Vital Signs and Monitoring Devices

• Vital signs and monitoring devices are essential for assessing a patient's condition and guiding medical decisions.

• Understanding and interpreting vital signs is closely connected to primary and secondary assessment, effective communication and documentation, and the management of specific emergencies such as diabetic emergencies and altered mental status.

• Chapters on primary assessment, secondary assessment, communication and documentation, and diabetic emergencies provide further context and detail for the use and importance of vital signs and monitoring devices.

Standard

• Effective emergency management relies on integrating information from the scene and patient assessments, including scene size-up, primary and secondary assessments, patient history, and ongoing reassessment.

• Scene size-up involves evaluating the environment for safety, identifying hazards, and determining the mechanism of injury or nature of illness.

• Primary assessment focuses on identifying and managing immediate life threats by assessing airway, breathing, circulation, and level of consciousness.

• Secondary assessment gathers more detailed information through physical examination and focused history to identify additional problems.

• Patient history provides context about the patient’s medical background, current complaints, and events leading up to the emergency.

• Reassessment ensures that any changes in the patient’s condition are detected promptly, allowing for adjustments in emergency management as needed.

Core Concepts

• Vital signs include pulse, respirations, blood pressure, skin condition, temperature, and pupil response. You assess these by checking heart rate, breathing rate, measuring blood pressure, observing skin color and moisture, taking temperature, and examining pupil size and reactivity.

• Documentation of vital signs is essential on a prehospital care report. You must record each measurement accurately, noting the time and any changes or trends.

• Various monitoring devices are used to obtain vital signs. These include blood pressure cuffs, pulse oximeters, thermometers, and devices for monitoring heart rate and respiratory rate. Proper use of these devices ensures reliable and consistent measurements.

Learning Objectives

• Vital signs are essential for assessing a patient's overall condition, as they provide key information about physiological status and help determine the urgency of care.

• Each vital sign reflects specific physiological processes: temperature indicates metabolic activity, pulse reflects heart rate and rhythm, respiration shows breathing effectiveness, and blood pressure measures circulatory status.

• Abnormal vital signs can result from various causes, such as illness, injury, stress, or environmental factors, and recognizing these helps identify underlying problems.

• Assessment of circulation in children requires modifications, such as checking capillary refill and using age-appropriate techniques, since their vital sign norms differ from adults.

• Infants and children have different normal ranges for vital signs compared to adults, with generally higher heart and respiratory rates and lower blood pressure.

• Proper techniques are necessary for accurate vital sign measurement, including correct placement of equipment and patient positioning.

• Vital signs should be integrated with other assessment findings to prioritize patient care and refine clinical decisions.

• Certain characteristics, such as patient movement, improper equipment use, or environmental factors, can cause difficulty or false readings when measuring vital signs.

• Blood pressure can be measured by auscultation, palpation, or automatic monitors, each with its own advantages and limitations.

• Monitoring devices provide additional information for patient assessment, especially in patients with specific conditions or when continuous monitoring is needed.

• Pulse oximetry is used to interpret oxygen saturation levels, and recognizing normal and abnormal values is crucial for patient care.

• Normal blood glucose levels should be recognized, and deviations may indicate metabolic or endocrine issues.

• Situations such as poor perfusion, movement, or equipment malfunction can lead to inaccurate readings with monitoring devices, so awareness of these factors is important for reliable assessment.

Key Terms

• Vital signs are key measurable indicators of a patient's condition, including pulse, blood pressure, and respirations.

• Pulse can be assessed at various sites such as the brachial, carotid, and radial arteries, and is characterized by rate, quality, and rhythm.

• Blood pressure is measured using a sphygmomanometer or blood pressure monitor, and includes systolic and diastolic values.

• Respiratory assessment involves evaluating respiratory rate, quality, and rhythm, as well as using tools like capnography (measuring end-tidal , or ETCO) and pulse oximetry (measuring oxygen saturation, ).

• Pupil reactivity and other signs such as bradycardia (slow heart rate) or tachycardia (fast heart rate) provide additional information about the patient's status.

