7.1 Vital Signs: Temperature, Pulse, Respiration & Blood Pressure

Vital Signs: Temperature, Pulse, Respiration & Blood Pressure

Vital signs—often referred to in clinical practice as TPR & BP (Temperature, Pulse, Respiration, and Blood Pressure)—represent the primary physiological indicators of homeostasis, organ perfusion, and autonomic nervous system function. In geriatric and long-term care nursing, monitoring vital signs is among the most frequent and critical clinical duties assigned to the Certified Nursing Assistant (CNA).

Because elderly residents frequently experience reduced physiological reserve, atypical symptom presentation, and diminished immune responsiveness, subtle shifts in baseline vital signs often serve as the earliest clinical warning signs of acute systemic decompensation, infection (such as pneumonia, sepsis, or urinary tract infections), medication toxicity, cardiovascular crisis, or respiratory compromise.

1. Geriatric Baseline Normals & Physiological Considerations

As the human body ages, structural and functional changes alter baseline physiological parameters. Arterial stiffening (arteriosclerosis), decreased elasticity of blood vessel walls, reduced cardiac output, loss of subcutaneous adipose tissue, sluggish hypothalamic thermoregulation, and decreased pulmonary compliance influence baseline readings in older adults.

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|                   GERIATRIC VITAL SIGN BASELINE REFERENCE RANGES            |
|                                                                             |
|   VITAL SIGN                 STANDARD NORMAL RANGE       REPORTABLE ALERTS  |
|   -------------------------  --------------------------  -----------------  |
|   Temperature (Oral)         97.6°F - 99.6°F (36.5-37.5°C) <96.0°F or ≥100.0°F |
|   Temperature (Rectal)       98.6°F - 100.6°F (37.0-38.1°C) Core Gold Standard|
|   Temperature (Axillary)     96.6°F - 98.6°F (35.9-37.0°C) Least Accurate   |
|   Temperature (Tympanic)     97.6°F - 99.6°F (36.5-37.5°C) Core Equivalent  |
|   Pulse Rate (Adult)         60 - 100 beats per minute   <60 bpm or >100 bpm|
|   Respiratory Rate           12 - 20 breaths per minute  <12 bpm or >20 bpm |
|   Blood Pressure (Systolic)  90 - 120 mmHg               <90 or ≥130 mmHg   |
|   Blood Pressure (Diastolic) 60 - 80 mmHg                <60 or ≥80 mmHg    |
+-----------------------------------------------------------------------------+

[!IMPORTANT] Atypical Geriatric Fever Presentation: Due to age-related blunting of the hypothalamic thermoregulatory setpoint and reduced basal metabolic rates, frail elderly residents may have a normal baseline temperature of 96.8°F to 97.4°F. In these individuals, a temperature of 99.0°F to 99.5°F (37.2°C to 37.5°C) or an elevation of 2.0°F (1.1°C) above personal baseline can represent severe systemic infection, bacterial sepsis, or acute pneumonia, even if it falls below the standard clinical fever definition of 100.4°F (38.0°C).

2. Body Temperature Measurement Routes & Clinical Protocols

Body temperature reflects the balance between heat generated by metabolic processes and heat lost to the external environment. CNAs measure body temperature using digital electronic thermometers, tympanic infrared scanners, temporal artery scanners, or chemical strip thermometers.

