Vital Signs

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Vital Signs

Albert J. Heuer

Learning Objectives

After reading this chapter, you will be able to:

1. Identify the four classic vital signs and the value of monitoring their trends.

2. Recognize the clinical significance of other bedside clinical findings including abnormal sensorium and level of pain.

3. Describe the normal values of the following vital signs and common causes of deviation from normal in the adult:

a. Pulse rate

b. Respiratory rate

c. Blood pressure

d. Body temperature

4. Describe the following issues related to body temperature measurement:

a. Types of devices commonly used

b. Factors affecting the accuracy of devices

c. Common sites and temperature ranges of those sites for measurement

5. Describe how fever affects the following:

a. Oxygen consumption and carbon dioxide production

b. Respiratory rate

c. Pulse

6. Define the following terms:

a. Fever

b. Tachycardia

c. Bradycardia

d. Bradypnea

e. Pulsus paradoxus

f. Pulsus alternans

g. Tachypnea

h. Systolic blood pressure

i. Diastolic blood pressure

j. Hypertension

k. Hypotension

l. Pulse pressure

m. Postural hypotension

7. Describe the technique, common sites for palpation, and characteristics for evaluating the pulse.

8. Describe the techniques for determining respiratory rate and blood pressure.

9. Explain how hypotension affects perfusion and tissue oxygen delivery.

10. Identify the factors that cause erroneously elevated blood pressure measurements.

11. Describe the mechanism by which pulsus paradoxus is produced.

The previous two chapters focused on subjective data—those that are perceived by the patient. We now turn our attention to more objective data—those that can be measured. Although subjective data are important, objective data are factual information that is generally not influenced by patient opinion or feelings. Therefore, they are most often relied on to make important clinical decisions. This chapter focuses mainly on vital signs, the most frequently measured objective data for monitoring vital body functions and often the first and most important indicator that the patient’s condition is changing. Given that obtaining vital signs generally requires direct patient interaction, the respiratory therapist (RT) or other member of the patient care team should give proper consideration to the principles relating to preparing for the patient encounter, as outlined in Chapter 1.

Vital signs are used for the following purposes:

Obtaining Vital Signs and Clinical Impression

The four classic vital sign measurements are temperature, pulse, respirations, and blood pressure. Although they are not always listed as vital signs, the patient’s height and weight, level of consciousness and responsiveness (sensorium), level and type of pain, and the RT or other patient care team member’s general clinical impression are also important observations often included with the vital sign assessment.

Patients who have intravenous or arterial lines and traumatic or surgical wounds have catheter insertion sites, wounds, and extremity checks performed as part of “routine vitals.” In addition, pulse oximetry with continuous heart rate and electrocardiogram (ECG) is often monitored along with vital signs of patients in acute care settings.

It should be noted that the vital signs, like other clinical findings, are only as accurate as the clinician or caregiver obtaining them and interpreting the results. Thus, it is important to properly obtain and monitor vital signs to help optimize patient care and avoid costly medical errors. In addition, significant inconsistencies among vital signs, clinical impression, and other clinical data can signal an error in measurement or the presence of a potentially serious medical condition despite certain normal findings. For example, a patient who has relatively normal vital signs but whose facial expression and general appearance suggest severe distress may still have an acute medical problem. As a result, it is recommended that RTs “don’t treat numbers.” Instead, they should rely on the critical analysis of several clinical findings, including but not limited to vital signs, in assessing the patient and making related recommendations.

Frequency of Vital Signs Measurement

The frequency of vital signs measurement depends on the condition of the patient; the nature and severity of the disorder; and the procedures, surgery, or treatments being performed. A baseline measurement should be taken on admission and at least at the beginning of each shift.

