2.1 Vital Signs & Measurement
Key Takeaways
- Normal adult vital sign ranges: Temperature (Oral: 97.6°F–99.6°F / 36.5°C–37.5°C), Pulse (60–100 bpm), Respiration (12–20 breaths/min), Blood Pressure (<120/<80 mmHg), and SpO2 (95%–100%).
- Pulse rates must be counted for 1 full minute when taking an apical pulse or evaluating a resident with an irregular pulse or known cardiac condition.
- Respirations should be counted immediately after taking the radial pulse without releasing the wrist so the resident remains unaware and breathes naturally.
- Michigan Headmaster CNA skill standards require reporting temperature variations >1°F from baseline, blood pressure readings above 140/90 mmHg or below 90/60 mmHg, and oxygen saturation levels below 95%.
- Axillary temperatures measure approximately 1°F lower than oral readings, while rectal and tympanic temperatures measure approximately 1°F higher than oral readings.
2.1 Vital Signs & Measurement
Quick Answer: Vital signs—temperature, pulse, respiration, blood pressure, and pulse oximetry—provide essential quantitative data regarding a resident's basic physiological status. Normal adult ranges are: Oral Temperature 97.6°F–99.6°F (36.5°C–37.5°C), Radial Pulse 60–100 beats per minute, Respiration 12–20 breaths per minute, Blood Pressure <120/<80 mmHg, and SpO2 95%–100%. On the Michigan Headmaster CNA skills exam, vital signs must be measured within strict accuracy margins (e.g., pulse within ±4 bpm, respiration within ±2 breaths/min, blood pressure within ±4 mmHg of the evaluator).
Measuring and recording vital signs is one of the most critical daily responsibilities of a Certified Nursing Assistant (CNA). Vital signs provide immediate indicators of changes in a resident's physical condition, metabolic rate, cardiovascular performance, and respiratory efficacy.
Clinical Significance of Vital Signs
Vital signs reflect the body's fundamental physiological functions. Changes in vital signs often serve as the earliest warning indicators of infection, fluid imbalance, cardiac stress, medication side effects, or respiratory distress. CNAs must measure vital signs accurately and report any deviations from baseline immediately to the charge nurse.
| Vital Sign | Normal Adult Range | Critical Low (Report Immediately) | Critical High (Report Immediately) |
|---|---|---|---|
| Oral Temperature | 97.6°F – 99.6°F (36.5°C – 37.5°C) | < 96.0°F (35.6°C) | > 100.0°F (37.8°C) |
| Radial Pulse | 60 – 100 beats per minute (bpm) | < 60 bpm (Bradycardia) | > 100 bpm (Tachycardia) |
| Respirations | 12 – 20 breaths per minute | < 12 breaths/min (Bradypnea) | > 20 breaths/min (Tachypnea) |
| Blood Pressure | Systolic < 120 / Diastolic < 80 mmHg | Systolic < 90 / Diastolic < 60 mmHg | Systolic ≥ 140 / Diastolic ≥ 90 mmHg |
| Pulse Oximetry (SpO2) | 95% – 100% | < 90% (Severe Hypoxia) | N/A |
Body Temperature Measurement
Body temperature represents the balance between the heat produced by metabolic body processes and the heat lost to the environment.
Temperature Routes & Normal Ranges
Different measurement routes yield slightly different baseline readings due to tissue vascularity and environmental exposure:
- Oral (Mouth): 97.6°F – 99.6°F (36.5°C – 37.5°C). Most common route for conscious, cooperative adults.
- Axillary (Armpit): 96.6°F – 98.6°F (35.9°C – 37.0°C). Least accurate route; measures approximately 1°F lower than oral temperature.
- Rectal (Rectum): 98.6°F – 100.6°F (37.0°C – 38.1°C). Most accurate core temperature route; measures approximately 1°F higher than oral temperature.
- Tympanic (Ear): 98.6°F – 100.6°F (37.0°C – 38.1°C). Fast core temperature measurement utilizing infrared sensors against the eardrum.
