VITAL SIGNS - Principles of Health Sciences - ثاني ثانوي
CHAPTER 1: HISTORY AND TRENDS OF HEALTH CARE
CHAPTER 10: PROMOTION OF SAFETY
CHAPTER 2: HEALTH CARE SYSTEMS
CHAPTER 11: INFECTION CONTROL
CHAPTER 3: CAREERS IN HEALTH CARE
CHAPTER 13: VITAL SIGNS
CHAPTER 4: PERSONAL AND PROFESSIONAL QUALITIES OF A HEALTH CARE TEAM MEMBER
CHAPTER 14: FIRST AID
CHAPTER 5: LEGAL AND ETHICAL RESPONSIBILITIES
CHAPTER 15: PREPARING FOR THE WORLD OF WORK
CHAPTER 6: MEDICAL TERMINOLOGY
CHAPTER 7: HUMAN GROWTH AND DEVELOPMENT
CHAPTER 8: NUTRITION AND DIETS
CHAPTER 9: COMPUTERS AND TECHNOLOGY IN HEALTH CARE
Link to digital lesson CHAPTER www.ien.edu.sa 3 VITAL SIGNS Case Study Investigation Salem is a 32-year-old man who is working in construction. He is married with two children and moved to a different city last month. He is 1.9 meters tall and weighs 130 kg. Salem has not seen a doctor in 3 years but goes to the clinic after experiencing a persistent headache and dizziness. Suspecting hypertension, the doctor asks him to stop by the clinic every afternoon for 2 weeks to have his blood pressure monitored. At the end of this chapter, you will be asked why this is a good plan for Salem. LEARNING OBJECTIVES After completing this chapter, you should be able to: • List the vital signs. • Identify methods of measuring and recording body temperature, pulse rate, respirations, and blood pressure. KEY TERMS blood pressure pain pulse oximeter 54 CHAPTER 3 وزارة التعليم Ministry of Education 2022-1444 DESPAWWWW.CY 22HI TH 58 th 34 respirations sphygmomanometer stethoscope temperature thermometers vital signs 18012023 1429)
وزارة التعليم 3:1 MEASURING AND RECORDING VITAL SIGNS Vital signs provide information about a patient's basic health condition. The main vital signs are temperature, pulse, respirations, blood pressure, and pain. Other important vital signs that provide information about the patient's condition include oxygen saturations (measurement of the per- centage of oxygen in the blood), the color of the skin, the size of the pupils in the eyes and their reaction to light, the level of consciousness, and the patient's response to stimuli. ⚫ Temperature is the balance between heat lost and heat produced by the body. Temperature can be measured in the mouth (oral), rectum (rectal), armpit (axillary), or ear (aural), on the forehead (temporal), or on the surface of the skin with a noncontact thermometer. A low or high reading can indicate infection or disease. ⚫ Pulse is the pressure of the blood felt against the wall of an artery as the heart contracts and relaxes, or beats. The rate, rhythm, and vol- ume are also important to record. Rate refers to the number of beats per minute, rhythm refers to regularity, and volume refers to strength, force, or quality. The pulse is usually taken over the radial artery, on the inside of the wrist. Any abnormality can indicate disease. . Respirations reflect the breathing rate of the patient. In addition to the respiration count, the rhythm (regularity) and character (type) of respirations are noted. Abnormal respirations usually indicate that a health problem or disease is present. ⚫ Blood pressure is the force exerted by the blood against the arterial walls when the heart contracts or relaxes. Two readings (systolic and diastolic) are noted to show the greatest pressure and the least pres- sure. Abnormal blood pressure is often the first indication of disease. . Pain is an unpleasant sensation that is perceived in the nervous system when illness or injury occurs. Pain can be acute or chronic. Acute pain lasts for a short time, for example, post-operative pain or pain from a physical injury. Chronic pain is long-term, for example, arthritis or back pain. Pain can be measured using a scale of 0-10, with 0 being no pain, 1 being very mild pain, and 10 being the worst pain imaginable. If the patient is unable to rate their pain with a number, a series of faces ranging from happy to very sad can be shown to describe how they are feeling, or they can choose words in a list that describe how they are feeling (Figure 3-1). Mining or Educamion 2022 1444 GE44.PATHWAYS.002.82.HLTH.58.indb 55 VITAL SIGNS 55 | 18/01/2023 14:29