• Vital signs should be measured early and repeated frequently to monitor changes in the patient's condition and guide further assessment and treatment.

Gathering the Vital Signs

• The chief complaint is the most important part of patient assessment, as it identifies the main reason the patient sought EMS help and is usually described by the patient.

• Obvious assessment findings include age, sex, and general alertness, which can typically be determined immediately upon seeing and talking to the patient.

• Vital signs are essential components of assessment but require a few minutes to obtain and are gathered for nearly every EMS patient, except in rare cases where immediate life threats take priority.

• Initial and ongoing measurement of vital signs is crucial for detecting important conditions or trends that may influence treatment decisions or the need for hospital transport.

• Vital signs are collected after the primary assessment, which addresses immediate life threats, and are part of the more detailed secondary assessment.

Vital Signs

• Vital signs are key indicators of internal body status, including pulse, respiration, skin color, temperature, condition (and capillary refill in infants/children), pupils, and blood pressure.

• Oxygen saturation and capnography (ETCO2 measurement) are often included in patient assessments, providing additional information about respiratory and metabolic status, even though oxygen saturation is not technically a vital sign.

• Baseline vital signs are the initial measurements you take, and repeating these measurements allows you to identify trends and changes in the patient’s condition over time.

• Mental status assessment is crucial and should be performed with every set of vital signs, as changes in mental status can indicate serious underlying issues such as hypoxia, hypoglycemia, or sepsis.

• Accurate documentation of all vital signs and the time they were taken is essential for effective patient care and communication among healthcare providers.

Pulse

• The heart pumps blood in rhythmic waves, creating a pulse that can be felt where arteries are close to the skin and over a bone.

• Pulse assessment involves two main factors: rate (beats per minute) and quality (strength and regularity).

• Normal resting pulse rates vary by age: adults and adolescents (11–18 years) have 60–100 bpm, school-age children (6–10 years) 65–120 bpm, preschoolers 70–120 bpm, toddlers (1–3 years) 80–140 bpm, infants (0–12 months) 90–160 bpm, and newborns 100–170 bpm.

• Pulse quality provides important clinical information: a rapid, regular, and full pulse may indicate exertion, fright, fever, high blood pressure, or early blood loss; a rapid, regular, and thready pulse suggests shock or late-stage blood loss; an irregular pulse points to abnormal heart electrical activity; a slow pulse can be due to head injury, drugs, poisons, heart problems, or lack of oxygen in children; absence of a pulse indicates cardiac arrest.

• Pulse rates are influenced by factors such as age, fitness, recent exercise, medications, blood loss, stress, and body temperature.

• Tachycardia is a pulse rate above 100 bpm; bradycardia is below 60 bpm. Well-conditioned athletes may have resting rates as low as 40–50 bpm, which is normal for them but may be concerning in others.

• Persistent pulse rates above 120 bpm or below 50 bpm, or rates higher than 150 bpm, are signs of possible serious medical conditions and require prompt medical attention.

• To measure pulse rate, count beats for 30 seconds and multiply by 2 to get beats per minute.

Chapter 13 Visual Guide

• The six vital signs you need to assess are pulse, blood pressure, skin, respirations, pupils, and pulse oximetry.

• Pulse assessment includes checking for presence, strength, and regularity.

• Blood pressure is measured as systolic and diastolic values; palpation can be used to obtain the systolic pressure only.

• Skin evaluation involves observing color, temperature, and condition.

• Respirations are assessed for rate, quality, and effort.

• Pupil assessment includes checking size, equality, and reactivity to light.

• Pulse oximetry measures the oxygen saturation level in the blood.

Think Like an EMT

• Obtaining accurate vital signs is essential for effective patient assessment and decision-making in EMS situations.

• If a patient is too talkative to count respiratory rate, you should observe their breathing discreetly when they pause between talking, or ask them to remain quiet for a short period to allow for an accurate count.

• For a patient with a dialysis shunt who cannot have a blood pressure cuff on one arm, you must use the other arm, even if access is difficult; reposition yourself or the patient as needed to avoid compromising the shunt.

