Biomedical subjects

Y Iyriboz

Publications and source records attributed to Y Iyriboz.

13 recordsLinked to original sources

PubMed1994

Agreement between large and small cuffs in sphygmomanometry: a quantitative assessment.

OBJECTIVE: The objective of this study is to quantify agreement and differences between blood pressure (BP) measurements by large cuffs (15 x 33 cm) and small cuffs (12 x 23 cm) in a representative sample of the U.S. population with varying arm circumferences. METHODS: The arm circumference and blood pressure (12 readings of each) of 85 subjects were measured, the latter with a mercury column sphygmomanometer. Data were classified according to arm circumference (small arm circumference, < or = 29 cm; large arm circumference, > 29 cm). Results were submitted to ANOVA, linear regression, difference between means (aggregate agreement), upper and lower limits of agreement at 95% confidence intervals, and intraclass correlation (individual-subject agreement/quantification of agreement). RESULTS: Small cuffs overestimated BP obtained from the large cuffs for the sample population as a whole, regardless of arm circumference. Limits of agreement at the lower end of 95% confidence interval were not clinically acceptable (SBP -1.56 to 11.05 mm Hg; DBP -2.06 to 8.63 mm Hg). However, measurements by both cuffs agreed among subjects with small arm circumferences (< or = 29 cm). CONCLUSION: Arm circumference plays an important role in determining proper cuff size for BP measurement. The small cuff overestimates BP in patients with large arm circumferences (> 29 cm), which represents more than 75% of the U.S. adult population. However, measurements of BP with the large cuff are not significantly different from those of small cuff measurements in subjects with small arm circumferences (< or = 29 cm). Therefore, we propose that the large cuff be used for routine BP measurement of the adults in the United States.

Adult↗

PubMed1994

A proposal for scientific validation of instruments for indirect blood pressure measurement at rest, during exercise, and in critical care.

OBJECTIVE: The purpose of this study was to provide a critical review and comprehensive outline of published guidelines for the validation of monitors for indirect blood pressure (BP) measurement in light of recent research and practical clinical experience. METHODS: Studies testing the reliability and validity of BP monitors and available guidelines for validation have been reviewed and compared. RESULTS: The validation studies of instruments for indirect BP measurement have used a wide variety of sample pools, BP ranges, protocols, reference instruments, and statistical procedures, thereby making it impossible to reach a consensus. Few existing recommendations for validation have been found to be incomplete with respect to BP in various physiological states, sequence of procedures, sample, and statistical analysis. CONCLUSIONS: A new sequence of procedures for validation, including assessment of instruments during exercise and in critical care, is introduced. Previously suggested sample sizes for study subjects, age, and BP groups, as well as margins of error, are statistically challenged. Insufficiency of linear relationship and aggregate agreement alone in determining the interchangeability between a reference and test instrument is demonstrated by quantification of agreement.

Adolescent↗

PubMed1994

Exercise blood pressure response and skeletal muscle vasodilator capacity in normotensives with positive and negative family history of hypertension.

OBJECTIVE: To study exercise blood pressure response in association with exercising muscle maximal vasodilatory capacity in normotensives with a positive and negative family history of hypertension. SUBJECTS: Twenty-eight normotensive healthy subjects were recruited. Of these, two females and 13 males had a positive, and three females and 10 males had a negative, family history of hypertension. METHODS: Both groups of subjects rode a bicycle ergometer while systolic blood pressure, diastolic blood pressure and heart rate were measured at 30%, 60% and peak oxygen uptake rate. The vasodilatory capacity was examined in the lower leg by measuring the minimal vascular resistance during peak reactive hyperemia after 10 min arterial occlusion. RESULTS: Age, body weight, resting blood pressure, peak oxygen uptake rate and casual lower leg vascular resistance were not significantly different between the two groups of subjects. Significantly higher exercise systolic blood pressure (9%) and diastolic blood pressure (9%) were seen in the subjects with positive family history of hypertension compared with the subjects with negative family history of hypertension. Exercise heart rate was significantly higher in the subjects with negative than in those with positive family history of hypertension. The vascular resistance at peak vasodilation was 22% higher in the subjects with positive than in the subjects with negative family history of hypertension. CONCLUSIONS: This study demonstrates that the dynamic exercise blood pressure is exaggerated and skeletal muscle vasodilatory capacity is limited in normotensives with genetic risk of hypertension. This suggests that the higher pressor response to physical stress that is found in normotensives with a family history of hypertension may be attributed to the resistance vessels in the exercising muscle.

