Cardiovascular System - Blood Pressure Measurement - PDF

Cardiovascular system Presente d by Asmaa Samy El Nagger Ass. Lecturer of Medical Physiology  Practical I Pulse and arterial blood pressure Introduction ► Blood pressure: It is the force exerted by the blood against any unit area of the vessel wall. ► Arterial p...

Cardiovascular system Presente d by Asmaa Samy El Nagger Ass. Lecturer of Medical Physiology  Practical I Pulse and arterial blood pressure Introduction ► Blood pressure: It is the force exerted by the blood against any unit area of the vessel wall. ► Arterial pulse: The pressure wave that travels along the arteries due to forcible ejection of blood into the arterial system during systole. Aortic pressure Pulse and mean ABP Definitions Systolic pressure: It is the max. pressure occur through out the cardiac cycle. Diastolic pressure: It is the mini. pressure occur through out the cardiac cycle. Pulse pressure (PP) = SP-DP  Mean pressure (MP) Average pressure during one cardiac cycle Mean pressure = Diastolic pressure+Pulse pressure/3 SP and DP may vary significantly throughout the arterial system but MP is quite uniform (in normal situations)  Blood Pressure abnormalities Physiological variations: However, the normal values differ 1. Site of measurement from person to another 2. Age 3. Sex High value increases the risk of heart 4. Body built attack and strokes. 5. Exercise 6. Emotions Low value increases the risk of lower 7. Meals oxygen perfusion e.g. in brains. 8. Sleep The classical sequence of clinical examination: 1.Inspection (look) 2.Palpation (feel) 3.Percussion (tap) 4.Auscultation (listen)  Experiment 1 Measuring Arterial Pulse Rate General rules Limb should be supported and relaxed Use 3 fingers Compare bilaterally Pulse sites A. Head and neck B. Upper limb C. Lower limb In the head and neck In the upper limb  Rate Form Rhythm Wall Other Force side Other Volume puls. The data gained by arterial pulse examination  Experiment 2 Measuring arterial blood pressure (Brachial artery)  Biceps Brachial artery In antecubital fossa medial to biceps tendon  Principle Measuring the external pressure needed to occlude the vessel and stop blood flow. All indirect (non-invasive) methods depend on this principle. The occluding pressure is applied by a cuff around the artery and flow or pulsation is tested distal to the cuff by palpation or auscultation.  Methods Palpatory Method Auscultatory Method Palpate the radial artery Auscultate the brachial artery Concept of palpatory method Palpation of radial artery while the cuff is wrapped around brachial artery Concept of auscultatory method Cuff pressure > Systolic pr. No sound Cuff pressure between systolic & diastolic Sound is heard Kortokov sounds Cuff pressure > Diastolic pr. No sound  Sphygmomanometer Instruments Stethoscope  Stéthoscope Directed medially and forward Use the Diaphragm Sphygmomanometer Mercury Sphygmomanometer Mercury column Cuff Mercury Inflation bulb Reservoir Control/ release valve Rubber tubing Cuff size  Blood pressure measurement technique Start by Palpatory Method Then Auscultatory Method Steps Auscultatory Palpatory General Step 1 Ensure that you have the necessary equipment Clockwise rotation→ allow cuff inflation Anticlockwise rotation→ allow cuff deflation Step 2 Wash your hands with alcohol cleanser and allow to dry. Step 3 Introduce yourself to the patient, explain the procedure Step 4: Patient position & sphygmomanometer Patient: ◦ Sitting position. ◦ Complete Physical and mental rest ◦ Arm supported. Sphygmomanometer: ▪On the level of the heart ▪Column of the mercury should be vertical Step 5: Cuff 2 figers above antecubital fossa ✓ Choose cuff of appropriate size Tubes down and medially ✓ Wrap the cuff around the patient’s upper arm ✓ 2 cm above the antecubital fossa ✓ Ensure the rubber tubes direction medially in line with the brachial artery The cuff should not be too tight or too loose Palpatory method  Step 6 : palpatory method Palpate the radial pulse  Step 6 : palpatory method Inflate the cuff (by closing the valve in a clockwise direction and pumping air into the cuff through the inflation bulb) until you can no longer feel this pulse  Step 6 : palpatory method Note the reading on the sphygmomanometer This is the estimated of the systolic blood pressure Step 7: After Knowing the estimated systolic blood pressure, deflate the cuff completely By rotating the valve in anticlockwise direction Auscultatory method  Step 8: Auscultatory method First Palpate the brachial artery 1. Flex and extend the forearm 2. Palpate the biceps tendon 3. Feel the brachial pulse just medial to the tendon Step 8: Auscultatory method Place the stethoscope’s diaphragm over the brachial artery Step 8: Auscultatory method Listen carefully → accurate reading for systolic and diastolic blood pressure  Step 8: Auscultatory method Re-inflate the cuff to 20-30 mmHg above the estimated systolic BP measured earlier Above systolic pressure So no sound is heard Step 8: Auscultatory method Begin to slowly deflate the cuff – around 2-3 mmHg per second Listen carefully and at some point you will begin to hear a thumping pulsatile noise (the first sound heard is the systolic pressure) This is known as the 1st Korotkoff sound The pressure at which this 1st sound is heard is the systolic blood pressure  Step 8: Auscultatory method Continue to deflate the cuff, continuing to listen until the sounds completely disappear (The last sound heard is the diastolic pressure) The point at which you hear the last sound is referred to as the 4th Korotkoff sound This is the diastolic blood pressure Step 9 ▪ Deflate the cuff and Remove it ▪ Measure the blood pressure in both arms to ensure the readings are similar. ▪ Wash your hands If the patient is noted to be hypertensive or hypotensive you should re-check the blood pressure after 2-5 minutes to confirm this is an accurate result (you can use the other arm and reconsider if the patient is not completely relaxed) Step 10 ▪ Document the recordings in the patient’s notes. ▪ Explain the need for follow up ▪ Thank the patient  Avoid undue rising of pressure in the sphygmomanometer with consequent pain Why palpatory production which will affect the blood before pressure. auscultatory? Avoid the "auscultatory gap”: a silent area occurring during the second phase of Kortokov sounds Thank you