4.1 Vital Signs: Temperature, Pulse, Respirations & Blood Pressure
Key Takeaways
- Vital signs provide baseline physiological data reflecting cardiovascular, respiratory, and metabolic homeostasis; any sudden deviation from a resident's baseline must be documented and reported immediately to the licensed charge nurse.
- Body temperature normal ranges vary by anatomical site: Oral (97.6°F–99.6°F / 36.5°C–37.5°C), Tympanic (98.6°F / 37.0°C), Temporal (99.6°F / 37.5°C), Axillary (96.6°F–98.6°F / 36.0°C–37.0°C), and Rectal (98.6°F–100.6°F / 37.0°C–38.1°C). Blue probes indicate oral/axillary use; red probes indicate rectal use.
- Radial pulse must be counted for 60 full seconds on the thumb side of the inner wrist; normal adult resting pulse is 60–100 beats per minute (bpm). Apical pulse is auscultated over the 5th intercostal space at the left midclavicular line.
- Respirations (normal adult resting rate 12–20 breaths per minute) must be counted unobtrusively for 60 seconds immediately following pulse assessment without alerting the resident, observing rate, rhythm, depth, and effort.
- South Carolina's tested blood pressure skill is Skill 12, Measures and Records Electronic Blood Pressure, whose critical element is recording both systolic and diastolic pressures exactly as displayed on the digital screen; Skill 23 (manual blood pressure, ±8 mmHg) is marked NOT TESTED in South Carolina.
Vital Signs: Temperature, Pulse, Respirations & Blood Pressure
Quick Reference: Vital signs—temperature (T), pulse (P), respirations (R), and blood pressure (BP)—constitute the foundational physiological markers of human life. As a Certified Nursing Assistant (CNA) in South Carolina, obtaining accurate, uncompromised vital signs is among your most critical clinical duties. Vital sign data detects acute clinical deterioration, monitors chronic disease progression, guides physician pharmacotherapy, and establishes baseline parameters upon admission.
1. Body Temperature: Physiology, Sites & Technique
Body temperature represents the precise balance between heat produced by metabolic cellular activity and heat lost to the external environment through radiation, conduction, convection, and evaporation. The body's thermoregulatory center is located in the hypothalamus.
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| BODY TEMPERATURE SITES & NORMAL RANGES |
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| Anatomical Site | Fahrenheit (°F) | Celsius (°C) | Clinical Characteristics |
+-------------------+--------------------+-------------------+----------------------------+
| Oral (Mouth) | 97.6°F – 99.6°F | 36.5°C – 37.5°C | Standard, convenient site |
| Tympanic (Ear) | 98.6°F (Baseline) | 37.0°C (Baseline) | Fast, shares core blood |
| Temporal (Forehead| 99.6°F (Baseline) | 37.5°C (Baseline) | Non-invasive, temporal art.|
| Axillary (Armpit) | 96.6°F – 98.6°F | 36.0°C – 37.0°C | Least accurate; safest |
| Rectal (Rectum) | 98.6°F – 100.6°F | 37.0°C – 38.1°C | Most accurate core temp |
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Thermometer Types and Color Coding
- Blue Probe / Blue Cap: Designated exclusively for oral and axillary temperature measurement.
- Red Probe / Red Cap: Designated exclusively for rectal temperature measurement. Never cross-contaminate probes.
- Tympanic Thermometer: Infrared sensor placed gently into the external auditory canal.
- Temporal Artery Thermometer: Infrared scanner gently slid across the forehead to the hairline and tapped behind the earlobe.
Site-Specific Clinical Procedures & Contraindications
1. Oral Temperature (Sublingual)
- Procedure: Place a clean disposable probe cover over the blue probe. Insert the probe tip into the sublingual pocket at the base of the tongue to the right or left of the frenulum. Instruct the resident to close their lips firmly around the probe while breathing through their nose. Do not allow the resident to bite down on the probe.
- Mandatory Wait Time: If the resident has eaten hot or cold food, consumed liquids, smoked, or chewed gum within the past 15 to 20 minutes, you must wait a full 15–20 minutes before taking an oral temperature to prevent false readings.
- Contraindications: Unconscious or comatose residents; residents with seizures, severe coughing, active oral trauma/surgery; nasogastric tubes in place; cognitively impaired or combative residents who may bite the probe; or young children.
2. Tympanic Temperature (Aural)
- Procedure: Attach a disposable sheath. For an adult, gently pull the pinna (outer ear) up and back to straighten the ear canal (for infants/young children, pull down and back). Gently insert the probe tip into the canal opening until snug, angle toward the eardrum, press the activation button, and hold until the digital beep sounds (typically 1–2 seconds).
