Vital Signs and Blood Pressure (RN 31: Unit 2) PDF

RN 31: Unit 2 Vital signs Describe the physiology and expected reference ranges of vital signs. Describe assessment techniques used to obtain vital signs. Analyze alterations in vital signs. Plan nursing inter...

RN 31: Unit 2 Vital signs Describe the physiology and expected reference ranges of vital signs. Describe assessment techniques used to obtain vital signs. Analyze alterations in vital signs. Plan nursing interventions in response to an alteration in vital signs. Evaluate the effectiveness of interventions to determine the extent to which client outcomes have been met. Demonstrate accurate documentation of vital signs. Blood Pressure What is blood pressure and how is it measured? Blood pressure is the pressure exerted by blood within the circulatory system. Measured in mm Hg, expressed as systolic over diastolic pressure. Systolic pressure: Maximum pressure when the heart contracts (systole). Diastolic pressure: Minimum pressure when the heart relaxes (diastole). How does cardiac output affect blood pressure? Cardiac output (CO): Blood pumped by the heart per minute. Stroke volume (SV): Blood ejected per contraction. Formula: CO = SV × HR (heart rate). Effects: Increased CO → Increased BP. Decreased CO → Decreased BP. Lower SV or HR → Lower BP. Higher SV or HR → Higher BP. RN 31: Unit 2 1  What factors influence blood pressure? Blood volume: More volume → Higher BP. Less volume (e.g., hemorrhage) → Lower BP. Blood viscosity (thickness): Increased viscosity → Increased resistance → Higher BP. How does vessel elasticity and vascular resistance affect blood pressure? Elasticity: Vessels stretch and compress with blood flow. Decreased elasticity → Increased vessel rigidity → Increased BP. Peripheral vascular resistance: Ability of vessels to accommodate blood flow without raising BP. Increased resistance (e.g., atherosclerosis) → Increased BP → Heart works harder. What are contractility, preload, and afterload, and how do they impact blood pressure? Contractility: Heart’s ability to contract efficiently. Measured by ejection fraction (percentage of blood ejected per contraction). Decreased contractility → Lower CO → Lower BP. Causes: Low oxygen, electrolyte imbalances. Preload: Blood volume in ventricles before contraction. Low preload (e.g., blood loss) → Lower SV & BP. High preload (e.g., exercise) → Stronger contraction & higher BP. Afterload: Resistance the heart must overcome to eject blood. Increased afterload → Heart hypertrophy → Reduced contractility. Hypertension is a common cause. What is the pathway of blood flow through the heart? RN 31: Unit 2 2  Deoxygenated blood: Systemic circulation → Inferior & superior vena cavae → Right atrium. Right atrium → Tricuspid valve → Right ventricle. Right ventricle → Pulmonary artery → Lungs. Oxygenated blood: Lungs → Pulmonary vein → Left atrium. Left atrium → Mitral valve → Left ventricle. Left ventricle → Aorta → Systemic circulation. When should blood pressure be measured, and why is accuracy important? BP should be measured in clients over 3 years old or younger with preexisting conditions. Accurate BP measurement is critical for treatment decisions. What equipment is used to measure blood pressure? Sphygmomanometer: Cuff with inflatable bladder connected to a manometer. Stethoscope: Used for auscultation to detect Korotkoff sounds. What is the palpation method for measuring blood pressure, and when is it used? Used when Korotkoff sounds are hard to hear or digital monitors are unreliable. Steps: Wrap the cuff around the limb (arm, forearm, thigh, or calf). Palpate the artery distal to the cuff (e.g., brachial, radial, popliteal). Inflate the cuff 30–50 mm Hg above where the pulse disappears. Slowly deflate the cuff at 2–3 mm Hg/sec. Note: First pulsatile thrill → Estimated systolic BP. RN 31: Unit 2 3  Thrill disappearance → Estimated diastolic BP. Accurate observation is essential. How is blood pressure measured electronically, and when should manual measurement be used? Electronic measurement: Uses a machine with an automatic cuff. Displays BP on a screen. Manual measurement is preferred: More accurate than electronic readings. Confirm manually if electronic reading is abnormal. Recommended for children, older adults, critically ill clients, and those with BP abnormalities. Why is selecting the correct cuff size important for accuracy? Upper arm is the most common site for BP measurement. Cuff selection: Should encircle ~80% of the limb circumference. Effect of improper sizing: Too narrow → Overestimates BP (false high). Too wide → Underestimates BP (false low). What should the nurse do before obtaining a blood pressure reading? Explain the procedure to the client. Ask the client to remove bulky clothing from the measurement site. Position the client: Supine or seated (standing if orthostatic BP is needed). If seated: Feet flat on the floor, legs uncrossed. Support the arm at heart level, palm facing upward. How is the blood pressure cuff applied correctly? RN 31: Unit 2 4  Wrap the cuff snugly around the upper arm, 1 inch above the antecubital fossa. Align the artery indicator with the brachial artery. Place the bell or