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|                    BODY TEMPERATURE ROUTES & COMPARISON                     |
|                                                                             |
|   [ORAL (BLUE PROBE)]         [RECTAL (RED PROBE)]      [AXILLARY (BLUE)]   |
|   - Range: 97.6°F - 99.6°F    - Range: 98.6°F - 100.6°F - Range: 96.6°-98.6°|
|   - Most common & convenient  - Gold standard CORE temp - Least accurate    |
|   - Wait 15-20 min post oral  - Sims' position; 1" deep - Underarm / axilla |
|     intake, smoking, or gum   - Red probe; lubricated   - Safe & noninvasive|
+-----------------------------------------------------------------------------+

Detailed Analysis of Measurement Routes

1. Oral Route (Sublingual):

   • Normal Range: 97.6°F to 99.6°F (36.5°C to 37.5°C).
   • Equipment: Electronic digital thermometer with a BLUE probe and disposable plastic probe cover.
   • Placement: The probe tip must be placed deep in the sublingual pocket (under the tongue) to the left or right of the frenulum. The resident must close their lips firmly around the probe and breathe through their nose without biting the probe.
   • The 15-to-20-Minute Waiting Rule: If the resident has consumed hot or cold liquids, eaten food, smoked a cigarette, chewed gum, or received respiratory inhalation treatments, the CNA MUST wait 15 to 20 minutes before taking an oral temperature. Ingestion of hot/cold substances or tobacco alters sublingual vascular blood flow and creates false readings.
   • Contraindications: Unconscious/comatose residents, individuals with active seizures, confused/combative residents, mouth breathers, residents receiving continuous high-flow oxygen via face mask, residents with oral trauma, recent oral/facial surgery, or children under 5 years old.

2. Rectal Route:

   • Normal Range: 98.6°F to 100.6°F (37.0°C to 38.1°C). Typically 1°F (0.5°C) higher than oral.
   • Clinical Status: The most accurate reflection of core body temperature because the rectal cavity is highly vascular and shielded from ambient air.
   • Equipment & Protocol: Electronic thermometer with a RED probe and disposable probe cover. Position resident in the left lateral Sims' position with upper knee flexed. Apply a water-soluble lubricant to the probe tip (1/2 to 1 inch). Gently insert the probe 1 inch (2.5 cm) into the adult rectum (maximum 1/2 inch for an infant). Hold the probe securely in place throughout the entire measurement cycle; never leave the resident unattended with an inserted rectal thermometer.
   • Strict Contraindications: Cardiac conditions (vagus nerve stimulation can trigger severe bradycardia, heart block, or syncope), rectal bleeding, active diarrhea, severe hemorrhoids, rectal surgery, severe thrombocytopenia (low platelets), or neutropenia.

3. Axillary Route:

   • Normal Range: 96.6°F to 98.6°F (35.9°C to 37.0°C). Typically 1°F (0.5°C) lower than oral.
   • Clinical Status: The least accurate measurement route; used when oral, tympanic, and rectal routes are contraindicated or unsafe.
   • Technique: Ensure the axilla (underarm) is clean and dry. If moist with perspiration, gently pat (do not vigorously rub) the axilla dry with a towel. Place the probe tip in the center of the axilla and hold the resident's arm snugly against their chest across the chest wall to seal the pocket until the unit signals completion.

4. Tympanic Route (Auditory Canal):

   • Normal Range: 97.6°F to 99.6°F (36.5°C to 37.5°C). Shares the same internal carotid arterial blood supply as the hypothalamic thermoregulatory center.
   • Technique: Attach a clean disposable probe cover. For an adult, gently pull the pinna (external ear) UP and BACK to straighten the ear canal (pull DOWN and BACK for children under 3). Insert the probe snugly into the ear canal opening and press the trigger for 1 to 2 seconds.
   • Contraindications: Severe cerumen (earwax) impaction, active ear drainage/infection (otitis media/externa), perforated eardrum, or ear canal lesions.

5. Temporal Artery Route:

   • Normal Range: 97.6°F to 99.6°F (36.5°C to 37.5°C).
   • Technique: An infrared scanner is pressed flat against the center of the dry forehead and slid smoothly horizontally across the forehead to the hairline, capturing arterial blood flow from the superficial temporal artery. If the forehead is diaphoretic (sweaty), touch the probe to the soft depression behind the earlobe as instructed by the manufacturer.

