Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Sphygmomanometers”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1975

Comparison of a semi-automated sphygmomanometer with the clinical sphygmomanometer.

A semi-automated sphygmomanometer Stanley B-200 has been compared with the clinical sphygmomanometer in 500 college boys by using a blind simultaneous method. Stanley B-200 has shown significantly higher systolic blood pressure (14.8 mmHg, P smaller than 0.05) and diastolic blood pressure (3.8 mmHg, P smaller than 0;05). This device also recorded 15 false positive systolic and 12 false negative diastolic results (P smaller than 0.05).

Adolescent↗
PubMed1995

Hawksley random zero sphygmomanometer versus the standard sphygmomanometer: an investigation of mechanisms.

There has been recent controversy over the accuracy of the Hawksley random zero sphygmomanometer (RZS). In most instances, there has been a bias towards lower recordings with the RZS. In an attempt to identify the mechanism, we designed a study to test the hypothesis that biased error is due to: (1) the magnitude of the random zero; and (2) the magnitude of the pressure being recorded. A RZS (60 mm Hg zero UK version) was connected via a Y-tube to a standard mercury sphygmomanometer (SMS). The circumference of the cam responsible for the variable reservoir size in the RZS was marked into quarters. Within each 10 mm Hg band from 300 to 60 mm Hg, 12 paired readings were taken randomly: three within each of the four quarters of the cam circumference. The mean SMS value was 148.8 vs. 148.2 mm Hg for the RZS. Although of minimal biological significance this difference was highly significant (t = 6.2; p < 0.0001). Our findings fail to confirm the difference between RZS and SMS previously reported and we did not find any evidence of a relation in the difference between SMS and RZS and either the random zero value or the height of the blood pressure. Our findings suggest that if the RZS does under record BP versus the SMS it may relate to a patient-machine interaction not detectable in our system.

Blood Pressure Determination↗
PubMed2001

[Evaluation of sphygmomanometers used by family physicians practicing outside the hospital environment in Bas-Saint-Laurent].

OBJECTIVE: To assess the precision and integrity of all aneroid and mercury sphygmomanometers regularly used by family physicians practising outside hospitals. DESIGN: Cross-sectional study. SETTING: Private medical clinics and local community health centres in Bas-Saint-Laurent, Qué. PARTICIPANTS: A total of 151 of the 166 physicians in this administrative region. MAIN OUTCOME MEASURES: Precision of the mercury sphygmomanometers was measured using the difference between a reading in the absence of pressure and level 0. Precision of the aneroid sphygmomanometers was measured using variations at pressures of 140 mm Hg and 90 mm Hg compared with those on a calibrated mercury sphygmomanometer. Integrity of sphygmomanometers, arm cuffs, and inflating bulbs was also assessed. RESULTS: In all, 258 sphygmomanometers met the inclusion criteria (111 mercury sphygmomanometers and 147 aneroid sphygmomanometers). Discrepancies of > or = 4 mm Hg were found in 15.5% of these instruments (12.6% and 17.7% of the mercury and aneroid sphygmomanometers, respectively). In 31.0% of the instruments (52.3% and 15.0% of the mercury and aneroid sphygmomanometers, respectively), one component was malfunctioning. CONCLUSION: Sphygmomanometers that measure patients' blood pressure inaccurately could result in an incorrect diagnosis of hypertension or in a normal blood pressure reading in a hypertensive patient.

Blood Pressure↗
PubMed1988

A comparison of the random-zero and standard mercury sphygmomanometers.

Both the standard mercury sphygmomanometer and the random-zero sphygmomanometer have been used in epidemiological studies and clinical trials. Problems arise in comparing studies since, in addition to other methodological differences, the readings obtained with the random-zero sphygmomanometer have been found to be lower than those obtained with the standard mercury sphygmomanometer. In the present study, blood pressures were measured in 66 subjects to examine the comparability of findings with the two instruments. Trained observers measured blood pressures simultaneously using a double-headed stethoscope and one cuff connected to the two sphygmomanometers. Use of instrument was randomly assigned for each blood pressure measurement; each observer was unaware of the other's blood pressure reading. Readings were lower with the random-zero sphygmomanometer; mean difference ranged from 2.5 to 3.3 mm Hg for systolic pressure and 1.9 to 2.7 mm Hg for diastolic pressure. Digit distributions recorded by the two observers for the standard mercury sphygmomanometer and the random-zero sphygmomanometer were not significantly different for either systolic or diastolic blood pressure. Intraindividual variation was greater with the random-zero sphygmomanometer than with the standard mercury sphygmomanometer. These data do not indicate that one instrument is clearly superior to the other, although in studies where the observer seeks to reduce the bias of multiple readings per person, the random-zero sphygmomanometer may be the more appropriate instrument. Critical to the use of either instrument are careful training, standardization, certification, and periodic recertification of observers.