diaphragm of the stethoscope over the brachial artery. What are the steps for obtaining a manual blood pressure reading? Inflate the cuff 30 mm Hg above the expected systolic BP. Slowly deflate at ~2 mm Hg per second. Korotkoff sounds: First sound → Systolic BP. Disappearance of sound → Diastolic BP. When should an alternative site be used for blood pressure measurement? Avoid the upper arm if the client has: Lymph node removal from breast surgery. Recent surgery or acute injury (e.g., fracture). Medical devices (e.g., central IV line, arteriovenous shunt, peripheral IV catheter). Use the thigh if both arms are unsuitable (e.g., severe edema). Thigh BP considerations: Use a thigh-specific or appropriately sized cuff. Palpate or auscultate the popliteal artery for measurement. Thigh BP is usually higher than arm BP in most adults. How does obesity impact blood pressure measurement? Challenge: Arm circumference >50 cm makes standard cuffs inaccurate. Solutions: Use forearm, thigh, or conical-shaped cuffs. Ensure proper cuff fit to prevent misdiagnosis or incorrect treatment. RN 31: Unit 2 5  What factors can cause inaccurate blood pressure readings? Cuff issues: Too small/tight → False high reading. Too large/loose → False low reading. Other factors: Unsupported arm during measurement. Not allowing rest after activity. White coat syndrome: Anxiety-induced BP elevation. Minimization: Build rapport and allow the client to rest before measuring. What factors influence blood pressure? Intrinsic (non-modifiable) factors: Age: Increases through childhood, peaks in adulthood, and slightly decreases in older age. Ethnicity & genetics: Some groups have a higher risk of hypertension. Hormonal variations: Natural fluctuations affect BP. Extrinsic (modifiable) factors: Weight: Higher weight often increases BP. Stimulants (caffeine, nicotine): Can cause temporary spikes. Medications & sodium intake: Some raise or lower BP. Stress & activity level: Stress elevates BP; exercise can help regulate it. Health conditions: Pain & fever → Increase BP. Hypoglycemia & heart failure → Decrease BP. Are wrist monitors and smartphone apps accurate for measuring blood pressure? RN 31: Unit 2 6  Popular for home use, but not suitable for clinical settings unless no alternatives are available. AHA recommends using validated devices to ensure accuracy. What are the classifications of hypertension? Elevated BP: Systolic 120–129 mm Hg, Diastolic 180 mm Hg and/or Diastolic >120 mm Hg (requires immediate intervention). Diagnosis: Requires at least two elevated readings on separate occasions. Blood Pressure Charts RN 31: Unit 2 7  How can nurses help clients manage hypertension? Lifestyle interventions: Exercise, stress reduction, low-sodium diet, weight loss if needed. Medication education: Explain antihypertensive drugs, side effects, and when to notify the provider. What is hypotension, and what are its causes and symptoms? Definition: BP below the expected range; generally systolic 120 mm Hg A nurse has implemented interventions for a client experiencing hypotension. Which of the following actions should the nurse take next to evaluate the effectiveness of the interventions? Recheck the client's blood pressure after having them relax and take slow, deep breaths. Avoid prolonged sitting, which can increase the risk of orthostatic hypotension. A nurse is caring for a client who reports dizziness when standing up. The client’s blood pressure after lying supine for 15 minutes is 136/86 mm Hg in the left arm. Which of the following findings would indicate the client is experiencing orthostatic hypotension? B/P 114/72 mm Hg, left arm, immediately after standing A nurse is discussing factors affecting blood pressure with an assistive personnel. Which of the following factors should the nurse identify as potential causes for an increase in a client’s blood pressure? (Select all that apply.) Factors such as anxiety, use of nicotine, obesity, and fear can cause an increase in blood pressure. Other factors that can cause such an increase RN 31: Unit 2 11  include older adult age, some types of medications, and medical conditions that affect blood volume or blood flow. The nurse should use clinical judgment and critical thinking when interpreting the significance of a client’s blood pressure measurement. Respiration How do you measure the client's respiration rate? 1. Opening procedure; 2. Position client sitting or lying, with head of bed elevated 40 to 65 degrees. 3. Keep your fingers in place to measure the pulse and observe the rise and fall of the client's chest for one full respiratory cycle. 4. Using a watch with a second hand, count the number of respirations for 30 seconds and multiply by 2. 5. If the rhythm is irregular or the rate is abnormal, count respirations for a full minute. 6. Note the depth (shallow, normal, or deep) and rhythm (regular or irregular). 7. Replace the client’s gown or bed linens. 8. Ensure the client is in a safe position, and the call light is within reach. 