Vital signs

Health Promotion

Section: Health Assessment/Data Collection

Vital Signs Overview

  • Vital signs are key measurements of the body's basic functions, essential for assessing health. They include:

    • Temperature

    • Pulse

    • Respiration

    • Blood Pressure (BP)

    • Pain Level & Oxygen Saturation (in some facilities)

Temperature

  • Reflects the balance between heat produced by the body and heat lost to the environment.

  • Measures core and surface temperatures.

Core Temperature Measurement Sites:

  • Rectum

  • Tympanic membrane

  • Temporal artery

  • Pulmonary artery

  • Esophagus

  • Urinary bladder

Surface Temperature Measurement Sites:

  • Skin

  • Mouth

  • Axillae

Factors Affecting Temperature Regulation

  • Regulated by neurological and cardiovascular systems; trauma or disease in hypothalamus/spinal cord can alter control.

  • Heat Production:

    • Increases in metabolic rate, muscle activity, hormones, and sympathetic stimulation.

  • Heat Loss Methods:

    • Conduction: Direct transfer to another surface (e.g., cold water).

    • Convection: Heat dispersion via air currents.

    • Evaporation: Heat loss via perspiration.

    • Radiation: Heat transfer without contact (e.g., from body to cold room).

Expected Temperature Ranges

  • Oral Temperature: 36° to 38° C (96.8° to 100.4° F), average 37° C (98.6° F).

  • Rectal Temperature: ~0.5° C (0.9° F) higher than oral.

  • Axillary Temperature: ~0.5° C (0.9° F) lower than oral.

  • Temporal Temperature: Close to rectal but ~1° F higher than axillary.

Age-Related Temperature Considerations

  • Newborns: Temperature range is 35.5° to 37.5° C (95.9° to 99.5° F).

  • Older Adults: Average body temperature is 35° to 36.1° C (95° to 97° F) with increased susceptibility to temperature extremes.

  • Hormonal Factors: Women may experience temperature fluctuations related to hormonal cycles.

Nursing Interventions for Temperature

Equipment:

  • Electronic thermometers with proper probe covers; disposable thermometers to prevent cross-infection.

  • Oral Measurement Procedure:

    • Place probe under the tongue.

    • Avoid after recent food/drink intake; wait 20-30 minutes.

  • Rectal Measurement Procedure:

    • More accurate than axillary. Require positioning and lubrication.

    • Not for clients with diarrhea, bleeding disorders, or infants <3 months.

  • Axillary Measurement Procedure:

    • Place thermometer in the center of a clean, dry axilla.

    • Lower the arm over probe.

  • Tympanic Measurement Procedure:

    • Pull ear for proper placement; note can be affected by earwax.

  • Temporal Measurement Procedure:

    • Clean lens and ensure proper alignment for accurate reading.

Fever and Hyperthermia

  • Fever is a response to infection/inflammation, stimulating immune response.

  • Hyperthermia is an abnormally elevated body temperature >40° C (104° F). Nursing actions include:

    • Monitor vitals and provide fluids/rest.

    • Antipyretics (avoid aspirin in children with viral illness).

Hypothermia

  • Body temperature <35° C (95° F). Nursing actions involve keeping the environment warm, providing heated fluids, and continuous monitoring.

Pulse and Heart Rate

Physiological Responses

  • Heart rate controlled by autonomic nervous system; sympathetic increases heart rate, parasympathetic decreases it.

Expected Heart Rate Ranges

  • Adult: 60-100 beats/min at rest.

  • Pediatric rates vary with age; newborns range from 90-160 beats/min.

Assessment Techniques

  • Evaluate rate, rhythm, strength, and equality.

    • Use a scale of 0 to 4 for amplitude.

Nursing Interventions

  • Gather equipment (clock/stethoscope). Employ hand hygiene and establish a quiet environment for accurate assessment.

Complications

  • Tachycardia: Rate >100/min from various factors like exercise or anxiety.

  • Bradycardia: Rate <60/min from hypothermia or medications.

Respirations

Physiological Responses

  • Monitoring via chemoreceptors; rate increases with CO2 buildup, especially in COPD patients.

Expected Respiratory Ranges

  • Adult: 12-20 breaths/min.

  • Newborns: 30-60 breaths/min.

Assessment Techniques

  • Observe rate, rhythm, and depth without informing the client to avoid altered patterns.

Nursing Interventions

  • Position client appropriately for assessment (semi-Fowler's preferred).

Complications

  • Bradypnea: <12 breaths/min.

  • Tachypnea: >20 breaths/min.

Pulse Oximetry

Overview

  • Measures oxygen saturation (SaO2) in arterial blood, expected range is 95%-100%.

Nursing Interventions for Measurement

  • Correct site selection for the pulse oximeter and ensure no external obstructions (e.g., nail polish).

Blood Pressure

Physiological Responses

  • Determined by cardiac output and systemic vascular resistance.

Blood Pressure Classifications (AHA Guidelines)

Classification

Systolic BP

Diastolic BP

Normal

< 120

< 80

Elevated

120-129

< 80

Stage 1 HTN

130-139

80-89

Stage 2 HTN

≥ 140

≥ 90

Hypotension

< 90 (SBP)


Nursing Interventions for BP Measurement

  • Correct positioning and technique; avoid nicotine/caffeine prior.

  • Average multiple measurements for accuracy.

Complications

  • Orthostatic Hypotension: Symptoms of dizziness with positional changes.

  • Hypertension Management: Monitor for symptoms and encourage lifestyle changes.