• If you cannot find a pulse at the wrist of an unconscious trauma patient, check for a pulse at a more central location, such as the carotid artery in the neck, as peripheral pulses may be absent due to shock or injury.

Pediatric Note

• A low pulse in infants or children is more concerning than a high pulse, as it may indicate hypoxia and risk of cardiac arrest.

• Pulse quality is determined by rhythm and force: rhythm refers to the regularity of beats (regular vs. irregular), and force refers to the strength of the pulse wave (strong/full vs. weak/thready).

• Irregular pulse rhythms should always be reported and documented.

• Pulse rate and quality can be assessed at different sites: use the radial pulse (wrist) for patients 1 year and older, the brachial pulse (upper arm) for infants under 1 year, and the carotid pulse (neck) if other sites are not accessible.

• When palpating the carotid pulse, avoid excessive pressure and never check both sides simultaneously, as this can slow the heart, especially in older patients.

• To measure the radial pulse, use your first three fingers (not your thumb) on the thumb side of the wrist, apply moderate pressure, and count beats for 30 seconds (multiply by 2 for beats per minute). If the pulse is abnormal, count for a full 60 seconds.

• While counting the pulse, assess both rhythm and force, and record findings with the time (e.g., "Pulse 72, strong and regular").

• Some patients with ventricular assist devices may have no palpable pulse or measurable blood pressure, even if they are awake and alert, due to continuous blood flow from the device.

• Vital signs, including pulse characteristics, should be documented accurately on prehospital care reports.

Respiration

• Respiration consists of inhalation (breathing in) and exhalation (breathing out), and is assessed by rate and quality.

• Respiratory rate is the number of breaths per minute, with normal adult rates at rest between 12–20 breaths/minute. Rates above 24 or below 10 in adults are considered serious. Rates vary by age: adolescents (12–20), school-age children (18–30), preschoolers (22–34), toddlers (24–40), infants (30–60 for 0–6 months, 24–30 for 6–12 months), and newborns (30–60; over 60 is tachypnea).

• Respiratory quality is categorized as normal, shallow, labored, or noisy. Normal breathing shows average chest/abdomen movement without use of accessory muscles. Shallow breathing involves slight movement and is especially serious in unconscious patients. Labored breathing includes increased effort, use of accessory muscles, nasal flaring, retractions, stridor, grunting, or gasping. Noisy breathing indicates obstruction and includes sounds like stridor, snoring, wheezing, gurgling, and crowing.

• Specific respiratory sounds indicate different problems and interventions: snoring (blocked airway, open airway and transport), wheezing (asthma, assist with medication and transport), gurgling (fluids in airway, suction and transport), crowing (serious medical problem, prompt transport).

• Respiratory rhythm is usually not significant in conscious patients due to variability, but irregular rhythm in unconscious patients should be reported and documented.

• To measure respiratory rate, count breaths for 30 seconds and multiply by 2. Observe rate, quality, and rhythm discreetly to avoid influencing the patient’s breathing, and record findings with the time of assessment.

Skin

• Skin color, temperature, and condition are important indicators of a patient’s circulation and overall health. Blood vessels in the skin constrict during blood loss or poor circulation, making the skin pale.

• Key assessment sites for skin color include nail beds, inside of the cheek, and lower eyelids in adults; palms and soles in children; lips and nail beds in patients with dark skin. These areas reflect changes in blood flow and oxygenation quickly.

• Normal skin color is pink. Abnormal colors and their significance:

  • Pale: Indicates constricted blood vessels, often from blood loss, shock, hypotension, or emotional distress.

  • Cyanotic (blue–gray): Suggests lack of oxygen in blood cells/tissues due to inadequate breathing or heart function.

  • Flushed (red): May result from heat exposure or emotional excitement.

  • Jaundiced (yellow): Indicates liver abnormalities.

  • Mottled (blotchy): Sometimes seen in shock, especially in children and older adults.

• Skin temperature and condition provide further diagnostic clues. Use the back of your hand to assess temperature, typically on the forehead or abdomen.

• Temperature and condition findings and their significance:

  • Cool, clammy: Sign of shock or anxiety.

  • Cold, moist: Indicates body is losing heat.