- Contraindications: Active ear drainage, otitis externa, ear canal impaction with cerumen (earwax), or recent ear surgery.
3. Temporal Artery Temperature
- Procedure: Place the sensor flush against the center of the resident's forehead. Depress and hold the scan button while sliding the probe straight across the forehead to the temporal hairline. If perspiration is present on the forehead, maintain the button press and touch the probe to the soft depression directly behind the earlobe.
4. Axillary Temperature
- Procedure: Ensure the resident's axilla (armpit) is clean and completely dry. If moist with perspiration, gently pat (do not vigorously rub) dry with a towel. Place the covered blue probe tip squarely into the center of the axilla. Lower the resident's arm snugly against their chest and have them place their forearm across their abdomen to hold the probe firmly in position until the unit registers.
- Clinical Note: Axillary temperatures measure approximately 1.0°F (0.5°C) lower than oral temperatures and are considered the least accurate method, though they present zero risk of mucosal injury.
5. Rectal Temperature (Core Temperature Standard)
- Procedure: Rectal temperature provides the most accurate core body measurement but is invasive. Position the resident in the left Sims' position (left side-lying with right knee flexed) and drape to expose only the anal area. Don clean gloves. Apply a disposable sheath to the red probe and lubricate the tip with 1 inch of water-soluble lubricant. Gently insert the lubricated probe 1 inch (2.5 cm) into the adult rectum (maximum 1/2 inch in infants). Hold the probe securely in place with your fingers at all times until the digital reading completes. Remove gently, discard sheath into infectious waste, wipe the anal area clean, remove gloves, wash hands, and document.
- Absolute Contraindications: Severe diarrhea, active rectal bleeding, hemorrhoids, rectal surgery, severe cardiac disease (rectal stimulation can stimulate the vagus nerve, precipitating severe bradycardia, syncope, or cardiac arrest), or residents with extreme immunosuppression/neutropenia.
2. Pulse Rate, Rhythm & Amplitude
The pulse is the rhythmic pressure wave generated by the contraction of the left ventricle of the heart propelling blood through the arterial system. Every cardiac contraction generates a palpable systolic pulsation.
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| MAJOR ARTERIAL PULSE SITES |
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| Pulse Landmark | Anatomical Location | Primary Clinical Indication |
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| Radial | Thumb side of inner wrist | Routine vital signs in adults |
| Apical | 5th intercostal space, left MCL | Cardiac meds / irregular pulse|
| Brachial | Inner antecubital fossa | Blood pressure / infant CPR |
| Carotid | Neck groove beside trachea | Adult CPR / cardiac arrest |
| Femoral | Inguinal groin crease | Lower extremity perfusion/CPR |
| Popliteal | Posterior crease of knee | Lower extremity arterial flow |
| Posterior Tibial | Inner ankle behind medial malleolus| Peripheral vascular assessment|
| Dorsalis Pedis | Dorsum (top surface) of the foot | Pedal perfusion check |
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Pulse Characteristics
- Rate: Number of beats per minute (bpm).
- Normal Adult Resting Rate: 60 to 100 bpm.
- Tachycardia: Resting heart rate greater than 100 bpm (causes: fever, pain, anxiety, hypovolemia, infection, exercise, heart failure).
- Bradycardia: Resting heart rate less than 60 bpm (causes: athletic conditioning, heart block, digoxin toxicity, hypothermia, vagal stimulation).
- Rhythm: The regularity of intervals between heartbeats (described as regular or irregular / arrhythmic).
- Volume / Force (Amplitude): The strength of the arterial pulsation:
0= Absent (non-palpable)1+= Thready, weak, easily obliterated with light pressure2+= Normal, expected palpable pulse3+= Full, bounding, difficult to compress (fluid overload, severe hypertension)
Clinical Skills Protocol: Radial Pulse Measurement
- Place the resident in a relaxed seated or supine position with the forearm resting comfortably, palm facing upward.
- Place the pads of your first two or three fingers (index and middle fingers) gently along the radial artery on the thumb side of the resident's wrist. Never use your thumb, as the thumb possesses its own strong arterial pulse which can be mistaken for the resident's pulse.
- Press gently until the pulsation is clearly felt.
- Counting Duration: For clinical training and Credentia skills examination, count the pulse for 60 full seconds using a watch with a second hand. Note the rate, rhythm, and strength.
Apical Pulse Auscultation & Pulse Deficit
- Landmark: Located at the apex of the heart at the 5th intercostal space (ICS) directly along the left midclavicular line (MCL) (directly below the left nipple).
