4.1 Vital Signs and Measurement

The Four Vital Signs Plus Pain

Vital signs are objective measurements of the body's most basic functions. The nurse aide measures four classic vital signs — temperature (T), pulse (P), respiration (R), and blood pressure (BP) — often abbreviated as TPR and BP. Pain is treated as the fifth vital sign. The CNA's job is to obtain accurate readings, record them, and report abnormal values to the licensed nurse. A nurse aide never diagnoses a condition, interprets results, or adjusts care based on a reading — that is the nurse's role.

Memorize the normal adult ranges. The exam tests both the numbers and the values that must be reported.

Temperature

Body temperature reflects the balance between heat produced and heat lost. The site changes the normal value, so always chart the route used. Rectal and temporal readings run about 1°F higher than oral; axillary (armpit) runs about 1°F lower.

• Oral: 97.0-99.0°F. Do not use within 15 minutes of hot or cold liquids, or for a confused resident who may bite the probe.
• Rectal: ~99.6°F average; most accurate. Used when oral is unsafe. Lubricate, insert gently, and never leave the resident.
• Axillary: ~97.6°F average; least accurate but safe for confused residents.
• Tympanic (ear): fast, non-invasive; pull the ear up and back.
• Temporal (forehead): quick scan across the forehead.

A reading over 100.4°F (38°C) signals fever and must be reported.

Pulse

The pulse is the beat felt as the heart pushes blood through an artery. The most common site is the radial pulse at the thumb side of the wrist. The apical pulse, taken with a stethoscope over the heart's apex for a full 60 seconds, is the most accurate and is used for irregular rhythms or before certain medications. Count for 30 seconds and multiply by two when the rhythm is regular; count a full minute if irregular. Note rate, rhythm (regular or irregular), and force (strong, weak, bounding, or thready). A rate under 60 is bradycardia; over 100 is tachycardia — both are reported.

Respiration and Blood Pressure

One respiration equals one full inhale plus one exhale. Count respirations without telling the resident, because people unconsciously change their breathing when they know they are being watched. A useful trick is to keep your fingers on the wrist as if still taking the pulse, then count chest rises. Normal is 12-20 breaths per minute. Watch for noisy, labored, shallow, or irregular breathing.

Blood pressure is the force of blood against artery walls, written as systolic over diastolic (e.g., 118/76). Systolic is the top number — pressure when the heart contracts; diastolic is the bottom — pressure at rest between beats. Use the correct cuff size (a too-small cuff gives a falsely high reading), position the arm at heart level, and place the cuff above the bend of the elbow over the brachial artery. Do not take BP on an arm with an IV, a dialysis shunt, or on the side of a mastectomy.

Pain, Height, and Weight

Pain is subjective — "whatever the resident says it is." Use a 0-10 scale (0 = none, 10 = worst imaginable) or a faces scale for residents who cannot give a number. Report new or worsening pain promptly; the CNA does not give pain medication.

Height and weight track nutrition and fluid status. Weigh at the same time of day, on the same scale, in similar clothing, after the resident voids. A sudden weight gain can signal fluid retention and is reported. Factors that normally affect vitals include exercise, eating, emotion, fever, pain, and time of day — let a resident rest before measuring.

Factors That Change Vital Signs and Reporting

Vital signs are not fixed numbers; many ordinary factors shift them, which is why timing and technique matter. Activity and exercise raise pulse, respiration, and blood pressure. Pain, fear, anxiety, and anger raise all four. Fever raises pulse and respiration. Eating, smoking, or caffeine can raise blood pressure and pulse. Position changes, age, medications, and time of day all play a role. Because of this, you let an excited or active resident rest 5-10 minutes before measuring, and you avoid taking an oral temperature right after hot or cold drinks.

The nurse aide's responsibility is to measure accurately, record promptly, and report abnormal values — never to interpret or treat. Report immediately any reading outside the normal range, plus any sudden change from the resident's usual baseline. Always compare today's numbers to the resident's prior readings: a blood pressure of 150/95 is abnormal, but even a "normal-looking" 118/78 may be a red flag if the resident normally runs 90/60. Chart every value clearly with the route used (for example, "T 99.2 oral"), and never guess or estimate a reading you did not actually take.