Vital Signs: Measurement, Assessment & Clinical Evaluation PDF

Vital sign are important assessment measurements for screening and to guide treatment. These measurements are termed "vital" as their measurement and assessment is the critical first step for any clinical evaluation. They are cardinal signs that reflects the body’s physiological state, which are con...

Vital sign are important assessment measurements for screening and to guide treatment. These measurements are termed "vital" as their measurement and assessment is the critical first step for any clinical evaluation. They are cardinal signs that reflects the body’s physiological state, which are controlled by body’s vital organs (brain, heart, lungs) and necessary for sustaining life. Vital signs are indicators of a persons health condition and normal measurements provide assurance of proper circulatory, respiratory, neural, and endocrinal functions. Furthermore, they are commonly used to universally communicate a patient's condition and severity of the disease. Vital signs consist of: Temperature, pulse rate, respiratory rate. blood pressure and blood oxygen saturation via pulse oximetry It can be influenced by a number of factors. It can vary based on age, time, gender, medication, or a result of the environment. Healthcare providers must understand the various physiologic and pathologic processes affecting these sets of measurements and their proper interpretation. Vital signs play an important role in determining patients at risk of deterioration. The degree of vital sign abnormalities may predict short or long term patient health outcome. Vital signs help to predict physical therapy indications, contraindications, and outcomes. Vital signs are appropriate assessment to characterize or quantify cardiovascular and pulmonary signs and symptoms. i. On admission to a healthcare agency to obtain baseline data. ii. When the patient’s/client’s general physical condition changes (as with loss of consciousness or increased intensity of pain) iii. Before and after surgery or an invasive diagnostic procedure. iv. Before and/or after administration of certain medication that affect the cardiovascular, respiratory, and temperature control function. v. Before and after nursing interventions influencing a vital sign (such as when a patient/client previously on bed rest ambulates or when a patient requires tracheal suctioning) vi. When the patient reports non-specific symptoms of physical distress (such as feeling ‘funny’ or ‘different. Temperature Temperature is defined as the degree of hotness or coldness of the body. It’s a state or degree of heat or coldness within a substance, which can be measured against a standard scale (0C or 0F) The body temperature is controlled by the hypothalamus through the anterior and posterior pituitary gland. When there is changes in the body temperature, the temperature center in the hypothalamus triggers or activates heat loss (cooling) or heat production to maintain body temperature. are homoeothermic, that is Humans are warm blooded and maintains their body temperature independently of the environment. As a by- product of metabolism the body continually produces heat which is transported round the body through the blood, heat is also continually lost from the body. This indicates that after taking temperature what is read on a clinical thermometer, is the balance between the heat produced and the heat lost from the body measured in heat units called degree that is the measure of heat inside the body. There are two kinds of body temperature: Core and Surface temperature. The core temperature is the temperature of the deep tissues such as the cranium, thorax, abdominal cavity, and pelvic region. It remains relatively constant. The surface temperature is the temperature of the skin, the subcutaneous tissue, and fat which rises and falls in response to the environment. The normal core body temperature is a range of temperatures fluctuating between 36.1 and 37.20C ) Physiologically the body regulates heat to maintain a relatively constant internal body temperature this is called thermoregulation. This process is possible through complex interplay of physical and chemical/hormonal mechanism and sympathetic stimulation that is coordinated by the heat- regulating center in the brain called the hypothalamus. The hypothalamus does this through its anterior and posterior part. The anterior hypothalamus is concerned with heat loss while the posterior hypothalamus controls heat conservation. If there are changes in body temperature the temperature center of the hypothalamus senses it and either activates heat loss (cooling) or heat production to ensure that the core temperature remains within the safe physiological range. The human body produces heat during oxidation of food substance, hormonal