Adult↗

PubMed1992

Efficacy of health services provided by the Area Agencies on Aging in Louisiana.

A randomly selected representative sample (61%) of Area Agencies on Aging (AAAs) in Louisiana was investigated for the efficacy of services provided. A great majority of directors and personnel (95%) were not trained for their job. More than 25% of the AAAs did not have sufficient demographic data on the elderly (60 and over) in their area. Only 37% of the AAAs were able to provide information on service barriers, availability, adequacy, and utilization. These findings seriously question the efficacy of services provided by the AAAs and their contribution to the health care of the elderly in Louisiana.

Aged↗

PubMed1991

Accuracy of pulse oximeters in estimating heart rate at rest and during exercise.

Pulse oximeters are being widely used for non-invasive, simultaneous assessment of haemoglobin oxygen saturation. They are reliable, accurate, relatively inexpensive and portable. Pulse oximeters are often used for estimating heart rate at rest and during exercise. However, at present the data available to validate their use as heart rate monitors are not sufficient. We evaluated the accuracy of two oximeters (Radiometer, ear and finger probe; Ohmeda 3700, ear probe) in monitoring heart rate during incremental exercise by comparing the pulse oximeters with simultaneous ECG readings. Data were collected on eight men (713 heart rate readings) during graded cycle ergometer and treadmill exercise to volitional fatigue. Analysis by linear regression revealed that general oximeter readings significantly correlated with those of ECG (r = 0.91, P less than 0.0001). However, comparison of heart rate at each level of work showed that oximeter readings significantly (P less than 0.05) under-estimated rates above 155 beats/min. These results indicate that the use of pulse oximeters as heart rate monitors during strenuous exercise is questionable. This inaccuracy may well originate from the instability of the probes, sweating, other artefacts during exercise, and measurement of different components in the cardiovascular cycle.

Adult↗

PubMed1990

Oscillometric finger blood pressure versus brachial auscultative blood pressure recording.

In this study, a recently marketed proprietary finger blood pressure monitor, the Marshall, Astro F-88, was compared with the standard auscultative brachial mercury sphygmomanometer on 125 subjects. Measurements were undertaken according to the standards set by the American Heart Association. Sensitivity of the finger blood pressure measurement was 76% for systolic and 75% for diastolic blood pressure in diagnosis of high blood pressure (systolic greater than 140 mm Hg and diastolic greater than 90 mm Hg). Specificity was 86% for systolic and 82% for diastolic blood pressure. Positive predictive values were 58% for systolic and 38% for diastolic blood pressure in the study population in which prevalence of hypertension was 12%. The correlation coefficient (Pearson) for systolic values between devices was 0.76 (P less than .0001) and 0.57 (P less than .0001) for diastolic pressure. Values obtained by the finger monitor were found to be higher than those obtained by the mercury sphygmomanometer. Mean differences and standard deviations (paired t test) for systolic and diastolic pressures between the two devices were 2.3 +/- 14.9 mm Hg (P less than .08) and 2.9 +/- 14.5 mm Hg (P less than .02), respectively. These values are not in accordance with the proposed national standards because only 48% of the systolic and 37% of the diastolic blood pressure measurements were within 5 mm Hg of the mercury sphygmomanometer measurements. Therefore, although these differences may well be due to different techniques of monitoring employed by the devices, this device is not recommended for evaluation of blood pressure.

Adolescent↗

PubMed1987