For acutely ill patients in an intensive care setting, vital signs may be monitored continuously with remote electronic monitoring and alarm interface. For patients with conditions affecting only selected organ systems such as the heart, monitoring can be focused on specific vital signs including heart rate and rhythm and can be done continuously through electronic transmitting devices known as telemetry. Similarly, patient’s heart rate and rhythm can be continuously monitored and digitally recorded for review by a physician, outside of the hospital or clinic using a Holter monitor. However, for more stable patients such as those on medical-surgical floors, “routine vitals” are generally measured and recorded every 4 to 6 hours (at beginning of shift and midshift), unless changes in conditions dictate otherwise.

In addition to acuity, certain procedures may determine the frequency with which vital signs are monitored. For example, patients undergoing a bronchoscopy (see Chapter 17) generally have baseline measurements taken before the procedure, at a maximum of 5-minute intervals during the procedure, and at similar intervals until they recover from moderate sedation and any lingering effects of the procedure. After surgery, vital signs are generally measured frequently to ensure the patient’s safety—often every 15 minutes for 2 hours, then every 30 minutes for 1 to 2 hours, then hourly until the patient is stable. The physician’s order in the chart is often written as “Vitals q15m × 2-4h, q30m × 4h, Q1H until stable, then per protocol.” Likewise, certain vital signs such as heart rate and respiratory rate should be monitored at a minimum before and after certain standard respiratory treatments like bronchodilator administration, to evaluate effectiveness of the treatment and for possible side effects.

Of course, vital signs should always be monitored and recorded as often as necessary for the safety of the patient. If the patient’s condition worsens unexpectedly, the patient appears to have an adverse reaction to a medical intervention, or the patient suddenly comments about “not feeling well,” vital signs should be measured immediately and strong consideration given to activating the Rapid Response Team (also known as the Medical Emergency Teams) in the hospital setting or calling 911 in an alternate care setting.

Trends in the Vital Signs

A single vital sign measurement gives information about the patient at that moment in time. Each measurement may be evaluated to see whether it is high or low compared with the normal value for the patient’s age; however, an isolated measurement does not provide much information about what is normal for the individual patient or how the patient is changing or responding to therapy over time. To evaluate whether an individual patient has “normal” vital signs, you must understand what is normal for them, given factors such as age, disease, and treatment protocols. Sometimes, chronic disease or treatment modalities cause expected alterations in heart rate, respiratory rate, blood pressure, or body temperature, which changes what is normal for an individual patient. If you doubt a finding, repeat the measurement and be sure the patient’s position and your technique are correct for the parameter you are measuring. If you still doubt the measurement or if you think the patient may be getting into trouble, get help.

The initial reading is generally referred to as the baseline measurement. A series of vital sign measurements over time establishes a trend and is far more important clinically than any single measurement. Each time vital signs are measured, they should be compared with the baseline values and the most recent measurements. Sometimes, the patient’s condition may be changing slowly, and comparison with one or two previous measurements does not indicate the trend, whereas comparison over an entire shift or 24 hours of vital signs may indicate clearly that the patient is slowly deteriorating. Because the trend of vital signs is so important, many physicians insist that vital signs on hospitalized patients be recorded on a multiple-day graph.

Additionally, the patient’s vital signs should be viewed in relation to their normal level or the values that can typically be obtained for them, even when they are not necessarily ill. For instance, a heart rate of 96 beats/minute is within normal limits for an adult but may be relatively high and have clinical significance for a patient whose heart rate is generally in the low 60s.

Comparing Vital Signs Information

Clues to whether a patient’s condition may be stable or changing may be obtained by comparing changes in vital signs and other signs and symptoms. For example, patients who are not maintaining adequate blood oxygen levels develop specific changes in general appearance, level of consciousness, heart and respiratory rates, and blood pressure. Table 4-1 lists these common signs of developing acute hypoxemia (partial pressure of arterial oxygen [Pao2] <75 to 80 mm Hg).