activities eg. Epinephrine and nor- epinephrine; muscular activities and physical exercises. and heat is loss from our body through the following processes Radiations convention conduction and evaporation. Heat Production i. Oxidation of food: during metabolism/breakdown of food substances energy is released. The activities that occurs during digestion to produce energy-Basal Metabolic rate (BMR) ii. Hormones: some hormones increases the rate of cellular activities (metabolism) eg. Epinephrine and norepinephrine causes vasoconstriction which increases hear in body tissues and internal organs also thyroxine and triodothyronine increases the basal metabolic rate (BMR) during the breakdown of glucose and fat. iii. Physical exercise: it increases metabolic processes and muscular activities. iv. Muscle activities The human skin has heat and cold receptors. During the breakdown of carbohydrate, fats and also when an individual is shivering, heat production occurs. When there is cold hypothalamus> shivering mechanism is initiated involuntary muscles contract, because of the cold and there is vasoconstriction which increases muscular tone. When there is there is heat loss hypothalamus is stimulated which leads to vasocontraction, muscle shivering – pilo-erection (standing of hair follicles) then sweating is inhibited. Heat loss The body losses heat through the following ways: convention, conduction, radiation and evaporation. i. Convention: is the mixture of warm air with the air on our body. It’s dispersion of heat by air current. The warm air rises and it’s replaced by cool air. ii. Conduction: heat loss from an object of higher temperature to that of lower temperature through direct contact. The amount of heat transferred depends on the temperature difference and the duration of contact. iii. Radiation Radiation is the transfer of heat from an object of higher temperature to that of lower temperature without direct contact. Eg. Hear radiates from the skin to a cooler nearby object s and radiates to the skin from a warmer object. iv. Evaporation Changing of fluid from liquid to gaseous state. Factors that influence temperature i. Age: in newborn the temperature in- utero is different from the one outside, also because the mechanism of temperature regulations is not well developed this so the temperature can be affected. Also at old ages due to reduced thermo- regulations, loss of subcutaneous fat and lack of activity, they are at risk of having low temperature (below 36°C) ii. Exercise Due to increase metabolism during exercise, there is increase temperature which leads to heat production. iii. Hormones Women tend to have an higher temperature than men due to menstruation and ovulation iv. Stress v. During physical and emotional stress adrenaline is produced, this in turn increases heart rate and metabolic processes > heat production vi. Environment Our living environment can also affect temperature depending on the weather. It could be extremely cold or hot, weather changes our thermo body regulation Eg. Heat exhaustion, Heat stroke hypothermia and frost bite. a) Heat exhaustion (100°F-104 °F): this is an increase in body temperature above 38-40°C due to environment that results in profuse perspirations, diaphoresis, weakness and disorientation it also leads to increase thirst. b. Heat stroke: also an increase to temperature 41°C-44c due to exposure to high environmental temperatures. The skin becomes dry and person exhausted.  c. Hypothermia Temperature below 35°c or 35°2. due to cold weather. It leads to impaired mental functioning, reduced pulse, respiration and blood pressure. d. Frost bite: extreme coldness in the body due to an extremely cold weather. It can lead to impaired circulation of blood, gangrene cardiac arrest etc. Assessing body temperature. Sites & taking temperature are: ❖ Mouth ( one to two minutes) ❖ Axial: one to three minutes. ❖ Groin ❖ Rectal ❖ Tympanic: infrared lights detects heat. Conversion of centigrade ( C") to Fahrenheit ( F) Multiply the number of centigrade (temperature) ℃x 9/5 +32 Eg. C=36℃ 36℃x 9/5 +32= 36x9/5 324/5=64.8+32=96.4°F From Fahrenheit to centigrade First substrate the -32 from the Fahrenheit and multiply by5/9 95°F-32*5/9 =63*5/9=315/9=35°C. Points to note when taking temperature. i. Inform and take consent from the patient. ii. Ensure patient’s comfort before the beginning of the procedure. iii. All requirements must be by the patient bed side iv. Inspect thermometer if its broken and to know the level of mercury, which is supposed to be below 35℃ before usage, shake mercury if necessary.  