|
 
 |
| ORIGINAL ARTICLE |
|
| Year : 2019 | Volume
: 5
| Issue : 3 | Page : 171-176 |
|
Impact on variation in the direction of cuff bladder on blood pressure readings
Bukar Alhaji Grema1, Ismail Inuwa Mohammed2, Godpower Chinedu Michael1, Ibrahim Aliyu3
1 Department of Family Medicine, Aminu Kano Teaching Hospital, Kano, Nigeria
2 Department of Surgery, Aminu Kano Teaching Hospital, Bayero University Kano, Kano, Nigeria
3 Department of Paediatrics, Aminu Kano Teaching Hospital, Bayero University Kano, Kano, Nigeria
| Date of Submission | 12-Jun-2019 |
| Date of Acceptance | 01-Sep-2019 |
| Date of Web Publication | 20-Dec-2019 |
Correspondence Address:
Dr. Ibrahim Aliyu
Department of Paediatrics, Aminu Kano Teaching Hospital, Bayero University Kano, Kano
Nigeria
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/jpcs.jpcs_36_19
Introduction: Elevated blood pressure (BP)/hypertension contributes significantly to global morbidity and mortality. It is a silent killer; therefore, earlier diagnosis is imperative. A simple instrument called sphygmomanometer measures BP. Getting an accurate and precise reading is essential for making the diagnosis. Our study sorts to determine if there is any significant change in BP readings when the bladder cuff is inverted during BP measurement. Materials and Methods: This was a cross-sectional study involving 540 individuals who were consecutively recruited from the outpatient clinics over a year period. BP was measured with a mercury sphygmomanometer in three postures of sitting, standing, and supine comparing the standard protocol (control) and our designed protocol of inverted cuff (test). Results: The mean systolic and diastolic BP for all the postures for both sexes were significantly corresponding for both test positions in majority of the age groups; all observed differences in means were <5 mmHg which is within the acceptable limit. The Bland–Altman plot showed significant agreement for the control and test positions in diastole and systole in all the three postures. The mean of the differences of the control and test procedures were −0.38 ± 2.70, 0.27 ± 2.18 (diastole and systole in sitting); −0.46 ± 2.88, 0.09 ± 1.58 (diastole and systole in standing); −0.62 ± 3.14, 0.09 ± 1.82 (diastole and systole in supine). Conclusion: Our test procedure showed agreement with the standard protocol of cuff positioning. Therefore, it could be used interchangeably.
Keywords: Bladder compression, blood pressure, cuff position, inverted cuff, sphygmomanometer
How to cite this article:
Grema BA, Mohammed II, Michael GC, Aliyu I. Impact on variation in the direction of cuff bladder on blood pressure readings. J Pract Cardiovasc Sci 2019;5:171-6 |
How to cite this URL:
Grema BA, Mohammed II, Michael GC, Aliyu I. Impact on variation in the direction of cuff bladder on blood pressure readings. J Pract Cardiovasc Sci [serial online] 2019 [cited 2023 Feb 7];5:171-6. Available from: https://www.j-pcs.org/text.asp?2019/5/3/171/273735 |
| Introduction | |  |
Blood pressure (BP) measurement is an integral part of the clinical evaluation of patients. Simple tools such as the sphygmomanometer and stethoscope are used in clinical practice. The history of BP measurement dates back to 1628[1] which established that the heart acts as a pump in blood circulation. However, early attempts at measuring the pressure of blood circulation dates back to 1733 when water manometer was used to determine the BP in several animals.[1] However, the first external device for measuring BP called sphygmograph was introduced by a German physiologist in 1854, and this formed the foundation of modern-day sphygmomanometer which was developed in 1881.[1] This was further improved upon in 1896.[1] Furthermore the systolic and diastolic blood pressures were further distinguished using an advanced device in 1905.[1]
Sphygmomanometer is a Greek word; sphygmos - pulse, manometer - pressure meter.[2] This piece of device consists essentially of the inflatable cuff with the bladder, the measuring device (manometer) which maybe mercury base or aneroid gauge, and then, the inflating mechanism which maybe manual (bulb and valve) or electronic.