- Temporal Artery (Forehead): 97.6°F – 99.6°F (36.5°C – 37.5°C). Non-invasive infrared scan across the forehead and behind the earlobe.
| Route | Normal Range (°F) | Normal Range (°C) | Key Clinical Considerations |
|---|---|---|---|
| Oral | 97.6°F – 99.6°F | 36.5°C – 37.5°C | Wait 15–20 minutes if resident ate, drank, or smoked |
| Axillary | 96.6°F – 98.6°F | 35.9°C – 37.0°C | Ensure dry armpit; hold probe securely for full duration |
| Rectal | 98.6°F – 100.6°F | 37.0°C – 38.1°C | Red probe stem; lubricate tip; insert 1 inch for adults |
| Tympanic | 98.6°F – 100.6°F | 37.0°C – 38.1°C | Pull pinna up and back for adults; ensure snug seal |
Temperature Contraindications
Selecting the correct route requires evaluating resident safety and clinical condition:
- Do NOT take an oral temperature if: The resident is confused, disoriented, unconscious, prone to seizures, breathing exclusively through the mouth, receiving oxygen via nasal cannula, experiencing stomatitis, or under 5 years of age.
- Do NOT take a rectal temperature if: The resident has severe diarrhea, rectal bleeding, hemorrhoids, recent rectal surgery, a heart condition (stimulation of the vagus nerve can slow heart rate dangerously), or severe neutropenia (low white blood cell count).
- Do NOT take a tympanic temperature if: The resident has ear pain, active ear infection, significant cerumen (earwax) impaction, or drainage from the ear canal.
Pulse Rate & Rhythm Assessment
The pulse is the pressure wave of blood created by the contraction of the left ventricle of the heart as it pumps blood into the aorta.
Pulse Sites & Measurement Techniques
- Radial Pulse: Located on the thumb side of the inner wrist. This is the standard site for routine vital sign assessment in adults. Locate the pulse using the pads of your middle two or three fingers (never use your thumb, as it has its own distinct pulse).
- Apical Pulse: Located over the apex of the heart at the 5th intercostal space at the left midclavicular line. Measured using a stethoscope. Must be counted for 1 full minute (60 seconds).
- Carotid Pulse: Located in the neck alongside the trachea. Used during CPR and emergency cardiovascular resuscitation.
- Brachial Pulse: Located in the inner aspect of the elbow (antecubital fossa). Used primarily for blood pressure measurement and infant pulse checks.
Apical Pulse Protocol & Pulse Deficit
When taking a radial pulse, count for 30 seconds and multiply by 2 if the rhythm is regular. If the pulse is irregular, weak, thready, or if the resident takes cardiac medications (such as digoxin), count for 1 full minute (60 seconds).
An apical-radial deficit occurs when the apical pulse rate is higher than the radial pulse rate. This indicates that some heart contractions are too weak to transmit a pulse wave to the peripheral radial artery. Two healthcare providers measure apical and radial pulses simultaneously for 1 full minute to determine the deficit.
Respiratory Rate & Pattern Assessment
Respiration is the biological process of exchanging oxygen and carbon dioxide between the atmosphere and body cells. One complete respiration consists of one inhalation (chest rises) and one exhalation (chest falls).
Normal Respiration & Abnormal Patterns
- Normal Adult Rate: 12 to 20 breaths per minute. Respirations should be smooth, quiet, effortless, and regular.
- Tachypnea: Respiratory rate greater than 20 breaths per minute.
- Bradypnea: Respiratory rate less than 12 breaths per minute.
- Apnea: Complete absence of breathing; a life-threatening medical emergency.
- Dyspnea: Difficult, labored, or painful breathing. Residents may exhibit flaring nostrils, neck muscle strain, or cyanosis.
- Cheyne-Stokes: An abnormal respiratory pattern characterized by alternating periods of deep, rapid breathing followed by shallow breathing and temporary apnea. Commonly observed in dying residents or severe brain injury.
Unobtrusive Respiration Counting Technique
Because breathing is under partial voluntary control, residents will alter their natural breathing pattern if they realize their respirations are being observed.
Headmaster Exam Protocol: Keep your fingers positioned over the resident's radial wrist artery immediately after finishing the radial pulse count. Pretend to continue counting the pulse while actually observing the rise and fall of the resident's chest for 30 seconds (multiply by 2) or for 1 full minute if irregular.
Blood Pressure (BP) Measurement
Blood pressure is the lateral force exerted by circulating blood against the arterial walls during cardiac contraction and relaxation.
Blood Pressure Categories & Terminology
- Systolic Pressure: The upper number. Represents the peak pressure exerted against arterial walls when the left ventricle contracts. Normal range is less than 120 mmHg.