(A) Comm Another vital sign is the apical pulse. This pulse is taken with a stethoscope at the apex of the heart. The actual heartbeat is heard and counted. The apical pulse is taken in patients with a weak radial pulse, or in infants or children who generally have a rapid radial pulse that is difficult to count. Health care providers are responsible for taking the patient's vital signs, which must be recorded accurately. Any change in vital signs must be reported immediately, as this is often the first indication of a change in the patient's condition. (B) 0 CODE DATE 2 4 Adolent and Pediatric Pain Tool (APP) INSTRUCTIONS: 1. Color in 1 areas on these drawings to show where you have pain. Make the marks as big or small as the place 10 2. Place straight, and down mark show how much pain you he 3. Point to or cele many of these words that describe ---- FIGURE 3-1 (A) Pain can be measured by asking the patient to rate the level of pain on a scale of 0-10. (B) For children, a special scale tool can be used that will allow a child to color an area of the body where they have pain or to choose words in a list that describe how they are feeling. 56 CHAPTER 3 وزارة التعليم Misting or EduCUDOO 2022 1444 GE44 PATHWAYS.G02.82.HLTH.S8.indb 56 checkpoint 1. What are the main vital signs? 2. Name two other important vital signs. 18/01/2023 14:29
وزارة التعليم 3:2 MEASURING AND RECORDING TEMPERATURE Heat is lost through perspiration, respiration, and excretion (urine and feces). Heat is produced by the metabolism of food and by muscle and gland activity. A constant state of fluid balance, known as homeostasis, is the body's ideal state of health. The rates of chemical reactions in the body are regulated by body temperature. If body temperature is too high or too low, the body's fluid balance and homeostatic state are affected. VARIATIONS IN BODY TEMPERATURE The normal range for body temperature is 36.1-37.8 degrees Celsius (°C), or 97-100 degrees Fahrenheit (°F) (Figure 3-2). However, varia- tions in body temperature can occur. Some rea- sons for variations include: • Individual differences. Time of day: body temperature is usually lower in the morning and higher in the evening. ⚫ Body sites: different body parts register tem- perature differently, as shown in Table 3-1. Celsius Thermometer Fahrenheit Thermometer A reading of 37°C is the average "normal" Celsius temperature. A reading of 98.6°F is the average "normal" Fahrenheit temperature. FIGURE 3-2 Normal oral body temperature on Celsius and Fahrenheit thermometers. TABLE 3-1 Average Temperature Variations by Body Site Temperature Average Normal range Oral and/or Tympanic 37°C (98.6°F) 36.5-37.5°C (97.6-99.6°F) Rectal, Aural, and/or Temporal Axillary and/or Groin 37.6°C (99.6°F) 36.4°C (97.6°F) 36-37°C (96.6-98.6°F) 37-38.1°C (98.6-100.6°F) Body temperatures can be above or below the normal range for a variety of reasons: ⚫ Causes of increased body temperature: illness, infection, exercise, excitement, and high temperatures in the environment. ⚫ Causes of decreased body temperature: starvation or fasting, sleep, decreased muscle activity, mouth breathing, exposure to cold temper- atures in the environment, and certain diseases. Very low or very high body temperatures are indicative of abnormal conditions: Mostjo EmucoDOO 2022-1444 GE44.PATHWAYS.002.82.HLTH.58.indb 57 VITAL SIGNS 57 18/01/2023 14:29
⚫ Hypothermia is a low body temperature, below 35°C (95°F) measured rectally. It can be caused by prolonged exposure to cold. Death occurs if body temperature drops below 33.9°C (93°F) for a period of time. . A fever is an elevated body temperature, usually above 38.3°C (101°F) measured rectally. Pyrexia is another term for fever. The term "febrile" means that a fever is present; "afebrile" means that no fever is present, or the temperature is within the normal range. Fevers are usually caused by infection or injury. ⚫ Hyperthermia occurs when the body temperature exceeds 40°C (104°F) measured rectally. It can be caused by prolonged exposure to hot temperatures, brain damage, and serious infections. Immediate actions must be taken to lower body temperature because temper- atures above 41.1°C (106°F) can quickly lead to convulsions, brain damage, and death. TEMPERATURE-MEASUREMENT SITES . Oral temperature is taken in the mouth. Eating, drinking hot or cold liquids, and/or using inhalers can alter the temperature in the mouth. It is important to make sure the patient has not had anything to eat or drink or has not used an inhaler for at least 15 minutes prior to taking the patient's oral temperature. FIGURE 3-3 To take an axillary temperature, insert the thermometer in the hollow