- Stethoscope Technique: Clean earpieces and diaphragm with an alcohol swab. Warm the diaphragm in your palm. Place the diaphragm over the 5th ICS MCL and listen for the characteristic "lub-dub" sound (S1 and S2 heart sounds). Each "lub-dub" cycle counts as ONE single heartbeat. Count for a full 60 seconds.
- Pulse Deficit: The numerical difference between the apical heart rate and the peripheral radial pulse rate when measured simultaneously by two healthcare providers. A pulse deficit indicates that weak ventricular contractions fail to transmit a palpable pressure wave to the peripheral arteries, commonly seen in atrial fibrillation.
3. Respirations: Observation & Patterns
Respiration is the mechanical and biochemical process of exchanging oxygen and carbon dioxide between the atmosphere and the body's cells. One full respiration consists of one complete inhalation (chest rise) and one complete exhalation (chest fall).
Normal Parameters & Covert Assessment Technique
- Normal Adult Resting Rate: 12 to 20 breaths per minute.
- Rhythm & Depth: Normal breathing (eupnea) is regular, quiet, effortless, and unlabored.
- The Covert Counting Technique: Breathing is partially under voluntary nervous system control. If you tell a resident, "I am going to count your breathing," they will unconsciously alter their respiratory rate, depth, and pattern.
- Best Practice Protocol: Immediately upon finishing counting the radial pulse, keep your fingers resting on the resident's wrist as if you are still taking the pulse. Direct your eyes toward the resident's chest or abdomen and count the respiratory cycles for 60 full seconds.
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| TERMINOLOGY FOR ABNORMAL RESPIRATORY PATTERNS |
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| Term | Clinical Definition & Manifestation |
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| Eupnea | Normal, quiet, rhythmic breathing (12–20 breaths/min in adults). |
| Tachypnea | Rapid, shallow breathing rate >20 breaths/min. |
| Bradypnea | Abnormally slow breathing rate <12 breaths/min. |
| Dyspnea | Difficult, painful, or labored breathing; shortness of breath. |
| Apnea | Complete temporary or permanent cessation of breathing. |
| Orthopnea | Inability to breathe comfortably unless sitting upright or standing|
| Cheyne-Stokes | Rhythmic breathing cycles alternating between increasing depth, |
| | decreasing depth, and periods of apnea (10–30 sec); near death. |
| Hypoxemia | Subnormal oxygen saturation in arterial blood (SpO2 <90%). |
| Cyanosis | Bluish/gray discoloration of lips, nailbeds, skin from hypoxemia. |
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4. Blood Pressure: Physiology, Equipment & Manual Technique
Blood pressure (BP) measures the lateral force exerted by circulating blood against the internal walls of the arterial vessels. It is recorded in millimeters of mercury (mmHg) as a fraction: Systolic / Diastolic.
- Systolic Pressure (Top Number): The peak pressure exerted against the arterial walls during ventricular contraction (systole).
- Diastolic Pressure (Bottom Number): The lowest residual resting pressure maintained within the arterial system during ventricular relaxation and filling (diastole).
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| AMERICAN HEART ASSOCIATION (AHA) BP CLASSIFICATIONS |
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| Category | Systolic (mmHg) | | Diastolic (mmHg) |
+------------------------+--------------------------+-----+-------------------------------+
| Normal | Less than 120 | AND | Less than 80 |
| Elevated | 120 – 129 | AND | Less than 80 |
| Stage 1 Hypertension | 130 – 139 | OR | 80 – 89 |
| Stage 2 Hypertension | 140 or higher | OR | 90 or higher |
| Hypertensive Crisis | Higher than 180 | AND/OR | Higher than 120 |
| Hypotension | Less than 90 | OR | Less than 60 |
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Orthostatic (Postural) Hypotension
Orthostatic hypotension is an abrupt drop in blood pressure that occurs when a person moves from a supine (lying) to a seated or standing position. Clinically defined as a systolic drop of ≥20 mmHg or a diastolic drop of ≥10 mmHg accompanied by compensatory tachycardia, dizziness, lightheadedness, blurred vision, or syncope (fainting). Always allow bed-bound residents to dangle their legs over the edge of the bed for 1 to 2 minutes before standing.
Blood Pressure Equipment & Cuff Sizing Rules
Using the wrong size blood pressure cuff generates major diagnostic errors:
- Cuff Bladder Width: Must equal 40% of the circumference of the midpoint of the resident's bare upper arm.
- Cuff Bladder Length: Must encircle at least 80% to 100% of the arm circumference.
- Error Rule: A cuff that is too narrow or too small produces a falsely high reading. A cuff that is too wide or too loose produces a falsely low reading.
Contraindications: When NOT to Use an Arm for BP
Never place a blood pressure cuff on an arm that has:
- An active intravenous (IV) infusion line or blood transfusion.
