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At least 37 records · Page 2Linked to original sources
PubMed2002

Inflationary oscillometry provides accurate measurement of blood pressure in pre-eclampsia.

OBJECTIVE: To evaluate the accuracy of the OMRON-MIT inflationary oscillometric device for blood pressure measurement in pregnancy and pre-eclampsia. DESIGN: Prospective observational study, using validation methods recommended by the British Hypertension Society (BHS) and the Association for the Advancement of Medical Instrumentation (AAMI). SETTINGS: Antenatal clinics and ward, Guy's Hospital, London. POPULATION: Normotensive pregnant women and those diagnosed with pre-eclampsia according to the definition of the International Society for the Study of Hypertension in Pregnancy. METHODS: Validation according to BHS protocol. MAIN OUTCOME MEASURES: Proportion of readings within 5, 10 and 15 mmHg (absolute differences) between the automated device and two trained, blinded observers, according to the BHS and AAMI criteria. RESULTS: The OMRON-MIT achieved an overall BHS grade B for systolic and grade A for diastolic blood pressure measurement in both pregnancy and pre-eclampsia. The mean (SD) differences between the standard and the test device were -5 (7) mmHg for systolic and 2 (6) mmHg for diastolic blood pressure in pregnancy and -4 (6) mmHg for systolic and 2 (7) mmHg for diastolic blood pressure in pre-eclampsia. This device therefore fulfils the AAMI criteria. CONCLUSION: The OMRON-MIT is the only automated oscillometric device that has proven to be accurate for blood pressure measurement in pre-eclampsia according to the BHS protocol in pregnancy. Inflationary oscillometry may correct the error associated with oscillometric devices in pre-eclampsia.

Adolescent↗
PubMed1988

Lung function and bronchial responsiveness measured by forced oscillometry after bronchopulmonary dysplasia.

Forced oscillometry was used to investigate whether lung injury due to bronchopulmonary dysplasia in early life caused abnormalities in bronchial calibre or an increase in bronchial responsiveness to histamine at school age. Results were compared with data obtained from healthy children born prematurely and from healthy children born at term. There was a mild increase in frequency dependence of total respiratory resistance in children who suffered from lung injury in early life, which indicates uneven ventilation in peripheral airways. Bronchial responsiveness to histamine in these subjects was normal. No abnormalities were found in the control group. We conclude that lung injury in early life may cause residual abnormalities of peripheral airways. This does not happen in premature babies who do not have respiratory problems in the neonatal period.

Bronchi↗
PubMed2002

No effect of chinese acupuncture on isocapnic hyperventilation with cold air in asthmatics, measured with impulse oscillometry.

The cost to society and the individual of treating asthma has been increasing in developed countries. This has given rise to studies of the efficacy of complementary treatments. The aim of this study was to evaluate the efficacy of traditional Chinese Acupuncture in patients with mild asthma. The method used for evaluation of efficacy was total airway resistance at 5Hz (R5) as measured by impulse oscillometry (IOS)--a forced oscillation technique, at baseline and after a bronchial challenge with voluntary isocapnic hyperventilation of cold air (IHCA). The study was a parallel group randomised placebo controlled trial with evaluator blinding. Twenty-seven asthmatics were recruited and 24 completed the study, 10 of them received acupuncture and 14 received a placebo treatment (mock-TENS). Treatment continued for 15 weeks, and efficacy was tested two weeks following the last treatment. Randomisation resulted in female over representation in the acupuncture group, but lung-function and bronchial responsiveness to IHCA were comparable in the two populations before the start of treatment (p>0.05 vs. p > 0.05). There were no statistically significant effects of the treatment before (p > 0.05) or after IHCA (p > 0.05) in either of the groups. The statistical power of the study to show a clinically relevant difference in bronchial responsiveness to IHCA after treatment was near 80%. We conclude that there were no significant effects of traditional Chinese Acupuncture on airway status in our patients with asthma.

Acupuncture Therapy↗
PubMed1999

The diagnostic value of total respiratory impedance by impulse oscillometry in chronic obstructive lung disease.