of the axilla, or armpit. Science ⚫ Rectal temperature is taken in the rectum. Rectal temperatures are frequently taken on infants and small children, and on patients with hypothermia (below-normal body temperature). • Axillary temperature is taken in the armpit, under the upper arm. The arm is held close to the body, and the thermometer is inserted between the two folds of skin (Figure 3-3). A groin temperature is taken between the two folds of skin formed by the inner part of the thigh and the lower abdomen. Both axillary and groin are external temperatures and are less accurate. Aural temperature is taken with a special tympanic thermome- ter that is placed in the outer ear. The thermometer measures the thermal, infrared energy radiating from blood vessels in the tympanic membrane, or eardrum. Because this provides a measure- ment of body core temperature, the range is similar to rectal or internal body temperature. 58 CHAPTER 3 وزارة التعليم Minising or Education 2022-1444 GE44 PATHWAYS.G02.82.HLTH.58.indb 58 18/01/2023 14:29
وزارة التعليم Temporal temperature is taken with a temporal scanning ther- mometer that is passed in a straight line across the forehead, midway between the eyebrows and upper hairline. The thermometer meas- ures the temperature in the temporal artery and is similar to a rectal temperature because it measures the temperature inside the body or bloodstream. TYPES OF THERMOMETER . A clinical thermometer consists of a slen- der glass tube containing mercury or a heat-reactive mercury-free liquid such as alcohol, which expands when exposed to heat. Thermometers containing mercury are banned in many countries. The bulb of the thermometer is inserted under the tongue (Figure 3-4). . An electronic thermometer uses a heat sen- sor to record temperature and displays the temperature on a viewer in a few seconds. Electronic thermometers can be used to take oral, rectal, axillary, and groin temperatures (Figure 3-5). Tympanic thermometers are specialized electronic thermometers that use an infra- red sensor to record the temperature in the ear (Figure 3-6). Temporal scanning thermometers are spe- cialized electronic thermometers that use an infrared scanner to measure the tempera- ture in the temporal artery of the forehead (Figure 3-7). FIGURE 3-4 Insert the bulb of the thermome- ter under the patient's tongue (sublingually). FIGURE 3-6 After inserting the covered probe of the tympanic thermometer into the ear canal, press the scan or activation button and hold the thermometer steady until the tempera- ture reading is displayed. ⚫ Noncontact infrared thermometers use light-wavelength technology to measure the thermal energy radiating from the skin without requir- ing any physical contact with the person (Figure 3-8). This type of thermometer was used widely during the COVID-19 pandemic and is ideal for screening the temperatures of many individuals quickly and accurately with no contamination of the thermometer. ⚫ Plastic or paper disposable thermometers contain chemical dots or strips that change color when exposed to specific temperatures. Some types are placed on the forehead, and record skin temperature. Other types are used orally. Both types are used once and discarded. FIGURE 3-5 Electronic thermometers can be used to take oral, rectal, axillary, and/or groin temperatures. While taking a temperature, hold the probe of the electronic thermometer in place. FIGURE 3-7 To take a temporal temperature, hold the scan button while lightly sliding the thermometer across the forehead midway between the eyebrow and hairline. FIGURE 3-8 Non- contact infrared ther- mometers can measure the thermal energy radi- ating from the skin. Milising of Educion 2022-1444 GE44.PATHWAYS.002.S2.HLTH.58.indb 59 VITAL SIGNS 59 18/01/2023 14:29