There are two types of sphygmomanometer: manual and digital. The manual are the aneroid and mercury sphygmomanometer. Mercury sphygmomanometer remains the gold standard in BP measurement despite concerns of mercury exposure and risk of toxicity. It needs no recalibrations unlike in the case of aneroid and digital devices;[3],[4] furthermore, population normative values were determined using the mercury sphygmomanometer.[5],[6],[7],[8]
In measurement of BP, the cuff should be applied smoothly and smugly over the upper arm, usually the right arm compressing the brachial artery, with the cuff bladder at the same level with the heart [Figure 1]; there should be enough space between the lower margin of the cuff and the cubital fossa of at least 2 cm to allow for easy placement of the stethoscope; however, this is not always the case; at times, the cuff extends into the cubital fossa and the tubes impede proper placement of the stethoscope. Over the years, we have noticed, especially in lean individuals the sphygmomanometer tubing interfere in the proper placing of the stethoscope during BP measurement; however, if the bladder cuff is inverted with the tubing facing upward, this creates enough space for easy placement of the stethoscope. Therefore, if this process does not affect the BP values, we believe this will ease this challenge; furthermore, in many resource-limited settings, appropriate BP bladder cuffs for all the age groups of varied sizes are limited; therefore, bigger-sized bladder cuff may be used on children 8 years and above; however, because of their lean size, the BP tubing may result in crowding of the cubital fossa with limited space for the stethoscope; however, inverting the bladder with the sphygmomanometer tubing facing upward will create enough space for stethoscope placement. | Figure 1: Cuff with the tubing conventional position (control position).
Click here to view |
There are several variations in the positioning of the cuff such as on the forearm, wrist, and even the fingers.[9] Therefore, this study sorts to determine if changing the direction of the cuff with the tubing facing upward will affect the BP reading.
>Objectives
To determine the impact of varying the position and direction of the sphygmomanometer cuff on BP readings.
| Materials and Methods | | |
This was a cross-sectional study. Five hundred and forty individuals were consecutively recruited from the outpatient clinics over a period of 1 year (April 2017–March 2018). The BP of the individuals was taken following the standard protocol (control position): the individuals were seated with armrest, shoulder rested, and feet on the floor uncrossed; after relaxing for at least 5 min using the right arm.[10] BP measurements were also done with the individuals in the supine and also standing posture; an average of two readings was recorded and entered into a pro forma. Afterward, the study protocol was adopted with the individuals in the same sitting, standing, and supine positions but with the bladder position inverted (test position) hence the tubes facing upward [Figure 1] and [Figure 2]. Mercury sphygmomanometer (accusson) with appropriate-sized cuffs for the various ages and stethoscope were used for the measurements. Mean difference within 5 mmHg between the control and test procedure was acceptable.[6]
Ethical approval was obtained from the Ethical Committee of Aminu Kano Teaching Hospital, and consent was obtained from the individuals.
All individuals seen in the clinics are eligible for recruitment; except those who declined consent, those without arms (amputees), those who find sitting uncomfortable, and younger children who were uncooperative.
Data analysis
Obtained data were entered into Statistical Package for Social Sciences version 16 (SPSS Inc., Chicago, Illinois, USA). The data were presented as tables, and the means with standard deviations (SDs) were calculated. The Bland–Altman plot was also constructed to determine the limit degree of agreement between both test methods.
| Results | | |
There were 298 males and 242 females recruited for this study constituting a male to female ratio of 1.2:1. Their age ranged from 3 to 14 years.
[Table 1] reports the BP readings among males in the sitting position; the mean systolic BP for both methods of BP measurement was the same for the 3-year-old, 4-year-old, 6-year-old, 7-year-old, 9-year-old, 10-year-old, 12-year-old, and 13-year-old groups, respectively; however, the observed difference in the 5-year-old, 8-year-old, 11-year-old, and 14-year-old groups were within acceptable limits of <5 mmHg. Furthermore, the mean diastolic BP for both methods was the same for the 5-year-old, 7-year-old, 10-year-old, and 13-year-old groups, respectively; however, the observed difference in the 3-year-old, 4-year-old, 6-year-old, 8-year-old, 9-year-old, 11-year-old, 12-year-old, and 14-year-old groups was not significant. The mean systolic BP measurements among males in the standing position for both methods were the same for the 3-year-old, 4-year-old, 6-year-old, 7-year-old, 9-year-old, 10-year-old, 11-year-old, and 12-year-old groups, respectively. Furthermore, the mean diastolic BP for both methods slightly differed for all the age groups.
