Understanding Vital Signs

• Vital signs are measurements of the body's most basic functions
• Monitoring vital signs is an important part of patient assessment
• The four main vital signs routinely monitored by healthcare professionals are body temperature, pulse rate, respiration rate, and blood pressure
• Vital signs are also known as cardinal signs
• Accurate vital sign measurement provides essential data about the patient's physiological status
• Changes in vital signs can indicate a patient's condition is worsening
• Vital signs provide a baseline against which to compare future measurements
• The normal ranges for vital signs vary based on factors such as age, sex, weight, exercise tolerance, and overall health condition

Body Temperature

• Body temperature reflects the balance between heat production and heat loss in the body
• Normal body temperature ranges from 36.5°C to 37.5°C (97.7°F to 99.5°F)
• Body temperature can be measured orally, rectally, axillary (armpit), tympanically (ear), or temporally (forehead)
• Oral temperatures are easily accessible and comfortable for the patient, but eating, drinking, and smoking can affect the accuracy
• Rectal temperatures are considered the most accurate, but are invasive and less comfortable
• Axillary temperatures are non-invasive but less accurate than oral or rectal
• Tympanic temperatures are quick and easy to obtain, but technique is important for accuracy
• Temporal artery temperatures are non-invasive and can be very accurate, but can be affected by sweating
• Fever (pyrexia) is an elevated body temperature, usually above 38°C (100.4°F)
• Hypothermia is a decreased body temperature, usually below 35°C (95°F)
• Several factors can affect body temperature, including age, exercise, hormone levels, circadian rhythm, stress, and environmental temperature

Pulse Rate

• Pulse rate is the number of times the heart beats per minute (bpm)
• Normal pulse rate ranges vary by age, but for adults, it's typically between 60 and 100 bpm
• Tachycardia is a pulse rate above 100 bpm
• Bradycardia is a pulse rate below 60 bpm
• The pulse can be palpated (felt) at various locations on the body where an artery passes close to the surface, such as the radial, brachial, carotid, and femoral arteries
• The radial pulse (wrist) is the most common site for pulse assessment
• When assessing the pulse, note the rate, rhythm (regularity), strength (amplitude), and equality
• Factors that can affect pulse rate include age, exercise, medications, blood volume, stress, and body position

Respiration Rate

• Respiration rate is the number of breaths a person takes per minute
• Normal respiration rate for adults is typically between 12 and 20 breaths per minute
• Tachypnea is a respiration rate above 20 breaths per minute
• Bradypnea is a respiration rate below 12 breaths per minute
• Apnea is the absence of breathing
• Dyspnea is difficult or labored breathing
• When assessing respiration, note the rate, depth (shallow, normal, deep), and rhythm (regularity)
• Factors that can affect respiration rate include age, exercise, anxiety, pain, respiratory disorders, and body position

Blood Pressure

• Blood pressure is the force of blood pushing against the walls of the arteries
• Blood pressure is measured in millimeters of mercury (mmHg) and is recorded as two numbers: systolic pressure (the pressure when the heart beats) and diastolic pressure (the pressure when the heart rests between beats)
• Normal blood pressure for adults is typically around 120/80 mmHg
• Hypertension is high blood pressure, generally defined as a systolic pressure of 130 mmHg or higher, or a diastolic pressure of 80 mmHg or higher
• Hypotension is low blood pressure, generally defined as a systolic pressure below 90 mmHg or a diastolic pressure below 60 mmHg
• Blood pressure is measured using a sphygmomanometer and a stethoscope
• The cuff of the sphygmomanometer is placed around the upper arm and inflated to compress the artery
• As the cuff is slowly deflated, the healthcare provider listens for the Korotkoff sounds (the sounds of blood flow returning to the artery) with the stethoscope
• The first Korotkoff sound indicates the systolic pressure, and the last Korotkoff sound indicates the diastolic pressure
• Factors that can affect blood pressure include age, race, family history, weight, diet, exercise, stress, smoking, and certain medical conditions
• Orthostatic hypotension (postural hypotension) is a drop in blood pressure that occurs when a person stands up from a sitting or lying position

Pain Assessment

• Often considered the "fifth vital sign," pain is a subjective experience and an important indicator of a patient's condition
• Pain assessment involves asking the patient about the location, intensity, quality, and duration of their pain
• Pain scales, such as the numerical rating scale (0-10) or the visual analog scale, are used to quantify pain intensity
• Non-verbal cues, such as facial expressions, body posture, and guarding, can also indicate pain
• Assessing pain should be a routine part of vital sign assessment

Documentation

• Accurate documentation of vital signs is essential for effective patient care
• Record the date, time, and method of measurement for each vital sign
• Document any factors that may have affected the vital sign measurements, such as exercise, medications, or emotional state
• Report any significant changes or abnormalities in vital signs to the healthcare provider

Considerations for Specific Populations

• Pediatrics: Normal vital sign ranges vary significantly by age in children; use pediatric-specific charts for accurate interpretation
• Geriatrics: Older adults may have altered physiological responses and may not exhibit typical signs of illness, requiring careful assessment and consideration of baseline values

Importance of Accurate Measurement Techniques

• Proper technique is crucial for obtaining accurate vital sign measurements
• Using the wrong size blood pressure cuff can lead to inaccurate readings
• Ensure the patient is properly positioned when measuring blood pressure
• Allow the patient to rest for a few minutes before taking vital signs
• Avoid taking blood pressure on an arm with an IV or a history of mastectomy

Common Errors in Vital Sign Measurement

• Applying a blood pressure cuff that is too small or too large
• Reinflating the blood pressure cuff during measurement
• Failing to properly position the patient when measuring blood pressure
• Using a tympanic thermometer incorrectly
• Counting respirations for an insufficient amount of time
• Not documenting vital sign measurements accurately and completely

Interrelation of Vital Signs

• Vital signs are interrelated and must be considered collectively
• For example, a patient with a fever may also have an elevated pulse and respiration rate
• Changes in one vital sign may affect other vital signs