Unit 6  Vital Signs

The vital or cardinal signs are body temperature, pulse, respiration, and blood pressure.

Chapter 1  Body Temperature

The body temperature is the temperature of inside the body, such as visceral cavity and center nervous system. It is also the balance of the heat produced and lost from the body.

Normal Body Temperature

A thermometer is placed in a person’s mouth to obtain an oral temperature; in the anal canal to obtain a rectal temperature; in an axilla (armpit) to obtain an axillary temperature, and in the esophagus to obtain a core temperature. The body’s internal organs require a fairly constant inner or core temperature for optimal functioning, whereas the surface and periphery of the body can fluctuate widely while gaining or losing heat.

Abnormal Body Temperature

Elevated body temperature 

Pyrexia is an elevation of normal body temperature. The layterm is fever. Hyperpyrexia is above 41℃(105.8℉) and survival is rare when the temperature reaches 44℃ (ll0℉). Death is probably due to damaging effects to the respiratory center but may be due to inactivation of body enzymes and destruction of tissue proteins as well.

Hypothermia 

A body temperature below the lower limit of normal is called hypothermia. Death may occur when the temperature falls below about 34℃ (93.2℉), but survival has been reported in isolated cases when body temperaturwww.med126.comes have fallen in the range of severe hypothermia (28℃ or 82.4℉). This may happen to a person drowning in cold water or buried by snow. Because body functions are almost imperceptible at this range, health care personnel should attempt to warm hypothermic clients and resuscitation efforts.

Clinical Signs of Fever

The clinical signs of a fever vary, depending on the stage of the fever, that is, the onset, the course, or the termination.

Signs during the onset of a fever are

●  Chill, the patient complains of feeling cold.

●  Shivering due to strong skeletal muscle contractions.

●  Pallid skin due to peripheral vasoconstriction.

● “Gooseflesh” appearance of the skin due to contraction of the arrector pill muscles.

●  Increasing pulse rate due to increased cardiac rate.

●  Rising rectal temperature even though skin is cool.

Ways of obtaining body temperature

Obtaining an oral temperature  Obtaining oral temperatures is most common. One criterion for selecting an oral route is that the client must be able to c會(huì)計(jì)資格lose his or her mouth around the thermometer. Obtaining an oral temperature using a glass thermometer is contraindicated for unconscious, irrational, and seizure-prone clients, and for infants and young children because of the danger of breaking the glass thermometer in the mouth. Oral temperatures are also contraindicated for people with the diseases of the oral cavity or who have had surgery of the nose or mouth. If a client has had either hot or cold food or fluids or has been smoking or chewing gum, it is generally recommended that a period of about 15 minutes elapse before taking an oral temperature and thus allows the oral tissues to return to normal.

Chapter 2  Pluse

The pulse is the pulse wave of blood created by the contraction of the left ventricle of the heart. A pulse can be palpated on certain superficial areas of the body, for example, where an artery passes over or alongside a bone. By slight pressure on the artery the pulse wave. The pulse is the pulse wave can be felt as the blood is pumped around the body.

The Physiologic Changes of Normal Pulse

Pulse rate  

The pulse rate is the number of pulsations felt in a minute. This rate ordinarily corresponds to the same rate at which the heart is beating. There are wide ranges for normal pulse rates. The pulse rate is 60-100 beats per minute for well adults at rest.

●  Age

●  Gender

●  Body size  It has been noted that the body size and build of a person may affect the pulse rate. Tall, slender people often have a slower rate than short, stout ones.

●  Autonomic nervous system  The rate of the heartbeat, and thus the pulse as well, readily responds to impulses conducted along the autonomic nervous system. This system is subdivided into parasympathetic and sympathetic networks of nerves. Stimulation of the parasympathetic system decreases the heart rate. The drug digitalis, commonly used by clients with certain heart ailments, decreases the heart’s contractions by stimulating the vagus nerve. Stimulation of the sympathetic system increases the heart rate.

