Best Method Measuring Blood Pressure

Question: Discuss about the Best Method for Measuring Blood Pressure. Answer: Introduction Blood pressure is the force/ pressure exerted by blood on the arterial walls when it flows through arteries. It maintains the needed flow of blood between heart and body organs. An accurate blood pressure measurement in children is very essential to prevent cardio vascular disorders. According to recent studies, hypertension is found to be increasing in children of many countries (Vidal, 2013). The increasing blood pressure should be controlled to prevent heart attacks and brain stroke. The hypertension that begins in the childhood period may be carried to adult stage and so early detection and prompt treatment of hypertension in children is required. In case of pediatric hypertension, there are several doubts about the accuracy of instruments and reference standards for comparing blood pressure. This is because of the constant change in blood pressure of the pediatrics based on their growth and development (Douglas, 2012). Various blood pressure measurement devices for children are available as non-automated, semi-automated and automated devices. This essay discusses about the auscultation and oscillometric methods of blood pressure measurement and evidences supporting their usage in children. Revising the problem and the question Basically, all the children above three years of age should be monitored for blood pressure every year (Douglas, 2012). There are various methods of blood pressure measurement in children as auscultating method (including mercury sphygmomanometer and aneroid devices), semi automated and automated (oscillometric) method. The auscultation method is the oldest method of measuring blood pressure. In this method, the technique of measuring blood pressure is that the cuffpressurebecomes more than the diastolicpressureand the systolic pressure is decreased. A tapping sound that is associated with the flow of blood called Korotkoff sounds are measured by using stethoscope whereas in oscillometric method, BP is measured by automated devices. These devices are mostly used in small children, critically ill and unstable children, at the time of invasive procedure and if frequent monitoring of a child is needed as intravenous blood pressure medications. In olden days, the auscultating method using mercury sphygmomanometer is considered as the golden standard of measuring blood pressure. But use of mercury sphygmomanometer was banned (Pickering, 2005).Then they were replaced by aneroid devices. Even these devices very also less accurate and often requires frequent calibrations.Later, it was replaced by other auscultating devices as hybrid sphygmomanometers by replacing mercury in devices. These devices have both auscultating and electronic features with pressure gauge but the same measurement technique of mercury device is followed. The main drawback is that, mercury is a human- neurotoxin. If it breaks, it will cause mercury toxicity in children. The health care institutions contribute to the mercury pollution by spills, device breaks and burning of mercury waste (Ogedegbe, 2010). The measurement of blood pressure in children is difficult as the appropriate selection of cuff based on the arm size is needed. Moreover measuring readings in small children, restless and irritable infants and children is difficult. Taking blood pressure by auscultation method takes time for measuring and the child may not cooperate. The stethoscope should be placed too firmly on the ante-cubital fossa of child which may cause auscultation errors and the child may not allow keeping stethoscope often. The korotkoff sounds are very difficult to hear in children as they will be of lower frequency and amplitude. For this pediatric bell could be used. Comparatively use of oscillometric method is perfect for a pediatric (Douglas, 2012). Locate best evidence and critically appraise evidence Eliasdottir (2013) has conducted a comparative study on the use of aneroid and oscillometric blood pressure measurements in children to investigate the difference in blood pressure obtained using oscillometric and aneroid blood pressure monitors in 9 to 10 year old children. He states that there was no apparent difference between the mean systolic blood pressure readings that is obtained by using these two methods but the mean of diastolic pressure was low in case of oscillometric devices. A decreased expression of BP with every consecutive reading was observed in both methods which suggest that multiple blood measurement is needed for both the methods before diagnosing the child to have hypertension. Flynn (2012) has assessed the reliability of blood pressure measurement and its classification by using an oscillometric model in children with chronic renal disease. He concluded that as compared to auscultation method, the oscillometric method apparently overestimates the blood pressure of a child leading to misclassification of blood pressure. This is similar to a study in which Dinamap oscillometric device was assessed by comparing sequential blood pressure readings in 63 patients by using mercury and Dinamap-8100 device in Australia (Heinemann, 2008). It was found that the blood pressure measured with Dinamap was apparently lower than that of mercury sphygmomanometer. The researcher concluded that Dinamap device can be used for systolic blood pressure but not for diastolic measurement. In 2012, Shah has compared the use of mercury and aneroid devices in youth. He found that both mercury and aneroid methods produce equal measure. This was also supported by a study conducted by Ma (2008) which implies that there is no difference in both these devices. In contrast, Markandu (2000) has conducted a study on mercury devices and found that 38% of devices had dirty mercury columns, 21% of markings were not clear due to mercury oxidation, 18% had obscured and faded markings and 3 with leaking mercury, 8% with worn out, splits and damaged