3.1 Vital Signs & Measurements

The Four Vital Signs and Why They Matter

Vital signs are objective measurements of the body's most basic functions: temperature (T), pulse (P), respirations (R), and blood pressure (BP). Together they are abbreviated TPR and BP, and most Kentucky facilities add a fifth reading — oxygen saturation (SpO2), measured with a pulse oximeter. As a Kentucky State Registered Nurse Aide (SRNA), you collect and record these numbers, but you never diagnose or interpret them. Your job is to measure accurately, document immediately, and report any value outside the normal range to the licensed nurse. On the KCTCS skills evaluation, accuracy counts: a pulse or respiration count must fall within 5 of the evaluator's count, and a manual blood pressure must fall within 4 mmHg. Sloppy technique fails the skill even when the resident is perfectly healthy.

Temperature: Routes and Normal Ranges

Body temperature can be taken by several routes, and the normal value shifts with each route. The oral route is most common; normal oral temperature is about 98.6°F (37°C), and a reading above 100.4°F (38°C) is a fever that must be reported. Never take an oral temperature within 15–20 minutes of the resident eating, drinking hot or cold liquids, chewing gum, or smoking — these change the reading. The axillary (underarm) route is the safest and least invasive but reads roughly 1°F lower than oral, so axillary fever begins near 99.4°F (37.4°C). The rectal route reads about 1°F higher and is the most accurate but the most invasive. Tympanic (ear) and temporal artery (forehead) thermometers are fast and non-invasive. Older adults often run a cooler baseline and may not spike a classic fever even during serious infection, so report any change from the resident's usual temperature — not just a number over 100.4°F.

Pulse: Radial, Apical, and the Pulse Deficit

The normal adult resting pulse (heart rate) is 60–100 beats per minute (bpm). Below 60 is bradycardia; above 100 at rest is tachycardia — both are reported. The radial pulse is felt by placing two fingers (never the thumb, which has its own pulse) on the thumb side of the inner wrist. If the rhythm is regular, count for 30 seconds and multiply by 2; if it is irregular, count for a full 60 seconds with no shortcut. You also assess rate, rhythm, and force (strength). The apical pulse is heard with a stethoscope over the heart's apex (left chest, roughly the fifth intercostal space) and is always counted for a full minute — it is used for very fast, slow, or irregular rates. When an apical and a radial pulse are taken at the same time, the difference is the pulse deficit (for example, apical 88 minus radial 72 equals a deficit of 16), which signals weak heartbeats that never reach the wrist and must be reported.

Respirations: Count Discreetly

Normal adult respirations are 12–20 breaths per minute. Below 12 is bradypnea; above 20 is tachypnea. One respiration equals one full inhale plus one exhale (watch the chest rise and fall). Because people unconsciously change their breathing when they know it is being watched, count respirations discreetly — keep your fingers on the wrist as if still taking the pulse and do not announce it. Count for a full 60 seconds when breathing is irregular, shallow, or labored.

Blood Pressure and Oxygen Saturation

Blood pressure is the force of blood against artery walls, written as systolic over diastolic in mmHg. Systolic is the first Korotkoff sound heard as the cuff deflates; diastolic is when the sounds disappear. A normal adult BP is roughly 90–120 / 60–80 mmHg. Place the cuff on the bare upper arm, arm supported at heart level, and use the brachial artery. Never take BP on an arm with an IV line, a dialysis fistula/shunt, or on the mastectomy side — cuff pressure can damage the site. Oxygen saturation (SpO2) measured by pulse oximeter is normally 95–100%; report readings below 90% (or below the resident's ordered threshold). Cold fingers, nail polish, or poor circulation can give false low readings.

Height, Weight, and When to Report

Weigh residents at the same time of day, on the same scale, in similar clothing, before breakfast when ordered. A sudden weight gain can signal fluid retention (heart failure); rapid loss can signal poor intake or illness — both are reported. The table below anchors the ranges you must memorize.

Always report a reading with symptoms immediately: a BP of 180/110 with headache is a possible hypertensive crisis, and 88/56 with dizziness and cool, clammy skin is symptomatic hypotension — stay with the resident and call the nurse.

Documentation and Common Traps

Record each vital sign immediately after measuring it in the designated clinical record, noting the exact value, date, time, the route or site used, and your name and title — never rely on memory or chart estimates. Two traps appear often on the KCTCS exam. First, the respiration trap: you must count respirations without telling the resident, because awareness changes the breathing pattern. Second, the irregular-rhythm trap: any time a pulse or breathing pattern is irregular, count for a full 60 seconds rather than counting 30 seconds and doubling. When in doubt about whether a value is abnormal, err on the side of reporting it — the nurse decides what it means, and a timely report can catch a developing infection, cardiac event, or dehydration early.