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Measuring Vital Signs - Vocabulary Flashcards

Learning outcomes

  • Describe physiological processes regulating body temperature, pulse, respirations, and blood pressure (BP).
  • Convert between Fahrenheit and Celsius scales.
  • Discuss normal vital signs by age groups and recognize readings warranting referral.
  • Define arterial oxygen saturation, hypoxia, hyperventilation, and hypoventilation.
  • Define hypotension, hypertension (essential vs secondary).
  • Choose correct sites and equipment for measuring temperature, pulse, respiration, and BP across age groups.
  • Demonstrate correct techniques for measuring vital signs.
  • Explain how multiple measurements contribute to interpreting BP.
  • State a nursing diagnosis for problems related to temperature, pulse, respirations, and BP.
  • Identify nursing interventions for patients with temperature alterations, impaired respiration, hypertension, and altered pulse.
  • Identify key teaching points for patients managing hypertension.
  • Understand core concepts: oxygenation (respirations), perfusion (pulse, BP), thermoregulation, vital signs.
  • Recognize related concepts and connections to foundational principles and real-world relevance.
  • Consider ethical, philosophical, or practical implications in vital signs assessment.
  • Note all numerical references, formulas, and equations in LaTeX format.
  • Use comprehensive, well-organized study notes that can replace the original source.

What are vital signs?

  • Vital signs (VS) assess critical physiological functions; variations indicate health status and organ-system function.
  • The four traditional VS are temperature, pulse, respirations, and BP; accuracy and documentation are top priorities. -4 traditional VS are essential but some experts advocate adding other factors.
    • Pain is often called the fifth vital sign (controversy: undertreatment, addiction concerns; multidimensional care is recommended).
    • Oxygen saturation via pulse oximetry provides info on arterial oxygen concentration.
    • Emotional distress also affects physiological functioning.
  • Baseline vital signs are crucial to detect trends; VS should be interpreted in the context of the overall assessment.
  • Concept map referrals: see Davis Advantage (concept map).

Temperature (thermoregulation)

  • Thermoregulation: maintaining a stable internal temperature by balancing heat production and heat loss; regulated by the hypothalamus.
  • Core temperature vs surface temperature:
    • Core temperature (e.g., rectal, pulmonary artery) reflects internal temperature and is ~0.6°C–1.2°C (1–2°F) higher than surface temperature.
    • Rectal measurements reflect core temperature; oral/axillary reflect surface temperature.
  • Normal temperature ranges and variability:
    • There is no single universal normal; recently suggested mean adult temperatures are lower than traditional 37°C (98.6°F).
    • Older adults tend to have lower temperatures; mean ranges vary by site and population.
  • Age-related variations (Table 18-2 overview):
    • Newborn: ~36.8°C (98.2°F) axillary; pulse 130 (80–180) bpm; resp 30–60/min; BP ~80/40 mmHg.
    • 1–3 years: ~37.7°C (99.9°F) rectal; pulse ~110 (80–150) bpm; resp ~20–40/min; BP ~98/64 mmHg.
    • 6–8 years: ~37.0°C (98.6°F) oral; pulse ~95 (75–115) bpm; resp ~20–25/min; BP ~102/56 mmHg.
    • 10 years: ~37.0°C (98.6°F) oral; pulse ~90 (70–100) bpm; resp ~17–22/min; BP ~110/58 mmHg.
    • Teen: ~37.0°C (98.6°F) oral; pulse ~80 (55–105) bpm; resp ~15–20/min; BP ~110/70 mmHg.
    • Adult: ~36.7°C (98.0°F) oral; pulse ~80 (60–100) bpm; resp 12–20/min; BP <120/80 mmHg.
    • Older than 70: ~35–36.0°C (95–96.8°F) oral; pulse ~80 (60–100) bpm; resp 12–20/min; BP ~120/80 (up to 160/95 in some cases).
    • Note: Pulse/respiration ranges shown as provided; extremes may occur, but are not necessarily alarming.
  • Fever (pyrexia):
    • Fever: oral > 37.8°C (100°F) or rectal > 38.3°C (101°F) in adults; febrile = febrile; afebrile = no fever.
    • Baseline considerations: older adults may fever at lower temps due to lower baseline.
    • Fever phases: initial (chills, possible shivering), course (fever elevated; flushed, warm, dry), defervescence (break/febrile-episode ends with diaphoresis).
    • Fever benefits: enhances immune response (antimicrobial effects, phagocytosis, interferon release).
    • Hyperpyrexia (>41.0°C / 105.8°F) is dangerous and requires intervention; risk of brain damage, delirium, seizures, cerebral edema, shock, death if >43–44°C (109–112°F).
  • Hyperthermia vs fever:
    • Fever: set point of hypothalamus is higher; body produces heat to reach new set point.
    • Hyperthermia: set point not reset; heat production/exhaust exceeds heat loss; environment/inability to dissipate heat.
  • Heat production mechanisms:
    • Metabolism (basal metabolic rate, BMR) and hormones (epinephrine, norepinephrine) increase heat production.
    • Skeletal muscle activity increases heat production; shivering raises temperature quickly.
    • Nonshivering thermogenesis (brown fat) in infants.
  • Heat exchange mechanisms with environment:
    • Radiation (loss of ~50% of body heat): heat transfer via electromagnetic waves from warmer surfaces to cooler surroundings.
    • Convection: air/water currents transfer heat; can be used therapeutically (warm bath) or to cool (airflow).
    • Evaporation: sweat or humid breath; insensible loss; humidity affects cooling effectiveness.
    • Conduction: heat transfer by direct contact; avoid resting on cold surfaces.
  • Internal/environmental factors influencing temperature:
    • Developmental level: infants and older adults most susceptible to temperature extremes.
    • Environment: warm/hot/humid environments raise temperature; cold environments lower it.
    • Sex: temperature variability with menstrual cycle and pregnancy; hot flashes in menopause.
    • Exercise: increases core temperature.
    • Emotions/stress: sympathetic activation raises metabolism and temperature.
    • Circadian rhythm: temp lowest in early morning, highest late afternoon/evening; readings may vary 0.6–1.2°C (1–2°F) daily.
  • Assessment/communication tips:
    • Approach calmly, introduce yourself, explain procedure, obtain consent.
    • Use appropriate environment and explain to patient to maintain autonomy and comfort.
    • Document temperature and related symptoms; monitor trends.

