Medical and Dental Consultantsí Association of Nigeria
Home - About us - Editorial board - Search - Ahead of print - Current issue - Archives - Submit article - Instructions - Subscribe - Advertise - Contacts - Login 
  Users Online: 1239   Home Print this page Email this page Small font sizeDefault font sizeIncrease font size

  Table of Contents 
Year : 2015  |  Volume : 18  |  Issue : 4  |  Page : 544-547

Availability and functionality of sphygmomanometers at health care institutions in Enugu, Nigeria

1 Department of Pharmacology and Therapeutics, College of Medicine, University of Nigeria, Enugu; Department of Medicine, College of Medicine, University of Nigeria, Enugu, Nigeria
2 Department of General Outpatients, University of Nigeria Teaching Hospital, Enugu, Nigeria
3 Department of Pharmacology and Therapeutics, College of Medicine, University of Nigeria, Enugu, Nigeria
4 Department of Medicine, College of Medicine, University of Nigeria, Enugu, Nigeria
5 Medical Laboratory Science, College of Medicine, University of Nigeria, Enugu, Nigeria

Date of Acceptance02-Feb-2015
Date of Web Publication13-May-2015

Correspondence Address:
C P Chijioke
PMB 01129, Enugu 400001, Enugu State
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/1119-3077.156899

Rights and Permissions

Objective: Our aim was to investigate the availability of functional blood pressure monitors at health care institutions in Enugu, Nigeria.
Methods: During repeated surveys of 15 (primary, secondary and tertiary) health care institutions in Enugu between 2007 and 2012, records were made of the availability and functional status of sphygmomanometers in the clinics and wards. We also assessed the degree of agreement between measurements by institutional staff and measurements by trained observers using the same or the standard sphygmomanometer.
Results: Apart from three institutions, there was inadequate availability of fully functional sphygmomanometers: 61 staff attending to outpatients were sharing 35 sphygmomanometers, 6 of which were faulty i.e. needing repairs. Wards invariably had only one or two functional sphygmomanometers, regardless of bed occupancy. Institutional staff ignored recommended guidelines for blood pressure measurement. The overall mean difference in blood pressure measurements between institutional staff and a trained observer (1.6 mmHg; 95% confidence interval, CI: -0.3 to 3.4; P = 0.1) was greater and more significant than the mean difference between the two observers (0.1 mmHg; CI: -1.5 to 1.7; P = 0.9) and the mean difference between institutional and standard sphygmomanometers (-0.2 mmHg; CI: -1.7 to 1.3; P = 0.8).
Conclusion: There has been a notable lack of reporting on the availability of blood pressure measuring devices in third world health care institutions. Our surveys have shown inadequate availability of functional sphygmomanometers in the institutions, but satisfactory agreement between measurements by institutional staff and trained observers. In view of recent guidelines and recommendations, there is need to supplement office readings with mercury devices with oscillometric home or automated office blood pressure recording.

Keywords: Blood pressure measurement, healthcare quality, hospital care, mercury devices, Nigeria, sphygmomanometers

How to cite this article:
Chijioke C P, Okolo T O, Nwadike K I, Ejim E C, Ekochin F C, Aronu G N, Ghasi S I, Chijioke O U. Availability and functionality of sphygmomanometers at health care institutions in Enugu, Nigeria. Niger J Clin Pract 2015;18:544-7

How to cite this URL:
Chijioke C P, Okolo T O, Nwadike K I, Ejim E C, Ekochin F C, Aronu G N, Ghasi S I, Chijioke O U. Availability and functionality of sphygmomanometers at health care institutions in Enugu, Nigeria. Niger J Clin Pract [serial online] 2015 [cited 2022 Jan 28];18:544-7. Available from:

   Introduction Top

The proportion of the world population with high blood pressure (BP) has increased from about a quarter to a third, and even up to half the adult population in some African countries, within just a few years. [1],[2],[3] The prevalence, awareness, treatment and control rates in developing countries are approaching the rates in developed countries. [3] To tackle this waxing pandemic, there should be safe, accurate and adequate BP monitoring in health care institutions, consonant with relevant guidelines. [4],[5] Studies of BP measurement, conducted in developed countries, suggest however that this may not be the case. [6],[7],[8],[9],[10],[11],[12] There has been a notable lack of such studies in developing countries, including Nigeria. A frequent concern during routine clinical practice on wards and in clinics at our institution in Nigeria is that sphygmomanometers are either not available, or they are dysfunctional due to lack of repairs and maintenance. This observation motivated us to investigate the availability of BP measuring devices in a range of health care institutions in and around Enugu, a major hub city of the south-eastern geopolitical zone of Nigeria. Our main objective was to investigate the availability of functional BP monitors at health care institutions in Enugu, Nigeria. Our specific aims were (1) To assess the availability of BP monitors on the wards and in the clinics at Enugu health care institutions, and (2) to assess the functionality of these BP monitors. A subsidiary aim was (3) to investigate the degree of agreement between institutional staff and trained observers using the institutional device and a known, reliable and functional sphygmomanometer.

