L2.4: Vital Signs - Blood Pressure

• Blood Pressure

  • It is the force of blood against the arterial walls.
  • Measure of the lateral pressure exerted by the blood as it flows through the arteries.
  • Can vary considerably among individuals, so it is important to know a client’s baseline blood pressure.
• Auscaltory Gap

  • Temporary disappearance of sounds normally heard over the brachial artery when the cuff pressure is high and the reappearance of the sounds at a lower level.
• Korotkoff Sound

  • Series of distinct sounds heard through the stethoscope.
  • Named after a Russian Scientist who first described these sounds
  • Nikolai Korotkov
• 2 Blood Pressure Measurements

  • Systolic Pressure
  • Diastolic Pressure
• 2 Blood Pressure Measurements

  • Systolic Pressure
  • Highest point of pressure induced by the contraction of the left ventricle.
• 2 Blood Pressure Measurements

  • Diastolic Pressure
  • Lowest point of pressure corresponds to the drop of arterial pressure occuring during the relaxation of the ventricles.
  • Measured in millimeters of mercury (mmHg) and recorded as a fraction: systolic over diastolic (SYS/DIA).
• Typical blood pressure for a healthy adult

  • 120/80 mmHg with 40 mmHg pulse pressure
  • 120 = systolic pressure
  • 80 = diastolic pressure
• Factors affecting blood pressure

  • Age
  • Rest and Exercise
  • Stress and Emotional State
  • Eating
  • Disease Processes
  • Obesity
  • Medications
  • Race
  • Environment
  • Diurnal Variations
• Variations in Blood Pressure by Age - Mean Blood Pressure (mmHg)

  • Newborn: 73/55
  • 1 year: 90/55
  • 6 years: 95/57
  • 10 years: 102/62
  • 14 years: 120/80
  • Adult: 120/80
  • Elderly (>70 years): DBP decreases
• Equipment for taking Blood Pressure

  • Sphygmomanometer
  • Aneroid type
  • Mercury type
  • Electronic/Digital type
• Equipment for taking Blood Pressure

  • Sphygmomanometer
  • Aneroid type
  • Calibrated dial with a needle that points to the calibrations.
• Equipment for taking Blood Pressure

  • Sphygmomanometer
  • Mercury type
  • Calibrated cylinder filled with mercury.
  • Pressure is indicated at the point to which the rounder curve of the meniscus rises.
  • Meniscus → Curve top of a column of liquid in a small tube.
  • Blood pressure reading should be made with the eye at the level of the rounded curve in order to be accurate.
• Equipment for taking Blood Pressure

  • Sphygmomanometer
  • Electronic/digital type
  • Eliminated the need to listen the sounds of the client’s systolic and diastolic blood pressure through a stethoscope.
  • Automated electronic devices have been shown to give higher values than manual cuffs.
• Parts of Aneroid Type

  • Pump
  • Valve
  • Dial
  • Cuff
  • Tube
• Parts of Aneroid Type

  • Pump
  • Inflated the cuff to stop the blood flow in your artery for a few seconds.

  
• Parts of Aneroid Type

  • Valve
  • Let some air out of the cuff, which allows the blood flow to start again.

  
• Parts of Aneroid Type

  • Dial
  • Numbered dial or a column of mercury can be used to record the blood pressure reading.

  
• Parts of Aneroid Type

  • Cuff
  • Wrapped around your upper arm.

  
• Parts of Aneroid Type

  • Tube
  • Connects the cuff to the dial.

  
• Blood Pressure Cuff

  • Consists of a rubber bag that can be inflated with air called the bladder.
  • Comes in various sizes.
  • Made of non-distensible material so that an even pressure is exerted around the limb.
  • Most cuffs are held in place by hooks, snaps, or velcro.

