2.1 Vital Signs & Measurement

Why Vital Signs Matter

Quick Answer: Normal adult vital signs are oral temperature about 97.0-99.0 F (roughly 37 C), pulse 60-100 beats/min, respirations 12-20/min, blood pressure below 120/80 mmHg, and oxygen saturation (SpO2) 95-100%. A Certified Nursing Assistant (CNA) measures and records these values, then reports anything outside the normal range to the nurse.

Vital signs are the body's basic indicators of life and health, and they are among the most frequently tested Basic Nursing Skills on the Minnesota CNA knowledge exam and the Headmaster/D&S skills evaluation. The CNA does not diagnose or treat, but accurate measurement and prompt reporting of changes drive the entire care plan. A single missed or altered reading can delay treatment for a serious problem such as infection, dehydration, or heart trouble.

Vital signs are measured on admission, at scheduled times, before and after certain treatments, and any time the resident's condition changes. The four classic vital signs are temperature, pulse, respirations, and blood pressure (often abbreviated TPR and BP). Oxygen saturation measured by pulse oximeter and the resident's reported pain level are sometimes called the fifth and sixth vital signs. The CNA must know each normal range cold, because the exam tests both the numbers and the correct action when a reading falls outside them.

Normal Adult Ranges

Memorize these baseline ranges. On the Minnesota skills test, your reading must fall within the accepted tolerance of the evaluator's measurement, so technique and accuracy both count.

Temperature varies by site. Rectal readings run about 1 degree F higher than oral and are the most accurate; axillary (armpit) readings run about 1 degree F lower than oral and are the least accurate; tympanic (ear) and temporal (forehead) thermometers give fast, comfortable readings. A reading of 100.4 F (38 C) or higher is generally considered a fever. Knowing the route is essential because the same person can show 98.6 F orally and 99.6 F rectally for the identical core temperature.

How to Measure Each Vital Sign

Temperature

Use the route ordered for the resident. Wait 15-20 minutes after the resident eats, drinks, or smokes before an oral reading, since hot or cold intake skews the result. Clean the thermometer and apply a fresh probe cover for each use.

Pulse

The radial pulse (thumb side of the wrist) is the most common site. Place two or three fingers over the artery and count beats for one full minute, noting rate, rhythm, and force. Never use your thumb, which has its own pulse and can give a false count. The apical pulse (heard with a stethoscope over the heart for one full minute) is used for irregular rhythms or before certain heart medications.

Respirations

Count respirations right after the pulse, while still holding the wrist, so the resident is unaware. One full rise and fall of the chest equals one respiration. Count for a full minute and note depth, effort, and any noise.

Blood Pressure

Use a correctly sized cuff on a bare upper arm supported at heart level, with the resident seated and rested for several minutes. Avoid an arm with an IV, a dialysis shunt, or on the side of a mastectomy. Record systolic (top) over diastolic (bottom), for example 118/76 mmHg.

Oxygen Saturation

Clip the pulse oximeter to a clean, warm finger (remove dark nail polish) and read the SpO2 percentage once the number stabilizes.

Accuracy, Reporting, and the MN Skills Tolerance

On the Minnesota Headmaster/D&S skills test, vital-sign skills are scored not only on technique but on accuracy: a measured pulse must fall within plus or minus 4 beats of the evaluator's reading, and blood pressure and respiration measurements have their own tight tolerances. This is why you count for a full minute and record the true value the moment you read it.

The CNA records vital signs accurately and reports values outside normal limits to the supervising nurse right away. Report immediately when you observe:

• A pulse below 60 (bradycardia) or above 100 (tachycardia), or a newly irregular pulse
• Respirations below 12 or above 20, or breathing that is labored, gasping, shallow, or noisy
• A temperature above 100.4 F (fever) or below 95 F
• A blood pressure much higher or lower than the resident's usual baseline
• Oxygen saturation below 90%

Never ignore an abnormal value, guess, or change a reading to look normal. Document the actual number, including the route and the arm or finger used, and notify the nurse. Falsifying a vital sign is both an exam failure and, in real practice, a reportable act that can harm a resident.

Height and Weight

Weight is monitored to track fluid balance and nutrition, and a sudden change is an early warning sign. For consistent, comparable readings:

• Weigh the resident at the same time of day (usually before breakfast), in similar clothing, after voiding
• Use the same scale each time and balance or zero it before the resident steps on
• For a chair scale or mechanical lift scale, follow the device instructions and make sure the resident is safely secured before lifting
• Measure height with the resident standing straight and looking forward; for a resident who cannot stand, lay them supine and use a tape measure from the top of the head to the heel

Report a sudden weight gain or loss. A rapid gain (for example, 2-3 pounds in a day or 5 pounds in a week) may signal fluid retention linked to heart or kidney problems, while a steady loss may signal poor intake, illness, or depression. Because the care team uses these numbers to adjust diet, fluids, and medication, an inaccurate weight can lead to the wrong treatment, so precision matters as much as it does with vital signs.