9. Compare your findings with the client’s baseline. Pulse How to Take the Apical-Radial Pulse Rate? Positioning: Have the patient rest in a comfortable position. Locate the apical pulse (at the 5th intercostal space, midclavicular line) and the radial pulse (at the wrist). Measurement: Apical pulse: Using a stethoscope, listen to the heartbeat at the apical site for a full minute. RN 31: Unit 2 12  Radial pulse: Use your fingers to feel for the pulse at the radial artery and count for a full minute. Simultaneous Measurement: Have one nurse listen to the apical pulse while another nurse measures the radial pulse simultaneously, or if done alone, take one pulse after the other but within the same time frame. The key is to compare the two pulse rates over the same period. What is a Pulse Deficit? Pulse deficit refers to the difference between the apical and radial pulse rates. Calculation: If the apical pulse is higher than the radial pulse, subtract the radial pulse rate from the apical pulse rate. Pulse Deficit = Apical Pulse - Radial Pulse Why Calculate Pulse Deficit? A pulse deficit indicates that some heartbeats are not being transmitted to the peripheral circulation, which can be caused by conditions like arrhythmias (e.g., atrial fibrillation). It helps assess the efficiency of the heart's pumping action and can be used to monitor for cardiac irregularities. Pulse deficit refers to the difference between the apical and radial pulse rates. Calculation: If the apical pulse is higher than the radial pulse, subtract the radial pulse rate from the apical pulse rate. Pulse Deficit = Apical Pulse - Radial Pulse What is a normal pulse rate for adults and how can it vary? RN 31: Unit 2 13  Normal adult pulse rate: 60–100 beats per minute (bpm). Variations: Slightly faster in females. More rapid in infants and children. Influenced by factors like exercise, medications, oxygen saturation, blood loss, body temperature, sex, and age. Important to determine the client’s baseline pulse rate for accurate assessment. What conditions are associated with bradycardia (pulse rate < 60 bpm)? Bradycardia is a pulse less than 60/min. It is common in physically fit individuals but may cause dizziness, fatigue, or chest pain in others. Possible causes include heart conditions or hypothyroidism. Nursing interventions include encouraging slow position changes, taking medications as prescribed, and notifying the provider if symptoms worsen. Causes: Decreased thyroid activity, hyperkalemia, irregular cardiac rhythm, and increased intracranial pressure. Note: Athletes with cardiovascular conditioning may have pulse rates in the 50s without issues. What conditions are associated with tachycardia (pulse rate > 100 bpm)? Tachycardia is defined as a pulse greater than 100/min. Common causes: exercise, anxiety, certain medications, caffeine, nicotine, or abnormal heart electrical activity. Causes: Congestive heart failure (CHF), hemorrhage, shock, dehydration, and anemia. Management includes relaxation techniques (meditation, yoga), the Valsalva maneuver (bearing down to decrease heart rate), and quitting smoking. If tachycardia persists, notify the provider. Symptoms: Dyspnea, fatigue, chest pain, palpitations, and edema. RN 31: Unit 2 14  When does an abnormal pulse rate require further evaluation? If the pulse is irregular, weak, slow, or rapid—especially if sustained—it might indicate the heart is not functioning properly and should be further evaluated. How should a nurse assess pulse rhythm and what actions should be taken if it's irregular? The nurse should assess both the pulse rate and rhythm, noting if it’s regular or irregular. An irregular rhythm or pulse rate outside the expected reference range is called arrhythmia. Some arrhythmias may not cause symptoms, while others may lead to shortness of breath or dizziness. If irregularity is detected, the nurse should auscultate the apical pulse for 1 full minute to confirm and notify the provider. Where is the apical pulse located, and how is it assessed in adults and children? In adults, adolescents, and children older than 7, the apical pulse is located at the fifth intercostal space on the left side of the chest at the midclavicular line. In children younger than 7, it is located at the fourth intercostal space to the left of the sternum. The nurse should palpate and auscultate over the apex of the heart. What are the heart sounds, and how should they be auscultated? The heart has two distinct sounds: S1 (dull, low-pitched “lub” when mitral and tricuspid valves close) and S2 (higher-pitched “dub” when aortic and pulmonic valves close). S1 is best auscultated with the bell of the stethoscope, and S2 with the diaphragm. The nurse should auscultate all four cardiac valves (aortic, pulmonic, tricuspid, and mitral) at their respective locations. RN 31: Unit 2 15  The number of “lub-dub” sounds in 1 minute is counted as the apical pulse rate. How is pulse strength assessed and rated during palpation? The nurse palpates the peripheral pulse and notes its strength, using the following scale: 0 = absent/nonpalpable pulse +1 = weak/diminished pulse +2 = normal pulse +3 = increased/strong pulse +4 = bounding pulse A strong pulse that can only be obliterated with significant pressure is an expected finding. Nonpalpable, weak, or bounding pulses are unexpected and require provider notification. What should the nurse do if the peripheral pulse is nonpalpable or difficult to assess? If the pulse is nonpalpable or difficult to assess, the nurse should use a Doppler ultrasound stethoscope (DUS) to auscultate the pulse. The nurse should also check for signs of impaired circulation, such as cool skin or a change in skin color. Any abnormal pulse findings or impaired circulation should be reported to the provider. Temperature What is the normal reference range for body temperature in adults? 