Blood pressure
The compensation abilities of the autonomic nervous system allow normal individuals to maintain an acceptable blood pressure over a wide range of activities and in many disease states.
Alterations in these networks can lead to abnormal blood pressures.
For people over 65 years the lower the diastolic blood pressure the greater the risk.
Systolic blood pressure lower in women younger than age 40 than in men of a similar age; after middle age, however, systolic blood pressure and diastolic blood pressure typically become higher in women
Systolic blood pressure increases with advancing age in both sexes.
Blood pressure must be measured in both arms and the thigh using appropriate technique and devices.
Most hospitals use automated devices that rely on oscillometric measurements and when compared oscillometric and intra-arterial measurements in critical care units show that the oscillometric devices consistently underestimate pressure levels by as much as 50/30 mmHg, when recorded intra-arterial levels are above 180/100 mmHg.
The use of oscillometric and auscultatory devices discouraged when evidence of organ damage is present and intravenous agents are required.
Auscultatory measurements that are aneroid or mercury devices have substantial discordance from intra-arterial measurements in high blood pressure ranges.
Systolic BP remains relative constant in adults up to approximately 40 years of age and then it progressively increases.
Diastolic BP rises progressively to age 50 years then decreases so that the pulse pressure (systolic minus diastolic BP) which is constant to age 40, begins to rise.
wider blood wider pulse pressure, the difference between systolic and diastolic blood pressure reflects increase vascular stiffness and is more common among older adults.
Framingham Heart study revealed that coronary risk best predicted by diastolic pressure up to age 40 years, by systolic blood pressures between 40-60 years and subsequently by pulse pressure after age 60 years.
Low diastolic BP in elderly persons associated with a more unfavorable prognosis.
Falls by 10-20% during the night in the majority of people.
Can be lowered by decreasing dietary sodium the less than 100 mmol per day and by a diet rich in fruit, vegetables, and low-fat dairy products.
Measurement should be done with an arm cuff width approximately 40% of the upper arm circumference.
24 hour BP measurements powerful predictors of cardiovascular morbidity and mortality independent of office measured BP.
Low diastolic BP associated with poor prognosis in coronary artery disease.
Aneroid Devices underestimate blood pressure in pregnancy and pre-eclampsia, specifically.