BLOOD PRESSURE DR RASHMI MISHRA OBJECTIVES At the
BLOOD PRESSURE DR RASHMI MISHRA
OBJECTIVES At the end of this class, you should able to recollect. Definition of Blood Pressure Its variations. Measurement - Korotkoff sound Factors contributing to B. P Peripheral resistance Regulation of BP Immediate regulation Short term regulation Long term regulation. Applied - Hypertension Hypotension Physiology of treatment.
ARTERIAL BLOOD PRESSURE Definition : Arterial blood pressure can be defined as the lateral pressure exerted by the moving column of blood on the walls of the arteries.
Tuesday, February 16, 2016
SIGNIFICANCE To ensure the blood flow To various organs. Plays an important role in exchange of nutrients and gases across the capillaries. Required to form urine. Required for the formation Of the lymph.
Normal Values ❖ Normal Adult range ❖ Can fluctuate within a wide range and still be normal ❖ Systolic/diastolic � 100/60 140/90
Systolic B. P (S. B. P) Defined as the maximum pressure exerted during ventricular systole. Normal 100 to 140 mm Hg within an average of 120 mm. Hg. This is mainly contributed by 1. Force of heart beat 2. Normal blood volume 3. Cardiac output
DIASTOLIC B. P (D. B. P) Def--- as the minimum pressure that is obtained at the end of the ventricular diastole. Normal range 60 -90 mm Hg. 1. It represents a constant load on the arterial walls with little or no fluctuation at all. 2. It is an index to the peripheral resistance and decides the filling of the Coronary system. 02/16/16
Pulse Pressure (P. P) Denotes the difference between systolic and diastolic pressure. Pulse pressure= SBP-DBP.
MEAN ARTERIAL PRESSURE It is the average pressure throughout the cardiac cycle. Mean arterial. BP = DBP + 1/3 Pulse Pressure Normal = 95 mm Hg. • Not the arithmetical mean but geometrical mean. • It is because the period of the systole is only 0. 3 sec when compared to 0. 5 sec of the diastole.
ARTERIAL BLOOD PRESSURE
PHYSIOLOGICAL VARIATION IN BLOOD PRESSURE Age B) Build C) Climate D) Diurnal Variation E) Exercise F) Fever Gestation H high Altitude I) Infusion/ Intake J) Pain K) Posture L) Sleep M) sex
RECORDING OF B. P Direct method Indirect method METHODS Indirect Methods 1. Palpatory method 2. Auscultatory method 02/16/16
PRINCIPLE INVOLVED IN RECORDING BLOOD PRESSURE Slide
Measurement Device Aneroid sphygmomanometer Simple mercury sphygmomanometer Automated bp device
RECOMMENDED BLOOD PRESSURE MEASUREMENT TECHNIQUE 2. 2. • Thecuffmustbe belevelwithheart. • Ifarm armcircumferenceexceeds 33 33 cm, a large must used. cm, acuff large cuffbemust be used. • Placestethoscopediaphragmover brachialartery. 1. 1. • • Thepatient should be relaxed and the be relaxed andarm the must be supported. arm must be supported. • Ensure no tight clothing • Ensureconstricts no tight the arm. clothing constricts the arm. 3. 3. Stethoscope Mercur y machin e • • Thecolumnof ofmercury must be vertical • Inflate to. occlude the pulse. at 2 the to 3 • Inflate. Deflate to occlude mm/s. pulse. Measure Deflate systolic at 2 to (first sound) and diastolic 3 mm/s. Measure (disappearance) to systolic (first sound) nearest 2 mm Hg. and diastolic (disappearance) to nearest 2 mm Hg. 3
AUSCULTATORY METHOD This method was introduced by a Russian physician Korotkoff SBP Recording of arterial BP by auscultatory method Korotkoff sounds 120 mm Hg 110 mm Hg 95 mm Hg Tapping sound 1 Murmurish 2 Banging sound 3 Muffing sound 4 85 mm Hg DBP- 80 mm Hg No sound 5
• FACTORS MAINTAINING BLOOD PRESSURE 1. Cardiac output (CO= SV X PR) 2. Circulating blood volume • (This mainly affects systolic B. P) 3. Elasticity of the vessel wall 4. Viscosity of blood
• Viscosity is affected by 1. Cell count 2. Plasma proteins 3. Chemical composition like CO 2, O 2 content, PH. 4. Temperature 5. Drugs like general anaesthetics. • All these factors influence • peripheral resistance through viscosity
Peripheral Vascular Resistance It is defined as the resistance offered to the flow of blood by the blood vessels. It is contributed by: The Smooth muscles of the arterioles in particular. 02/16/16
FACTORS AFFECTING BLOOD PRESSURE ❖ Disease ❖ Age ❖ Heredity ❖ Blood Volume ❖ Weight ❖ Diet ❖ Hormones ❖ Salt ❖ Caffeine Environmental factors ❖ Psychological factors ❖ Stress/Anxiety ❖ Gravity ❖ Drugs ❖ Alcohol ❖ Time of day
BLOOD PRESSURE BP = Cardiac output X PR Peripheral resistance(PR) in a normal healthy young adult is 20 mm Hg/lit/mt. Peripheral vascular resistance: depends upon A) Velocity of blood D) Lumen of the vessels B) Viscosity of blood E)Length of the vessels C) Elasticity of the vessels wall F) Extra vascular compression 02/16/16
Peripheral Resistance (Relative unit) When there is a difference of 1 mm Hg and a flow of 1 ml/sec then it is called one PRU unit. absolute units : Dyne/sec/cm 2 Pressure dyne/cm 2 PR = Flow = dyne/sec/cm 2 cc/sec
� Central Factors Cardiac output: systolic pressure is directly proportional to cardiac output. Hear t Rate : marked alteration in heart rate effects BP by altering the cardiac output. Peripheral factors: Peripheral Resistance : Diastolic pressure is directly proportional to peripheral resistance
Blood Volume: BP is directly proportional to volume. Venous Return: blood pressure is directly proportional to venous return. Elasticity of blood vessels: BP is inversely proportional to of blood vessels. the elasticity �Velocity of Blood Flow: BP is directly proportional to the velocity of blood flow. Diameter of Blood Vessels: BP is inversely proportional to the diameter of blood vessel. Viscosity of Blood: BP is directly proportional to the viscosity of blood.
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