University:
American Career College
Course:
NURS112 | Fundamentals of Nursing
Academic year:

2020
Views:

446

Pages:

22
Author:

TwelveAlemat7c

Definitions blood pressure: refers to the force exerted by the blood as it presses against and attempts to stretch the walls of blood vessels Systolic blood pressure: ✓ Pressure exerted on arterial walls during systole It is the highest pressure inside the artery It equals 120 mm Hg Diastolic blood pressure: ✓ Pressure of blood inside the artery during diastole ✓ It is the lowest pressure inside the artery It equals 80 mm Hg Pulse pressure: ✓The difference between systolic pressure and diastolic pressure It equals 40 mm Hg Mean arterial blood pressure: It is the average pressure throughout the cardiac cycle ✓ Diastole + 1/3 pulse pressure It equals (96-100) mm Hg Physiologic variations in ABP Age Infants: 80/40 mm Hg ✓Children: 100/65 mm Hg ✓ Adults: 120/80 mm Hg Sex ✓ Women < men before menopause Circadian rhythm peak value early in the morning ✓ lowest level at midnight Emotions, Race & Exercise: SBP ĮDBP Effect of gravity on ABP: + 0.77 mmHg/cm 1 2 Methods Of Measurement 1-Direct or invasive technique ✓ Direct method of recording blood pressure (BP), in which an artery is punctured with a cannula connected to a manometer. Direct method is used in research work in animals, and during cardiac and arterial catheterization in man. 2- Indirect or noninvasive technique ✓ This measurement is one of most famous clinical techniques ✓Used by the medical and paramedical professions, because it is a non invasive (indirect), simple technique as well as it reflects the state of contractility of the heart and the state of the arterial system Apparatuses Stethoscope Sphygmomanometer (Mercury, aneroid and electronic one) ✓ Different types of BP instruments are in use, but the one in common use is the mercury sphygmomanometer Precautions before measurement The subject may be lying down (supine) or sitting, but should be mentally and physically relaxed Surroundings A quit non noisy room. ✓ Comfortable room temperature Patient ✓ Evacuate the urinary bladder ✓ Seated in comfortable chair with back supported and feet flat on the ground The arm should be at heart level and supported The cuff should be applied directly in the skin, Sleeves should be opened Equipment The mercury of the apparatus should be at level zero before measurement ✓Should not bubble during inflation ✓ Two more spare cuffs should be ready, one a smaller and another larger than the standard ✓ Use cone of stethoscope basically, and diaphragm with very obese patients ✓ Electronic sphygmomanometer is for use only by the patient Doctor: student: or any measuring personnel Do not conversant with patient during measurement Technique Do not put the diaphragm of stethoscope underneath the cuff Do not inflate or deflate cuff rapidly or very slowly The arm cuff should be placed on your arm at the same level as your heart. Sit upright with your back straight. Relax your hand. 11 12 Sit comfortably on a chair with your feet flat on the floor. Physical principles of technique of measurement 1. The tissues of the arm or thigh are composed of incompressible tissues(muscles and bones) and compressible blood vessels 2. Application of external pressure on the arm or thigh within the fixed size of inelastic sphygmomanometer cuff, compressed only blood vessels, 3. The veins (low pressure) are compressed at first, and then the arteries are compressed gradually till the external pressure is just higher than the intra-arterial pressure, at that moment, the blood flow distal to the compression stops. 4. Monitoring (carful observation) of the blood flow distal to the compression can be: by one of two methods: Palpatory method: palpation of pulse distal to the compression. Auscultatory method: Auscultation (hearing) of the blood flow, in an artery distal to the compression site 11 12 Procedure of ABP measurement Indirect method for arterial blood pressure measurement Includes two methods: Palpation (palpatory) method: ✓ Avoids missing the auscultatory gap ✓ measures only the systolic pressure ✓lacks accuracy because the systolic pressure measured by it is lower than the actual by 4-6 mm Hg Auscultation method: ✔This method by itself is not a second method Is for verification of systolic pressure value done by palpation method ✔ Is also complementary because it measures the diastolic pressure