OBJECTIVE: To investigate the diagnostic significance of total respiratory impedance for chronic obstructive lung disease. METHODS: The impedance of respiratory system was measured by impulse oscillometry method and compared with parameter values of routine pulmonary function in 57 patients with chronic obstructive pulmonary disease (COPD). RESULTS: It significantly increased in viscous resistance ranging from 5 Hz and 35 Hz and resonant frequency in COPD group than that in healthy group. Reactance from 5 Hz and 35 Hz in COPD group was marked lower than that in healthy group. There were marked frequency dependence of viscous resistance and reactance in COPD patients. Resonant frequency was markedly and negatively correlated with parameters of pulmonary ventilation indices; X5 was positively correlated with parameters of pulmonary ventilation indices. But no statistical correlation was showed between R20 and parameters of pulmonary ventilation indices. Correlation was found between resonance frequency and FEV1, resonance frequency and Vmax. The correlation coefficient values were -0.671 and -0.666 respectively. The sensitivity of resonant frequency, R5 and X5 for diagnosing COPD were 94.74%, 59.65% and 54.38%, respectively. The specificity of them were 86.66%, 96.66% and 90%, respectively. CONCLUSIONS: Resonant frequency was the most sensitive index in the parameters measured by IOS for diagnosing COPD. Since impedance measurement was a non-invasive method and only passive co-operation of the patient was needed. This technique could therefore be applied in COPD patients with acute attack for dynamic examination.

Aged↗
PubMed1999

[Clinical application of impulse oscillometry].

OBJECTIVE: To discuss the clinical significance of impulse oscillometry(IOS) to determine the resistance of large and small airways and the compliance of lung. METHODS: The IOS indices of 40 normal cases, 50 cases of chronic obstructive pulmonary diseases (COPD) and 60 cases of pleural effusion were determined at 5-35 Hz. Their FEV1/FVC and maximal expiratory flow-volume curve (MEFV curve) were measured in conventional method at the same time. RESULTS: Compared with normal cases, the peripheral resistance of the 50 patients with COPD rose obviously and the central airway resistance rose in some of them, the resonance frequency increased, but the peripheral reactance descended at the same time (P < 0.01). Resistance curve show markedly nonlinear decreasing course with increasing frequency. The resistance increased and the reactance descended in end-expiration. FEV1/FVC < 50%, MEFV curve showed severe obstructive shape. 60 patients with pleural effusion were found the resistance increasing and reactance descending to negative values in end-inpiration at low frequencies (inverse values relation at low frequencies). FEV1/FVC were nearly normal, MEFV curve showed restrictive dysfunction shape only in half of them. CONCLUSIONS: IOS can reflect variation of airway resistance and lung compliance. The future development of IOS could be prosperous.

Humans↗
PubMed1990

[Lung function diagnosis using multi-frequency oscillometry with reference to lung volume].

The ranking of various oscillometry parameters was to be tested in patients with a broad spectrum of disturbances of pulmonary function, objectified by body plethysmographic and technical oesophageal pressure measurement of the respiratory resistance, lung volumes and lung elasticity. For this purpose the oscillatory resistance Rfo and the phase angle phi were measured at 8, 12 and 16Hz and phi was measured as it changed, depending on the lung volume V. It was found that enhanced respiratory resistance values are satisfactorily represented by Rfo for the purposes of preliminary and basic diagnostics. Besides, enhanced Rfo values are markedly dependent on the frequency, phi being shifted to negative values. Difference between Rfo values at 8 and 16 Hz (delta R8-16) less than 0.7 hPa/l/s phi greater than or equal to -10 degrees can be considered as being still normal with the employed measuring principle and are a valuable supplement for assessing the degree of obstruction. The difference between phi in the medium respiratory position and at 90 or 100% total capacity (delta phi) is less than 5 degrees during slow inspiration in 80% of the patients suffering from emphysema. In 80% of the persons with healthy lungs and those suffering from fibrosis there is an inspiratory negativation of phi (delta phi greater than 5 degrees) so that the phi-V relationship appear suitable for distinguishing patients with restricted vital capacity in respect of emphysema and fibrosis. Patients suffering fron fibrosis differ from healthy subjects by slightly more negative phi values. The borderline values for delta R8-16, phi and delta phi were confirmed in two further series of examinations on children and adolescents.

Adult↗
PubMedDate not supplied

Comparison of forced oscillometry and forced expirations for measuring dose-related responses to inhaled methacholine in asthmatic children.

The forced oscillation technique (FOT) is a lung function method which is applicable from the age of 2.5 years onwards, because only passive co-operation is needed. We used the method as described by Làndsér et al. The aim of this study was to compare indices of bronchial responsiveness obtained by FOT (Rrs6, Rrs, dRrs/df, Xrs), with indices derived from maximal and partial expiratory flow-volume curves (MEFV25, PEFV25, FEV1). Bronchial responsiveness was assessed by methacholine inhalation. Threshold dose (TD), i.e. the dose which caused a 2 SD change from baseline lung function, and provocation dose (PD), i.e. the dose which caused a 20% fall in FEV1, a 40% fall in MEFV25 and PEFV25 and a 40% increase in Rrs and Rrs6, were determined. We found that the indices derived from forced oscillometry compared well to those from maximal and partial flow-volume curves. PD20 FEV1 and PD40 Rrs6 were highly correlated (r = 0.84). TD appeared to be as good as PD to measure bronchial responsiveness and is preferred to PD because of the lower dose needed and limited bronchoconstriction obtained.