v. Note: each individual may have their own thermometer otherwise the general one is kept centrally. vi. Ask patient to expose the axilla, and dry with towel. vii. Insert the thermometer into the axilla. and assist the patient to close their arm against the chest wall to ensure good contact with the skins. viii. Leave in positions for 2-3 minutes -Afterwards, bring out the thermometer and hold it horizontally at eye level, note the level of the mercury. ix. Chart accurately in the chart. x. If temperature is high or low report to your Nurse is charge. xi. When taking temperature orally. Ask patient to open his or her mouth and insert under the tongue, and it should be individual thermometer then tell the patient to close their lips not teeth. xii. Keep for 2-3 minutes and bring out, be careful not to touch the area that was inside the patients mouth. xiii. Oral temperature is contraindicated in the following: unconscious, epileptic, mentally ill patient and infants. xiv. If temperature is taken rectally make sure you use a rectal thermometer and it is lubricated before insertion. Pyrexia( fever) Pyrexia is an increase in body temperature above the normal range of 36.2-37.2. It can occur due to the body's response to infection an invading pyrogene/ infection. Pyrogenes are bacteria, virus, fungi infection which could be from internal or external route that enters the body to cause harm. When this occurs there is increase production of white blood cells (antibodies) which tries to fight against the invading organism. These activities leads an increase in the body temperature, which is referee to as pyrexia. Fever can also occur due to immunization, hypersensitive reaction such as allergies to drugs or blood. Different ranges of pyrexia. Low pyrexia: 37.3 -38-3°C  Moderate pyrexia: 3.8.4-39.4°C High: 39.5 - 40°C Hyper pyrexia: over 40°C After cause of fever has been taken care of through antibiotic for the person’s immune system, the body initiates heat loss mechanism (conduction etc. ). Temperature reduces in two ways lysis or crisis. Lysis: this is a process whereby temperature drops gradually and becomes normal eg: after tepid sponging, or exposure if the skin to air. Crisis: this is a Sudden fall (crash, drop) of temperature to normal. Types of Pyrexia Constant or Continuous, intermittent, remittent and relapsing fever. Constant or continuous This a type of fever that remains above normal throughout a 24hour period, the temperature gets higher with 1°C. It occurs in lobar pneumonia, typhoid and urinary tract infections. Intermittent fever The body temperature increases in some hour of the day and becomes normal again. It can occur esame time each day. Remittent fever Temperature is never normal, always above the normal temperature all through the day. Relapsing fever Increase temperature for one to two days then normal body temperature, occurs Signs and symptoms of pyrexia Increased heart rate Increased respiratory rate Shivering Cold skin Increase thirst. Mild to severe dehydration  Gooseflesh appearance Restlessness bleakness Convulsion Sweating Management Monitor vital signs Expose patient and put on fan Tepid sponge from 380c Apply cold compresses (ice block, cold water) Assess skin color and temperature Provide adequate nutrition to improve metabolic demand and prevent dehydration (clients who Sweat profusely can become dehydrated). Reduce physical activity to reduce heat production. Measure intake and output Remove blanket when client fees warm and provide warmth when client feels warm Give antipyretic. Tepid sponging Tepid sponging is a process of applying or neither warm or cold water (lukewarm or tepid water) with a sponge on the skin in order to reduce the body temperature. Indication for tepid sponging. To reduce body temperature (high) To prevent brain damage and convulsion. To aid blood circulation. To make patient comfortable. Points to note when tepid sponging Do not expose patient unnecessarily Apply cold compress. The procedure should end about 15 to 20minutes  After sponging wait for 30minutes, then repeat temperature repeat procedure if temperature to still high. Chart various temperature accurately. While tepid sponging if patient complains of cold or shivering, stop tepid sponging immediately and cover up the patient Rigor Rigor is an episode of sudden chill (cold) accompanied by shivering as a result of increase temperature due to the presences of circulating toxins in the blood stream. There are three stages of rigor: cold, hot and Sweating stage. 1. The cold stage This is the stage where shivering occurs, there is increase temperature and pulse. rate. Respiratory rate is fast and patient exhibit signs of weakness. Management Note time the rigor started. Immediately cover up the patient with blanket and extra top lining. Don't leave patient alone, continue to reassure the patient. Give patient hot drink (Tea, Lipton). Note time shivering sto -Monitor vital signs closely and record. Donut use hot water bottle. 