Signs of Hypoxemia Assessed During Vital Signs Measurement

Vital Signs Measurement Sign
General clinical presentation Impaired coordination or cooperation
Cool extremities (can be felt while taking the heart rate and blood pressure)
Diaphoresis (profuse sweating)
Sensorium (level of consciousness) Decreased mental function
Impaired judgment, confusion
Loss of consciousness
Decreased pain perception
Respiration Increased rate and depth of breathing
Difficulty breathing, use of accessory muscles
Heart rate Tachycardia
Arrhythmia (irregular heart rate), especially during sleep
Blood pressure Increased blood pressure initially


Temperature of the extremities, as well as diaphoresis, can be felt at the time the heart rate and blood pressure readings are obtained.

In the field of medicine, this comparison of multiple signs and symptoms to arrive at the patient’s diagnosis is called the differential diagnosis. Of course, it takes time for the beginning student to learn all these relationships, but remember, the difference between the novice and expert clinician is not just knowledge. The distinction is also the ability to assess and compare multiple types of subjective and objective data over time and to identify patterns and relationships in an individual patient. The key to expert assessment of vital signs at the bedside is to be constantly aware and to look for change, as follows:

• Look at the patient: watch facial expressions, body movements, coordination, position, color, skin, anatomic landmarks, and effort to breathe or move.

• Listen to the patient: hear words, tones, sounds, rhythms, patterns, silence, feelings, and fears.

• Touch: feel moisture, temperature, air movement, change in temperature, muscle and skin tone, resistance, and quality of pulses.

• Analyze: collect information in a timely manner; compare it with normal values and the patient’s baseline and the disease procession. Mentally update this information whenever you are around the patient. Validate its accuracy. Does the information make sense? Is something wrong with the picture?

• Trend, trend, trend: what has changed about the patient? How has the patient changed and why? What has not changed? Why? What does it mean? Does the change indicate a need for immediate action?

Height and Weight

Height and weight are routinely measured as part of the physical examination and usually as part of every outpatient appointment. A patient’s height is normally taken without shoes or boots, and their weight is obtained while wearing only a hospital gown or indoor clothing. For hospitalized patients, the admitting height and weight are obtained and recorded either when the patient goes to a preadmitting testing service or by the admitting nurse; thereafter, weight is usually measured every day or two. If there is concern about either dehydration or fluid overload, fluid intake and output and weight may be recorded each shift until the patient’s fluid balance is stable. Because weight is often used to calculate medication doses and ventilator settings related to ventilator volumes, the weight may be recorded in kilograms (1 kg = 2.2 lb) on the patient’s medication record and, if appropriate, the ventilator-patient flow sheet, in addition to the vital signs record. Scales and measurement standards should be selected in sizes and styles appropriate for the age of the patient and should be calibrated regularly to ensure accuracy.

General Clinical Presentation

General observation begins the moment you first see the patient and continues throughout the examination and care. The patient’s general appearance gives clues to the level of distress and severity of illness as well as information about the patient’s personality, hygiene, culture, and reaction to illness. This first step may dictate the order of care or physical examination. If the patient is in distress, the priority is to evaluate the problem in the most efficient and rapid way possible and to intervene or locate someone who can assist the patient. A more complete examination can be performed when the patient is more stable. Some visual signs of distress include the following:

When a patient is not in acute distress, this initial observation provides an opportunity to see the patient as a whole person. Using all your senses—hearing, smelling, seeing, touching, and perception—during this head-to-toe inspection gives information about the patient’s apparent age, state of health, body structure, nutritional status, posture, motor activity, physical and sensory limitations, and mental acuity. It helps assess the reliability of the patient as a historian. It also helps identify what type of assistance and teaching the patient may need.

A written description of these initial observations helps others involved in the patient’s care know how to plan care and relate to the patient’s needs. Usually, these descriptive statements are written in language everyone can understand (e.g., “J.C. is a cooperative, alert, well-nourished, 43-year-old man who appears younger than his stated age and exhibits no indication of distress. He shows no signs of acute or chronic illness and is admitted for …”). You may occasionally find that more specific terms for body types have been used in the written physical examination report. Box 4-1 lists and defines some of those terms.