Adult↗
PubMed1990

Inaccuracy of the Hawksley random zero sphygmomanometer.

To examine the accuracy of the Hawksley random zero sphygmomanometer two studies were done with subjects with a wide range of blood pressure. When readings made by one observer on the UK model of the Hawksley sphygmomanometer were compared with readings by two independent observers on separate mercury sphygmomanometers, the Hawksley device underestimated systolic readings by a mean (SD) of 2.0 (2.4) and 0.5 (3.6) mm Hg and diastolic readings by a mean of 3.7 (2.7) and 2.8 (2.9) mm Hg. When readings made on the UK and US models of the Hawksley sphygmomanometer were compared with those made on mercury sphygmomanometers, with observers exchanging devices half way during the experiment, the UK Hawksley device underestimated systolic pressure by a mean of 3.8 (SD 3.5) mm Hg and diastolic blood pressure by 7.5 (3.8) mm Hg; and the US model by 2.6 (3.4) mm Hg for systolic pressure and 6.2 (3.7) mm Hg for diastolic pressure. There was better agreement between two observers using standard sphygmomanometers than between an observer using the Hawksley random zero sphygmomanometer and an observer using a standard sphygmomanometer. Thus, the quantitative aspects of blood pressure in epidemiological and intervention studies in which the Hawksley random zero sphygmomanometer was used need re-evaluation. Moreover, the Hawksley random zero sphygmomanometer, in its present design, should not be used in hypertension research.

Adolescent↗
PubMed1995

Does the Hawksley random zero sphygmomanometer underestimate blood pressure, and by how much?

The study objective was to compare blood pressure (BP) measurement by the Hawksley random-zero sphygmomanometer and the standard mercury sphygmomanometer. Comparison of simultaneous 'blind' BP measurements were made using the Hawksley random-zero sphygmomanometer and the standard mercury sphygmomanometer linked by a Y-connector to a single cuff, in the general practice and office environments. Sixty five healthy volunteers and general practice patients, aged between 20 and 50 years (SBP range 82-184 mm Hg, DBP range 38-112 mm Hg), were studied. Each had three blood pressure measurements taken. Mean BPs recorded by the Hawksley random-zero sphygmomanometer were lower than those recorded by the standard mercury sphygmomanometer. The Hawksley random-zero sphygmomanometer underestimated SBP by 1.3 mm Hg (95% CI 0.9-1.8 mm Hg) and DBP by 1.7 mm Hg (95% CI 1.1-2.3 mm Hg). These differences between instruments were independent of BP level both for systolic and diastolic measurements. An overview including this study and six other published reports describing nine studies examining the performance of the Hawksley random-zero sphygmomanometer suggested a similar degree of underestimation for SBP (mean difference 1.35 mm Hg, 95% CI 1.24-1.46 mm Hg). Underestimation of DBP appeared greater (mean difference 2.54 mm Hg, 95% CI 2.43-2.65 mm Hg) but was reduced when two outlying studies were removed from analysis (mean 1.97, 95% CI 1.85-2.09 mm Hg). We conclude that the Hawksley random-zero sphygmomanometer underestimates systolic and diastolic pressure, when compared with the standard mercury sphygmomanometer. However, the degree of underestimation is small and appears consistent across a wide range of blood pressure levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

The random-zero versus the standard mercury sphygmomanometer: a systematic blood pressure difference.