   Methods Top

The protocol for this study was approved by the University of Nigeria Teaching Hospital Ethics Committee. The settings are tertiary level and major primary and secondary level health care institutions in and around Enugu, Nigeria (which were visited between 2007 and 2012). Some of the institutions, as indicated in the tables, were visited twice or thrice during this period. Observers were medical doctors who were further trained by performing triplicate BP measurements on consenting subjects, using mercury column, aneroid and oscillometric devices respectively, with careful observation of measurement technique, and correction of errors in technique. Normotensive or hypertensive nonpregnant adults (at least 16 years old, arm circumference 22-32 cm), without concurrent illness or complications of hypertension, were recruited for the study. They gave informed consent to four sequential BP measurements. A recently purchased mercury column sphygmomanometer (Accoson ® , UK) was used as a "standard sphygmomanometer." The number of sphygmomanometers available in the clinics and wards at the health institution was recorded, and their functional status classified as GOOD (functional, in good working order), POOR (dysfunctional, usable but technical problems requiring repairs) or BAD (nonfunctional, not usable). A trained observer conducted a "blind" comparison of the standard sphygmomanometer with the sphygmomanometers in the wards and clinics. The observer and a member of the institution's nursing or medical staff measured the BP of a consenting patient using the sphygmomanometer available on the ward or in the clinic. Finally, the observer measured the BP using the standard sphygmomanometer. Although the same observer undertook most of the measurements, a second trained observer duplicated the measurement with the institutional device; the aim was to ascertain and maintain between-observer consistency, bearing in mind the inherent variability of BP. Blinding meant that the observers and the institutional staff did not know each other's measurements. For "GOOD" devices, the degree of agreement for mean BP between the observers and the institutional staff, and between test and standard sphygmomanometers, was assessed using the method of Bland and Altman. [13] All data were computerized and analyzed using SPSS software, version 17.0.(Accoson UK).

   Results Top

[Table 1] and [Table 2] portray the availability of sphygmomanometers at the tertiary, secondary and primary health care institutions, compared to the number of doctors working in the clinics and to the bed occupancy of the wards. [Table 3] reflects the degree of agreement between BP measurements at the institutions by comparing the trained observers and standard sphygmomanometer with the institutional staff and BP device.
Table 1: Sphygmomanometer availability and functional status (outpatient clinics)

Click here to view
Table 2: Sphygmomanometer availability and functional status (wards)

Click here to view
Table 3: Between-observer and between-sphygmomanometer agreement of blood pressure measurements (Bland - Altman analysis[12])

Click here to view

For dysfunctional or nonfunctional devices, the problems included bladder stiffness (difficult or impossible to inflate), air leakage from cuff or bladder with constant or uncontrollable falling of the mercury column, leakage of mercury (empty column), unequal double mercury column, baseline reading up to 4-7 mmHg above zero.

On three occasions, we observed with alarm, "BAD," unusable sphygmomanometers from which there was neglected leakage and spillage of mercury from its usual confine, obviously contaminating the environment. We noticed that in the routine use of mercury sphygmomanometers in the wards and clinics that the institutional staffs invariably do not bother to return the mercury to its storage compartment below the inflation column and close the safety lock. More attention to this safety maneuver would help in the prevention of leakage: There is clearly a need for education and training in this regard.

Common human errors (committed invariably by institutional staff) included unduly tight application of the cuff to the arm and failure to cross-check the systolic pressure by palpation before auscultation. None of the staff adhered to guidelines such as comparing the BP in the two arms, ensuring 5 min' rest before BP measurement or measuring arm circumference. Almost all the staff (over 90%) only paid cursory attention to other guidelines such as avoiding noise and distractions, correct positioning and support for the back and arm, asking about recent smoking, caffeine intake, exercise, and anxiety.

   Discussion Top

During the period covered by this report (2007-2012), studies in developed countries were demonstrating the superiority of ambulatory, home and automated office BP measurements to manual office BP monitoring for the prediction of long-term risk from hypertension. [14],[15],[16],[17],[18],[19],[20] Although there is increasing uptake of home BP monitoring by patients who can afford it (<5% of hypertensives), manual office BP monitoring with conventional mercury column sphygmomanometers remains the widespread usual practice in our setting. As shown in the tables, there were only two aneroid devices seen in all our surveys and no oscillometric devices.

