Physiology of Blood Pressure Regulation

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Questions and Answers

What is the normal range of oxygen saturation in a healthy person?

85-90%

90-95%

95-100% (correct)

100-105%

What is the difference between systolic pressure and diastolic pressure?

Systolic is the average pressure, diastolic is the minimum pressure

Systolic is the pressure during left ventricular contraction, diastolic is the pressure during left ventricular relaxation (correct)

Systolic is the pressure during left ventricular relaxation, diastolic is the pressure during left ventricular contraction

Systolic is the minimum pressure, diastolic is the maximum pressure

Where can a pulse oximeter sensor be applied?

To the finger, forehead, or earlobe (correct)

Only to the forehead or earlobe

Only to the finger

To the toe or nose

What is pulse pressure?

The difference between systolic and diastolic pressure Signup and view all the answers

What is the minimum mean arterial pressure required to maintain adequate tissue perfusion?

60mmHg Signup and view all the answers

What is the force that pushes against the arterial walls?

Blood pressure Signup and view all the answers

What is the normal temperature range in Celsius?

36°C to 38°C Signup and view all the answers

Which of the following routes of temperature measurement yields a reading 0.5°C higher than oral temperature?

Rectal Signup and view all the answers

What is the average oral temperature in Fahrenheit?

98.6°F Signup and view all the answers

When assessing pulse, how long should you count for if the rhythm is regular?

30 seconds Signup and view all the answers

What is the term for a temperature below 36°C (96.8°F)?

Hypothermia Signup and view all the answers

When palpating peripheral pulse, what part of the fingers should be used to compress the artery?

Pads of the first 2 fingers Signup and view all the answers

What is one of the factors that increases blood pressure?

Stiff vessel walls Signup and view all the answers

Why is it recommended to avoid smoking or drinking caffeinated beverages 30 minutes prior to measuring blood pressure?

To prevent temporary increases in blood pressure Signup and view all the answers

What is the correct position of the arm during blood pressure measurement?

Arm should be at heart level Signup and view all the answers

What is the purpose of adding 20-30mmHg to the pressure at which the pulse disappears during palpation?

To determine the maximum inflation pressure Signup and view all the answers

What is the auscultatory gap?

A period of silence between SBP and DBP Signup and view all the answers

Why is it important to palpate the brachial artery during blood pressure measurement?

To locate the correct position for the cuff Signup and view all the answers

What is the correct sequence of steps during blood pressure measurement?

Palpate the brachial artery, rapidly inflate the cuff, and then listen for Korotkoff sounds Signup and view all the answers

Why is it important to use the correct size cuff for the patient?

To reduce the risk of inaccurate measurement Signup and view all the answers

Study Notes

Blood Pressure

Cardiac output, vascular resistance, blood volume, and elasticity of vessel walls all impact blood pressure
Increased cardiac output, vascular resistance, or blood volume, or decreased elasticity of vessel walls can lead to increased blood pressure

Optimal Conditions for Blood Pressure Measurement

Avoid smoking or drinking caffeinated beverages 30 minutes prior to measurement
Ensure a quiet, comfortably warm room
Patient should be seated quietly in a chair with both feet on the floor for at least 5 minutes
Arm should be free of clothing
Use the correct size cuff for the patient
Palpate the brachial artery, not the radial artery
Position the arm so that the brachial artery is at heart level

Measurement of Blood Pressure (Part I)

Determine max inflation pressure by palpating the brachial artery
Center the cuff over the brachial artery, 2.5cm above the antecubital crease, and secure it snugly
Palpate the brachial artery while inflating the cuff and note the mmHg when the pulse disappears
Deflate the cuff, wait 15-30 seconds, and re-inflate to max inflation pressure

Auscultatory Gap

A period of silence between systolic and diastolic blood pressure that occurs in ~5% of people, often in hypertension
Caused by a non-compliant arterial system

Measurement of Blood Pressure (Part II)

Listen for Korotkoff sounds with a stethoscope
Rapidly inflate the cuff to max inflation pressure, then deflate and listen for sounds

Vital Signs

Temperature: influenced by diurnal cycle, menstrual cycle, stress, exercise, age, and external temperature
Routes of temperature measurement: oral, temporal artery, rectal, axillary, and tympanic membrane
Normal temperature range: 96.8°F to 100.4°F (36°C to 38°C)

Pulse

Rate: measured by auscultating the apical pulse or palpating the peripheral pulse
Rhythm: regular or irregular
Effort: diaphragmatic or thoracic, with or without accessory muscle use

Oxygen Saturation (SpO2)

Measurement of arterial oxygenation using a pulse oximeter
Normal SpO2 range: 95-100%

Blood Pressure Terminology

Systolic pressure (SBP): maximum pressure during left ventricular contraction
Diastolic pressure (DBP): minimum pressure between left ventricular contractions
Pulse pressure: difference between SBP and DBP
Mean arterial pressure (MAP): average pressure forcing blood into tissues over the cardiac cycle, ≥ 60mmHg needed for adequate tissue perfusion