2. Hot stage Shivering stops Temperature still high Restlessness Patient complains of thirst. Management of hot stage. Remove blanker and top lining. Expose the patient and tepid sponge  Apply cold compress Give patient cold drink. Serve anti pyretic (paracetamol etc) Continue to monitor patient 3. Sweating stage Sweat Reduce temperature Patient complains tiredness Management of 3rd Stage Squeeze cold towel a mop the sweat Allow patient to sleep PULSE Pulse is a wave of distension and elongation felt on an artery wall as the left ventricle contracts and ejects blood into the system. Each contraction of the left ventricle forces about 60 to 80 millilitres of blood through the already full aorta and into the arterial system. When the heart beats, it squeezes and pushes blood through the arteries. This pressure in the artery is felt as pulse, when the fingers is firmly placed on the arteries located at the surface of the skin over a prominent bone. The number of pulse beats per minute normally represents the heart rate and varies considerably in different people and in the same person at different times. The heart rate is the number of times each minute that the heart beats, which is normally between 60 to 100 times per minute for adults, pulse is felt each time the heart beats. When taking pulse, its essential to note the following: the rate, rhythm and volume.  Rate: this is the number of beats per minute. Rate is between 60 to 100 bears per minute. If it’s higher it’s tachycardia when lower than the normal count for that age it’s called bradycardia. Rhythm: it’s the regularity or interval between two successive pulse beat. It’s the interval between beats and it should be regular, equal and or even. It can be regular, irregular or intermittent. Volume: the force ejected blood exerts against the artery in each contraction, it depicts the rate at which the heart is beating. It’s the strength or amplitude of the beat. Eg.: thready pulse Pulse rate in different age groups Fetus: 120 to 160 beats per minute. Infant: 120 to 140 beats per minute. Adult: 60 to 100 beats per minute. Older adult above 60 years: 60-65 beats per minute. Sites of taking Pulse rate Pulse rate is taking in two ways: the apical and peripheral pulse. i. Apical pulse: this is taken on the chest just above the heart, by using the diaphragm of a stethoscope to place on the chest wall. ii. Peripheral pulse: brachial, radial, femoral etc. The radial, ulna, brachial pulse is found on the upper extremity, and femoral, posterior tibialis or the dorsalis pedis pulse sites are on the lower extremity.  Radial artery: is located at the wrist joint where the radial artery runs against the radial bone. Temporal artery: found in front of the ear , where the temporal artery passes over the bone of the head Carotid artery: on the neck, it’s located on the side of the neck, where the carotid artery runs between the sternocleidomastoid muscle and the trachea. Brachial artery: located at the inner aspect of the bicep muscle of the arm. (at the center hollow area of the inside of the elbow. Femoral artery: can be found in the groins, where the femoral artery passes alongside the inguinal ligament Popliteal artery: behind the knee Posterior tibial and dorsalis pedis arteries located on the feet. Figure showing sites of taking pulse Points to note when taking pulse. Requirement: a second hand watch i. Patient must be comfortable.  ii. Inform the client and explain procedure to the client. iii. Use the first and second fingers. iv. Select the pulse site you want to use. v. If the client is in supine position, the arm can rest alongside the body with the palm facing downward or over the abdomen except contra indicated. In a sitting position, the forearm can be placed across the thigh, with the palm facing downwards. vi. Place the first two or three fingers lightly over the medial aspect of the wrist. vii. Palpate and count puts for the minute viii. Record your findings on the appropriate chart. ix. Do not use the thumb to take pulse, because it has a pulse that can be mistaken for patients own. x. Feel the pulsation before counting xi. Note the rhythm rate and volume Types of abnormal pulse Tachycardia: It is a fast rapid pulse rate found in certain heart condition and in some cases of anemia. Bradycardia: pulse rate less than 60 counts per minute in an adult. It is a slow pulse rate, it can occur in cases of shock and head injury etc. Irregular: the interval between two beats are uneven. Intermittent: when there is missing pulse beat in-between, and it may occur at regular or irregular intervals. Arrthythmia is the irregularities in heart rhythm. Thready pulse: very faint pulse Factors that affect pulse rate i. Sex: after puberty, the female have a slightly higher pulse rate than male due to hormonal activities. ii. Exercise iii. Posture/Position: when a person assumes a sitting