Pulse (perfusion)

  • Pulse definition: rhythmic arterial expansion caused by heart ejecting blood into the aorta; relates to perfusion.
  • Normal pulse: beats per minute (bpm). Normal range for healthy adults: 60–100 bpm; average ~70–80 bpm.
  • Cardiac output (CO): the total blood pumped per minute; CO = SV × HR, where SV is stroke volume and HR is heart rate. Example: with HR = 80 bpm and SV ≈ 70 mL, CO ≈ 5600 mL/min (≈5.6 L/min).
  • Autonomic control:
    • Sympathetic increases heart rate and cardiac output; parasympathetic decreases.
  • Pulse rate factors:
    • Volume of blood pumped, heart rate changes, arterial wall elasticity, and conditions affecting heart function.
    • Developmental level: newborns have high rates; rate stabilizes with age.
    • Sex: adult females have slightly higher resting pulse.
    • Exercise: trained individuals have lower resting HR; post-exercise recovery is faster.
    • Food intake, stress, fever (↑ ~+10 bpm per °F rise), disease (e.g., thyroid conditions), blood loss, position changes (standing increases HR due to pooling), medications (stimulants ↑ HR; digitalis, opioids ↓ HR).
  • Pulse sites:
    • Peripheral: radial (most common), brachial, carotid, temporal, dorsalis pedis, posterior tibial, femoral, popliteal.
    • Apical pulse: auscultated at the apex; most accurate; often used in infants, those with weak peripheral pulses, or when discrepancies exist.
  • Apical vs radial/pulse deficit:
    • Pulse deficit: difference between apical and radial counts; indicates some beats not transmitted to peripheral arteries (e.g., atrial fibrillation).
    • When apical > radial, report promptly.
  • Pulse assessment data: rate, rhythm, quality (volume), bilaterality.
  • Pulse quality scale (0–3): 0 Absent; 1 Weak/thready; 2 Normal; 3 Bounding.
  • Clinical cues and diagnoses:
    • Tissue perfusion alteration (peripheral) when pulse is absent/weak with cool, pale skin.
    • Fluid volume status (deficit/excess) affects pulse strength.
    • Cardiac output alteration (tachycardia/bradycardia) depends on etiologies.
    • Plan/Outcomes (NOC): Vital Signs Status; Circulation Status; etc.
  • Practical notes:
    • If pulse is irregular, count for 60 seconds; for regular pulse, you can count 15 seconds × 4 or 30 seconds × 2.
    • If pulse is irregular or slow, count for 60 seconds to determine rhythm and rate.
    • Document bilateral equality to assess circulatory adequacy.
  • Interventions and nursing considerations:
    • Dysrhythmia management may involve monitoring, activity tolerance, electrolytes, antidysrhythmic medications, and patient education.
    • When a dysrhythmia is present, provide emotional support and explain procedures clearly.