- Diastolic Pressure: The lower number. Represents the constant resting pressure in the arteries when the heart relaxes between beats. Normal range is less than 80 mmHg.
| BP Category | Systolic (mmHg) | Diastolic (mmHg) | Nursing Assistant Action |
|---|---|---|---|
| Normal | < 120 | and < 80 | Reassess per routine care plan |
| Elevated | 120 – 129 | and < 80 | Document and notify nurse at end of shift |
| Hypertension Stage 1 | 130 – 139 | or 80 – 89 | Document and report to nurse |
| Hypertension Stage 2 | ≥ 140 | or ≥ 90 | Document and report immediately |
| Hypertensive Crisis | > 180 | and/or > 120 | Emergency notification to nurse |
| Hypotension | < 90 | or < 60 | Report immediately; check for dizziness |
Equipment & Korotkoff Sounds
Measuring blood pressure manually requires a sphygmomanometer (blood pressure cuff and pressure gauge) and a stethoscope.
- Position the resident comfortably with the arm supported at heart level, palm facing up.
- Wrap the deflation-cleared cuff smoothly around the upper arm, 1 inch above the antecubital fossa, with the arrow centered over the brachial artery.
- Inflate the cuff to 160 mmHg (or 30 mmHg above the point where the radial pulse disappears).
- Deflate the cuff slowly at a rate of 2 to 3 mmHg per second.
- Korotkoff Phase I (Systolic): The exact gauge reading where the first clear, tapping sound is heard.
- Korotkoff Phase V (Diastolic): The exact gauge reading where the tapping sound completely disappears.
Arm Selection & Contraindications
NEVER measure blood pressure on an arm that has:
- An intravenous (IV) infusion line running
- A hemodialysis arteriovenous (AV) shunt or fistula
- A history of mastectomy or lymph node dissection on that side
- Severe paralysis, trauma, open wounds, or a cast
Pulse Oximetry (SpO2)
Pulse oximetry measures the percentage of hemoglobin in arterial blood that is saturated with oxygen (SpO2). Normal oxygen saturation ranges from 95% to 100%.
- Sensor sites include fingertips, earlobes, or toes.
- Factors causing inaccurate readings: Dark nail polish, artificial acrylic nails, cold extremities (poor peripheral perfusion), bright overhead lighting, tremors, or movement.
- Report any SpO2 reading below 95% to the nurse promptly.
Clinical Scenario: Managing Complex Vital Signs
Clinical Scenario: CNA Marcus enters Room 104 to take morning vital signs for Mr. Henderson, an 82-year-old resident with history of congestive heart failure and chronic obstructive pulmonary disease (COPD). Marcus notes Mr. Henderson is sitting upright in bed, breathing rapidly with visible chest exertion. Marcus measures the following: Oral Temperature 98.2°F, Radial Pulse 108 bpm (irregular), Respirations 24 breaths/min, Blood Pressure 148/92 mmHg, and SpO2 91% on room air.
CNA Action: Marcus recognizes that Mr. Henderson exhibits tachycardia (108 bpm), tachypnea (24 breaths/min), Stage 2 hypertension (148/92 mmHg), and hypoxia (SpO2 91%). Marcus immediately ensures Mr. Henderson is in High Fowler's position, keeps him calm, stays with him, and uses the emergency call light to summon the nurse right away.
Michigan Headmaster CNA Exam Testing Guidelines
| Skill Procedure | Required Accuracy Margin | Key Critical Performance Steps |
|---|---|---|
| Pulse Measurement | Within ±4 bpm of evaluator | Count radial pulse for 60 seconds; record accurately on candidate documentation form |
| Respiration Measurement | Within ±2 breaths/min of evaluator | Count respirations for 60 seconds without alerting resident; record accurately |
| Blood Pressure Measurement | Within ±4 mmHg of evaluator (systolic & diastolic) | Locate brachial artery; position cuff correctly; inflate 30 mmHg above radial obliteration; deflate at 2-3 mmHg/sec |
Which of the following conditions is a strict contraindication for taking an oral temperature on an adult resident?
When measuring a resident's respiratory rate during the Michigan CNA practical exam, what is the correct clinical procedure?
What does the systolic blood pressure reading represent in cardiovascular physiology?
Where should a nursing assistant place the stethoscope bell or diaphragm when assessing a resident's apical pulse, and for how long must it be counted?