cuff, 35% cuffs didnt stick and 7 with wrong size. This study states that mercury devices should be replaced by advanced methods whereas Shah (2004) suggests that mercury devices are more accurate. In auscultation method, there are greater chances of both observer and methodological errors. The observer errors may include the preference of finger digit, lack of attention, rapid and more cuff deflations and hearing deficits. It may cause methodological errors such as not accounting the variations in pulse and not comparing the beats sequence (Jahangir, 2015). On the other hand, oscillometric devices eliminate the observer errors that occur in auscultation method. But there are discrepancies in accuracy of oscillometric devices on children with hypotension, hypertensive and cardiac arrhythmia children leading to inappropriate treatment (Jahangir, 2015). In spite of these inaccuracies; they are sufficiently accurate for the clinical purposes. Moreover, oscillometric devices are completely automated and hence observer participation is needed other than placing the cuff and recording the blood pressure. In this, the cuff is inflated and deflated electronically which avoids cuff pres sure alterations that affect blood pressure. The pressure wave produced by the brachial arterial wall is sensed by a transducer in the device. There are no particular systolic and diastolic pressure points on the pressure wave and so they are calculated electronically using an algorithm (Jahangir, 2015). There are a variety of these devices in market having different algorithms. Oscillometric method requires no transducer to be placed on the brachial artery, and is less affected by external noise. It is useful in home care setting. But the pressure sensor should be calibrated to maintain accuracy. Its measurement requires lesser skill than that of auscultator technique and could be used by an untrained staff and for home monitoring (Ogedegbe, 2010). Alpert, 2014 has conducted a study on using oscillometric blood pressure and suggested that these devices have developed as clinical standard due to simple training need, less cost and mercury ban in many countries. All the evidences suggest that using oscillometric devices for blood pressure is easy and effective. Recommendations To summarize, mercury can cause environmental pollution and neuro-toxic to children and so its usage should be banned. WHO (2005) instructed to remove mercury devices from hospitals. Many countries have replaced mercury devices with other devices. Yet, few studies suggest that mercury sphygmomanometers are needed to get accurate readings. Even if automated devices are available, mercury readings are needed to generalize the results. Based on the review of these devices, the following result is summarized. The aneroid devices should be appropriately calibrated and maintained to be equal or more accurate than that of mercury device. It has to be calibrated every 6 months to maintain accuracy. The validated oscillometric models should have digital displays to promote accuracy and to remove inter observer changes in BP measurement of children (Buchanan, 2009). Even if there is good evidence about oscillometric models, they are not validated to be used in some conditions as arrhythmias in children. All the aneroid and oscillometric devices that are available on the market should be validated with same protocols to maintain uniformity. Oscillometric devices may eliminate the observer errors that are associated withauscultatorymethods. But apparent differences are observed between both measurements. It is both device and user dependent. Moreover they are used by untrained persons and in homes. Previously, mercury device was considered as golden standard. Yet using electronic pressure gauge is more reliable than mercury device in repeated measure of pressure. The use of oscillometric devices seems to be superior to other types. Therefore these devices should be used as substitute for mercury devices for validation purposes. It appears that oscillometric device with most accurate calibrating protocol should be adapted validating organizations. Conclusion To conclude, blood pressure measurement devices should be reliable and suitable for all age groups. Nowadays people measure BP for needed children at home regularly. Mostly mercury should be avoided for children as it may cause toxicity. The results suggest that the measurement of BP in children is difficult, yet to get accurate result oscillometric devices should be used. Reference Alpert, B.S.,Quinn, D. Gallick, D. (2014). Oscillometric blood pressure: a review for clinicians. J Am Soc Hypertens.8(12):930-8. doi: 10.1016/j.jash.2014.08.014 Buchanan, S. (2009). The Accuracy of Alternatives to Mercury Sphygmomanometers. Retrieved from https://noharm.org/sites/default/files/.../Accuracy_Alts_Mercury_Sphyg_rev10-09.pdf Douglas, C. (2012). Potter and Perrys Fundamentals of Nursing- Australian version. (4th ed.). St. Louis, Missouri: Elsevier. Eliasdottir, S.B. (2013). Comparison of aneroid and oscillometric blood pressure measurements in children: J Clin Hypertens (Greenwich).15(11):776-83. doi: 10.1111/jch.12196 Flynn, J.T.,Pierce, C.B.,Miller, E.R. Charleston, J. (2012). Reliability of resting blood pressure measurement and classification using an oscillometric device in children with chronic kidney disease: J Pediatr.60(3):434-440.doi: 10.1016/j.jpeds.2011.08.071. Gilhotra, Y. Willis, F. (2006). Blood pressure measurements on children in the emergency department:Emerg Med Australians.18:148.[PubMed] Heinemann, M. (2008). Automated versus manual blood pressure measurement: A randomized crossover trial: Int J Nurs Pract.14:296-302. Jahangir, E. (2015). Blood Pressure Assessment. Retrieved from https://emedicine.medscape.com/article/1948157-overview#a7 Ma,Y. (2008). Evaluating the accuracy of an aneroid sphygmomanometer in a clinical trial setting: Am J Hypertension: 1-4. Markandu, N.D. (2000). 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