Clinical Terminology for Temperature Alterations

• Afebrile: State of normal body temperature without fever.
• Febrile (Pyrexia): Elevated body temperature above normal baseline (typically ≥100.4°F / 38.0°C in general adults; ≥99.5°F in frail elderly).
• Hyperthermia: Life-threatening elevation of body temperature resulting from failed thermoregulation (e.g., heat stroke), characterized by hot, dry, flushed skin and confusion.
• Hypothermia: Core body temperature dropping below 95.0°F (35.0°C), resulting in severe shivering, lethargy, bradycardia, hypotension, and cardiac dysrhythmias.

3. Pulse Assessment & Apical-Radial Measurements

The pulse represents the palpable rhythmic expansion and recoil of an artery as a wave of blood is ejected from the left ventricle into the arterial system with each heartbeat.

+-----------------------------------------------------------------------------+
|                        PULSE PARAMETERS & SITES                             |
|                                                                             |
|   [RADIAL ARTERY]             [APICAL (HEART APEX)]     [PULSE DEFICIT]     |
|   - Thumb side of wrist.      - 5th Intercostal Space,  - Apical rate MINUS |
|   - Palpate with 2-3 fingers.   Left Midclavicular line.  Radial rate.      |
|   - Count 60 seconds (exam).  - Auscultate 60 seconds   - Requires 2 staff  |
|   - Never use thumb.            with stethoscope.         counting together.|
+-----------------------------------------------------------------------------+

Pulse Characteristics

When assessing a resident's pulse, the CNA must evaluate three distinct clinical parameters:

1. Rate: The number of pulsations per minute. Normal adult resting rate is 60 to 100 beats per minute (bpm).
   • Tachycardia: Resting heart rate greater than 100 bpm (causes: fever, pain, anxiety, hypoxia, hemorrhage, dehydration, exercise).
   • Bradycardia: Resting heart rate less than 60 bpm (causes: cardiac conduction disease, vagal stimulation, hypothermia, athletic conditioning, medications like beta-blockers and digoxin).
2. Rhythm: The regular spacing between heartbeats. Recorded as regular (even intervals) or irregular / dysrhythmic (skipped beats, premature beats, uneven spacing).
3. Volume / Quality (Force): The strength of the arterial pressure wave. Commonly graded on a descriptive scale:
   • 0: Absent / non-palpable.
   • 1+ (Thready / Weak): Difficult to palpate, easily obliterated by slight finger pressure (indicates shock, hypovolemia, heart failure).
   • 2+ (Normal): Easily palpable, obliterated only with moderate pressure.
   • 3+ (Bounding / Full): Strong, forceful, difficult to obliterate (indicates hypertension, fluid overload, severe fever, extreme exertion).

Radial Pulse Assessment Protocol

• Hand Placement: Place the pads of your index and middle fingers (and optionally the ring finger) lightly over the radial artery on the thumb side (lateral aspect) of the resident's inner wrist.
• Never Use Your Thumb: The human thumb contains its own strong arterial pulse (arteria princeps pollicis). Using your thumb can cause you to count your own pulse instead of the resident's.
• Timing Duration: In the Mississippi Manual Demonstration Skill Test and in geriatric long-term care facilities, the CNA must count the radial pulse for a full 60 seconds (1 minute) to accurately detect subtle rate variations or dysrhythmias.

Apical Pulse Auscultation Protocol

An apical pulse is auscultated directly over the apex of the heart using a stethoscope.

