or an implanted device—stop and report to the supervising clinician before proceeding. This is a non-negotiable scope-of-practice boundary.

Measuring Vital Signs

Vital signs give you an objective snapshot of the patient's physiologic stability. In limited radiography practice you will most often assess vital signs when a patient appears distressed, when a procedure involves contrast, or when facility protocol requires it.

Blood Pressure

Blood pressure (BP) is measured with a sphygmomanometer and stethoscope (manual/auscultatory method) or an automated cuff. For the manual method: apply the cuff snugly over the brachial artery, inflate to approximately 30 mmHg above the point where the radial pulse disappears, then deflate slowly at about 2–3 mmHg per second while auscultating for Korotkoff sounds. The first sound is systolic pressure; the disappearance of sound is diastolic pressure. Record as systolic/diastolic (e.g., 118/76 mmHg).

Generally accepted adult reference ranges: normal systolic 90–119 mmHg; normal diastolic 60–79 mmHg. Values outside these ranges—especially systolic ≥140 mmHg or diastolic ≥90 mmHg (elevated/hypertensive), or systolic <90 mmHg (hypotensive)—require reporting.

Pulse

Palpate the radial pulse at the wrist using two or three fingers (never the thumb). Count beats for a full 60 seconds for accuracy, or 30 seconds and multiply by 2 if rhythm is regular. Note rate, rhythm, and quality. Normal adult resting pulse: approximately 60–100 beats per minute (bpm). A pulse below 60 bpm (bradycardia) or above 100 bpm (tachycardia) at rest is reportable.

Respiratory Rate

Count chest rises for 60 seconds without alerting the patient (patients alter their breathing when they know it is being observed). Normal adult range: approximately 12–20 breaths per minute. Note any labored breathing, wheezing, or use of accessory muscles, and report these findings regardless of rate.

Oxygen Saturation (SpO₂)

A pulse oximeter clips onto a fingertip (or earlobe) and uses light absorption to estimate the percentage of hemoglobin saturated with oxygen. Normal SpO₂ in a healthy adult: 95–100%. A reading of 94% or below warrants reporting; below 90% is a medical emergency requiring immediate notification and activation of emergency protocols. Nail polish, poor perfusion, or patient movement can produce inaccurate readings—remove polish and reposition the probe before recording.

Temperature

A digital oral thermometer provides a quick assessment. Normal adult oral temperature is approximately 97–99°F (36.1–37.2°C). Fever (≥100.4°F / 38°C) or subnormal temperature should be documented and reported.

Classifying Findings: Normal, Reportable, or Emergency

Use a three-tier framework when interpreting any vital sign or history finding:

1. Normal — within accepted reference ranges; no action beyond documentation required.

2. Reportable — outside normal range but patient is currently stable; report to supervising clinician before or immediately after imaging, per facility protocol.

3. Emergency — values indicating immediate physiologic threat (e.g., SpO₂ <90%, unresponsive patient, absent pulse). Stop the procedure, activate emergency response, and stay with the patient.

Safety Points

• Never assume. A patient who looks well can have a critically abnormal vital sign. Measure; do not estimate.
• Scope of practice: You collect and report findings; you do not diagnose, interpret clinically, or initiate treatment. Always escalate to a licensed clinician.
• Infection control: Clean equipment between patients. Pulse oximeter probes and BP cuffs are vectors for pathogen transmission.
• Radiation protection: The history—especially pregnancy status—directly determines whether you expose the patient. When in doubt, ask and document before exposing.
• Documentation accuracy: Record the actual values you measured, the time, and your name. Falsifying or estimating values is an ethical and legal violation.