Measuring and Recording Vital Signs

The Four Classic Vital Signs (Plus Two More)

Vital signs are measurements of the body's basic functions. The four classic ones are Temperature, Pulse, Respirations, and Blood Pressure — remembered as TPR and BP. Modern practice adds pain (the 'fifth vital sign') and oxygen saturation (SpO2) measured by pulse oximetry.

Vitals are a big slice of the Basic Nursing content (part of the 39% Basic Nursing block on the Connecticut exam) and are a common clinical-skills station. The CNA's job is to measure accurately, record correctly, and report abnormal values to the nurse. The CNA does not interpret results or diagnose.

Normal Adult Ranges (Memorize These)

Temperature varies by site: rectal and temporal readings run about 1 degree higher than oral, and axillary (armpit) runs about 1 degree lower than oral. Always record the site used.

These ranges change with age and condition. A resident's own baseline matters as much as the textbook range — a reading that is normal for one person may be abnormal for another. That is why the CNA records every value and reports anything that differs from the resident's usual pattern, even if it is technically 'in range.'

Pulse and Respirations

The pulse is the wave of blood pushed through an artery with each heartbeat. The most common site is the radial pulse (thumb side of the wrist). For a regular pulse, count for 30 seconds and multiply by 2; if the pulse is irregular, count a full 60 seconds.

The apical pulse is heard with a stethoscope over the apex of the heart (left side, just below the nipple, 5th intercostal space). It is always counted for a full 60 seconds and is used for residents on heart medications such as digoxin.

Respirations must be counted without the resident's knowledge — if people know you are watching their breathing, they unconsciously change it. The trick: after taking the radial pulse, keep your fingers on the wrist and count the rise-and-fall of the chest as if you were still timing the pulse. One full breath = one inhale + one exhale. Count for 30 seconds x 2, or a full minute if irregular.

Blood Pressure and Korotkoff Sounds

Blood pressure (BP) is the force of blood against the artery walls, written as systolic over diastolic in millimeters of mercury (mmHg).

• Systolic = pressure when the heart contracts (the top, larger number). It is the FIRST tapping (Korotkoff) sound you hear as you release the cuff.
• Diastolic = pressure when the heart rests between beats (the bottom number). It is the point where the sounds DISAPPEAR.

Proper technique:

1. Use the correct cuff size — a cuff too small gives a falsely HIGH reading; too large gives a falsely LOW reading.
2. Position the arm at heart level, palm up, resident seated and relaxed.
3. Place the cuff about 1 inch above the antecubital (elbow) crease; put the stethoscope over the brachial artery.
4. Avoid an arm with an IV, dialysis shunt/fistula, or mastectomy on that side.

A reading of 140/90 mmHg or higher (hypertension) or below normal (hypotension) should be reported to the nurse.

Additional accuracy rules: deflate the cuff fully and wait 1-2 minutes before re-checking the same arm; the resident should not have their legs crossed or be talking; and a too-tight or too-loose cuff distorts the reading. Pulse pressure is the difference between systolic and diastolic (for 120/80 it is 40) — you do not calculate it, but a widening or narrowing gap is worth reporting.

Oxygen Saturation and Pain

Pulse oximetry clips a sensor on a finger and reports the percent of hemoglobin carrying oxygen (SpO2). Normal is 95-100%; report below 90%. Cold fingers, nail polish, or motion can give false low readings. Pain, the fifth vital sign, is whatever the resident says it is — report a resident's report of new or worsening pain to the nurse; the CNA does not give pain medication.

Temperature Methods

The CNA may take temperature orally, rectally, axillary, tympanic (ear), or temporal (forehead).

• Wait 15-20 minutes after a resident eats, drinks, or smokes before an oral temperature.
• Rectal is most accurate but is never used on residents with diarrhea, rectal surgery, or certain heart conditions; lubricate the probe and never force it.
• Hold an axillary thermometer in place and add note that it reads lowest.

When and What to Report

The CNA reports any reading outside the normal range to the nurse promptly. Examples that require immediate reporting:

• Temperature above 100.4 F (possible infection/fever) or below 95 F.
• Pulse below 60 (bradycardia) or above 100 (tachycardia).
• Respirations below 12 or above 20, or labored breathing.
• Blood pressure 140/90 or higher, or a sudden drop.
• SpO2 below 90%.

Common Exam Traps

• Telling the resident you are counting their respirations (changes the rate — count it secretly).
• Counting an apical or irregular pulse for only 30 seconds (must be a full minute).
• Calling the diastolic the first sound — it is the LAST sound (sounds disappear).
• Using a wrong-size cuff and not realizing it skews the reading.
• Taking BP on an arm with a dialysis fistula, IV, or recent mastectomy.