The vital signs include assessment of temperature, pulse, respiration, and blood pressure. They are considered the baseline indicators of a patient’s health status.
Pain assessment is considered the fifth vital sign. Pain is a subjective unpleasant symptom of many conditions and injuries. The pain experience, its characteristics, and intensity are unique for each person. The Joint Commission (2013) requires that all patients in all healthcare facilities have a documented pain assessment. Repeat assessment of pain is performed to evaluate the treatment response and to identify the presence of new or recurring pain.
Temperature
Pulse rate
Respiratory rate
Blood pressure
Self-report pain rating scales
Assessing pain behaviors
Pain scales for children
Anatomy and Physiology
Vital Signs
Temperature
Body temperature is regulated and maintained by the hypothalamus. When pathogens invade the body, exogenous pyrogens, endotoxins produced by the pathogen, are released and travel to the hypothalamus. Endogenous pyrogens such as prostaglandins are produced when phagocytic cells destroy microorganisms. The hypothalamus responds to the pyrogens by temporarily raising the body’s temperature set point, leading to a fever (pyrexia). Epinephrine is released, which increases the metabolic rate and muscle tone. The body generates heat by shivering, a rapid contraction and relaxation of the skeletal muscles. The body conserves heat by vasoconstriction, which reduces heat loss through the skin. Body cooling occurs by vasodilation, which increases heat loss through the skin, increased sweating, and evaporation of perspiration.
Pulse Rate
The arterial pulse results when the ventricular heart contraction pushes a pressure wave of blood throughout the arterial system.
Respiratory Rate
The primary muscles of respiration are the diaphragm and the intercostal muscles. The diaphragm is the dominant muscle. It contracts and moves downward during inspiration to increase the intrathoracic space. The external intercostal muscles increase the anteroposterior chest diameter during inspiration, and the internal intercostal muscles decrease the lateral diameter during expiration. Air is drawn into the lungs during inspiration and expelled during expiration when the intercostal muscles and diaphragm relax, allowing the chest wall to recoil.
Blood Pressure
The arterial blood pressure is the force of the blood against the wall of an artery as the ventricles of the heart contract and relax. Systolic pressure, the force exerted when the ventricles contract, is largely the result of cardiac output, blood volume, and compliance of the arteries. Diastolic pressure is the force exerted by peripheral vascular resistance when the heart is in the filling or relaxed state. Blood pressure is highest during systole and falls to the lowest point during diastole. The pulse pressure is the difference between the systolic and diastolic pressures.
Pain
Pain is an uncomfortable sensation and emotional experience associated with actual or potential tissue damage. Acute pain is of short duration and has a sudden onset in association with injury, surgery, or an acute illness episode. Inflammation helps sustain the pain response. Persistent (chronic) pain lasts several months or longer and is often sustained by a pathophysiologic process (e.g., joint disease, chronic inflammation, headache, or cancer). Neuropathic pain is long-term pain associated with damage or dysfunction of the central or peripheral nervous system (e.g., amputation, complex regional pain syndrome).
Nociceptors are free nerve endings in the peripheral nervous system that are activated to transmit pain impulses from the site of injury. Biochemical mediators such as bradykinin, prostaglandins, serotonin, glutamate, and substance P help transmit the pain impulses from the nerve endings along nerve pathways. Pain impulses travel from the site of injury to the dorsal horn of the spinal cord through the ascending spinal tracts to the thalamus and cerebral cortex. Two specialized nerve fibers transmit pain impulses (nociception). Sharp, well-localized pain is quickly transmitted by the large, myelinated A-delta fibers. Dull, burning, diffuse, and chronic pain is slowly transmitted by the small, unmyelinated C-polymodal fibers ( Fig. 6.1 ).
A two-way control of pain transmission occurs in the spinal nerve pathways. After the pain impulses reach the spinal cord’s dorsal horn, the pain signal may be modified when other stimuli are present from either the brain or the periphery. Substances such as endorphins (endogenous opioids), and gamma-aminobutyric acid (GABA) can change or inhibit the pain perceived. Pain impulse transmission may be reduced when nonpain impulses (e.g., ice, massage) compete to transmit sensations along the same spinal pathways to the brain.
Response to pain is individualized because it is a physiologic, behavioral, and emotional phenomenon. Individuals have different thresholds at which pain is perceived and different pain tolerance levels. Emotions, cultural background, sleep deprivation, previous pain experience, and age are some factors that have an impact on a person’s perception and interpretation of pain.
Infants
Infants are more susceptible to hypothermia—low body temperature—because of their large body surface area for weight ratio, thinner skin, and limited ability to cope with cold stress. Infants have a higher pulse rate and respiratory rate than adults, and the rates decrease as the child ages. Infants have a lower blood pressure than adults, and blood pressure increases as the child ages.