• Indications: Required for residents with irregular radial pulses, known cardiac arrhythmias (such as atrial fibrillation), infants/children, and always prior to administering cardiac medications (such as digoxin / Lanoxin, beta-blockers, or calcium channel blockers).
• Anatomical Landmark: Locate the 5th intercostal space (ICS) at the left midclavicular line (MCL). This point is found by counting down five intercostal spaces from the clavicle and moving horizontally to the vertical line dropped straight down from the midpoint of the left collarbone (just below the left nipple).
• Stethoscope Preparation: Clean the stethoscope earpieces and diaphragm thoroughly with 70% isopropyl alcohol wipes before and after resident contact. Warm the metal diaphragm in your hand before placing it on the resident's bare chest.
• Auscultation Technique: Place the diaphragm flat against the 5th ICS MCL landmark. Each heartbeat produces two sounds: "lub-dub" (S1 and S2). The combined "lub-dub" sound counts as ONE single beat. Count for a full 60 seconds.

[!CAUTION] The Digoxin (Lanoxin) 60 bpm Safety Rule: Digoxin is a cardiac glycoside that increases cardiac contractility while slowing electrical conduction through the AV node. If a resident's apical pulse is less than 60 bpm (bradycardia), the CNA must immediately withhold any pending digitalis medication and report the reading to the charge nurse prior to administration to prevent fatal cardiac toxicity.

Apical-Radial Pulse Deficit Assessment

A pulse deficit occurs when the electrical contraction of the heart is too weak to create a palpable peripheral pressure wave at the radial artery, resulting in an apical pulse rate that is higher than the radial pulse rate (common in atrial fibrillation and severe congestive heart failure).

• Procedure: Requires two healthcare providers assessing simultaneously using the same watch:
  • Caregiver 1 auscultates the apical pulse with a stethoscope for 60 seconds.
  • Caregiver 2 palpates the radial pulse for the exact same 60 seconds.
  • Caregiver 1 signals "Start" and "Stop" aloud.
• Calculation: $\text{Pulse Deficit} = \text{Apical Pulse Rate} - \text{Radial Pulse Rate}$.
• Example: Apical rate = 88 bpm; Radial rate = 74 bpm. Pulse deficit = $88 - 74 = 14\text{ bpm}$. Any pulse deficit must be documented and reported immediately.

4. Respiration Assessment & Respiratory Characteristics

Respiration is the physiological process of gas exchange between the atmosphere and the body's cells, consisting of inspiration (inhalation) and expiration (exhalation).

+-----------------------------------------------------------------------------+
|                        RESPIRATORY RATE & MONITORING                        |
|                                                                             |
|   [NORMAL RATE]               [UNOBTRUSIVE TECHNIQUE]   [REPORTABLE SIGNS]  |
|   - 12 to 20 breaths/min.     - Count immediately after - Dyspnea / SOB.    |
|   - 1 inhalation +            radial pulse.             - Tachypnea (>20).  |
|     1 exhalation = 1 breath.  - Keep fingers on wrist.  - Bradypnea (<12).  |
|   - Full 60-second count.     - Resident unaware of     - Cheyne-Stokes     |
|                                 respiration count.        or cyanosis.      |
+-----------------------------------------------------------------------------+

Characteristics of Normal Respirations

• Rate: Normal resting adult respiratory rate is 12 to 20 breaths per minute (bpm).
• Cycle Definition: One complete respiratory cycle consists of one inhalation (chest rise) and one exhalation (chest fall).
• Rhythm: Regular, rhythmic, and effortless.
• Depth: Normal thoracic expansion without shallow chest movement or hyperventilation.
• Effort: Quiet, unlabored, effortless, and painless without the use of accessory neck or abdominal muscles.

The Unobtrusive Counting Technique (Headmaster Critical Rule)

Respiration is under both involuntary autonomic control and voluntary conscious control. If a resident knows their breathing is being counted, they will subconsciously alter their breathing rate, depth, or pattern.

[!IMPORTANT] The Unobtrusive 60-Second Respiratory Count Technique:

1. Complete counting the resident's radial pulse for 60 seconds.
2. DO NOT remove your fingers from the resident's radial wrist.
3. Maintain your fingers on the wrist as if you are continuing to assess the pulse.
4. Shift your visual focus to the resident's chest or abdomen.
5. Count the rise and fall of the chest for a full 60 seconds (1 minute).
6. Record both the pulse rate and respiratory rate accurately.