Respirations

  • Respirations: mechanical ventilation (breathing) and chemical feedback regulation.
  • Normal respiratory rate (adult): 12–20 breaths per minute (varies by age and condition).
  • Regulation:
    • Primary stimulus is CO2 tension (central chemoreceptors in medulla/pons respond to CO2 and H+); peripheral chemoreceptors (carotid/aortic bodies) respond to PaO2 below normal (80–100 mmHg).
    • Breathing is normally involuntary but can be voluntarily controlled.
  • Mechanics of breathing:
    • Inspiration: diaphragmatic and intercostal muscle contraction expands thoracic cavity; air flows in due to decreased intrapulmonary pressure.
    • Expiration: diaphragms/muscles relax; lungs recoil; air exits; expiration is usually passive and lasts 2–3 seconds.
    • Tidal volume: ~300–500 mL per inspiration for a healthy adult; used to estimate adequacy of ventilation.
  • Respiratory patterns and depths (Table 18-5):
    • Eupnea: normal 12–20 breaths/min, regular rate/depth.
    • Bradypnea: <10 breaths/min.
    • Tachypnea: >24 breaths/min, usually shallow.
    • Kussmaul: regular but abnormally deep and rapid.
    • Biot: irregular with varying depth and periods of apnea.
    • Cheyne-Stokes: gradual crescendo/decrescendo with apnea in between.
    • Apnea: absence of breathing.
  • Respiratory depth and effort:
    • Depth: Deep, Normal, Shallow.
    • Effort: normal breathing is effortless; dyspnea indicates increased work of breathing.
    • Orthopnea: difficult breathing when supine.
  • Breath sounds (auscultation): normal quiet; adventitious sounds include
    • Wheezes: high-pitched, expiratory; narrowed airways.
    • Rhonchi: low-pitched, gurgling; secretions.
    • Crackles (rales): fluid in alveoli; inspiratory or throughout.
    • Stridor: high-pitched inspiratory sound; airway obstruction.
    • Stertor: snoring-like; mouth breathing due to congestion.
  • Oxygenation assessment:
    • Arterial blood gas (ABG) provides direct measures of PaO2, PaCO2, pH, etc. but is invasive.
    • Pulse oximetry (SpO2) noninvasive; estimates arterial oxygen saturation; not a replacement for full respiratory assessment.
  • Hypoxia indicators: pallor, cyanosis, restlessness, confusion, dizziness, fatigue, tachycardia, tachypnea, BP changes; cyanosis best seen in tongue/oral mucosa.
  • Nursing diagnoses related to respiration: Impaired Gas Exchange; Ineffective Breathing Patterns; other related diagnoses as appropriate.
  • Practical notes:
    • If patient’s tachypnea is present with high effort, assess for underlying causes (pain, fever, hypoxia, pulmonary disease, anemia, altitude, medications).
    • When counting respirations, observe without the patient noticing to avoid altered breathing.

Arterial oxygen saturation (SpO2)

  • SpO2 via pulse oximetry estimates arterial oxygen saturation; noninvasive, quick.
  • ABG provides comprehensive arterial gas data but is invasive.
  • Cautions:
    • Readings can be affected by poor perfusion, nail polish, skin pigmentation, motion, ambient light, and device calibration.
    • Do not rely solely on SpO2; correlate with clinical assessment and other vital signs.
  • Use in routine monitoring and to track trends; educate patients on home monitoring when appropriate.