- An arteriovenous (AV) fistula or graft used for hemodialysis.
- A side affected by radical mastectomy or axillary lymph node dissection (risk of severe lymphedema).
- A side affected by cerebrovascular accident (paralyzed / flaccid hemiplegic arm).
- An extremity with a cast, severe contracture, active burn, or extensive orthopedic trauma.
5. The Blood Pressure Skill South Carolina Actually Tests
[!WARNING] Read this before you practice with a manual cuff. Credentia's South Carolina skills listing contains two blood pressure skills. Skill 12, Measures and Records Electronic Blood Pressure, is the one South Carolina tests, and it is annotated state specific with an evaluator instruction not to substitute it for the manual skill. Skill 23, Measures and Records Manual Blood Pressure, is printed in the listing with the note "THIS SKILL IS NOT TESTED." If blood pressure is drawn as your measurement skill on exam day, you will be handed an electronic device.
5a. The Electronic Blood Pressure Skill (Skill 12 — what you will be tested on)
The electronic skill still carries the full set of scored courtesy, privacy, and safety steps — explain the procedure clearly, slowly, and directly while maintaining face-to-face contact; provide privacy with a curtain, screen, or door; verify the client is in a comfortable lying or sitting position; expose the bare upper arm; apply the cuff snugly with the sensor over the brachial artery; leave the signaling device within reach and the bed in low position; and wash your hands after completing the skill.
The bold Critical Element Step is deceptively simple and is where candidates lose the skill:
After obtaining the reading using the blood pressure cuff, record both systolic and diastolic pressures exactly as displayed on the digital screen.
There is no tolerance band on the electronic skill. You are not being asked to estimate — you are being asked to transcribe. Read the display, say the numbers aloud to yourself, and write both values on the Recording Sheet for Measurement Skills exactly as shown. Transposing 138/82 as 183/82, or rounding 137 to 140, fails the critical element.
5b. Manual Auscultation (worth knowing, not tested in South Carolina)
Manual technique still matters for the written exam, for facility practice, and for any state that tests Skill 23 — where the published critical element is that both recorded pressures fall within plus or minus 8 mm of the evaluator's reading. Learn the technique below for competence, not for South Carolina exam day.
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| 12-STEP MANUAL BLOOD PRESSURE AUSCULTATION PROTOCOL |
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| 1. Identify resident, wash hands, explain procedure, and ensure quiet room. |
| 2. Position resident seated or supine; support bare arm at heart level, palm up. |
| 3. Palpate brachial artery pulse on inner antecubital fossa. |
| 4. Wrap deflated cuff smoothly 1 inch (2.5 cm) above antecubital space with artery |
| arrow centered over the brachial artery. |
| 5. DETERMINE PALPATORY BASELINE: Palpate radial pulse, close valve, inflate cuff until |
| radial pulse disappears. Note pressure gauge value (e.g., 110 mmHg). Deflate fully. |
| 6. Wait 30 to 60 seconds before auscultation to restore venous blood flow. |
| 7. Clean stethoscope earpieces/diaphragm; insert earpieces angled forward into ears. |
| 8. Place stethoscope diaphragm gently over palpated brachial artery (not under cuff). |
| 9. Rapidly inflate cuff to 30 mmHg ABOVE the palpatory pulse disappearance point |
| (e.g., 110 + 30 = 140 mmHg). This prevents missing an auscultatory gap. |
| 10. Open thumb valve slowly, deflating gauge at a steady rate of 2 to 3 mmHg per sec. |
| 11. IDENTIFY KOROTKOFF SOUNDS: |
| - Phase 1 (Systolic): First clear, faint rhythmic tapping sound heard. |
| - Phase 5 (Diastolic): Point where all rhythmic tapping sounds completely vanish. |
| 12. Deflate cuff rapidly to zero, remove equipment, record the reading immediately, |
| and report abnormal readings to the charge nurse. |
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When obtaining a rectal temperature on an adult resident, what is the correct procedural technique regarding positioning, lubrication, and insertion depth?
A nurse aide notes that a resident's breathing pattern alternates between deep, rapid breathing, increasingly shallow breaths, and periods of complete apnea lasting 15 seconds. What is the clinical term for this breathing pattern, and what is the proper method to assess respirations?
Blood pressure is drawn as a South Carolina candidate's measurement skill. What does Credentia's bold critical element step require, and what happens with cuff size errors in general practice?
A nurse aide is assigned to measure an apical pulse on a resident receiving cardiac medication. What anatomical landmark must the nurse aide locate to position the stethoscope diaphragm, and what defines a pulse deficit?