[Table 2] shows the BP readings among males in the supine position; the mean systolic BP for both methods was the same for the 3-year-old, 4-year-old, 6-year-old, 7-year-old, 9-year-old, 10-year-old, and 12-year-old groups, respectively; however, the observed differences in the 5-year-old, 8-year-old, 11-year-old, 13-year-old, and 14-year-old groups were not significant. Furthermore, the mean diastolic BP for both methods was slightly different for all the age groups, except for the 6-year-old, 7-year-old, 9-year-old, and 10-year-old groups; however, the observed differences were within the acceptable limit of 5 mmHg.
[Table 3] showed that both mean systolic and diastolic BP among the female individuals in the sitting position were almost similar for both methods. Furthermore, [Table 3] showed an almost similar mean systolic and diastolic BP reading among the females taken during standing position although the 14-year-old group showed a slightly higher mean value for the test position; however, there was only a point difference in their mean diastolic BP which was acceptable.
[Table 4] showed an almost similar mean systolic and diastolic BP reading among the females taken during supine position except for the 14-year-old group which showed a difference in their diastolic BP; those in the test position had higher mean value, though there was only a two point difference; which was of no clinical significance, and therefore acceptable.
The mean of the difference between applying the cuff in the normal upright position and the inverted position according to the study protocol were: −0.38 ± 2.70, 0.27 ± 2.18, −0.46 ± 2.88, 0.09 ± 1.58, −0.62 ± 3.14, and 0.09 ± 1.82; as shown in [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], respectively. There were significant agreements between both methods. However, this was most noticeable for the systolic BPs in the sitting and standing positions as was depicted by fewer outliers. | Figure 3: The difference in diastolic readings between control and test cuff position in the sitting posture compared with the mean difference.
Click here to view |
 | Figure 4: The difference in systolic readings between control and test cuff position in the sitting posture compared with the mean difference.
Click here to view |
 | Figure 5: The difference in diastolic readings between control and test cuff position in the standing posture compared with the mean difference.
Click here to view |
 | Figure 6: The difference in systolic readings between control and test cuff position in the standing posture compared with the mean difference.
Click here to view |
 | Figure 7: The difference in diastolic readings between control and test cuff position in the spine posture compared with the mean difference.
Click here to view |
 | Figure 8: The difference in systolic readings between control and test cuff position in the spine posture compared with the mean difference.
Click here to view |
| Discussion | | |
The practice of BP measurement is routine in adults; however, in pediatric practice, all children from the age of 3 years should have a routine BP measurement during clinic visits; however, those younger than 3 years with the risk of elevated BP such as renal or cardiovascular diseases should also have BP measured.[11] Standard protocol in BP measurement requires taking the readings at least from an average of two to three readings after at least a 5-min rest, patient seated, with the arm, legs uncrossed supported, and the bladder cuff at the level of the heart; the bladder cuff center should overlie the brachial artery.[6],[12] However, aberrations from this protocol are not uncommon in clinical practice, and some studies have shown significant[13] while others showed insignificant differences between the varied protocols.[14],[15]
Palatini et al.[13] while comparing BP measurements of the arm and the forearm and the arm and wrist, respectively, reported overestimation of BP readings in both procedures. However, Bilo et al.[14] reported that incorrect bladder cuff position did not have any significant impact on BP readings; so far, the bladder size was appropriate. Similarly, Thilagavathy et al.[15] did not find any difference in measuring the BP of pregnant women while their garments covered the arm during BP measurement.
From our study, there was no significant difference in the systolic BPs from both methods in the sitting, standing, and supine positions among the male individuals; however, the diastolic pressures were slightly higher in the test position; but, these were within the acceptable criterion for BP measurements of 5 mmHg. The American Association of Medical Instrumentation states that a test method/device for BP measurement must not differ from the mercury standard protocol by a mean difference of more than 5 mmHg or a SD of more than 8 mmHg.[16] Similarly, Emerick in their criterion specified that a variation in means between BP measurement methods not exceeding 5 mmHg allow both methods to be used interchangeably.[17] The British Hypertension Society[18] developed a grading system (A–D) based on the cumulative percentages of mean difference readings that fall within 5, 10, or 15 mmHg. All our readings were of Grade A; furthermore, similar pattern was noticed for the systolic BP for the female individuals; however, there were no clear differences in the diastolic pressures among the female individuals. Again, the Bland–Atman plot showed acceptable level of agreement between both measurement methods. Although the mean differences (bias) for most of the comparisons were predominantly negative highlighting that the test method underestimates the BP readings, they were all <5 mmHg. This is possibly attributed to relatively lesser compression applied by the test procedure.
| Conclusion | | |
Our test procedure showed agreement with the standard position of bladder cuff positioning. Therefore, it could be used interchangeably.