position, blood supply usually pools in dependent vessels of the venous system. Pooling results in transient decrease in the venous blood return to the heart and a subsequent reduction in blood pressure and an increase in heart rate. iv. Stress: in response to stress, sympathetic nervous stimulation increases the activity of the heart. Stress increases the rate and force of the heartbeat. v. Fear, anxiety and perception of pain stimulate the sympathetic system. vi. Medications: some medications decrease the pulse rate while others increase it. Example: digitalis (digoxin) decrease the pulse rate while epinephrine increases it. vii. Hemorrhage : loss of significant amount of blood from the cardiovascular system results in an increase in pulse because the body tries to compensate for the loss. viii. Fever: when fever occurs, there is peripheral vasodilation of the vessels, and increased metabolism associated which results in an increase in pulse rate. RESPIRATION Definition Respiration is the interchange of gases between the atmosphericair and the circulating blood in the lungs, it’s an act of breathing. Normal breathing is passive without efforts, quiet, rhythmic (regular) not deep not shallow and has a rate which is normal for that age group. Normal breathing is termed Eupnoea. The process of breathing is automatic controlled and it’s regulated by respiratory centers in the medulla oblongata, pons of the brain; chemoreceptors found in the medulla, carotid arteries and aortic bodies. These control mechanism depends on the level of oxygen, carbon dioxide and PH of arterial blood gases (ABG). This means these centers are sensitive to the changes of the above mentioned. For example increase in carbondioxide(CO2) pressure of arterial blood causes the respiratory center to increase the rate and depth of breathing. This increased ventilatory effort removes excess partial pressure of carbon dioxide (pCO2) during exhalation. Similarly, if the arterial oxygen(O2) level falls, the chemoreceptors signals the respiratory center to increase the rate and depth of ventilation. The human cell depends on the supply of oxygen and the removal of carbon dioxide from the body (respiration) for it’s survival. This process of breathing and interchange of gases is achieved through two ways: external and internal respiration. External respiration External respiration is the intake of oxygen and removal of carbon dioxide as a waste. It’s the exchange of gases between an organism and its environment (lungs and pulmonary). External respiration is made up of inspiration and expiration. Inspiration is the intake of air into the lungs while expiration is the bringing out of air from the lungs to the atmosphere. Internal respiration Internal respiration also known as tissue respiration is the interchange of gases between the blood and cells, it takes place through out the body. It’s important to note the following when taking respiration: the rate, depth ( observe the degree of movement in the chest wall, it could be shallow, normal or deep); rhythm (regularity of ventilatory movements, it indicates the quality and efficiency of the respiratory process) and the pattern (difficult breathing). 1. Respiratory rate Respiratory rate is the number of breath or ventilation that occurs in one minute. It is described in breath per minute. Ventilation is also used to describe the movement of air in and out of the lungs: it could be high (hyperventilation) or low (hypoventilation). Rate is recorded as the number of cycles (with one cycle consisting of inspiration and expiration) per minute. The rate is usually counted when a person is at rest and the number of breaths for one minute. As the chest rises up and falls, it is counted as one breath. Normal breathing rate is about 12 to 20 breaths per minute in an average adult. In pediatric, it is defined according to different age group. Rate varies with age and reduces as a person grows older. It is usually slightly rapid in women than in men and during exercise etc. Infant: 30 to 40 count or cycle per minute. Adult: 18 to 20 cycle per minute. Normal respiratory rate is called Eupnoea, rate higher than normal for that age is called tachypnea and a lower rate is termed bradypnea. 