FIGURE 3-9 A clinical thermometer is held at eye level to find the solid column of mercury or mercury-free liquid. READING AND RECORDING TEMPERATURE Electronic, tympanic, temporal, and noncontact infrared thermometers are easy to read because they have digital displays. To read a glass clinical thermometer, it is held at eye level and rotated slowly to find the solid col- umn of mercury or mercury-free liquid (Figure 3-9). The thermometer is read at the point where the liquid line ends. CLEANING THERMOMETERS Thermometers must be cleaned thoroughly after use. Glass clinical thermometers can be washed and rinsed. Cool water is used to prevent breakage and to avoid destroying the column of liquid. The thermometer is then soaked in a disinfectant solution (frequently 70% alcohol) for a minimum of 30 minutes before it is used again. Some clinical thermome- ters are covered with a plastic sheath that is discarded after use. The probe on electronic thermometers is covered with a plastic sheath that is discarded after each use. These covers prevent the thermometers from coming into contact with the patient's mouth and prevent transmis- sion of germs. D H FIGURE 3-10 Major pulse sites. 60 CHAPTER 3 وزارة التعليم Missing or Education 2022 1444 GE44 PATHWAYS.G02.82.HLTH.S8.indb 60 A checkpoint 1. What are three reasons for variation in body temperature? 2. What is a tympanic thermometer? F 3:3 MEASURING AND RECORDING PULSE Pulse refers to the pressure of the blood pushing against the wall of an artery as the heart beats and Science rests. The pulse is felt more easily in arteries that lie fairly close to the skin and can be pressed against a bone by the fingers. The pulse can be felt at different arterial sites on the body. Some of the major sites are shown in Figure 3-10: Temporal (A): on either side of the forehead. ⚫ Carotid (B): at the neck on either side of the trachea. Brachial (C): at the inner forearm in the antecubital space (crease of the elbow). 18/01/2023 14:29
وزارة التعليم Radial (D): at the inner wrist, on the same side as the thumb, taken over the radial artery (Figure 3-11). ⚫ Femoral (E): at the upper thigh where the thigh joins the trunk of the body. Popliteal (F): behind the knee. Dorsalis pedis or pedal (G): at the top of the arch of the foot. ⚫Posterior tibial (H): just below and behind the medial malleolus (the bony part of the ankle that sticks out on the inner side of the leg). Each time a pulse is measured, three different facts must be noted: the rate, the rhythm, and the volume of the pulse. TABLE 3-2 Pulse Rates The rate of the pulse is measured as the number of beats per minute. Pulse rates vary among individuals, depending on age, gender, Individuals and body size (Table 3-2). .The rhythm of the pulse refers to how regular (normal) or irregular (abnormal) a pulse is. Arrhythmia is the medical word for an irregu- lar or abnormal rhythm. The volume, or the strength, force, quality, or intensity of the pulse, is also noted. It is described by words such as bounding, strong, weak, or thready. Various factors will change pulse rate: Adults generally Adult men Adult women Children aged over 7 Children aged 1-7 Infants Bradycardia (slow heart rate) Tachycardia (fast heart rate) • Increased, or accelerated, rates can be caused by exercise, stimulant drugs, excitement, fever, dehydration, shock, nervous tension, and other similar factors. ⚫ Decreased, or slower, rates can be caused by sleep, depres- sant drugs, heart disease, coma, physical training, and other similar factors. FIGURE 3-11 To count a radial pulse, put the tips of two or three fin- gers on the thumb side of the patient's wrist. Range of Pulse Rate (Beats Per Minute) 60-100 60-70 65-80 70-100 80-110 100-160 Under 60 Over 100 (except in children) FIGURE 3-12 A pulse oximeter measures the percentage of oxygen in the blood. Many oximeters also measure the pulse rate per minute. Another vital sign that is taken is the measurement of the oxy- gen level of the blood using a pulse oximeter (Figure 3-12). Pulse oximeters are simple clip-like devices that are placed on a finger, toe, or ear lobe. Oximeters use light to determine the percentage of oxygen in the blood and display the result on the screen. In addition, many oximeters also measure pulse rate. A normal range of blood oxygen saturation level is 95-100%. Levels below 90% are consid- ered to be hypoxia, a deficiency of oxygen reaching the tissues, and may indicate the need for supplemental oxygen. checkpoint 1. What artery site is usually used to obtain a pulse? 2. What is the normal range of pulse rate for adult women? Mijnsting or Eduction 2022 1444 GE44.PATHWAYS.002.82.HLTH.58.indb 61 VITAL SIGNS 61 | 18/01/2023 14:29