Blood Pressure (BP)

  • BP definition: the pressure of blood against arterial walls during cardiac cycle.
  • Systolic pressure (SBP): peak pressure during ventricular contraction; diastolic pressure (DBP): minimum pressure during ventricular relaxation.
  • BP is recorded as SBP/DBP in mm Hg (e.g., 120/80 mm Hg).
  • Pulse pressure: difference between SBP and DBP; PP = SBP − DBP. Example: 120/80 → PP = 40 mm Hg; normal PP should be no greater than about one-third of SBP (rule of thirds).
  • Cardiac output (CO) and BP:
    • CO = SV × HR; increased CO raises BP; decreased CO reduces BP (assuming other factors constant).
  • BP regulation factors: cardiac function, peripheral vascular resistance, blood volume.
  • Normal BP classifications (2017 ACC/AHA guidelines):
    • Normal: SBP < 120 and DBP < 80
    • Elevated: SBP 120–129 and DBP < 80
    • Stage 1 Hypertension: SBP 130–139 or DBP 80–89
    • Stage 2 Hypertension: SBP ≥ 140 or DBP ≥ 90
    • Hypertensive crisis: SBP > 180 or DBP > 120
  • Factors influencing BP (overview):
    • Developmental stage; sex; family history; lifestyle (sodium intake, smoking, alcohol, obesity, exercise); diurnal variation (BP lower at night; rises during the day);
    • Medications; diseases affecting circulatory system or kidneys; race; genetics; body position; pain; stress; caffeine effects; altitude.
  • Direct vs indirect BP measurement:
    • Direct (invasive): arterial line; continuous waveform monitoring; highly accurate; used in critical care or surgery.
    • Indirect (noninvasive): most common; auscultation with sphygmomanometer or electronic BP monitor.
  • Equipment for BP measurement:
    • Stethoscope (bell for low-frequency sounds; diaphragm for high-frequency sounds), with either single or double lumen.
    • Sphygmomanometer: cuff with bladder, bulb, and manometer; cuffs sized by site/arm.
    • Electronic BP monitors: automatic; may be less accurate than auscultatory method; require baseline auscultation initially.
  • Cuff sizing and accuracy:
    • Proper cuff width: about two-thirds of arm length; bladder encircles ~80% of arm circumference.
    • Inaccurate cuff size can introduce up to ~30 mm Hg error: too small yields readings that are too high; too large yields readings too low.
    • If the correct size is unavailable, choose the next larger size and document cuff size.
  • Korotkoff sounds (BP auscultation):
    • First sound: systolic pressure.
    • Second sound: turbulent flow; diastolic after the sounds disappear.
    • Third sound: rhythmic tapping; Fourth sound: muffled; Fifth sound: diastolic pressure (silence).
  • Auscultatory gap: possible loss of sounds during deflation, followed by reappearance; risk of underestimating SBP if not detected.
  • Palpation method for BP: can estimate SBP when auscultation is difficult; typically cannot determine DBP by palpation.
  • BP measurement steps (high-level):
    • Position patient seated with feet uncrossed and flat on the floor; arm supported at heart level; proper cuff size; ensure inactivity for ~5 minutes.
    • Inflate cuff to ~20–30 mm Hg above point where pulse is lost; deflate slowly; record first and last sounds (SBP/DBP).
    • Re-measure after at least 2 minutes; consider multiple readings to establish pattern and trend.
  • Pulse site considerations for BP:
    • Brachial artery is common; avoid reading on arms with IVs, fistulas, injuries, or recent breast/shoulder surgery; alternate sites may be forearm, thigh, or calf (note: SBP may be higher in legs; DBP similar).
  • BP self-monitoring and home care:
    • Home BP monitors offer pattern recognition and can distinguish white-coat hypertension from true hypertension.
    • Teach proper cuff placement, technique, and interpretation; maintain a baseline with clinician; document patterns, times, and dates.
    • Calibration and device maintenance are important; bring devices for clinic comparison.
  • Practical tips and clinical judgment:
    • When unsure about readings or technique, validate with provider; consider multiple measurements and patient factors (activity, position, meds, pain).
    • The BP assessment should be interpreted in the broader clinical context, not in isolation.