2. Respiratory Depth The depth of respiration is assessed by observing the degree of movement on the chest wall. It is the volume of air inhaled and exhaled with each respiration. This movement of the chest wall is described as normal, shallow, or deep. a. Normal breathing Normal breathing is passive without efforts, quiet, rhythmic (regular) not deep not shallow and has a rate which is normal for that age group. Normal breathing is termed Eupnoea. The normal amount of air inhaled during relaxation is approximately 500ml of air and it’s called tidal volume. b. Shallow respiratory depth This involves the exchange of little volume of air. c. Deep respiration: this is when large volume of air is exhaled, it occurs in anxiety state and congestive cardiac failure etc. Example: hyperpnea, hyperventilation and hypoventilation. Hyperpnea: an increase in depth of breathing but not faster, which leads to increase in oxygen intake due to response to an increase in metabolic demand of oxygen by the body, eg. exercise, anxiety states, lung infections, and congestive heart failure. Hyperventilation: is both increased in the rate and depth ( fast and deep) and exhaling more air than it’s taken- in, eg. anxiety states or pathological conditions such as diabetic ketoacidosis or lactic acidosis. Hypoventilation: decreased rate and depth of ventilation, eg. excessive sedation, metabolic alkalosis. 3. Respiratory Rhythm This refers to the regularity of ventilatory movements, it is the regularity of the cycle and depth as volume of air is inhaled and exhaled with each respiration and sound. it indicates the quality and efficiency of the respiratory process. Normal breathing is evenly space i.e. regular and uninterrupted. Hence respiratory rhythm is described as regular or irregular. A regular rhythm means that the frequency of the respiration follows an even tempo with equal intervals between each respiration. An irregular breathing occurs when the interval between two breaths are not continues, not of the same length or even. Points to note when taking respiration 1. Introduce self to the patient. 2. Explain the procedure to him or her to reduce apprehension and enhance cooperation. 3. Ensure your patient is comfortable 4. Raise the height of bed or help patient to a sitting or lying position. 5. Wash your hands to reduce spread of microorganisms. 6. Use a watch with second hand and note the position of the second hand on the wrist watch before you start counting. 7. Choose a time when the patient is unaware of being watched then count the respiratory rate while appearing to count the pulse. To prevent conscious control of breathing during the assessment. 8. Observe the upward and downward movement of the chest wall or abdominal wall. 9. Observe to find out if breathing is noiseless or effortless, the rate, depth and rhythm. 10. Observe the rise and fall of the chest, this is counted as one. 11. Count respiratory rate for one minute 12. Chart accurately  13. Report any abnormality noticed as regards the rate, depth and regularity to your ward charge or any senior on duty. 14. Document accurately. Types of abnormal respiration 1) Tachypnea: fast or rapid breathing marked by quick shallow breath more than 20 breaths per minute or greater than the normal for the person' s age. It can occur in physiological conditions like exercise, emotional changes, or pregnancy. Pathological conditions like pain, pneumonia, pulmonary embolism, asthma, foreign body aspiration, sepsis, carbon monoxide poisoning, and diabetic ketoacidosis. 2) Bradypnea: slow breath less than 10 to 12 breath per minute. It can be seen in patients with underlying respiratory conditions that is not resolving resulting to respiratory failure. Also during the use of central nervous system depressants like alcohol, narcotics, benzodiazepines, or metabolic derangements. 3) Dyspnea: is difficulty in breathing, labored respiration and presence of nose flaring. The nostrils flare (widen) as the patient struggles to fill the lungs with air. Usually patients appear anxious and worried, can be observed in patients with lung and heart diseases. 4) Orthopnea: refers to difficulty in respiration that is noticed when patient is lying down, but relieved when patient is put up in an upright position with pillow, eg. Patients with congestive cardiac failure. 5) Apnea: stoppage or cessation of breathing. Apnea is the complete cessation of airflow to the lungs for a total of 15 seconds. It occurs in cardiopulmonary arrests, airway obstructions, overdose of narcotics, and benzodiazepines. 6) Shallow: a deep breath it can be fast or slow  7) Biot: is a pattern of breathing with periods of increased rate and depth of breathing, followed by periods of no breathing or apnea. These can vary in length of time. Example: patients with intracranial pressure and meningitis. 8) Cheyne-Stokes is a pattern of breathing where there is an increase in the depth of ventilation followed by periods of no breathing or apnea, and cycle starts over and over again. Occurs in a patient with cardiac failure, drug overdose, excessive usage of sedatives, worsening congestive heart failure and a dyeing patient, 9) Kussmaul breathing refers to the increased depth of ventilation, with rate still regular. Example: patients with renal failure and diabetic ketoacidosis. 