36° C to 38° C (96.8° F to 100.4° F). What is the average adult body temperature? 37° C (98.6° F), with a slightly lower average in older adults. How does body temperature fluctuate throughout the day? RN 31: Unit 2 16  The lowest temperature occurs early in the morning, and the highest temperature occurs in late afternoon. What factors can influence body temperature? Exercise, stress, and the environment can increase or decrease body temperature. What is thermoregulation? The body’s mechanism for balancing body temperature through processes like shivering, sweating, and vasodilation/constriction. What are the four processes through which the body loses heat to the environment? Conduction, convection, evaporation, and radiation. What is a fever? An increase in body temperature above the expected reference range due to a shift in the hypothalamus' set point, often caused by infection. What are common signs and symptoms of a fever? Flushed face, diaphoresis (sweating), hot skin on palpation, tachycardia, and increased respiratory rate. What is the difference between febrile and afebrile? Febrile means the client has a fever; afebrile means the fever has resolved and body temperature has returned to normal. What is hyperthermia? An increase in body temperature due to the body’s inability to regulate heat production or loss, often caused by hypothalamus dysfunction. What are the signs and symptoms of hyperthermia? Dizziness, weakness, thirst, nausea, hypotension, syncope, confusion, tachycardia, and impaired coordination. If untreated, it may lead to organ failure and death. What are nursing interventions for hyperthermia? RN 31: Unit 2 17  Move the client to a cooler environment, remove excess clothing, apply cold packs to the neck, axillae, and groin, use a fan, administer IV fluids, and monitor the client's temperature. Notify the provider of any changes in health status. What is hypothermia and what causes it? Hypothermia is a decrease in core body temperature caused by extended cold exposure or the inability to generate heat. What are the early and severe manifestations of hypothermia? Early: shivering, decreased motor skills, impaired peripheral perfusion. Severe: confusion, poor concentration, dilated pupils, loss of consciousness, deep tendon reflex loss, coma, cardiac arrest. What nursing interventions are effective for clients with mild hypothermia? Increase room temperature, add clothing layers, and place a hat on the client's head. What are the interventions for significant hypothermia and how should the nurse monitor the client? Use warming mats/blankets, administer warmed IV fluids, and monitor core temperature frequently. Notify the provider if the temperature doesn’t increase. What factors should the nurse consider when selecting a site for body temperature measurement? Age, health status, and environmental factors that could affect the client's temperature. When should the nurse wait to obtain an oral temperature after a client has eaten, drunk, or smoked? The nurse should wait 15 to 30 minutes before taking an oral temperature after these activities. Why is the rectal route for temperature measurement avoided in newborns or young infants? RN 31: Unit 2 18  It can cause trauma to the delicate rectal mucosa unless specifically prescribed by the provider. What is a temporal thermometer and how does it measure temperature? A temporal thermometer uses an infrared sensor to measure the temperature of blood flow through the temporal artery. How do electronic thermometers work and what must the nurse do before using them? Electronic thermometers display temperature in a window after a quick reading. The probe must be covered with a disposable cover before use. How does a tympanic thermometer work and how is it used? A tympanic thermometer uses infrared scanning from a speculum inserted into the auditory canal to measure heat radiating from the tympanic membrane. What are chemical dot thermometers, and how can they be used? They are thin strips of plastic with temperature-sensitive dots that change color. They can be used orally, in the axilla, or rectally if covered with a sheath. How do temperature-sensitive patches or tapes work to measure body temperature? They contain liquid crystals that change color based on temperature, applied to a dry area of the skin. What is the correct technique for measuring an oral temperature? Apply a disposable probe cover, ensure the client hasn’t smoked or consumed hot/cold food/drink in the last 30 minutes, place the probe under the tongue, instruct the client to close lips, and hold until the temperature is displayed. Remove the probe, discard the cover, and document the result. RN 31: Unit 2 19 RN 31: Unit 2 20 RN 31: Unit 2 21