Abnormal Respiratory Terminology & Clinical Signs

5. Blood Pressure (BP) Measurement & Sphygmomanometer Protocols

Blood pressure (BP) is the lateral force exerted by circulating blood against the internal walls of the arterial vessels. It is expressed as a fraction in millimeters of mercury (mmHg): $\text{Blood Pressure} = \frac{\text{Systolic Blood Pressure (SBP)}}{\text{Diastolic Blood Pressure (DBP)}}$

+-----------------------------------------------------------------------------+
|                        BLOOD PRESSURE CLASSIFICATIONS                       |
|                                                                             |
|   CATEGORY                   SYSTOLIC (mmHg)            DIASTOLIC (mmHg)    |
|   -------------------------  -------------------------  ------------------  |
|   Normal                     < 120            and       < 80                |
|   Elevated                   120 - 129        and       < 80                |
|   Hypertension (Stage 1)     130 - 139        or        80 - 89             |
|   Hypertension (Stage 2)     ≥ 140            or        ≥ 90                |
|   Hypertensive Crisis        > 180            and/or    > 120 (EMERGENCY)   |
|   Hypotension                < 90             or        < 60                |
+-----------------------------------------------------------------------------+

Key Physiological Concepts

• Systolic Blood Pressure (SBP): The maximum pressure generated against arterial walls during left ventricular contraction (systole). Recorded as the top number.
• Diastolic Blood Pressure (DBP): The minimum resting pressure sustained within arterial walls when the left ventricle relaxes and fills between heartbeats (diastole). Recorded as the bottom number.
• Pulse Pressure: The numerical difference between the systolic and diastolic pressures (e.g., $120 - 80 = 40\text{ mmHg}$). Normal pulse pressure is 30 to 50 mmHg.
• Orthostatic (Postural) Hypotension: A sudden drop in systolic blood pressure of ≥20 mmHg or a drop in diastolic blood pressure of ≥10 mmHg within 3 minutes of moving from a lying (supine) to a sitting or standing position. Often accompanied by dizziness, lightheadedness, pallor, visual graying, and syncope (fainting). To prevent falls, CNAs must have residents dangle their legs over the edge of the bed for 1 to 2 minutes before standing.

Sphygmomanometer Anatomy & Cuff Sizing Rules

An aneroid sphygmomanometer consists of an inflatable rubber bladder inside a fabric cuff, an inflation bulb with a controlled air release screw valve, and a calibrated dial gauge graduated in 2-mmHg increments.

+-----------------------------------------------------------------------------+
|                    THE CRITICAL CUFF SIZING RULE (80/40)                    |
|                                                                             |
|   [BLADDER LENGTH]                      [BLADDER WIDTH]                     |
|   - Must encircle at least 80%          - Must equal at least 40% of the    |
|     of the resident's upper arm           circumference of the upper arm    |
|     circumference (80-100%).              (midway between shoulder & elbow).|
|                                                                             |
|   IMPACT OF INCORRECT CUFF SIZES:                                           |
|   - Cuff TOO SMALL / NARROW  ------> Yields a FALSELY HIGH blood pressure   |
|   - Cuff TOO LARGE / WIDE    ------> Yields a FALSELY LOW blood pressure    |
+-----------------------------------------------------------------------------+

Clinical Contraindications for Arm Selection

A blood pressure cuff must NEVER be applied to an arm with any of the following clinical conditions:

1. Intravenous (IV) Infusions: IV line, saline lock, or blood transfusion infusing in the extremity (cuff pressure halts flow, infiltrates vein, or damages catheter).
2. Mastectomy with Axillary Lymph Node Dissection: Lymphedema risk due to impaired lymphatic drainage (cuff inflation causes permanent tissue swelling and lymphangitis).
3. Arteriovenous (AV) Fistula or Graft: Vascular access used for hemodialysis (cuff pressure can cause thrombosis and destroy the graft).
4. Cast, Splint, or Skeletal Traction: Inability to wrap cuff evenly.
5. Paralyzed, Paretic, or Stroke-Affected Arm (Hemiplegia): Altered vasomotor tone causes inaccurate readings.
6. Recent Trauma, Burn, or Open Wound.