The random-zero and standard mercury sphygmomanometers are used frequently, and sometimes interchangeably, in epidemiologic studies. To determine whether there is a systematic difference between them, the authors measured systolic, fourth-phase, and fifth-phase diastolic blood pressures using both sphygmomanometers simultaneously in a series of six experiments. For most experiments, the system for simultaneous blood pressure measurements employed one cuff connected to both sphygmomanometers, which were carefully calibrated and read by two trained technicians using a double stethoscope. Order of use of the random-zero sphygmomanometer was randomly assigned, and technicians were blind to each others readings. At deflation rates of 2 mmHg/second, readings of the random-zero sphygmomanometer were systematically lower than those of the standard mercury sphygmomanometer: -0.9 mmHg for systolic, -1.8 mmHg for fourth-phase, and -1.8 mmHg for fifth-phase diastolic blood pressures (all differences, p less than 0.001). The difference persisted after adjustment for subject age, sex, heart rate, blood pressure level, observer, and room temperature, and was present for varying deflation rates. However, by draining the residual mercury from a random-zero sphygmomanometer and using the instrument as if it were a standard mercury sphygmomanometer, much of the difference between the two was eliminated. This suggests that the mechanism for the difference relates to the increased height of mercury in the random-zero manometer tube. The authors conclude that the random-zero and standard mercury sphygmomanometers should not be used interchangeably in epidemiologic studies.

Adult↗
PubMed1994

Using Hawksley random zero sphygmomanometer as a gold standard may result in misleading conclusions.

We combined a database of paired blood pressure measurements taken using the Hawksley random-zero sphygmonanometer and a standard mercury sphygmomanometer and a database of paired measurements made on a SpaceLabs 90202 ambulatory blood pressure recorder and standard sphygmomanometer to determine how the SpaceLabs 90202 would have fared if it had been assessed against the Hawksley random-zero sphygmomanometer instead of a standard sphygmomanometer. The pooled database contained 255 triplicate readings. Using the standard sphygmomanometer as gold standard, the Spacelabs had a median error of 2 mm/Hg for both systolic and diastolic. Against the Hawksley random-zero sphygmomanometer, median error was -3 mm systolic and -6 mm diastolic. The proportion of errors > 10 mm rose from 11% (systolic) and 9% (diastolic) with the standard sphygmomanometer to 16% and 29% with the Hawksley random-zero sphygmomanometer. Because it underestimates systolic and diastolic pressures, the use of the Hawksley random-zero sphygmomanometer as a gold standard may have resulted in misleading conclusions about performance of some automated BP recorders.

Adult↗
PubMed1991

[Measurement of arterial blood pressure using the sphygmomanometer-S and the direct method].

Sphygmomanometer--S is the microcomputer device measuring blood pressure (BP) by the noninvasive sphygmooscillographic method following standard algorithm. When compared sphygmomanometer--S with auscultatory method, this device overestimated systolic BP by 7 mm Hg, and underestimated diastolic BP by 9 mm Hg on the average. In other words, sphygmomanometer--S overestimated systolic pressure and lowers diastolic pressure in relation to auscultatory method in the same ratio and value, as the direct method in relation to the auscultatory method. In this study, we evaluated the accuracy of the results obtained by sphygmomanometer--S, with simultaneously recorded radial artery pressure by direct method. In 15 patients 27-60 years of age undergoing cardiac surgery BP was measured by sphygmomanometer--S and direct method simultaneously on the same left upper extremity. We measured direct radial artery pressure using AE 840 Nycotron transducer and Philips amplifier. BP by sphygmomanometer--S was obtained on the same left arm using cuffs of size 11 x 24 cm and 13 x 35 cm. In 15 patients 124 pairs of BP measurement were carried out with sphygmomanometer--S and direct method. The regression equation for systolic, diastolic and mean pressure demonstrated the coincidence of the BP results obtained by sphygmomanometer--S with direct method. The correlation coefficient (r) was 0.97 for systolic, 0.90 for diastolic and 0.92 for mean pressure. Systolic and diastolic pressure measured by the sphygmomanometer--S were 2 mm Hg and mean 0.6 mm Hg higher on the average, than the same pressures obtained by direct method (ryc. 1). These differences were statistically not significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Hospital sphygmomanometer use: an audit.

