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Andrew Pollack-Gray

Nursing Notes

Measuring Blood Pressure

3 min read

When & Why?

Measure the force of circulating blood against arterial walls to monitor cardiovascular status and identify changes.
Blood Pressure Components:

  • Systolic: Pressure during ventricular contraction (top number).
  • Diastolic: Pressure during ventricular relaxation (bottom number).
  • Units: Millimeters of mercury (mmHg).

Before You Start

Equipment:

  • Correctly sized blood pressure cuff.
  • Manual sphygmomanometer and stethoscope, or validated automatic monitor.
  • Documentation equipment.
    Preparation:
  1. Perform hand hygiene.
  2. Explain the procedure and obtain permission.
  3. Review the care plan and measurement restrictions.
  4. Select an appropriate arm and cuff size.
  5. Allow the resident to rest quietly for approximately 5 minutes when feasible.
  6. Position the resident with back supported, feet flat, palms facing upward, and legs uncrossed when possible.
  7. Support the bare upper arm at heart level.
  8. Ask the resident not to talk or move during measurement.

Steps

Manual Blood Pressure — Auscultatory Method (One Step)

  1. Locate the brachial artery on the inner upper arm.
    1. Check the side closer to pinky, and slightly on or closer to the heart than the elbow fold.
  2. Wrap the cuff snugly around the bare upper arm, with the lower edge approximately 2–3 cm above the elbow crease.
  3. Position the cuff’s artery marker over the brachial artery.
    1. Make sure it’s ~1 finger worth of space.
  4. Estimate systolic pressure by palpation according to the trained procedure, to avoid missing an auscultatory gap.
    1. Pump to ~160 mmHg, confirming you do not hear the heartrate. If you do, up by 10 mmHg.
  5. Place the stethoscope over the brachial artery without positioning it beneath the cuff.
    1. Use two fingers to place. Like -0-
  6. Inflate the cuff approximately 20–30 mmHg above the estimated systolic pressure.
  7. Deflate slowly, approximately 2–3 mmHg per second.
  8. Listen for Korotkoff sounds:
    • First clear tapping sound: Systolic pressure.
    • Disappearance of sounds: Diastolic pressure in most adults.
  9. Deflate the cuff fully and remove it.
  10. Record the measurement and report concerning results.

Automatic Blood Pressure

  1. Select the correct cuff size and site.
  2. Position the resident and arm appropriately.
  3. Apply the cuff according to manufacturer instructions.
  4. Start the measurement.
  5. Ensure the resident remains still and quiet.
  6. Read and document the result.
  7. Repeat or confirm unexpected readings according to facility policy.

Safety & Observations

  • Avoid measuring over clothing.
  • Use the correct cuff size; a poorly sized cuff can produce inaccurate readings.
  • Follow restrictions for arms with vascular access, injuries, or other contraindications.
  • Do not allow the arm to hang unsupported.
  • Avoid talking or moving during measurement.
  • Follow instructions for residents who cannot tolerate standard seated positioning.
  • Report unexpectedly high or low readings, especially with concerning symptoms.
  • Notify the nurse if readings are difficult to obtain or appear inconsistent.
  • Don’t take BP from same side as a masectomy. It can cause painful lymphedema (swelling in that arm)

What Should I Remember?

  • Rest → Position → Cuff → Measure → Document.
  • First Korotkoff sound = systolic.
  • Disappearance of sounds = diastolic.
  • Correct cuff size and arm positioning matter.
  • A single abnormal reading does not establish a diagnosis.
  • Use the exact sequence required by your CNA skills checklist.

Practice

  • Studied
  • Observed
  • Practiced
  • Passed checkoff

Sources

Flashcards

What does the first Korotkoff sound indicate?01-foundations / clinical-skills
Answer

Systolic pressure.

What does disappearance of Korotkoff sounds usually indicate in adults?01-foundations / clinical-skills
Answer

Diastolic pressure.

Why should the arm be supported at heart level?03-application / clinical-skills
Answer

Incorrect positioning can distort the reading.

Graph View

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