4.1 Measuring and Recording Vital Signs

Why Vital Signs Matter

Vital signs are the measurable, objective signs of how well a resident's basic body systems are working: temperature, pulse, respirations, blood pressure, and oxygen saturation. The Nevada NNAAP (National Nurse Aide Assessment Program) written exam tests both the correct technique for taking each vital sign and the ability to recognize a reading serious enough to report immediately. Because vital signs fall under Basic Nursing Skills — the largest single sub-domain of the exam — expect several scenario-style questions that give you a specific number and ask what you should do next.

Body Temperature

Body temperature reflects the balance between heat produced and heat lost by the body. A nurse aide can take temperature at four common sites, and each site has its own normal range because each measures a slightly different part of the body:

• Oral (by mouth, under the tongue): 97.6°F-99.6°F (36.5°C-37.5°C). This is the reference range most exam questions use unless another site is specified.
• Rectal: runs about 1°F higher than oral, so the normal range is roughly 98.6°F-100.6°F. Rectal temperature is considered the most accurate core measurement and is used for infants or residents who cannot safely hold an oral thermometer, but it is invasive and used only when ordered.
• Axillary (armpit): runs about 1°F lower than oral, roughly 96.6°F-98.6°F. It is the least accurate site because it measures skin surface temperature, but it is the safest choice for a confused resident or one with oral or rectal contraindications.
• Tympanic (ear): close to the oral range, fast, and well tolerated, but accuracy depends on correct positioning — for an adult, gently pull the pinna (outer ear) up and back to straighten the ear canal before inserting the probe.

A classic exam trap asks which site reads highest or lowest. Remember the order from highest to lowest: rectal is highest, tympanic and oral are close together in the middle, and axillary is lowest.

Report to the nurse immediately: an oral temperature above 101°F (38.3°C), a temperature far below the resident's normal baseline, or any fever accompanied by confusion, chills, or a change in behavior.

Pulse

The pulse is the number of times the heart beats per minute, felt as a wave of pressure in an artery. A normal adult pulse is 60-100 beats per minute (bpm). The radial pulse, felt with two or three fingers (never the thumb, which has its own pulse) at the wrist on the thumb side, is the routine site for most residents.

An apical pulse is taken with a stethoscope over the apex of the heart — the point of maximal impulse, roughly the fifth intercostal space at the left midclavicular line, just below the left nipple. Use the apical site, and always count it for a full 60 seconds, when the resident has a known irregular heartbeat, heart disease, or takes certain heart medications, or when the radial pulse is weak, irregular, or hard to find. Counting a full minute — never 15 or 30 seconds multiplied out — is essential because an irregular rhythm can be missed or misrepresented by a short count.

Report immediately: a pulse below 60 (bradycardia) or above 100 (tachycardia) that is new or symptomatic, a pulse that suddenly becomes irregular, or one that is too weak or rapid to count accurately.

Respirations

A respiration is one complete breath — one inhalation plus one exhalation — counted by watching or feeling the chest rise and fall. The normal adult rate is 12-20 breaths per minute. Because people who know they are being watched often unconsciously change their breathing pattern, respirations are counted discreetly, typically immediately after counting the pulse while your fingers are still resting on the resident's wrist, so the resident believes you are still checking the pulse.

Report immediately: a respiratory rate below 12 (bradypnea) or above 24 (tachypnea) breaths per minute, as well as labored, noisy, gasping, or irregular breathing, regardless of the exact number.

Blood Pressure

Blood pressure (BP) measures the force of blood against artery walls, recorded as systolic pressure (during a heartbeat) over diastolic pressure (between beats). A commonly used adult reference point is below 120/80 mmHg; readings that trend toward or above 140/90 mmHg suggest hypertension, and readings at or below 90/60 mmHg suggest hypotension.

Correct cuff size is critical: a cuff that is too small produces a falsely high reading, and a cuff that is too large produces a falsely low reading — a favorite exam trap. Position the bare arm at heart level, wrap the cuff snugly with the lower edge about one inch above the antecubital area (the elbow crease), and avoid an arm with an intravenous (IV) line, a dialysis fistula or graft, a cast, or a history of mastectomy on that side. The resident should be seated, relaxed, and not talking, and should not have exercised, smoked, or had caffeine in the prior 30 minutes.

Report immediately: a systolic reading above 180 or below 90 mmHg, or any blood pressure paired with symptoms such as dizziness, severe headache, chest pain, or visual changes.

Pulse Oximetry

Pulse oximetry measures the oxygen saturation (SpO2) of the blood using a small sensor clipped to a fingertip, earlobe, or toe. A normal adult SpO2 is 95-100%. Cold hands, poor circulation, and dark nail polish can all cause a falsely low reading, so check the sensor placement before assuming a low number reflects the resident's true condition.

Report immediately: an SpO2 below 90-92% (per facility policy), a sudden drop from the resident's baseline, or a low reading accompanied by shortness of breath or bluish lips or nail beds (cyanosis).

Vital Signs at a Glance

On exam day, expect a scenario rather than a bare definition — for example, a resident's respirations are 26 per minute and shallow, or a blood pressure reads 86/54 mmHg with the resident reporting dizziness. In both cases, the correct nurse aide action is the same two-step process: accurately measure and record the vital sign, then report the abnormal finding to the nurse right away rather than simply writing it in the chart and moving on.