[!NOTE] If both upper extremities have contraindications, consult the charge nurse for alternative measurement sites, such as the thigh (popliteal artery) or forearm (radial artery) using appropriately sized cuffs.

Step-by-Step Palpatory-Auscultatory BP Measurement Protocol

+-----------------------------------------------------------------------------+
|                   PALPATORY-AUSCULTATORY BP WORKFLOW                        |
|                                                                             |
|   [1. PREPARATION]           [2. PALPATORY ESTIMATE]    [3. AUSCULTATION]   |
|   - Rest 5 minutes.          - Palpate radial pulse.    - Stethoscope on    |
|   - Arm at heart level.      - Inflate cuff until       brachial artery.    |
|   - Cuff 1" above fossa.       radial pulse vanishes.   - Inflate 30 mmHg   |
|   - Align artery arrow.      - Note reading & deflate.    above estimate.   |
|                              - Wait 30-60 seconds.      - Deflate 2-3 mmHg/s|
+-----------------------------------------------------------------------------+

1. Resident Preparation: Ensure the resident has been resting comfortably in a chair or bed for at least 5 minutes. Position the resident's bare arm supported at heart level, with the palm facing upward. Unroll any tight sleeves that constrict the upper arm.
2. Cuff Placement: Palpate the brachial artery in the antecubital fossa (inner bend of the elbow). Position the center of the inflatable bladder (marked with an arrow on commercial cuffs) directly over the brachial artery. Wrap the cuff smoothly and snugly around the upper arm, positioning the lower edge 1 inch (2.5 cm) above the antecubital space.
3. Step 1: Palpatory Method (Determining Inflation Level):
   • Palpate the resident's radial artery with your fingertips.
   • Close the thumb screw valve clockwise.
   • Rapidly inflate the cuff while feeling the radial pulse until the pulse is no longer palpable (radial obliteration point). Note the gauge pressure (e.g., 110 mmHg).
   • Rapidly and completely deflate the cuff.
   • Wait 30 to 60 seconds to allow normal venous blood flow to return to the arm.
4. Step 2: Auscultatory Measurement (Korotkoff Sounds):
   • Insert clean stethoscope earpieces angled forward toward your nose.
   • Place the stethoscope diaphragm lightly over the brachial artery just below the cuff in the antecubital fossa. Never press too hard or tuck the diaphragm underneath the blood pressure cuff (tucking introduces friction artifact sounds).
   • Close the valve and inflate the cuff rapidly to 30 mmHg above the palpatory obliteration point (e.g., $110 + 30 = 140\text{ mmHg}$). This prevents underestimating systolic pressure due to an auscultatory gap (a silent interval between true systolic pressure and lower sounds common in hypertensive elderly).
   • Open the screw valve gently to release pressure at a smooth, constant rate of 2 to 3 mmHg per second.
5. Identifying Korotkoff Sounds:
   • Phase I (Systolic Pressure): The pressure point where the first clear, rhythmic tapping sound is heard. Record this exact number as the systolic reading.
   • Phase IV (Muffling): The sound changes from crisp tapping to a soft, muffled murmur.
   • Phase V (Diastolic Pressure): The pressure point where all sound completely disappears (cessation of sound). Record this exact number as the diastolic reading.
   • Continue deflating slowly for another 10 to 20 mmHg past the last sound to confirm silence, then open the valve completely to release all residual air.
   • Remove the cuff, clean equipment, perform hand hygiene, and immediately record reading.

6. Clinical Summary & Immediate Reporting Mandates