Vital Signs and Respiratory Assessment

Vital Signs

• Vital signs include respiration and blood pressure.
• Respiration is measured in breaths per minute.
• Inspiration is inhaling air into the lungs, expiration is exhaling gases.
• One breath consists of one inhalation and one exhalation.
• There are two main types of breathing: costal (thoracic) and diaphragmatic (abdominal).
• Costal breathing uses intercostal muscles for moving the chest, diaphragmatic breathing uses the diaphragm.
• Normal breathing is automatic and effortless.
• Normal adult inspiration is 1-1.5 seconds and expiration is 2-3 seconds.
• Expiration takes twice as long as inspiration.
• When assessing respiration, consider the client's normal pattern, health problems, medications, and cardiovascular function.
• Assess rate, depth, rhythm, quality, and effectiveness of respiration.
• Eupnea is normal respiration rate and depth (12-20 breaths per minute).
• Bradypnea is abnormally slow respiration (<12 breaths per minute).
• Tachypnea/polypnea is abnormally fast respiration (>20 breaths per minute).
• Apnea is absence of breathing.
• Assessing depth/volume: normal is 500 mL, deep is over 500 mL, shallow is under 500 mL.
• Hyperventilation is very deep, rapid respiration.
• Hypoventilation is very shallow respiration.
• Regualrity of inspiration and expiration is assessed using rhythm.
• Normal breathing is silent and effortless. Labored breathing shows effort in breathing with substantial effort.
• Abnormal breathing sounds like wheezing can be detected.
• The effectiveness of respiration is measured partially by uptake of oxygen and release of carbon dioxide from the blood.
• Pulse oximeter is used to check pulse rate and oxygen saturation in arterial blood.

Factors Affecting Respiration

• Factors increasing respiration rate (RR): exercise, stress, increased environmental temperature, low oxygen concentration, fever, health status such as anemia.
• Factors decreasing respiration rate: decreased environmental temperature, certain medications, increased intracranial pressure, body position affecting inhaled air.

Blood Pressure

• Blood pressure is the force exerted by blood on artery walls and measured using a sphygmomanometer, stethoscope, and cuff.
• Systolic pressure is the pressure when the heart contracts.
• Diastolic pressure is pressure when the heart relaxes.
• Pulse pressure is the difference between systolic and diastolic pressure, usually 40 mmHg.
• Blood pressure is measured in millimeters of mercury (mmHg).
• Normal systolic blood pressure is 120 and diastolic is 80, stated as 120/80 mmHg.
• Factors affecting BP: age, exercise, stress, race, gender, medication, obesity, diurnal variation, and medical conditions.

Hypertension

• Hypertension is persistently high blood pressure.
• It's often asymptomatic but can lead to complications like a myocardial infarction (MI).
• Primary hypertension has no known cause, while secondary hypertension has a known cause.
• Patients are diagnosed as hypertensive when their diastolic pressure is above 90 mmHg or systolic pressure is above 140 mmHg for more than two readings.

Hypotension

• Hypotension is persistently low blood pressure.
• Systolic BP is measured as 85-110 mmHg.
• Orthostatic hypotension is a drop in blood pressure when standing up, due to peripheral vasodilation, blood leaving the central body organs.
• Other causes of hypotension may include analgesia, bleeding, severe burns, and dehydration.
• Orthostatic hypotension can be assessed by observing the patient in a supine position for 10 minutes, then have the patient sit or stand, reassess the pulse and BP, then assess again after 3 minutes. A 15-30 beat per minute rise in pulse or a 20 mmHg drop in systolic BP, or 10 mmHg drop in diastolic BP indicate orthostatic hypotension.

Assessing Blood Pressure

• Blood pressure is measured using a blood pressure cuff, sphygmomanometer, and stethoscope.
• The cuff width should be 40% of the arm circumference, and the length needs to cover about two-thirds of the arm circumference. Sites for measurement include the upper arm (brachial artery), and thigh (popliteal artery).
• Types of sphygmomanometers include aneroid, mercury, and electronic/digital.
• There are 5 Korotkoff phases, the sounds heard during blood pressure measurement.

Common Errors in Blood Pressure Assessment

• Common errors include using a cuff that is too narrow or too wide, not supporting the arm adequately, taking readings too frequently, deflating the cuff incorrectly, and not having the arm at heart level.