Adolescent↗
PubMed1997

Comparison of blood pressure measurements obtained in dogs by use of indirect oscillometry in a veterinary clinic versus at home.

OBJECTIVE: To compare blood pressure and heart rate measurements performed in a veterinary clinic to similar measurements performed in a dog's home. DESIGN: Prospective study. ANIMALS: 14 client-owned, clinically normal dogs. PROCEDURE: Sequential blood pressure and heart rate measurements were recorded from the metatarsus and metacarpus of conscious dogs by indirect oscillometry. Measurements were performed in the dogs' homes and were repeated in a veterinary clinic. Blood pressures and heart rate were derived from 7 serial estimates over 8 to 10 minutes. Statistical differences between the home and clinic and between recording sites were calculated. RESULTS: Systolic, diastolic, and mean blood pressure and heart rate measurements obtained from the metatarsus and metacarpus in the dogs' homes were significantly lower than measurements from the metatarsus in the clinic, but were similar to measurements from the metacarpus in the clinic. Significant differences were not found between blood pressure measurements from the metatarsus and metacarpus in the dogs' homes, but systolic and mean blood pressure and heart rate measurements from the metacarpus in the clinic were significantly lower than measurements from the metatarsus. Whereas all dogs had normal blood pressure in their homes, 5 of 14 dogs had transient hypertension (systolic pressure > 165 mm of Hg or diastolic pressure > 95 mm of Hg) in the clinic. CLINICAL IMPLICATIONS: Blood pressure and heart rate measurements obtained in the clinic initially overestimate comparable measurements in a dog's home. The differences are best explained by transient autonomic responses to the stress of the clinic. Blood pressure must be measured by use of standardized techniques on dogs acclimated to the clinic environment.

Acclimatization↗
PubMed1997

[Technical adaptation of impulse oscillometry to special research conditions].

The technical adaptation of the Impulse-Oscillometry (IOS) to different conditions of measurement allows a wide range of applications so that even questions of peripheral user groups using lung function tests can be answered. Thus, the variable connection of the IOS head via fold hose opens the field of bedside measurements and additional applications in pediatrics, intensive care and veterinary medicine. Rhinomanometric examinations are possible with little expenditure and high practicability using nasal tips.

Adult↗
PubMed1997

[Impulse oscillometry and body position].

To assess diurnal profiles of impulse-oscillometry (IOS) changes of IOS-parameters between different body positions have been studied using a special set IOS-Bedside for individual home care. IOS has been applied in lateral lying and in sitting position in 20 healthy female and male probands, aged 10-67, during 24 hours in intervals of 3 hours. In each test during normal breathing for approximately 30 sec about 130 spectral and structural analyses have been performed at an impulse distance of 0.2 sec. The global means of resistance at 5 Hz (R5) in lying position are in men about 0.6 and in women about 0.3 hPa/l/s higher than in sitting position, those of reactance in men and women are only about 0.2 hPa/l/s lower. There is a distinct diurnal periodicity of the differences. The maxima of them may occur at different hours of the day in single probands; but at the average mean the maxima are found at the end of night. The differences of oscillation parameters between lying and sitting position are bigger at end-expiration than at end-inspiration. The resistance-flow-gradients, representing the component of turbulent flow, are enlarged in lying position especially at night.

Adolescent↗
PubMed1997

[Effect of various factors on the results of lung function tests using multifrequent impulse oscillometry in calves and young cattle].

The applicability of impulse oscillometry (IOS) under clinical and field conditions was tested on 31 calves and 27 young bulls over a period from 3 to 5 months, respectively. Based on the obtained 492 test results (the average of four measurements), lung function criteria resistance and reactance, measured at frequencies of 5 to 15 Hz, showed to be diagnostically relevant. In healthy calves aged 4 to 12 weeks, resistance values lay between 0.22 to 0.36 kPa/(l/s) irrespective of frequency. Reactance values were in the range of -0.014 to 0.055 kPa/(l/s) at 5 Hz, but increased with growing frequency. Within the investigated groups no correlation could be established between factors age or body mass of the animals and resistance. Increasing age, however, led to a considerable increase in reactance. Alterations of the upper airway system were coupled with an increase in resistance values while reactance remained constant. Diagnostic evaluation of individual results relating to this category was hampered by the high interindividual test value variance of 25 to 31% between healthy animals. Diseases of the peripheral respiratory system, however, were clearly characterised by a significant decrease in reactance, as well as a negative frequency dependence of resistance. It is concluded that this method at lung function testing provides a sensitive tool for detecting and recording lung function disorders in young cattle.