Periodic evaluation over the past 20 years of the ability of clinical staff to accurately measure blood pressure, as well as the functional state of sphygmomanometers, has frequently demonstrated significant deficiencies. The data presented here are the results of a recent audit in the Newcastle area. Medical (48) and nursing (217) staff in five general hospitals (3 public, 2 private), were questioned on sphygmomanometer use, observed taking a blood pressure reading and asked to record blood pressures from a videotape. In addition, all hospital sphygmomanometers were checked to see if they were in working order. Of 463 sphygmomanometers evaluated, 58% were in perfect working order. There was a marked variation in the state of equipment between institutions (40 to 94%). Staff knowledge and technical ability in sphygmomanometer use was similar in doctors and nurses, with 69% of doctors and 71% of nurses knowing that phase V Korotkoff sounds best approximated adult diastolic blood pressure. Knowledge of appropriate cuff size and ability to use a sphygmomanometer was also similar between the two groups. However, doctors performed better in measuring systolic and diastolic blood pressures from a videotape (9.3 +/- 1.7 correct compared with 7.8 +/- 1.9 for nurses; P < 0.01). It was concluded that, with the exception of one hospital, the state of repair of sphygmomanometers was poor. Staff knowledge of sphygmomanometer usage and their ability to record blood pressure was satisfactory. However, not all practising health professionals are competent in using a sphygmomanometer.

Blood Pressure Determination↗
PubMed1998

How accurate are sphygmomanometers?

The objective of this study was to assess the accuracy and reliability of mercury and aneroid sphygmomanometers. Measurement of accuracy of calibration and evaluation of physical conditions were carried out in 524 sphygmomanometers, 351 from a hospital setting, and 173 from private medical offices. Mercury sphygmomanometers were considered inaccurate if the meniscus was not '0' at rest. Aneroid sphygmomanometers were tested against a properly calibrated mercury manometer, and were considered calibrated when the error was < or =3 mm Hg. Both types of sphygmomanometers were evaluated for conditions of cuff/bladder, bulb, pump and valve. Of the mercury sphygmomanometers tested 21 % were found to be inaccurate. Of this group, unreliability was noted due to: excessive bouncing (14%), illegibility of the gauge (7%), blockage of the filter (6%), and lack of mercury in the reservoir (3%). Bladder damage was noted in 10% of the hospital devices and in 6% of private medical practices. Rubber aging occurred in 34% and 25%, leaks/holes in 19% and 18%, and leaks in the pump bulb in 16% and 30% of hospital devices and private practice devices, respectively. Of the aneroid sphygmomanometers tested, 44% in the hospital setting and 61% in private medical practices were found to be inaccurate. Of these, the magnitude of inaccuracy was 4-6 mm Hg in 32%, 7-12 mm Hg in 19% and > 13 mm Hg in 7%. In summary, most of the mercury and aneroid sphygmomanometers showed inaccuracy (21% vs 58%) and unreliability (64% vs 70%).

Blood Pressure Determination↗
PubMed2001

The extent and implications of sphygmomanometer calibration error in primary care.

AIM: The sphygmomanometer is an essential piece of diagnostic equipment, used in many routine consultations in primary care. Its accuracy depends on correct maintenance and calibration. This study was designed to: (1) assess the maintenance and calibration of sphygmomanometers in use in primary care; (2) assess the clinical, ethical, legal and public health implications of our findings. METHOD: A researcher assessed the accuracy of mercury and aneroid sphygmomanometers in use in 231 English general practices. He also made enquiries about arrangements for the maintenance and calibration of sphygmomanometers. We conducted a small telephone survey in general practices across the country to determine maintenance and calibration arrangements across the country. We carried out a modelling exercise to explore the clinical, ethical and public health implications of our findings. RESULTS: Of 1462 sphygmomanometers, 9.2% gave readings were more than 5 mm Hg inaccurate. No practice had arrangements for maintenance and calibration of sphygmomanometers. Nationally, one of 54 practices had an arrangement for maintenance and calibration. True hypertension is very uncommon in women under 35, a blood pressure which is measured as high is much more likely to be caused by calibration error than by hypertension. CONCLUSION: It is rare for sphygmomanometers used in primary care to be maintained and calibrated. Because of this women under 35 are at risk of misclassification and inappropriate treatment. This has ethical and public health implications. Clinicians using equipment which has not been maintained and calibrated may be medically negligent.

Adolescent↗
PubMed1992

[Calibration and safety of sphygmomanometers in health centers of Murcia].