  • Cold, dry: Suggests exposure to cold.

  • Hot, dry or hot, moist: Associated with high fever or heat exposure.

  • Goose pimples with shivering, chattering teeth, blue lips, and pale skin: Associated with chills, communicable disease, cold exposure, pain, or fear.

• Differences in temperature between body parts (e.g., warm trunk, cold limb) can indicate localized circulation problems.

Pediatric Note

• Capillary refill is used to assess circulation in infants and children under 6 years old by pressing on the nail bed or top of the hand or foot and observing how quickly the pink color returns.

• Normal capillary refill time is 2 seconds or less; if it takes longer, this suggests poor blood circulation.

• Prolonged or absent capillary refill indicates abnormal circulation, but this test is not reliable if the child has been exposed to cold temperatures.

Pupils

• The pupil changes size in response to light: In dim environments, your pupil dilates (gets larger) to let in more light; in bright environments, it constricts (gets smaller) to reduce light entry.

• Assessment of pupils involves checking size, equality, and reactivity: Normally, both pupils are midpoint in size, equal, and constrict equally when exposed to light.

• Testing procedure: Observe the initial size, then shine a light into one eye (while covering the other) to check for constriction; repeat for the other eye. Light in one eye usually affects both pupils.

• Abnormal pupil findings can indicate medical issues:

  • Dilated pupils may result from fright, blood loss, certain drugs, or prescription eye drops.

  • Constricted pupils can be caused by narcotics or prescription eye drops.

  • Unequal pupils may signal stroke, head or eye injury, artificial eye, or use of prescription eye drops.

  • Nonreactive (fixed) pupils may indicate drug use or lack of oxygen to the brain.

• Any deviation from normal pupil size, equality, or reactivity should be reported and documented, as these may indicate serious underlying conditions.

Point of View: Patient

• EMTs can appear intimidating when they arrive, especially in emergency situations, due to their urgent actions and medical procedures.

• Patients may feel disoriented or unable to respond to questions immediately after an injury, particularly with head trauma.

• EMTs assess patients for "altered mental status," which refers to changes in awareness, responsiveness, or behavior following an injury.

• Checking pupil response with a flashlight is a standard procedure to evaluate neurological function and detect possible brain injury.

• Clear communication and reassurance from EMTs can help patients feel more in control and less anxious as their condition stabilizes.

Blood Pressure

• Blood pressure is the force of blood against vessel walls, measured as systolic (pressure during heart contraction) and diastolic (pressure during heart relaxation); it is reported as systolic over diastolic, e.g., 120/80 mmHg.

• Pulse pressure is the difference between systolic and diastolic pressures (); it should be at least 25% of the systolic pressure, and a narrowed pulse pressure (less than 25%) may indicate shock, especially with other signs like tachycardia or injury.

• Normal adult blood pressure is ≤120/80 mmHg; hypertension is defined as systolic ≥140 mmHg or diastolic ≥90 mmHg, while prehypertension is systolic 121–139 mmHg or diastolic 81–89 mmHg.

• Blood pressure ranges vary by age: adolescents (107–117 mmHg systolic), ages 1–10 years (mean systolic = ), infants (about 90 mmHg), at birth (50–70 mmHg).

• High blood pressure can result from medical conditions, exertion, emotional distress, or excitement; low blood pressure may be normal for athletes, but can also indicate blood loss or late-stage shock.

• Blood pressure should be measured multiple times to assess trends, as single readings may be affected by temporary factors like stress; a drop in blood pressure can signal developing shock.

• Blood pressure is measured using a sphygmomanometer (cuff and gauge) with three main techniques: auscultation (listening with a stethoscope), palpation (feeling for pulse), and automated blood pressure monitors.

• Auscultation is the standard method: inflate the cuff, listen for the first pulse sound (systolic pressure), and note when sounds fade or disappear (diastolic pressure); record measurements in even numbers and repeat if uncertain.

• Palpation determines only the systolic pressure by noting when the radial pulse returns as the cuff is deflated; record as “systolic/P.”

• Automated monitors can provide systolic, diastolic, and mean arterial pressure (MAP); MAP below 60–65 mmHg indicates shock.