  
• Bladder

  • Covered with cloth and has two tubes attached to it.
  • One tube connects to a rubber bulb that inflates the bladder.
  • One tube is attaches to the sphygmomanometer.
  • Must be correct in width and length for the client’s arm
  • Width of the cuff should be 40% of the circumference, or 20% wider than the diameter of the midpoint of the limb.

  
• Recommended Bladder Sizes of Blood Pressure Cuffs (Age - Length - Width)

  • Newborn: 5 x 3
  • Infant: 8 x 5
  • Child: 13 x 8
  • Adult: 24 x 13
  • Large Adult: 32 x 17
  • Thigh: 42 x 20
• Sthethoscope

  • Gadget that transmits and magnifies the sounds obtain in the body.
  • In taking blood pressure, the bell or diaphragm of this equipment is placed directly over the brachial artery.
  • It consists of the earpieces, rubber tubing, and the bell.
  • Doppler Ultrasound Stethoscope
  • Used when blood pressure sounds are difficult to hear
• Sites of Taking Blood Pressure

  • Upper arm
  • Leg
  • Forearm
  • Thigh
• Sites of Taking Blood Pressure

  • Upper arm
  • Where blood pressure is routinely and usually assessed using the brachial artery and a standard stethoscope
• Sites of Taking Blood Pressure

  • Leg and Forearm
  • in some situations
• Sites of Taking Blood Pressure

  • Thigh
  • When blood pressure cannot be measured on either arm, or if blood pressure in one thigh is to be compared with the blood pressure in the other thigh.
• Methods in Taking Blood Pressure

  • Indirect or Non-Invasive
  • Direct or Invasive
• Methods in Taking Blood Pressure

  • Indirect or Non-Invasive
  • Auscultatory method:
  • Most commonly used
  • Uses sphygmomanometer and stethoscope.
  • Palpatory method:
  • Used when Korotkoff’s sounds cannot be heard or when auscultatory gap occurs.
• Methods in Taking Blood Pressure

  • Direct or Invasive
  • An instrument is inserted inside the body invasively to measure the blood pressure via catheter.
• 5 Phases of Korotkoff's Sounds

  • Phase 1: pressure level at which the first faint clear tapping sounds are heard, which gradually become more intense.

  
• 5 Phases of Korotkoff's Sounds

  • Phase 2: The period during deflation when the sounds have a swishing quality.

  
• 5 Phases of Korotkoff's Sounds

  • Phase 3: The period during which the sounds are crisper and more intense.

  
• 5 Phases of Korotkoff's Sounds

  • Phase 4: The time when the sounds become muffled and have soft, glowing quality.

  
• 5 Phases of Korotkoff's Sounds

  • Phase 5: The pressure level when the last sound is heard. This is followed by a period of silence.

  
• Assessing Blood Pressure (1-5)

  • Gather and prepare necessary equipment.
  • Wash hands.
  • Introduce yourself and verify the client’s identity.
  • Explain the purpose and procedure to the client.
  • Provide for the client’s privacy
• Assessing Blood Pressure (6)

  • Prepare and position the client appropriately.
  • Adult client should be in sitting position unless otherwise specified. Both feet should be flat on the floor (legs crossed at the knee result in elevated blood pressure).
  • The elbow should be slightly flexed with the palm of the hand facing up and the forearm supported at heart level.
  • Expose the upper arm.
• Assessing Blood Pressure (7-9)

  • Wrap the deflated cuff evenly around the upper arm.
  • If this is the client’s initial examination, perform a preliminary palpatory method of determining systolic pressure.
  • After obtaining the palpatory systolic pressure, position the stethoscope appropriately.
• Assessing Blood Pressure (10)

  • Auscultate the client’s blood pressure
  • Inflate the cuff 30 mmHg above the palpatory systolic pressure obtained previously or above the point where the brachial pulse disappeared.
  • Release the valve at the rate of 2-3 mmHg per second.
• Assessing Blood Pressure (11-14)

  • Deflate the cuff completely.
  • Remove the cuff from the client’s arm.
  • Do the aftercare.
  • Wash your hands.