The peripheral and central nervous systems are adequately developed for neonates to feel pain. The ability to process pain develops early in fetal life. The immaturity of the neurologic system results in some differences in pain transmission and processing. Most pain impulses are transmitted along the nonmyelinated slower C fibers because myelination of the A-delta fibers continues to develop after birth. The transmission distance to the brain is short. Infants are less able to modify pain impulses due to immaturity of their dorsal horn synaptic connection and inhibition circuits in the descending spinal cord pathways. This results in greater sensitivity of the central nervous system to repeated painful stimuli. ( American Academy of Pediatrics, Committee on Fetus and Newborn and Section on Anesthesiology and Pain Medicine, 2016 ).
Pregnant Patients
Blood pressure commonly decreases beginning at about 8 weeks’ gestation, gradually falling until a low point is reached at midpregnancy. The diastolic blood pressure gradually rises to prepregnant levels by term ( Gabbe et al, 2012 ).
During pregnancy, some patients may experience pain due to several physiologic processes:
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Back pain may be related to lax ligaments, weight gain, hyperlordosis, and anterior tilt of the pelvis.
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Cramping or pressure may be signs of premature labor or Braxton Hicks contractions (sporadic uterine contractions that start at around 6 weeks of pregnancy).
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Pressure from the gravid uterus may cause epigastric pain.
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Round ligament pain may be due to the stretching of the ligaments by the enlarging uterus.
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Pressure on the bladder may occur from the weight of the enlarging uterus.
During labor, pain may be related to dilation of the cervix, stretching of the lower uterine segment, and pressure on adjacent structures. During delivery additional pain is caused by pressure of the fetal head against the pelvic floor, vagina, and perineum.
Older Adults
No evidence exists that older adults have a diminished perception of pain. However, some older adults may have a decreased pain threshold associated with peripheral neuropathies, thickened skin, or cognitive impairment ( Huether et al, 2014 ). Many have chronic health conditions associated with pain, such as arthritis, osteoporosis, or peripheral neuropathy.
Review of Related History
For each of the conditions discussed in this section, topics to include in the history of the present illness are listed. Responses to questions about these topics help to assess the patient’s condition and provide clues for focusing the physical examination.
Present Problem
Fever
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Onset: date of onset, duration, cyclic nature, variability; related to injury or illness exposure
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Associated symptoms: sweating, chills, irritability, nausea, vomiting, fatigue
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Medications: acetaminophen or nonsteroidal antiinflammatory drugs (NSAIDs)
Pain
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Onset: date of onset, sudden or gradual, time of day, duration, precipitating factors, variation, rhythm (constant or intermittent)
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Quality: throbbing, shooting, stabbing, sharp, cramping, gnawing, hot or burning, aching, heavy, tender, splitting, tiring or exhausting, sickening, fear producing, punishing or cruel
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Intensity: ranges from slight to severe using a pain scale from 1 to 10 or from little to worst pain ever felt
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Location: Identify all sites: Can the patient point a finger to it? Does it travel or radiate?
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Associated symptoms: nausea, fatigue, behavior change, irritability, disturbed sleep, distress caused by pain
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What the patient thinks is causing the pain or what was the inciting event
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Effect of pain on daily activities: activity limitation, sleep disruption, need for increased rest, appetite change
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Effect of pain on psyche: change in mood or social interactions, poor concentration, can think only about pain; irritability
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Pain control measures: distraction, relaxation, ice, heat, massage, electrical stimulation, acupuncture
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Medications: opioids, anxiolytics, NSAIDs, nonprescription medications
Personal and Social History
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Previous experiences with pain and its effect; typical coping strategies for pain control
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Family’s concerns and cultural beliefs about pain: Is pain expected or tolerated in certain situations?
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Attitude toward the use of opioids, anxiolytics, and other pain medications for pain control; fear of addiction
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Current or past use of recreational drugs
Children
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Word(s) the child uses for pain, such as “owie,” “ouch,” “ache,” or “hurt”
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What do you tell your parent when you hurt? What do you want him or her to do for the hurt?
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What kinds of things caused hurt in the past? What made the hurt feel better?
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Pain behaviors (facial expressions, grimacing, protective posture) the parent identifies in the infant or child
Pregnant Patients
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Discomforts associated with increasing fetal size, description of discomfort, location, and when it occurs
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Investigate all known medical conditions and physical limitations to identify sources for persistent or acute pain.
Older Adults
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Investigate all known medical conditions and physical limitations to identify potential sources for persistent or acute pain.
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Word(s) used by the older adult for pain, such as “achy,” “sore,” or “discomfort.” Use this word consistently during the pain assessment.
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When the older adult is cognitively impaired, have a family member describe cues to the patient’s expression of pain.