Box 4-1   Terms Used to Describe Body Types

Ectomorphic Slight development, body linear and delicate with sparse muscular development
Endomorphic Soft, roundness throughout the body; large trunk and thighs with tapering extremities
Mesomorphic Preponderance of muscle, bone, and connective tissue, with heavy hard physique of rectangular outline (between endomorphic and ectomorphic)
Sthenic Average height; well-developed musculature, wide shoulders, flat abdomen; oval face
Hypersthenic Short, stocky, may be obese; shorter, broader chest; thicker abdominal wall; rectangular-shaped face
Hyposthenic Tall, willowy, musculature poorly developed; long, flat chest; abdomen may sag; long neck; triangular face
Asthenic Exaggeration of hyposthenic body type
Cachectic Profound and marked malnutrition; wasting; ill health
Debilitated Weak, feeble, lack of strength (with weakness and loss of energy)
Failure to thrive Physical and developmental delay or retardation in infants and children; seen in children with illness but more often in children with psychosocial or maternal deprivation

A statement is usually made in the documentation of the patient’s general appearance regarding the apparent age of the patient relative to his or her stated age. Patients who appear much older than their stated age often suffer from chronic illness such as heart disease, diabetes, or chronic pulmonary disease. For example, the patient with chronic obstructive pulmonary disease often appears older than his or her stated age.

Pain Level and Type

Pain is referred to by some clinicians as the “fifth vital sign.” In the past, the assessment of pain was considered to be mainly a subjective measure. More recently, pain intensity scales have been developed and validated to help accurately quantify a patient’s level of pain. One commonly used pain measurement instrument uses a 10-point scale, with 10 being “hurts worst,” and corresponding facial expressions and verbal description to assess pain level. In assessing pain, it is important to be mindful of certain cultural differences that may affect the patient’s accurate reporting of pain, or lack thereof. For example, some cultures may deny or understate massive pain because of cultural beliefs and stigmas. With this in mind, when a patient’s accurate pain rating score is coupled with additional information regarding its location and actions that worsen or alleviate it, this information can be quite useful in clinical assessment. For example, chest pain originating from the cardiac versus the pulmonary system (e.g., myocardial infarction versus pleuritis) can vary in features such as intensity, location, and duration. As a result, rapid assessment and characterization of pain may assist in making a differential diagnosis and implementing the appropriate treatment.

The use of analgesic (pain-relieving medication) before assessing a patient is somewhat controversial in that the immediate administration of such medications can cause the patient to understate the pain severity, altering the assessment. However, in extreme cases, the pain may be so severe that it interferes with the assessment of the patient. In such cases, it may be necessary to administer a modest initial dose of analgesic to assess the patient.

Level of Consciousness (Sensorium)

Evaluation of the patient’s level of consciousness is a simple but important task. Adequate cerebral oxygenation must be present for the patient to be conscious, alert, and oriented. The conscious patient also should be evaluated for orientation to time, place, and person. This is referred to as evaluating the patient’s sensorium or mental status. The alert patient whose orientation to time, place, and person is accurate is said to be “oriented × 3,” and the sensorium is considered normal.

An abnormal sensorium and loss of consciousness may occur when cerebral perfusion is inadequate or when poorly oxygenated blood is delivered to the brain. As cerebral oxygenation deteriorates, the patient initially is restless, confused, and disoriented. If tissue hypoxia continues to deteriorate, the patient eventually becomes comatose. An abnormal sensorium also may occur as a side effect of certain medications and in drug overdose cases. Deterioration of the patient’s sensorium often indicates the need for mechanical ventilation in the presence of acute respiratory dysfunction.

Evaluation of the patient’s sensorium helps determine not only the status of tissue oxygenation but also the ability of the patient to cooperate and participate in treatment. Patients who are alert and oriented can take an active role in their care, whereas those who are disoriented or comatose cannot. The treatment plan is often adjusted according to the evaluation of sensorium.