Ans. a. Bladder in the blood pressure cuff should cover more than 80% of the arm area (Ref: Ganong 22/e p. 589-90; Guyton 11/e p166-67, 175-76)In blood pressure measurement by BP apparatus, bladder in the blood pressure cuff should cover more than 80% of the arm area.Appropriate Cuff SizeRatio of width of compression cavity of cuff (bladder) to circumference of extremity is of critical importance.According to American Heart Association:Bladder width should he 40% of circumference or 1.2 times of diameter of extremityQBladder length should be 80% of arm circumferenceQLength to width ratio is 2:1QIf the person's limb measurement is on the borderline of two different cuff sizes the chance of error is decreased if the linger of two cuff sizes is usedSo in obese and recording BP in thigh wider cuff size provide more accurate resultsBlood pressureBlood pressure is measured by auscultatory method using sphygmomanometer tends to be higher than true intraarterial pressure measured by arterial cannulation, because some cuff pressure gets dissipated between the cuff and arteryin the soft tissue.Systolic pressure is best indicated by 1st korotkoff's sound and diastolic pressure in adults by 5th korotkoff's soundQ. Where as diastolic pressure in children, in adults after exercise, hyperthyroidism and aortic insufficiency best correlates with 4th Korotkoff's sound.Using relatively small cuff obesity and persons with thick calcified and sclerotic vessels that are difficult to compress (e.g. in elderly, atherosclerosis, diabetics and Monkenberg's arteriosclerosis) are the reasons of spuriously high blood pressure (Pseudohypertension).TechniqueKorotkoff's soundSource of error* Person should be comfortably seated, with back and arm supported, legs uncrossed and upper arm at the level of right atrium.* Snugly wrapped cuff should allow only one finger to be slipped between it and skin.* The cuff is rapidly inflated to 30 mm Hg above the point at which radial pulse disappears. Deflation rate should be 2-3 mm/ second.* Two readings should be at least 1 minute apart.* Are produced by turbulent flow in artery. The sound gradually become louder, then dull and muffledFalse High values are found in:* Thick overlying soft tissue causing more dissipation of pressure e.g. obese* Hard sclerotic vessels with low compressibility such as- Elderly- Atherosclerosis- Diabetics* Mokenberg's arteriosclerosisQ* Relatively small size of cuff (bladder) e.g. standard arm cuff used in thigh* Too slow inflation rate leading to too high diastoli* pressureFalse low values are found in:* Large (wide) cuff e.g. standard arm cuff used in forearm.* Too fast Deflation rate leads to too low systolic pressure.1Faint, clear, tapping soundsIt indicates systolic BPQ2Murmur/swishing sounds3More intense, crisper sounds4Distinct abrupt muffled- soundsIndicates diastolic BP in children, in adutts after exercise, hyperthyroidism, and aortic insufficiency.5No soundBest correlates with diastolic BP in normal adults.* It tends to give values for systolic pressure that are lower than true intra arterial pressure and diastolic values that are higherQ.Appropriate Cuff SizeRatio of width of compression cavity of cuff (bladder) to circumference of extremity is of critical importance.According to American Heart Association:Bladder width should be 40% of circumference or 1.2 times of diameter of extremityBladder length should be 80% of arm circumferenceQLength to width ratio is 2:1QIf the person's limb measurement is on the borderline of two different cuff sizes the chance of error is decreased if the larger of two cuff sizes is used.So in obese and recording BP in thigh wider cuff size provide more accurate results.