Examination and Findings
Temperature
The assessment of body temperature may often provide an important clue to the severity of a patient’s illness. Temperature measurement is most commonly performed by oral, rectal, axillary, tympanic, and forehead routes. The temperature is read in either Fahrenheit or Celsius. The expected temperature range is 97.2° to 99.9° F (36.2° to 37.7° C) with an average of 98.6° F or 37.0° C ( Huether et al, 2014 ). The body temperature normally varies over a 24-hour period and in response to activity.
Pulse Rate
The pulse rate is best palpated over an artery close to the surface of the body that lies over bones, such as the carotid, brachial, radial, femoral, popliteal, dorsalis pedis, and posterior tibial arteries ( Fig. 6.2 ). The radial pulse is most often used to assess the heart rate. With the pads of your second and third fingers, palpate the radial pulse on the flexor surface of the wrist laterally. If you have difficulty finding a pulse, vary your pressure, feeling carefully throughout the area (see Fig. 16.8, C ). Count the pulsations for 60 seconds (or count for 30 seconds and multiply by 2).
The average resting pulse rate in adults is 70 beats per minute, and ranges between 60 and 100 beats per minute. Well-conditioned athletes or individuals taking beta-blockers may have a resting pulse rate of 50 to 60 beats per minute. In adults, tachycardia is a pulse rate that exceeds 100 beats per minute, and bradycardia is a pulse rate less than 60 beats per minute.
Determine the steadiness of the heart rhythm; it should be regular. If an irregular rhythm is detected, count for a full 60 seconds. See Chapter 15 for more information about heart rhythm assessment. While counting the heart rate, also note the contour (waveform) and amplitude (force) of each pulsation. See Chapter 16 for a more detailed discussion of arterial pulse evaluation.
Respiratory Rate
Assess the respiratory rate (number of breaths per minute) by inspecting the rise and fall of the chest. Count the number of breaths (inspiration and expiration) that occur in 1 minute, or count the number of breaths for 30 seconds and multiply by 2. Avoid telling the patient that you are counting the respiratory rate so the patient will not vary the rate or pattern of breathing. A good way to do this is to count the respirations just after counting the pulse, while you are still palpating the radial artery.
The expected adult resting respiratory rate is 12 to 20 breaths per minute. The ratio of the respiratory rate to the heart rate is approximately 1 : 4. Respiratory rates can vary between waking and sleep states. The normal rate of respirations (breaths per minute) depends on a number of factors, including the age of the individual and the amount of activity. Tachypnea is a faster-than-normal respiratory rate. Bradypnea is a slower-than-normal respiratory rate. See Chapter 14 to further evaluate respiratory patterns.
Blood Pressure
The blood pressure is most often measured in the arm when the patient is seated. Blood pressure readings taken in supine position tend to be lower than those taken in sitting position. Standards for blood pressure readings are based upon the seated position using the right arm.
Free the arm of clothing and apply a cuff of appropriate size around the upper arm ( Box 6.1 ). Center the deflated bladder over the brachial artery, just medial to the biceps tendon, with the lower edge 2 to 3 cm above the antecubital crease. Make sure the cuff is snug and secure because a loose cuff will give an inaccurate diastolic reading. Flex the patient’s arm to be at the level of the heart and support it comfortably on a table, pillow, or your arm.
Cuffs are available in several sizes to match the size of the patient’s limb (see Fig. 6.3 ). The correct cuff size ensures that equal pressure will be exerted around the artery, resulting in an accurate measurement. If the cuff is too wide, the blood pressure will be underestimated. If the cuff is too narrow, an artificially high blood pressure reading will result. The size of the cuff is measured by the width and length of bladder, not the material covering the bladder.
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For adults, choose a width that is one-third to one-half the circumference of the limb.
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The length of the bladder should be twice the width or about 80% of the limb circumference. The bladder should not completely encircle the limb.
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If the patient has an obese arm, attempt to find a cuff size appropriate for the arm size. If a sufficiently large cuff is not available, wrap a standard-size cuff around the forearm and auscultate over the radial artery.
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If the adult patient is very thin, a pediatric cuff may be necessary.
Record the size of the cuff used and the site of auscultation.
Check the palpable systolic blood pressure first to avoid being misled by an auscultatory gap when using the stethoscope. Place the fingers of one hand over the brachial or radial artery and palpate the pulse. Rapidly inflate the cuff with the hand bulb 20 to 30 mm Hg above the point at which you no longer feel the peripheral pulse. Deflate the cuff slowly at a rate of 2 to 3 mm Hg per second until you again feel at least two beats of the pulse. This point is the palpable systolic blood pressure. Immediately deflate the cuff completely ( Fig. 6.4, A ).