Although the risk to the environment has encouraged the move away from mercury devices in developed countries, [16],[21] there are reminders that automated oscillometric devices may not be accurate in some circumstances, for example marked hypertension or hypotension, arrhythmias. [18],[22] Furthermore, specific populations would need separate validation of the oscillometric method (e.g., elderly, diabetics, pregnancy, renal failure, obese, children). [18]

Apart from such circumstances, in which the conventional mercury sphygmomanometer is necessary, another reason for retaining the use of these devices in our environment would be the issue of cost. With the progressive reduction of cost of validated oscillometric monitors, however (some of which are now comparable in cost to a conventional mercury sphygmomanometer), they are becoming more affordable in our setting.

The data in [Table 1] and [Table 2] show inadequate availability of "GOOD," functional sphygmomanometers for BP monitoring in the wards and clinics. For example, up to 15 doctors would share one "GOOD" device in tertiary institution surgical outpatients. In one primary care institution, the only available functional device could not be used because it was locked up for security reasons. The key was not available to the staff on duty. In 7 out of 26 wards surveyed, there was no functional device available.

The results of manual office BP measurement may be quite variable for several reasons, apart from the human and machine error factors we observed, as listed above. The reasons include inherent biological variability, the presence of a clinician (white coat effect, masked hypertension), casual/sub-optimal technique and the use of unreliable (unvalidated) devices. [6],[7],[8],[9],[19] This protean variability would explain the wide 95% confidence intervals of the mean differences in [Table 3], implying lack of a statistically significant difference between the observers and between the institutional and standard sphygmomanometers. The data in [Table 3] however, show that the mean differences between the institutional staff and the first observer were on the whole greater than the mean differences between the two trained observers, perhaps reflecting the additional human error factor, even though statistically significant in only two instances (at the conventional level of P < 0.05). The magnitude of differences between test (institutional) and standard sphygmomanometers was similar to the differences between the two trained observers using the same device. These mean differences were on the whole relatively small, again without statistical significance, suggesting that the degree of agreement of "GOOD" sphygmomanometers at the institutions visited (with the standard device) was adequate.

Other limitations of this report include the limited number of institutions included in the survey. Being unfunded, this research relied on the good will and spare time of volunteer observers. Hence, although the three main tertiary referral centers were covered, only five secondary care and five primary care centers were included. Limitation of time and resources also stretched out the overall time-span of the surveys. Although this may suggest that some of the earlier data are outdated, similar observations and results were obtained with later repeat visits to the same institutions. Our current ongoing experience during practice on the wards and in the clinics also suggests that the earlier data are still applicable and worth reporting.

   Conclusion Top

These institutional sphygmomanometer surveys at Enugu have shown general poor availability of BP measurement devices in the wards and clinics, errors of technique which are readily correctable with appropriate training, and satisfactory agreement between functional devices and the standard sphygmomanometer. There was neglect of mercury spillage from some dysfunctional devices and failure to handle sphygmomanometers with the necessary care to minimize the risks of environmental contamination. The use of manual office BP monitoring with mercury devices remains the widespread norm in our setting, in spite of recommendations, [16],[21] albeit controversial, [23] to use nonmercury devices instead.

Thus the main priority is the adequate provision of functional BP monitoring devices on the wards (say at least one device for ten inpatients) and in the clinics (at least one per doctor). Education should encourage the need to supplement manual office measurements with more prognostic methods such as home and automated office BP monitoring.

   Acknowledgment Top

We do hereby acknowledge the effort of Dr. C. Uzoke who helped to provide some recent update data on the availability and functionality of sphygmomanometers at one of the tertiary healthcare institutions.