Related concepts and practical integration

  • Continuous monitoring and smart beds: under-the-mattress sensors can monitor respiratory and heart rates; alerts aid early detection of deterioration; still, BP and temperature must be reassessed by clinician.
  • Documentation: document all VS, associated symptoms, and interventions; use standardized flowsheets and nurses’ notes for abnormal readings.
  • Delegation: UAPs may take VS in some settings; the RN remains responsible for interpretation, trend analysis, and complex decisions.
  • ThinkLike a Nurse prompts: clinical judgment in action scenarios for fever, hypotension, hypertension, and respiratory distress; assess pattern changes and need for provider notification.

Highlights of procedures (summary references)

  • Procedure 18-1: Assessing Body Temperature
    • Select site, prepare thermometer, use patient-specific probe, insert properly, wait for reading, avoid cross-contamination.
  • Procedure 18-2: Assessing Peripheral Pulses
    • Ensure patient is resting; count 15–30s for regular, 60s for irregular; record rate, rhythm, quality; compare bilaterally.
  • Procedure 18-3: Assessing the Apical Pulse
    • Position patient; locate apex at 5th intercostal space midclavicular line; count 60s; assess S1/S2.
  • Procedure 18-4: Assessing for Apical-Radial Pulse Deficit
    • Simultaneously compare apical and radial pulses; report deficits.
  • Procedure 18-5: Assessing Respirations
    • Count respirations for 60s if irregular; observe rate, rhythm, depth; assess effort and sounds.
  • Procedure 18-6: Measuring Blood Pressure
    • Patient position, cuff size, inflation/deflation rates, Korotkoff sounds, and recording SBP/DBP; wait between readings.

Quick reference: key formulas and numbers (LaTeX)

  • Cardiac output: CO = SV imes HR
  • Pulse pressure: PP = SBP - DBP
  • Temperature conversions:
    • Fahrenheit to Celsius: C = \frac{5}{9} \,(F - 32)
    • Celsius to Fahrenheit: F = \frac{9}{5}C + 32
  • Blood pressure categories (adult):
    • Normal: SBP < 120 and DBP < 80
    • Elevated: 120 ≤ SBP ≤ 129 and DBP < 80
    • Stage 1 Hypertension: 130 ≤ SBP ≤ 139 or 80 ≤ DBP ≤ 89
    • Stage 2 Hypertension: SBP ≥ 140 or DBP ≥ 90
    • Hypertensive crisis: SBP > 180 or DBP > 120
  • Normal ranges (adult):
    • Temperature: approximately 36.7–37.0 °C (98.0–98.6 °F) for oral; core temps higher by ~0.6–1.2 °C depending on site
    • Pulse: 60–100 bpm; average ~70–80 bpm
    • Respirations: 12–20 breaths/min
    • BP: <120/80 mm Hg

Practical teaching points for patients (Hypertension)

  • Encourage lifestyle modifications: weight management, reduced sodium intake, regular physical activity, moderate alcohol, smoking cessation, and stress management.
  • Teach proper home BP monitoring: cuff size, placement, resting baseline measurements, trend analysis, and when to seek care.
  • Discuss potential medications and the importance of adherence, monitoring for side effects, and follow-up.
  • Address disparities and higher risk in certain populations; consider family history and genetics as risk factors.

Think about the context (clinical scenarios)

  • Interpreting fever in children (e.g., a 2-year-old with 101.8°F axillary temperature) requires understanding age-based baselines, hydration status, and the need for parental guidance.
  • In older adults with irregular pulses, assess for atrial fibrillation or other arrhythmias; verify with apical pulse when needed and consider ECG referral.
  • A BP of 150/98 mm Hg in a 35-year-old reports stress; determine pattern with multiple readings, lifestyle factors, and possible secondary causes.
  • Temperature, pulse, respiration, and BP must be interpreted together with the overall clinical picture, including activity, medications, and comorbidities.

Final notes for exam readiness

  • Master the definitions: fever vs hyperthermia, hypoxia, hypoventilation, hyperventilation, hypotension, hypertension (essential vs secondary).
  • Be fluent in measurement techniques, appropriate site selection, cuff sizing, and step-by-step procedures.
  • Know the significance of baseline data, trend interpretation, and how to respond to abnormal findings in collaboration with the primary care provider.
  • Practice converting temperatures, calculating CO and PP, and describing patterns of vital signs across age groups.
  • Review the ThinkLike a Nurse case prompts to apply knowledge to real-world assessment and decision-making.