• Proper cuff placement is essential: use the arm opposite any mastectomy, dialysis graft, or IV site, and ensure the cuff covers two-thirds of the upper arm with no clothing underneath.

• Blood pressure readings may be inaccurate if the cuff is too tight, placed incorrectly, or if the patient’s heartbeat is irregular; deflate the cuff slowly and listen carefully for accurate results.

• Age is a key factor in normal vital sign ranges; infants and children have lower blood pressure and faster pulse/respiratory rates than adults.* Vital signs must be taken repeatedly; the frequency depends on the patient's condition and any interventions performed.

• Stable patients require vital signs every 15 minutes, while unstable patients require them every 5 minutes.

• Vital signs should also be reassessed after every medical intervention to monitor changes and effectiveness.

• All vital sign readings must be recorded immediately, as relying on memory can lead to errors.

• Automated devices (like blood pressure monitors) should be used according to manufacturer’s instructions and local protocols.

• Vital signs include pulse (rate, strength, regularity), respirations (rate), blood pressure, pupil response (equality, reactivity, size), and skin assessment (color, temperature, condition).

• Examples of documentation: Pulse 88 (strong, regular), respirations 28, blood pressure 132/84, pupils equal and reactive, skin pale, cool, and moist.

Pediatric Note

• Blood pressure should be measured on all patients older than 3 years.

• Accurate blood pressure readings are challenging and less relevant for infants and children under 3 years old.

• For infants and very young children, assessment should focus on observable signs such as overall appearance, respiratory distress, and level of consciousness.

• Always adhere to local protocols when assessing vital signs in children.

SCAN 13-1

• Body temperature is tightly regulated to support essential chemical reactions and organ function, with core temperature (not skin temperature) being the most relevant measurement.

• Abnormal temperatures can indicate medical issues such as hypothermia (low temperature), hyperthermia (high temperature), fever (febrile state), or generalized infection (sepsis).

• Temperature screening is important for detecting infectious diseases like influenza, as fever is a key symptom and EMS data can help identify outbreaks.

• Core temperature is best measured orally or rectally, but in the field, oral and axillary (armpit) measurements are most practical; rectal temperatures are rarely used by EMTs.

• Electronic thermometers are preferred over glass thermometers in emergency settings because they are safer, faster, and more hygienic, using disposable covers to prevent contamination.

• Tympanic (ear) and forehead thermometers are not reliable enough for EMS use due to significant margins of error and frequent misclassification of patient temperatures.

• Normal body temperature varies by individual, time of day, activity, age, and measurement site; it is not always exactly 98.6°F (37°C).

• Rectal temperatures are about 1°F higher than oral, and axillary temperatures are about 1°F lower than oral.

• A healthy temperature range is generally between 96.8°F (36°C) and 101.3°F (38.5°C), but some healthy individuals may fall outside the traditional “normal” range.

Monitoring Devices

• Pulse oximeters measure the oxygen saturation () in blood using light sensors on a finger or earlobe, providing a percentage value that reflects the proportion of oxygenated hemoglobin.

• CO-oximeters use different wavelengths to detect both oxygen and carbon monoxide levels in the blood, which is important for identifying carbon monoxide poisoning.

• Pulse oximetry is used to assess hypoxia, monitor pulse rate, and evaluate the effectiveness of interventions like artificial respirations, oxygen therapy, and bronchodilator treatments.

• Normal oxygen saturation () is 96–100%; 91–95% may indicate mild hypoxia, 86–90% moderate hypoxia, and 85% or less severe hypoxia.

• Oxygen administration for acute coronary syndrome is recommended only if is below 90%, and decisions should combine clinical judgment with oximetry readings.

• Patients with respiratory distress, abnormal lung sounds, accessory muscle use, heart failure, cyanosis, or shock may require oxygen even if saturation readings are normal; reassessment is necessary to adjust oxygen levels.

• Pulse oximetry readings can be inaccurate in patients with shock, hypothermia, dark skin pigmentation, carbon monoxide poisoning, excessive movement, certain nail polishes or artificial nails, anemia, and hypovolemia.