   References Top

Kaplan NM, Opie LH. Controversies in hypertension. Lancet 2006;367:168-76.  Back to cited text no. 1
World Health Organization. World Health Statistics 2012. Geneva: World Health Organization; 2012.  Back to cited text no. 2
Pereira M, Lunet N, Azevedo A, Barros H. Differences in prevalence, awareness, treatment and control of hypertension between developing and developed countries. J Hypertens 2009;27:963-75.  Back to cited text no. 3
Beevers G, Lip GY, O'Brien E. ABC of hypertension: Blood pressure measurement. Part II-conventional sphygmomanometry: Technique of auscultatory blood pressure measurement. BMJ 2001;322:1043-7.  Back to cited text no. 4
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.  Back to cited text no. 5
Coleman AJ, Steel SD, Ashworth M, Vowler SL, Shennan A. Accuracy of the pressure scale of sphygmomanometers in clinical use within primary care. Blood Press Monit 2005;10:181-8.  Back to cited text no. 6
Kim JW, Bosworth HB, Voils CI, Olsen M, Dudley T, Gribbin M, et al. How well do clinic-based blood pressure measurements agree with the mercury standard? J Gen Intern Med 2005;20:647-9.  Back to cited text no. 7
Manzoli L, Simonetti V, D'Errico MM, De Vito C, Flacco ME, Forni C, et al. (In) accuracy of blood pressure measurement in 14 Italian hospitals. J Hypertens 2012;30:1955-60.  Back to cited text no. 8
Rayner B, Blockman M, Baines D, Trinder Y. A survey of hypertensive practices at two community health centres in Cape Town. S Afr Med J 2007;97:280-4.  Back to cited text no. 9
Myers MG, Godwin M, Dawes M, Kiss A, Tobe SW, Kaczorowski J. The conventional versus automated measurement of blood pressure in the office (CAMBO) trial: Masked hypertension sub-study. J Hypertens 2012;30:1937-41.  Back to cited text no. 10
Myers MG, Godwin M. Automated office blood pressure. Can J Cardiol 2012;28:341-6.  Back to cited text no. 11
Bland JM, Altman DG. Statistical methods for assessing agreement between two methods of clinical measurement. Lancet 1986;1:307-10.  Back to cited text no. 12
Hodgkinson J, Mant J, Martin U, Guo B, Hobbs FD, Deeks JJ, et al. Relative effectiveness of clinic and home blood pressure monitoring compared with ambulatory blood pressure monitoring in diagnosis of hypertension: Systematic review. BMJ 2011;342:d3621.  Back to cited text no. 13
Sheikh S, Sinha AD, Agarwal R. Home blood pressure monitoring: How good a predictor of long-term risk? Curr Hypertens Rep 2011;13:192-9.  Back to cited text no. 14
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.  Back to cited text no. 15
Myers MG. The great myth of office blood pressure measurement. J Hypertens 2012;30:1894-8.  Back to cited text no. 16
Stergiou GS, Parati G. Should the measurement of blood pressure in the office be redefined? J Hypertens 2012;30:1906-8.  Back to cited text no. 17
O'Brien E. Has conventional sphygmomanometry ended with the banning of mercury? Blood Press Monit 2002;7:37-40.  Back to cited text no. 18
Myers MG, Godwin M, Dawes M, Kiss A, Tobe SW, Grant FC, et al. Conventional versus automated measurement of blood pressure in primary care patients with systolic hypertension: Randomised parallel design controlled trial. BMJ 2011;342:d286.  Back to cited text no. 19
McVicker JT. Blood pressure measurement - Does anyone do it right? An assessment of the reliability of equipment in use and the measurement techniques of clinicians. J Fam Plann Reprod Health Care 2001;27:163-4.  Back to cited text no. 20
Villegas I, Arias IC, Botero A, Escobar A. Evaluation of the technique used by health-care workers for taking blood pressure. Hypertension 1995;26:1204-6.  Back to cited text no. 21
Buchanan S, Orris P, Karliner J. Alternatives to the mercury sphygmomanometer. J Public Health Policy 2011;32:107-20.  Back to cited text no. 22
Jones DW, Frohlich ED, Grim CM, Grim CE, Taubert KA. Mercury sphygmomanometers should not be abandoned: An advisory statement from the Council for High Blood Pressure Research, American Heart Association. Hypertension 2001;37:185-6.  Back to cited text no. 23


  [Table 1], [Table 2], [Table 3]

This article has been cited by
1 Results of a project to calibrate mercury sphygmomanometer blood pressure-measuring devices in Egypt
Soliman Ghareeb,Ghada Youssef,Haytham Soliman Ghareeb,Hazem Abd El-Mageed,Muhammad H. Mesalm,Remon Talaat,Alaaeldin Eltawil,Doaa M. Hasan,M. Mohsen Ibrahim
Journal of Human Hypertension. 2020;
[Pubmed] | [DOI]
2 Inability to Walk Predicts Death among Adult Patients in Hospitals in Malawi
Raphael Kazidule Kayambankadzanja,Carl Otto Schell,Grace Nsanjama,Isaac Mbingwani,Samson Kwazizira Mndolo,Jamie Rylance,Tim Baker
Emergency Medicine International. 2019; 2019: 1
[Pubmed] | [DOI]


    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Access Statistics
    Email Alert *
    Add to My List *
* Registration required (free)  

  In this article
    Article Tables

 Article Access Statistics
    PDF Downloaded221    
    Comments [Add]    
    Cited by others 2    

Recommend this journal