Abnormal Pulse

Abnormal pulse rate 

The pulse rate of over 100 beats per minute for an adult is called Tachycardia. The pulse rate is more rapid if a person has a fever or the thyroid gland is overactive, or heart failure and hemorrhage. The pulse rate of below 60 beats per minute for an adult is called Bradycardia. It may occur in convalescence from a long feverish illness. It is a sign of cerebral hemorrhage, indicating increased pressure on the brain. It is also a sign of complete heart block.

Abnormal pulse rhythm 

The irregular pulse rhythm or the pulsations or pauses occur with no pattern or predictability is called Arrhythmia.  

● Intermittent  A normal pulse rhythm is broken by periods of irregularity.

● Bigeminal  A normal pulse rhythm of two beats is followed by a pause.

● Premature beat  A heartbeat occurs before the normal one.

● Pulse deficit  The difference between the apical and radial pulse is called Pulse deficit, namely the rate of apical pulse is more than that of the radial pulse.

Abnormal pulse amplltude 

Under abnormal conditions, the amplitude of each pulse beat is very strong or very weak and feels not similar.

● Bounding pulse  The pulsation is strong and dose not disappear with moderate pressure. It usually occurs in the patient due to fever.

● Absent pulse  No pulse is felt despite extreme pressure. It usually occurs in the patient due to no heart- beat.

● Thready pulse  The pulsation is not easily felt and slight pressure causes it to disappear. It usually occurs in the patient due to severe hemorrhage and shock.

● Weak pulse  It is stronger than a thready pulse. Light pressure causes it to disappear. It usually occurs in the patient due to hemorrhage and dehydration.

Assessing Methods

Obtaining a radial pulse  Most commonly, the radial artery at the wrist is used for palpating the pulse because it is easily accessible. It is located on the inner, thumb-side of the wrist. If this site is inaccessible, select an alternative artery that does not require exertion or cause discomfort for the person, which could alter the pulse rate.

Chapter 3  Blood Pressure

Arterial blood pressure is a measure of' the pressure exerted by the blood as it pulsates through the arteries.

Normal Blood Pressure and Physiologic Changes

Factors affecting blood pressure

The studies of healthy people indicate that blood pressure can be within a wide range and still be normal. Because individual differences are considerable, it is important to know what is the normal blood pressure for a particular person.

Age  A person’s age influences his or her blood pressure.

The time of day   Normal fluctuations occur during the day. The blood pressure is usually lowest on arising in the morning, before breakfast, and before activity commences. The blood pressure has been noted to rise as much as 5 to 10 mm Hg by late afternoon, and it gradually falls again during sleep.

Gender  A person’s gender also influences blood pressure. Women usually have a lower blood pressure than men of the same age, especially before at age of 50 years.

Diet  Blood pressure has been observed to rise after the ingestion of food.

Activity  Systolic blood pressure rises during periods of exercise and strenuous activity.

Emotion status  Emotions, such as anger, fear, excitement, and pain, generally can cause the blood pressure to rise, but the pressure falls to normal when the situation passes. A person’s blood pressure tends to be lower when he or she is in a prone or supine position than when he or she is sitting or standing.

The measurements of normal blood pressure

Because of the many factors that influence blood pressure, the measurements of a single blood pressure are not necessarily significant. People with a reading near or above the upper limits of normal should be reexamined to determine if the measurement persists.

Abnormal Blood Pressure

Hypertension 

A person whose blood pressure is above normal for a sustained period is in a state of hypertension. When the cause of hypertension is due to known pathology, it is called secondary hypertension. Primary or essential hypertension is hypertension without a known cause.

Hypertension is a prevalent health problem. The public as well as health practitioners are becoming increasingly aware of the importance of having regular blood pressure measurements because of the many dangers associated with hypertension. Persistent diastolic hypertension is the most serious and most common blood pressure disturbance. It is a major cause of early death and serious disability in millions of people. Although the exact reason has not been determined, hypertension occurs almost twice as frequently in blacks as in whites.