Ethics clearance
Ethical approval was obtained from the Ethical Committee of Aminu Kano Teaching Hospital, and consent was obtained from the individuals.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
| References | | |
| 1. | Booth J. A short history of blood pressure measurement. Proc R Soc Med 1977;70:793-9.  |
| 2. | Turner MJ, Speechly C, Bignell N. Sphygmomanometer calibration – Why, how and how often? Aust Fam Physician 2007;36:834-8. |
| 3. | van Montfrans GA. Oscillometric blood pressure measurement: Progress and problems. Blood Press Monit 2001;6:287-90. |
| 4. | Turner MJ, van Schalkwyk JM. Automated sphygmomanometers should not replace manual ones, based on current evidence. Am J Hypertens 2008;21:845. |
| 5. | Skirton H, Chamberlain W, Lawson C, Ryan H, Young E. A systematic review of variability and reliability of manual and automated blood pressure readings. J Clin Nurs 2011;20:602-14. |
| 6. | Pickering TG, Hall JE, Appel LJ, Falkner BE, Graves J, Hill MN, et al. Recommendations for blood pressure measurement in humans and experimental animals: Part 1: Blood pressure measurement in humans: A statement for professionals from the subcommittee of professional and public education of the american heart association council on high blood pressure research. Hypertension 2005;45:142-61. |
| 7. | Perloff D, Grim C, Flack J, Frohlich ED, Hill M, McDonald M. Human blood pressure determination by sphygmomanometry. Circulation 1993;88:2460-70. |
| 8. | Chobanian AV, Bakris GL, Black HR, Cushman WC, Green LA, Izzo JL Jr., et al. Seventh report of the joint national committee on prevention, detection, evaluation, and treatment of high blood pressure. Hypertension 2003;42:1206-52. |
| 9. | Gillman MW, Cook NR. Blood pressure measurement in childhood epidemiological studies. Circulation 1995;92:1049-57. |
| 10. | Report of the second task force on blood pressure control in children – 1987. Task force on blood pressure control in children. National heart, lung, and blood institute, Bethesda, Maryland. Pediatrics 1987;79:1-25. |
| 11. | Flynn JT, Kaelber DC, Baker-Smith CM, Blowey D, Carroll AE, Daniels SR, et al. Subcommittee on screening and management of high blood pressure in children. Clinical practice guideline for screening and management of high blood pressure in children and adolescents. Pediatrics. 2017;140(3):e20171904. Pediatrics 2017;140. pii: e20173035. |
| 12. | White WB, Berson AS, Robbins C, Jamieson MJ, Prisant LM, Roccella E, et al. National standard for measurement of resting and ambulatory blood pressures with automated sphygmomanometers. Hypertension 1993;21:504-9. |
| 13. | Palatini P, Longo D, Toffanin G, Bertolo O, Zaetta V, Pessina AC. Wrist blood pressure overestimates blood pressure measured at the upper arm. Blood Press Monit 2004;9:77-81. |
| 14. | Bilo G, Sala O, Perego C, Faini A, Gao L, Głuszewska A, et al. Impact of cuff positioning on blood pressure measurement accuracy: May a specially designed cuff make a difference? Hypertens Res 2017;40:573-80. |
| 15. | Thilagavathy G, Al Furaikh SS. Effect of garment on the arm under the auscultatory manometer cuff among primigravidae. J NTR Univ Health Sci 2018;7:129-33. [Full text] |
| 16. | O'Brien E, Waeber B, Parati G, Staessen J, Myers MG. Blood pressure measuring devices: Recommendations of the European society of hypertension. BMJ 2001;322:531-6. |
| 17. | Emerick DR. An evaluation of Non-Invasive Blood Pressure (NIBP) monitoring on the wrist: Comparison with upper arm NIBP measurement. Anaesth Intensive Care 2002;30:43-7. |
| 18. | O'Brien E, Pickering T, Asmar R, Myers M, Parati G, Staessen J, et al. Working group on blood pressure monitoring of the European society of hypertension international protocol for validation of blood pressure measuring devices in adults. Blood Press Monit 2002;7:3-17. |
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8]
[Table 1], [Table 2], [Table 3], [Table 4]
|
Search Pubmed for