10) Wheezy or sighing is an abnormal high pitched sound during respiration characterized by whistling. It occurs due to airway obstruction/ narrowing of the bronchi trees causing forceful air passage e.g. asthma. 11) Stertorous: loud snoring respiratiory sound due to partial blockage of the upper airway. 12) Stridor: abnormal shrill, harsh sound heard during inspiration, seen on patients with laryngeal obstruction. BLOOD PRESSURE Blood pressure(BP) is the force the blood exerts on the walls of the blood vessels. It is the measurement of the pressure or force of blood inside the arteries. Each time the heart beats, it pumps blood into arteries that carry blood throughout the body. This happens 60 to 100 times a minute, although the day, and varies according to age, gender, posture, activity etc. Maintenance of BP is essential, because if it’s too high blood vessels are damaged leading to clots and bleeding from the ruptured blood vessels. If it’s too low it affects the blood flow through the tissue beds, and it’s dangerous for organs like the heart, brain and kidney. BP is measured with an instrument called sphygmomanometer and a stethoscope to listen to the sound. It’s recorded in millimeters of mercury) mmhg). It is taken using two measurements: systolic and diastolic pressure. The systolic is the highest pressure, it's the first sound heard when the ventricle contracts and pushes blood into the aorta. The diastolic is the last sound heard when the ventricles relaxes before it starts to contract again, and it’s lower than the systolic. Both pressure are recorded as a fraction with the systolic over the diastolic. Example: BP =120/70mmmHg. Bp can either be high(hypertension) or low (hypotension) depending on the World Health Organization recommendation according to age of the individual. Parts of BP apparatus When a sphygmomanometer is opened, there us a mercury glass tube known as mercury manometer. It had a cuff band covered with cloth, and attached to with two tubes, one tube is attached to the mercury manometer while the other to the knob. The knob is used for opening and closing of the tube. The cuff band is wrapped round the upper arm of the client or patient. Factors that determine Blood Pressure Blood pressure (Bp) is the force exerted by the blood against the walls of the vessels. It depends on the amount of blood pumped out of the heart per minute known as cardiac output (CO) and the ,the total force exerted by the heart and the walls of the vessels against the blood called Total peripheral resistance (TPR) Bp = cardiac output (CO) Total peripheral resistance (TPR ). 1. Cardiac output Cardiac output refers to the volume of blood pumped out per ventricle per minute It is the amount of blood pumped by the heart per minute. Cardiac output (CO) is the product of the heart rate (HR), i.e. the number of heartbeats per minute (bpm), and the stroke volume (SV), which is the volume of blood pumped from the left ventricle per beat every heart beat. 2. Total peripheral resistance As the blood passes through the lumen of the arteries there is no opposite pressure that is no resistance. The resistance to flow of blood depends on the arterial length, blood viscosity, and the size of the lumen i. Blood viscosity: this is the thickness of blood and it depends on the erythrocyte count and albumin concentration. If erythrocyte count is low incase of anaemia or reduced proteins, the viscosity is reduced and blood flow is increased. If viscosity is too thick the BP is higher because in a viscous fluid there is illegal friction between the molecules as they slide by each other. ii. Radius or size of arteries The arteries and arterioles help in transportation of blood from the heart, these vessels have layers of smooth muscles elastic tissues which helps in the elongation and recoil to push blood, also it responds to nerve and chemical innervation. If these elastic qualities of the vessels are replaced with inelastic fibrous tissues or weakened due to age, the force of recoil is affected thereby causing an increase in resistance to flow of blood leading to increase BP. iii. The lumen of the arteries becomes smaller in size due to fatty deposition on its walls, the smaller the lumen of a vessel, the greater the resistance. Mechanism involved in Blood Pressure Regulation 1. Sympathetic Stimulation During sympathetic stimulation adrenalin (cardiac accelerator) is released and this increases the peripheral resistance and heart rate, which increases blood flow and further rises Bp. 2. Parasympathetic (Vagal) Stimulation When there rise in BP, it excite the vagal nerve, this effect reduces the heart rate and cardiac output by dilating the arteries and veins. 