OBJECTIVE: To find the levels of calibration, safety and physical faults in the sphygmomanometers used in Health Centres. DESIGN: A multi-centre, observational, descriptive and crossover study. SITE. 7 Health Centres in the urban zone of Murcia and nearby towns. All the sphygmomanometers in the 7 Health Centres, that is 80 aneroid and 62 mercury ones. MAIN MEASUREMENTS AND RESULTS: It needs high-lighting that 43.7% of the aneroid sphygmomanometers and 12.3% of the mercury ones were wrongly calibrated. We noted that 20% of the measurements made with wrongly calibrated aneroid sphygmomanometers had a margin of error above +/- 8 mmHg, with a tendency towards under-registering. We found very significant differences between the average arterial pressure measured by aneroid instruments as against mercury ones (p < 0.001). The number of sphygmomanometers which show a margin of error greater than +/- 3 mmHg at every level of pressure is significantly greater in aneroid instruments than in mercury ones (p < 0.001). We found physical faults in 23.9% of the instruments. CONCLUSIONS: We consider the number of wrongly calibrated aneroid sphygmomanometers to be excessively high. Therefore mercury ones should be used whenever possible and particularly during diagnosis and treatment. Both aneroid and mercury sphygmomanometers should be regularly checked, using a proper procedure. Mercury instruments set at zero are correctly calibrated and can be used as a model for checking aneroid ones.

Blood Pressure Determination↗
PubMed2002

Practice audits: reliability of sphygmomanometers and blood pressure recording bias.

It is well established that numerous errors, biases and omissions in recording blood pressure exist. This study had two objectives. Firstly, to measure the accuracy of sphygmomanometers used in general practice and secondly to assess digit bias in blood pressure recording. This study was carried out in the then Northfield PCG, which comprised 18 practices and 67 GPs. A total of 131 mercury and aneroid sphygmomanometers were tested for accuracy by a trained technician in accordance with the methods specified in BS 2743 (1990). Accuracy was defined as an error of greater than 10 mm Hg. The second part of the methodology involved undertaking an audit of the proportion of registered patients aged 35-80 years who had their blood pressure measured within the last 5 years by members of the Primary Health Care Team. The results were that of the mercury and aneroid sphygmomanometers tested, 17% were inaccurate. Of these, 4% recorded an error greater than 10 mm Hg. One percent of mercury and 10% of aneroid sphygmomanometers recorded an error greater than 10 mm Hg respectively. Sixteen (12%) sphygmomanometers were so deteriorated (air leaks, dirt in mercury) that the researcher suggested their immediate withdrawal from service. The results of the blood pressure recording audit suggested digit bias of both systolic and diastolic recordings to the nearest 10 mm Hg. This study suggests that sphygmomanometers used in general practice are very likely to be inaccurate and some may well be so deteriorated that they should be withdrawn from service. The results of the blood pressure audit showed digit bias in systolic and diastolic readings to the nearest 10 mm Hg. The implications for clinical care-both over diagnosis and under diagnosis-although not assessed are likely to be appreciable. PCG Clinical Governance teams in conjunction with Practice Clinical Leads must address these basic issues.

Adult↗
PubMed1994

Ensuring the accuracy of digital sphygmomanometers for home use.

OBJECTIVE: To describe the techniques for assessing the accuracy of digital sphygmomanometers. DESIGN: The necessary equipment and the recommended procedures for determining the accuracy of digital units by comparison with a mercury sphygmomanometer were reviewed. RESULTS: Evaluation of the accuracy of digital sphygmomanometers is a simple two-phase process: (1) comparison of the pressure sensors against a mercury column and (2) assessment of the ability to detect Korotkoff sounds. The only equipment needed is a mercury column, a Y tubing, a "dummy" arm, two male-female adapters, and a stethoscope. The two short ends of the Y tubing are used to connect the mercury sphygmomanometer and the digital unit, and the long end of the Y tubing is attached to the cuff of the digital unit. The inflation mechanism of the digital unit (manual or automatic) influences the approach used for comparing the two units. For both manually and automatically inflatable digital units, the digital display should be within +/- 4 mm Hg of the mercury level; likewise, a properly functioning digital unit should detect Korotkoff sounds (both systolic and diastolic readings) within +/- 4 mm Hg of the auscultated blood pressure measurements. If the digital sphygmomanometer is judged to be accurate, 6-month reevaluations are suggested. CONCLUSION: With use of minimal equipment, digital sphygmomanometers (except the new finger blood pressure monitors) can easily be assessed for accuracy by comparing the pressure sensors against a mercury unit and testing the sensitivity for detecting Korotkoff sounds. Self-monitoring of the blood pressure is helpful in assessing blood pressure changes over time and in evaluating antihypertensive therapy.

Blood Pressure Monitors↗