62 CHAPTER 3 وزارة التعليم Maistry of Eduction 2022-1444 GE44 PATHWAYS.G02.82.HLTH.58.indb 62 3:4 MEASURING AND RECORDING RESPIRATIONS Respiration is the process of taking in oxygen (O) and expelling carbon dioxide (CO) from the lungs and respiratory tract. One Science respiration consists of one inspiration (breathing in) and one expiration (breathing out). Each time respiration is measured, three different facts must be noted: the rate, the character, and the rhythm of respirations. These three facts provide complete information about how the patient is breathing. For example, a respiration measurement of 18, deep and regular, is much dif- ferent to a measurement of 18, very shallow and irregular. ⚫ The respiration rate counts the numbers of breaths per minute. • . The normal respiration rate in adults is 12-20 breaths per minute. In children, respirations are slightly faster than those for adults and average 16-30 per minute. In infants, the rate may be 30-50 per minute. ⚫ Character refers to the depth and quality of respirations. Words used to describe character include deep, shallow, labored, difficult, sterto- rous (abnormal sounds like snoring), and moist. Rhythm refers to the regularity of respirations, or equal spacing between breaths. It is described as regular or irregular. The following terminology is used to describe abnormal respirations: ⚫ Dyspnea: difficult or labored breathing. ⚫ Apnea: absence of respirations, usually a period of no respirations. ⚫ Tachypnea: rapid, shallow respiratory rate above 25 respirations per minute. ⚫ Bradypnea: slow respiratory rate, usually below 10 respirations per minute. ⚫ Orthopnea: severe dyspnea in which breathing is very difficult when lying flat. • ⚫ Rales: bubbling, crackling, or noisy sounds caused by fluids or mucus in the air passages. 18/01/2023 14:29
وزارة التعليم Minustojo Emcoon Wheezing: difficult breathing, with a high-pitched whistling or sigh- ing sound during expiration; caused by a narrowing of the airway (for example, in asthma). ⚫ Cyanosis: a dusky, bluish discoloration of the skin, lips, and/or nail beds as a result of decreased oxygen and increased carbon dioxide in the bloodstream. Respirations must be counted in such a way that the patient is unaware of the procedure. Because respirations are partially under voluntary con- trol, patients may breathe more quickly or more slowly when they become aware of the fact that respirations are being counted. checkpoint 1. What three facts provide complete information about respirations? 2. What is apnea? 3:5 MEASURING AND RECORDING APICAL PULSE An apical pulse is a pulse count taken with a stethoscope at the apex (the lower left side) of the heart. A stethoscope is an instrument which amplifies sounds, making them louder so they are easier to hear. Parts of the stetho- scope include the earpieces, tubing, and the bell or thin, flexible disk called a diaphragm (Figure 3-13). Earpieces Rubber or Diaphragm Chest piece O-Bell- plastic tubing FIGURE 3-13 Parts of a stethoscope. 2022-1444 GE44.PATHWAYS.002.S2.HLTH.58.indb 63 FIGURE 3-14 An apical pulse is frequently taken on infants and small children because their pulses are more rapid. VITAL SIGNS 63 | 18/01/2023 14:29
-Mid-clavicular 5th intercostal space Apex FIGURE 3-15 Locate the apex of the heart at the fifth intercostal (between the ribs) space by the midclavic- ular (middle of the collarbone) line. An apical pulse is taken for patients with irregular heartbeats, hardening of the arteries, or weak or rapid radial pulses. Because children and infants have very rapid radial pulse counts, apical pulse counts are usually taken (Figure 3-14). It is generally easier to count a rapid pulse using a stethoscope than by feeling it with your fingers. Place the diaphragm 5-7 cm to the left of the breastbone. Use your index finger to locate the fifth intercostal (between the ribs) space at the midclavicular (middle of the collarbone) line (Figure 3-15). Listen for heart sounds. Two separate heart sounds are heard while listening to the heartbeat. The Science sounds resemble a "lubb-dupp." Each lubb-dupp counts as one heartbeat. The sounds are caused by the closing of the heart valves as blood flows through the chambers of the heart. Any abnormal sounds or beats should be reported immediately. 64 CHAPTER 3 وزارة التعليم Missing Educ 2022-1444 GE44 PATHWAYS.G02.82.HLTH.58.indb 64 checkpoint 1. What are the three parts of a stethoscope? 2. Why are apical pulse counts usually taken in children? Science MEASURING AND RECORDING BLOOD PRESSURE Blood pressure is a measurement of the pressure that the blood exerts on the walls of the arteries during the various stages of heart activity. diastolic: There are two types of blood pressure measurements: systolic and Systolic pressure is the pressure of the left ventricle of the heart as it is contracting and pushing blood into the arteries. .Diastolic pressure is the pressure when the left ventricle of the heart is at rest, or between contractions. During the rest period, the volume of blood in the arteries has decreased. Normal values and classifications for diastolic and systolic pressure are shown in Table 3-3. 18/01/2023 14:29