3. Baroreceptor Mechanism The baroreceptor are nerve receptors in the wall of the great vessels like the aorta and the carotids that are sensitive to changes in Bp. When the arterial pressure becomes high, these baroreceptors are stimulated and impulses are transmitted to the medulla of the brain to inhibit the vasomotor center, which in turn decreases the number of impulses transmitted through the sympathetic nervous system to the heart and blood vessels. Lack of these impulses causes diminished pumping activity of the heart and an increased ease of blood flow through the peripheral vessels both of which lowers the arterial pressure back to  normal. Conversely, a fall in arterial pressure relaxes the stretch receptors, allowing the vasomotor center to become more active than usual with resultant rise in Bp. 4. Renin-Angiotensin If the lumen of the artery is narrowed due to arteriosclerosis or renal artery stenosis, this results in a decrease in the volume of blood supplies to the kidney. The receptors of the kidney sensitive to changes in blood volume then secretes a substance called renin. Renin while circulating in the blood acts on a protein component (angiotensinogen) and convert it to angiotensin. Angiotensin causes constriction of blood vessels and also stimulates the release of aldosterone from the adrenal gland. Aldosterone causes salt and water retention. The above leads to increase in Bp. Factors Influencing Blood Pressure The following are factors that influences Bp a. Age: At old age due to degenerative process, the arterial wall becomes more rigid and less yielding to pressure and no longer retract as flexibly to decreased pressure, hence the high Bp. b. Exercise: this increases cardiac output with consequent increase in Bp. c. Stress: during stress there is stimulation of the sympathetic nervous system leading to increased cardiac output with increased vasoconstriction which results in BP. d. Obesity: Bp is higher in obese people due to arteriosclerosis. e. Sex: after puberty, females usually have lower Bp than males of the same age due to hormonal variation. Medications: some medication increases the Bp while drug like digoxin reduces it. How to assess BP Equipment BP is measured non-invasively, with a sphygmomanometer with appropriate cuff and a stethoscope; and the most common site used is the brachial artery. Alcohol soaked swabs, observation chart Procedure a. Assess the patients knowledge of the procedure and explain as necessary b. Ensure the patient is resting in a comfortable position. c. When applying the cuff, no clothing should be underneath it if clothing constricts the arm remove the arm from the sleeve. d. Apply the cuff so that the center is over the brachial artery 2 - 3cm above the antecubital fossa. e. Position the arm so that the cuff is level with the heart and may be more comfortable resting on a pillow f. Ensure you place the sphygmomanometer on a firm surface, facing you, with the center of the mercury column at eye level. g. Connect the cuff tubing to the sphygmomanometer. h. Locate the radial pulse. Squeeze the bulb slowly to inflate the cuff while still feeling the pulse. Observe the mercury column and note the level when the pulse can no longer be felt. Unscrew the valve and quickly release the pressure in the cuff. i. If using a general stethoscope clean the earpieces with an alcohol soaked swab. Curving the ends of the stethoscope slightly forward, place the earpieces in your ears. Place earpiece in your ear, ensure tubes are not twisted, clean earpiece if it's general. Tap the diaphragm part of with your finger to ensure its not faulty.  j. Palpate the brachial artery, which is located on the medial aspects of antecubital fossa. k. Place the diaphragm of the stethoscope over the artery, and hold it in place with your thumb while using your fingers to support the patient’s elbow. l. Ensure your facing the mercury column of the sphygmomanometer. m. Ensure that the valve on the bulb is closed firmly but not too tightly, so that it can be loosened with one hand. Inflate the cuff to 20 - 30 mmHg above the level noted. Open the valve to allow the column of mercury to drop slowly. n. While observing the level of mercury as it falls, listen for korotkoff (thudding) sounds: Sudden appearance of a sharp click sound which increases in intensity and duration until it reaches a peak, then suddenly becomes muffled and less intense after a further fall of about 5mmHg. The systolic pressure is the level where this is first heard; the diastolic pressure is the level where the sounds disappear. o. Once the sounds have disappeared, open the valve fully, to completely deflate the cuff, and remove it from the patient’s arm. p. Document accurately, note and report any abnormal BP. Earlier BP is measured with a stethoscope and sphygmomanometer (i.e auscultation). However, semi automated and automated devices that use the oscillometry method, which detects the amplitude of the BP oscillations on the arterial wall, have become widely used over the years.