• Chronic smokers may have falsely high readings due to carbon monoxide binding to hemoglobin, which the device misinterprets as oxygen saturation.

• Device accuracy depends on proper maintenance, including clean probes and good battery condition; readings should be checked regularly and the probe cleaned between patients.

• Pulse oximetry is useful for monitoring changes in oxygen saturation after interventions, but should not be the sole indicator—clinical assessment remains essential.

• To determine oxygen saturation: connect the sensor, turn on the device, verify the displayed heart rate matches the palpated pulse, reposition the sensor if needed, and check readings every 5 minutes during vital sign assessments.

Blood Glucose Meters

• Portable blood glucose meters have improved diabetes management by allowing easy, accurate, and frequent monitoring of blood glucose levels, both for patients and EMS providers.

• Frequent self-monitoring helps patients adjust insulin and diet to keep blood glucose as close to normal as possible, reducing the risk of complications like heart disease, blindness, and kidney failure.

• Continuous glucose monitoring devices can transmit real-time blood glucose data to smartphones, alerting patients and caregivers to hypo- or hyperglycemia and providing trends and historical data.

• EMS providers may use patient device readings if the device is reliable and properly maintained, but can verify with their own meter if needed; sensors for continuous monitors are typically replaced every 10 days.

• Blood glucose meters work by analyzing a drop of blood (usually from a finger stick) placed on a test strip, with results displayed in mg/dL in the U.S.; other units may be used internationally.

• EMTs must follow local protocols and manufacturer guidelines for using ambulance blood glucose meters, ensuring proper calibration and storage for accurate readings.

• General steps for using a blood glucose meter include preparing the device, cleansing the finger, performing a finger stick, wiping the first drop, collecting a second drop, applying it to the test strip, and reading the result within seconds.

SCAN 13-2

• Normal blood glucose levels typically range from 70–110 mg/dL, but you should always follow the specific instructions provided by the device manufacturer and local protocols.

• Proper training and familiarity with the blood glucose meter are essential for accurate readings; improper use is a common cause of inaccurate results.

• Regular calibration and scheduled testing of the device are necessary to maintain accuracy and reliability in blood glucose measurements.

• Blood glucose monitoring is only one part of patient assessment and should not replace a thorough primary assessment of the patient.

• In some settings, blood glucose measurements may be recommended during transport to the hospital rather than at the scene.

Capnography

• Pulse oximetry measures blood oxygen levels but does not assess tissue oxygen utilization; capnography indirectly evaluates tissue oxygen use by measuring exhaled carbon dioxide (CO2), specifically end-tidal carbon dioxide (ETCO2).

• Capnography provides both a numerical value and a graphical waveform (capnogram) of exhaled CO2 over time, while capnometry only gives the number; capnography is generally preferred for its detailed information.

• The capnogram displays distinct phases of the respiratory cycle:

  • Baseline (Phase 0): Indicates no CO2 during inhalation.

  • Phase I: Rapid rise in CO2 as dead space air is expelled.

  • Phase II: Steady increase as alveolar CO2 mixes with dead space air.

  • Phase III: Plateau showing peak CO2 concentration (end-tidal CO2), followed by a return to baseline as inhalation begins.

• Normal ETCO2 values range from 35 to 45 mmHg in healthy individuals, but can vary with age and respiratory rate.

• Capnography sensors are placed near the patient’s airway, such as on a nasal cannula or endotracheal tube, to continuously monitor exhaled CO2 and ensure proper airway placement.

• Abnormal capnogram waveforms and ETCO2 levels can indicate clinical issues:

  • Changes in ventilation (e.g., hypoventilation, hyperventilation) alter ETCO2 levels.

  • Airway obstructions (asthma, COPD) may cause increased CO2 and a “shark fin” waveform.

  • Respiratory distress or failure can lead to elevated ETCO2 due to poor gas exchange.

  • During CPR, rising ETCO2 may signal effective compressions or return of spontaneous circulation (ROSC).

• Interpretation of ETCO2 and capnogram waveforms provides critical information about ventilation, airway status, and overall patient condition.