Aging↗
PubMed1991

Blood pressure changes associated with tilting in normotensive subjects: differences in response pattern as measured by oscillometry and auscultation.

Three non-invasive instruments were used to measure blood pressure in the supine position and on tilting--a conventional and a random-zero sphygmomanometer, and an oscillometric device (Accutorr 1A). Twenty normotensives volunteered for the study. There was no statistically significant difference in systolic blood pressure and diastolic blood pressure measured by the conventional and random-zero sphygmomanometers in the supine position. There was a difference between these recordings and those of the Accutorr, with the Accutorr giving higher readings of systolic blood pressure (p less than 0.001), analysis of variance, 95% confidence interval of the difference between the Accutorr and the random-zero was 5.1-15.7 mmHg) and lower readings of diastolic blood pressure (p less than 0.0001, analysis of variance, 95% confidence interval of the difference between the Accutorr and the random-zero was -12.2- -2.2 mmHg). On tilting, the Accutorr showed an increase in systolic blood pressure while the other two machines did not (p less than 0.01, analysis of variance). By contrast, the Accutorr detected a smaller rise in diastolic blood pressure than with the other two instruments (p less than 0.05, analysis of variance). The difference between blood pressure measurements made in the supine position by the two different techniques, auscultation and oscillometry, might be expected. However, the two different techniques do not detect the same blood pressure responses to a change in posture.

Adult↗
PubMed1986

Skin avulsion during oscillometry.

We observed a case of skin avulsion associated with measurement of blood pressure by oscillometry on an anesthetized patient in the prone position. Epidermal shearing may be avoided in the prone patient by either wrapping the antecubital skin underlying the blood pressure cuff with gauze or preventing weight-bearing by the cuffed portion of the arm.

Blood Pressure Determination↗
PubMed1999

Wrist measurement of blood pressure: some critical remarks to oscillometry.

UNLABELLED: Oscillometric blood pressure measuring devices worn at the wrist are preferred by a growing part of hypertensive patients for self-measurement because of their compactness and ease of use. However, little is known about the accuracy of such instruments. The accuracy of such devices was evaluated by measuring the blood pressure at the end of a coronary angiography procedure in 27 subjects nearly simultaneously in the aortic arch, using a Statham P23 transducer, and at the wrist, using the blood pressure watch (BPW) by NAIS-Matsushita. Four replicate comparative measurements were performed in each subject. On average, the blood pressure measured by the BPW was found to be higher: systolic +1.2+/-(SD)10.2 mm Hg, diastolic +4.1+/-7.2 mm Hg. The correlation coefficient between the two methods was 0.85 for the systolic and 0.84 for the diastolic pressure, but 39% of the systolic and 22% of the diastolic differences were outside the range of +/-1 SD. There was no correlation between systolic differences and blood pressure or patients' variables, but multiple regression analysis revealed that the diastolic blood pressure differences were negatively correlated with the aortic diastolic pressure (r = 0.89, p<0.001), indicating that the BPW is less accurate to detect lower values. CONCLUSIONS: (1) Though the average systolic and diastolic deviations between both methods and the relative correlation coefficients suggest that the BPW is to be used carefully for monitoring blood pressure, the great variability of differences and the inability of the BPW to detect lower diastolic blood pressure calls for a mandatory validation test by an approved protocol before this new device can be recommended for general use. (2) On the basis of our results for wrist oscillometry with the BPW and data reported in the literature for upper-arm oscillometric devices, we recommend to use oscillometric devices only when they were validated properly. In particular, the oscillometric measurement should be employed with caution for epidemiological studies or for investigation of population groups (e.g., children or pregnant women) that are expected to display lower diastolic pressures.

Adult↗
PubMed1998

Comparison of blood pressure measured by oscillometry from the supraorbital artery and invasively from the radial artery.

In previous studies, oscillometric blood pressure measured from the supraorbital artery has been shown to agree quite well with pressure measured from the brachial artery in normal subjects. In this study, surgical patients whose conditions warranted the use of invasive blood pressure monitoring during the surgery were chosen. We compared systolic and diastolic blood pressure measured oscillometrically from the supraorbital artery with intraarterial blood pressures, measured invasively from the radial artery. A pressure bladder was attached to the forehead of each patient. The bladder was connected to a forehead blood pressure monitor. A catheter was inserted in a radial artery, and connected to a pressure monitor. Forehead blood pressure was measured every 5 min. Radial arterial pressure was averaged over the same period during which the forehead measurement was made. Blood pressures measured with the two methods were compared. For the systolic pressure, the difference between the two methods was -9.9 +/- 17.9 mm Hg (mean +/- SD). For diastolic pressure, the difference was -8.0 +/- 10.9 mm Hg. There was a significant difference between the two methods in the patient population chosen in this study.

Adult↗