وزارة التعليم Blood pressure is recorded as a frac- tion. The systolic reading is the top number, or numerator. The diastolic reading is the bottom number, or denominator. For example, a systolic reading of 120 and a diastolic read- ing of 80 are record3d as 120/80. TABLE 3-3 Classifications of Blood Pressure in Adults in Millimeters of Mercury (mmHg) Normal blood pressure Elevated Stage 1 Stage 2 <120 and <80 120-129 and <80 130-139 ог 80-89 >140 or >90 Hypertensive crisis >180 and/or >120 Note: <= less than; >= greater than. ⚫ Elevated blood pressure is when systolic blood pressure is between 120 and 129 millimeters (mm) of mercury (Hg), and diastolic is less than 80 mmHg. Elevated blood pressure is a warning that high blood pressure will develop unless steps are taken to prevent it. Elevated blood pressure can harden arteries and block vessels that nourish the heart. Proper nutrition and regular exercise are the main treatments for elevated blood pressure. ⚫ Hypertension, or high blood pressure, is indicated when pressures are greater than 130 mmHg systolic and 80 mmHg diastolic: ⚫ Stage 1 hypertension: systolic between 130 and 139 mmHg or a diastolic between 80 and 89 mmHg. People in this category take medication if they have had a heart attack or cerebrovascular accident (stroke), or have an underlying condition. They are also recommended to make lifestyle changes like eating a low-salt diet and exercising more. ⚫ Stage 2 hypertension occurs when blood pressure is a systolic of more than 140 mmHg or a diastolic of more than 90 mmHg. Stage 2 hypertension is treated with medication and lifestyle changes. . A hypertensive crisis occurs when blood pressure is measured at a systolic over 180 mmHg and/or a diastolic over 120 mmHg. Immediate medication changes are indicated, and possible hospi- talization, as this level of blood pressure can damage blood vessels and cause stroke. Common causes include obesity, high salt intake, kidney disease, thyroid deficiency, and vascular conditions such as arteriosclerosis (hardening of the arteries). ⚫ Hypertension is often called a "silent killer" because most individ- uals do not have any signs or symptoms of the disease. Common causes include a poor diet, lack of exercise, being overweight, genetic predisposition, use of some medications, and some diseases such as diabetes or kidney disease. If hypertension is not treated, it can lead to stroke, kidney disease, and/or heart disease. Mesenjor Educsiooni 2022-1444 GE44.PATHWAYS.002.82.HLTH.58.indb 65 VITAL SIGNS 65 | 18/01/2023 14:29
FIGURE 3-16 Automatic sphygmomanometers provide a digital display of blood pressure and pulse readings. . Hypotension, or low blood pressure, is indicated when pressures are less than 90 mmHg systolic and 60 mmHg diastolic. Hypotension can be caused by strenuous exercise, endocrine problems, hormonal changes, excessive heat, low blood volume, widening of blood vessels, anemia, vitamin B₁₂ deficiency, anaphylaxis, heart problems, or use of some medications. Hypotension may also occur with heart failure, dehydration, depression, severe burns, hemorrhage, and shock. Orthostatic, or postural, hypotension occurs when there is a sud- den drop in both systolic and diastolic pressure when an individual moves from a lying to a sitting or standing position. It is caused by the inability of blood vessels to compensate quickly to the change in position. The individual becomes light-headed and dizzy, and may experience blurred vision. Many factors can influence blood pressure readings. These factors can cause blood pressure to be high or low. Some examples include: ⚫ Factors causing changes in readings: force of the heartbeat, resistance of the arterial system, elasticity of the arteries, volume of blood in the arteries, and position of the patient (lying down, sitting, or standing). ⚫ Factors that may increase blood pressure: excitement, anxiety, nerv- ous tension, exercise, eating, pain, obesity, and/or stimulant drugs. Factors that may decrease blood pressure: rest or