PA Ch 10-11

What are the four traditional vital signs?

Temperature, respirations, pulse, and blood pressure.

What is the average core body temperature?

37.2°C (99°F).

What part of the brain regulates body temperature?

The hypothalamus.

What is the purpose of the hypothalamus in temperature regulation?

It balances heat production and heat loss.

What are the four mechanisms of heat loss?

Conduction, convection, evaporation, and radiation.

What is conduction?

Transfer of heat through direct contact with another surface.

What is convection?

Loss of heat through air currents moving across the skin.

What is evaporation?

Loss of heat through water evaporation such as sweating.

What is radiation?

Transfer of heat without direct contact between objects.

What is diaphoresis?

Visible perspiration on the skin.

How does exercise affect body temperature?

It increases body temperature.

How does ovulation affect body temperature?

It causes a slight increase due to progesterone release.

How does aging affect body temperature?

Older adults generally have lower baseline temperatures.

What is hyperthermia?

Elevated body temperature above normal range.

What temperature is considered hyperthermia?

Greater than 37.5°C.

What is hypothermia?

Abnormally low body temperature.

What temperature is considered hypothermia?

Less than 36°C.

What are common causes of fever?

Infection, inflammation, dehydration, and tissue breakdown.

Why do newborns lose heat easily?

They have a large surface area relative to body mass.

What is the normal temperature range for newborns?

36.5°C–37.5°C (97.7°F–99.5°F).

What is the average normal oral temperature?

37°C (98.6°F).

How does rectal temperature compare with oral temperature?

Rectal temperature is about 0.4–0.5°C higher.

Which sites reflect core temperature?

Rectum, tympanic membrane, temporal artery, pulmonary artery, esophagus, and urinary bladder.

What are the advantages of oral temperature measurement?

Accurate, convenient, and reflects core temperature.

Why should oral temperature not be taken immediately after eating or drinking?

It can falsely alter the reading.

What age is generally appropriate for oral temperature measurement?

Age 4 years and older.

When should oral temperature not be used?

Facial trauma, mouth breathing, or inability to cooperate.

How is axillary temperature obtained?

By placing the probe in the center of the axilla and holding the arm against the body.

When is rectal temperature used?

When other routes are impractical or unreliable.

What are disadvantages of rectal temperatures?

Discomfort, invasiveness, and time required.

What is a tympanic thermometer?

A device that measures infrared heat from the eardrum.

Why is the tympanic membrane useful for temperature assessment?

It shares blood supply with the hypothalamus.

What are advantages of tympanic thermometers?

Fast, safe, noninvasive, and useful for unconscious patients.

What is a temporal artery thermometer?

A device that measures infrared heat from the temporal artery.

How is a temporal artery temperature obtained?

By sliding the probe across the forehead and behind the ear.

What is the formula for Fahrenheit to Celsius conversion?

(F − 32) ÷ 1.8.

What is the formula for Celsius to Fahrenheit conversion?

(C × 1.8) + 32.

How should respirations normally appear?

Relaxed, regular, automatic, and silent.

Why should a patient not be told that respirations are being counted?

Awareness may alter breathing patterns.

How long should respirations generally be counted?

30 seconds or 1 full minute if irregular.

What is the normal adult respiratory rate?

12–20 breaths per minute.

What three characteristics are assessed during respiratory assessment?

Rate, depth, and rhythm.

What is respiratory rate?

The number of respirations per minute.

What is respiratory depth?

The amount of chest expansion with each breath.

What is respiratory rhythm?

The pattern and regularity of breathing.

What is eupnea?

Normal breathing pattern.

What is tachypnea?

Abnormally rapid breathing.

What is dyspnea?

Difficult or labored breathing.

What is shortness of breath (SOB)?

A sensation of difficult breathing.

What are accessory muscles?

Muscles used to assist breathing during respiratory distress.

What is nasal flaring?

Widening of the nostrils during breathing effort.

What are intercostal retractions?

Inward movement of tissues between the ribs during breathing.

How does pain affect respirations?

It may increase the rate and decrease the depth.

How does anxiety affect respirations?

It increases rate and depth.

How does smoking affect respirations?

It increases resting respiratory rate.

How does upright positioning affect breathing?

It allows greater chest expansion.

What is pulse oximetry?

A noninvasive method of measuring oxygen saturation.

What does SpO2 represent?

The percentage of hemoglobin saturated with oxygen.

What is the expected normal SpO2 range?

95%–100%.

What is a normal SpO2 for a healthy adult?

97%–98%.

What is pulse?

A palpable pressure wave produced by heart contraction.

What four pulse characteristics are assessed?

Rate, rhythm, force, and elasticity.

Where is the radial pulse located?

On the thumb side of the wrist.

How long should a regular pulse be counted?

30 seconds and multiplied by 2.

How long should an irregular pulse be counted?

One full minute.

What is the normal adult pulse rate?

60–100 beats per minute.

What is bradycardia?

A heart rate less than 60 bpm.

What is tachycardia?

A heart rate greater than 100 bpm.

What causes tachycardia?

Fever, exercise, anxiety, pain, anemia, hypoxemia, shock, or hyperthyroidism.

What causes bradycardia?

Hypothermia, certain medications, hypothyroidism, athletics, and relaxation.

What is sinus dysrhythmia?

A normal variation where heart rate changes with respiration.

What is pulse symmetry?

Equal pulse quality and strength on both sides of the body.

What may an unequal pulse indicate?

Trauma, thrombus, or vascular disease.

What does a bounding pulse indicate?

Increased stroke volume.

What does a weak, thready pulse indicate?

Decreased stroke volume.

What is the pulse strength scale?

0 absent, 1+ weak, 2+ normal, 3+ bounding.

Where is the apical pulse located?

5th intercostal space at the left midclavicular line.

When should the apical pulse be assessed?

Infants, irregular rhythms, heart rate >100 bpm, and before cardiovascular medications.

What is blood pressure?

The force of blood against vessel walls.

What equation describes blood pressure?

BP = Cardiac Output × Systemic Vascular Resistance.

What is cardiac output?

The amount of blood pumped by the heart per minute.

What factors affect cardiac output?

Heart rate, contractility, blood volume, and venous return.

What is systemic vascular resistance?

The resistance blood encounters in the vessels.

What is systolic blood pressure?

The maximum pressure during ventricular contraction.

What is diastolic blood pressure?

The pressure during ventricular relaxation.

What is pulse pressure?

The difference between systolic and diastolic pressure.

What is mean arterial pressure (MAP)?

The average pressure forcing blood into tissues.

What is the average adult blood pressure?

120/80 mmHg.

How does obesity affect blood pressure?

It increases blood pressure.

How does acute stress affect blood pressure?

It increases blood pressure.

What medications can lower blood pressure?

Opiates, antihypertensives, and some cardiac medications.

What medications can increase blood pressure?

Cocaine, nicotine, oral contraceptives, alcohol, and some antidepressants.

What are the five major determinants of blood pressure?

Cardiac output, peripheral resistance, blood volume, blood viscosity, and vessel elasticity.

What is hypotension?

Blood pressure below normal range.

What systolic pressure is considered hypotension?

Less than 90 mmHg.

What conditions can cause hypotension?

Shock, hemorrhage, myocardial infarction, vasodilation, and Addison disease.

What is orthostatic hypotension?

A decrease in blood pressure when changing positions.

What are causes of orthostatic hypotension?

Fluid depletion, medications, anemia, vasodilation, and prolonged bed rest.

What is hypertension?

Persistently elevated blood pressure.

What are hypertension risk factors?

Smoking, obesity, diabetes, age, stress, family history, and high sodium intake.