METHODS OF BP MEASUREMENT::
BP is commonly measured by the sphygmonometer commonly used is the mercurial manometer its height indicates the extent of BP Another compact instrument works on the basis of aneroid type of sphygmomanometer in which the elasticity of the spring acts as an indicator through a compass needle
1. Palpatory Method: With this method only SP can be measured and that too a rough estimate can be obtained
The cuff is tied round the lower part of the upper arm The radial arterial pulse at the wrist is felt and the BP is raised upto 200 mmHg till pluse stops The pressure is slowly lowered by unscrewing the bulb till one feels the reappearance of the radial pulse which had disappeared on BP instrument reading (being raised above the normal) The reading is recorded in the sphygmomanometer when the radial pulse restarts it is the approximate systolic blood pressure in mmHg
2.Auscultatory method: Sphygmomanometer is kept at the heart level The cuff is tied round the lower part of the upper arm and the pressure is raised to 200 mmHg The stethoscope is placed in cubital fossa at the elbow near the bifurcation of the brachial artery first sound which is heard on lowering the pressure is the point indicating systolic pressure in the cuff and therefore the reading in the sphygmomanometer at this point is the systolic BP of the patient
The sound starts appearing first with the thud second is the tapping sound third is the going sound and the fourth is the fainting sound which fades finally to no sound the disappearance of the sound indicates the diastolic pressure the series of sounds of changing characteristic as described above would be heard on further lowering the pressure after the systolic thud the lowest point at which the sound just disappears is the diastolic BP During BP measurement the cuff should not be held pressed for more than a few minutes at a time
0 Comments