sleep, depressant drugs, shock, dehydration, hemorrhage (excessive loss of blood), and fasting. Stress triggers the body to produce hormones that temporarily increase the blood pressure by causing the heart to beat faster and the blood vessels to narrow. This can cause "white-coat" hypertension, when blood pressure readings are higher at the doctors' office than in other settings. TAKING A BLOOD PRESSURE READING Blood pressure is read on an instrument known as a sphygmomanometer. There are three main types of manual sphygmomanometers: mercury, aneroid, and electronic. Blood pressure and pulse readings are shown on a digital display after a cuff is placed on the patient. Automatic sphygmo- manometers are also available (Figure 3-16). To obtain accurate blood pressure readings, the patient should sit qui- etly for at least 5 minutes before blood pressure is taken, so they are not stressed. Two separate readings should be taken and averaged, with a minimum wait of 30 seconds between readings. The size and placement of the sphygmomanometer cuff are also impor- tant (Figure 3-17). The cuff contains a rubber bladder that fills with air 66 CHAPTER 3 وزارة التعليم Maising or Education 2022-1444 GE44 PATHWAYS.G02.82.HLTH.S8.indb 66 18/01/2023 14:29
وزارة التعليم to apply pressure to the arteries. Cuffs that are too wide or too narrow give inaccurate readings. A cuff that is too small will give an artificially high reading; if it is too large, it will give an artificially low reading. The bell/diaphragm should be placed directly over the brachial artery on the antecubital area (the inside of the elbow) and held securely but with as little pressure as possible. checkpoint 1. Blood pressure is read in millimeters of what? 2. Which artery is used to obtain a blood pressure reading? FIGURE 3-17 It is important to use the correct size cuff because cuffs that are too wide or too narrow will result in inaccurate readings. Today's Research Tomorrow's Health Care An Artificial Heart That Eliminates the Need for Heart Transplants? Artificial hearts have been in use for many years. They are used to keep a patient alive until a heart transplant can be found. Researchers have developed a new type of artificial heart. By using miniaturized electronics and high-capacity lithium batteries, scientists have created a heart that allows a patient to wear a battery pack on their waist. Electrical energy passes through the patient's skin to power the implanted heart. This allows the patient to resume many normal daily activities. The patient is no longer attached by wires to a power source. Patients have lived for many months with this type of heart while waiting for a suitable transplant. Most of these devices are called ventricular-assist devices (VADS) (Figure 3-18) because they work with the patient's diseased heart to maintain circulation in the body. Researchers are now working on an artificial heart that will work in place of a patient's damaged heart. Currently, one total artificial heart is available in the United States. It consists of two ventricles and four valves that allow blood to be pumped through the body. It has a preset rate of 125 beats per minute. It works efficiently, but it is still meant to be a temporary replacement while a patient waits for a heart transplant. It requires a person to carry a backpack containing an external air compressor that pumps the implanted heart from the outside. The compressor can be powered with batteries or plugged into an electrical source. Research now is directed toward creating a total artificial heart with an internal compressor and/or electrical source. This total artificial heart will have computerized intelligence to understand when additional blood is needed by the body. It will be able to respond to the demands of the body and increase or decrease the heart rate as needed. It will be created from materials that will not cause a rejection reaction in the body. And finally, it will last for many years. FIGURE 3-18 A ventricular-assist device (VAD). Case Study Investigation Conclusion What were possible reasons for monitoring Salem's blood pressure for 2 weeks? What psychological reasons may be impacting his blood pressure? What other possible factors do you think the doctor may have considered when having Salem monitored before prescribing medication? Mistojor Education 2022 1444 GE44.PATHWAYS.002.82.HLTH.58.indb 67 VITAL SIGNS 67 | 18/01/2023 14:29