The measurement of arterial and blood pressure - Lab Report Example

The measurement of arterial and blood pressure Section B B1 i) According to the JNC 7 Report the BP reading of subject N which is reported to be 125/78 is classified as prehypertension stage since it is greater than the prescribed systole limit of ≤ 120. Subject K on the other hand will be classified as a patient of hypertension stage – I which has a systolic range of 140-159 and a diastolic range of 90-99. The reading of subject K reported to be 150/90 comes under this category. ii) Mean arterial pressure (MAP) can be estimated through the following formula MAP ≈ DP + 1/3 (SP – DP) Accordingly subject N has a MAP of 93.67 mmHg while subject K has a MAP of 110 mmHg iii) Auscultation : A phenomenon describing the use of stethoscope in order to listen the internal sounds of the body clearly. It requires considerable clinical experience and is an integral skill which is a part of the examination of three organ systems of the body namely cardiovascular (heart sounds), respiratory (breath sounds) and gastrointestinal (bowel sounds) Korotkoff sounds : A sound heard during the measurement of blood pressure by a sphygmomanometer. The pressure differences created in the cuff results in turbulence of blood flow which leads to the audible sound known as first korotkoff sound. Korotkoff sounds can be classified into five types. First heard when the pressure in the cuff is equal to the systolic pressure, second and third can be described as murmurs and tapping sounds respectively. Fourth sound is heard at 10mm above diastolic pressure while the last korotkoff sound is heard at the precise diastolic pressure. Oscillometric principle : Another method of measuring blood pressure. It makes use of the same instrument but in addition uses a transducer which gives the oscillation readings of the blood flow. As the pressure in the cuff varies with simultaneous expansion and contraction of brachial artery an oscillation is produced. Hypertension : A medical phenomenon indicating an increased systemic blood pressure. Normal blood pressure is described as ≤ 120 systolic and ≤ 80 diastolic. Generally it is classified as primary and secondary hypertension with primary meaning with no apparent cause. Hypertension is a risk factor for many diseases and its control is necessary for a healthy long life. iv) S1 and S2 heart sounds are produced due to the closure of valves in the heart namely the atrioventricular valves and the semilunar valves. On the other hand korotkoff sounds are produced when the pressure in the cuff varies and creates turbulence for the blood flowing through the brachial artery. v) Though appearing to be quite similar heart rate denotes the number of times a heart contracts or a number of apical contractions of the heart which is measured directly with an auscultation on the chest. However the pulse is a mechanical blood flow which is caused due to this contraction but is not similar to the contraction. It is measured by palpating different arterial vessels throughout the body. Under certain conditions like arrhythmias heart rate and pulse rate are different. This the need to differentiate between the two vi) Precautions are very necessary while measuring blood pressure. An inability to take care of these may lead to an abnormal reading. Firstly proper cuff size should be selected. A smaller cuff size may result in a falsely high reading. Secondly the position of the body should be noted while taking measurement. Also the arm should be at the level of the heart. Thirdly the blood pressure should never be measured after heavy exercise or after taking drugs like alcohol or caffeine as these are proven to increase the reading. B2 i) These three leads are classified as the bipolar limb leads. Lead I gives the picture of the lateral aspect of the heart. Lead II and III give the picture of superior inferior aspect of the heart. ii) The two electrodes of Lead I are present on the arms with the negative electrode is connected to the right and the positive electrode to the left arm. Lead II has its negative electrode connected to the right arm and the positive electrode to the left foot. Lead III negative electrode is connected to the left arm while the positive electrode has a similar connection as Lead II. Electrodes on arm are placed in a way to avoid thick muscle while calf muscle is used to place electrode on the foot. There are four main colors used to code the wires involved in ECG. Leads involved in inferior aspect are coded yellow, those showing lateral aspect are coded green, anterior is labeled blue while septal aspect is coded orange. According to this Lead I electrodes have green wires while wires of both Lead II and III have yellow wires. iii) P - Atrial depolarization QRS - Ventricular depolarization T - Ventricular repolarization iv) As one large box represents 5mm, 15mm is equal to 3 large boxes. A R – R interval of 1 large square is equal to 300 beats / min. Therefore 15mm / 3 large boxes gives a heart rate of 100 beats / min. v) Precaution should be kept while carrying out ECG. Effort should be made to not touch the patient or equipment during defibrillation. It is necessary to confirm that while connecting patient cable there is no contact with any other electrical conduction part or ground. At any sign of allergy the position of electrical poles should be changed. Read More