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Biomedical subjects

A Halligan

Publications and source records attributed to A Halligan.

At least 19 recordsLinked to original sources

Effect of concentration and biochemical assay on the accuracy of urine dipsticks in hypertensive pregnancies.

OBJECTIVE: To assess how urine concentration and biochemical assay influence the assessment of proteinuria. METHODS: This was a prospective study to assess the accuracy of detection and quantification of proteinuria within the day assessment unit and antenatal ward of a teaching hospital in Leicester, United Kingdom. We studied hypertensive pregnancies (of mixed parity) referred to day care assessment or attending the antenatal hypertension clinic after 20 completed weeks of gestation (n = 197). Aliquots of a well-mixed 24-h urine collection were tested by routine dipstick urinalysis and then assayed for protein using the Benzethonium Chloride and the Bradford assays (n = 197). MAIN OUTCOME MEASURES: Total protein excretion in 24 h and protein concentration per liter of urine for both biochemical assays were compared to semiquantitative dipstick protein measurement. RESULTS: The prevalence of proteinuria in the study group varied according to the method used for testing. Dipstick urinalysis recorded the lowest prevalence (16.2%) and the Benzethonium Chloride assay measuring total protein excretion in 24 h recorded the highest (70.1%). When the positive and negative predictive values for dipstick urinalysis were calculated, performance was found to be dependent on both the units of measurement compared and the type of assay used as the "gold standard." Positive predictive values ranged from 87.5% to 96.9% and negative predictive values ranged from 35.2% to 92.1%. CONCLUSIONS: The prevalence of proteinuria in hypertensive pregnancies is dependent on the method used to detect it. The amount of protein assessed quantitatively is further dependent on the biochemical assay employed. However, regardless of the quantitative assessment, dipstick urinalysis has a significant false-negative rate. This first reporting of a variation in performance between dipstick urinalysis and two different biochemical assays in pregnancy may be explained in relation to protein assay specificity and the observed protein compositions of the samples on electrophoretic analysis. The significance of proteinuria should be considered in light of the method used to detect it, but, ultimately, it must be related to clinical outcome.

Adolescent↗

Clinical governance: its origins and its foundations.

This article from the NHS Clinical Governance Support Team (NCGST) outlines the development of quality concerns since the NHS was founded in 1948. It traces the development of clinical governance as a means of achieving continuous quality improvement and describes what the implementation of clinical governance means for patients and professionals. It analyses features of the cultural shift necessary to underpin quality improvement initiatives and describes with practical examples the constituents of the culture necessary for successful clinical governance. Future articles in this series will address other issues around clinical governance and will explain the model being followed by delegates to the NCGST's Clinical Governance Development Programme as they implement clinical governance "on the ground".

Communication↗

Reviewing a service--discovering the unwritten rules.

In our previous article we looked at the history of quality development and discussed how the implementation of clinical governance provides the opportunity to begin the cultural shift necessary to underpin quality in the modern NHS. This article begins an explanation of the model of quality improvement followed by delegates to the Clinical Governance Development Programme by looking at the service review process delegate teams undertake.

Data Collection↗

Lack of consistency in research papers over the definition of pre-eclampsia.

The most common definition of pre-eclampsia involves hypertension and proteinuria. This has changed little in over a hundred years despite advances in understanding the underlying pathological process. However, a number of variations in definition exist, and this paper demonstrates a lack of consistency in research articles in defining pre-eclampsia. A quarter of papers omit description, and many authors choose their own interpretation of the standard classification. Editors and reviewers should ensure that papers include a clear description of the definition used and an adequate description of the population studied to allow meaningful interpretation of research findings.

Female↗

Accuracy of oscillometric blood pressure monitoring in pregnancy and pre-eclampsia.

OBJECTIVE: To assess the accuracy of the Omron HEM 705 CP oscillometric device for the measurement of blood pressure in pregnancy and pre-eclampsia. SETTING: Two teaching hospitals. PARTICIPANTS: Eighty-five pregnant women with a wide range of blood pressures, and 43 women with pre-eclampsia. METHODS: Evaluation was carried out according to the British Hypertension Society protocol, incorporating criteria of the Association for the Advancement of Medical Instrumentation (AAMI). RESULTS: Mean differences (device minus observer) for systolic blood pressure were -0.9 mmHg (SD 10) in normal pregnancy, and -2 mmHg (SD 10) in the women with pre-eclampsia. For diastolic blood pressure, Korotkoff phase V, the differences were -1.5 mmHg (SD 10), and -8 mmHg (SD 8) respectively; i.e. the device consistently under-read the diastolic blood pressure in pre-eclamptic women by a mean of 8 mmHg when compared with conventional sphygmomanometry. Korotkoff phase IV could not be accurately reproduced. According to the British Hypertension Society grading criteria, the device reached a 'B' grading in the 85 pregnant women. In pre-eclampsia only a 'C' grade was reached for systolic blood pressure, and 'D' grade for diastolic blood pressure. Accuracy criteria stipulated by the AAMI were not met in any situation. CONCLUSION: The Omron HEM 705 CP does not reach acceptable accuracy criteria for blood pressure measurement when compared with trained observers in women with pre-eclampsia, as judged by the British Hypertension Society Protocol. It also failed to meet the AAMI criteria, although the methodology stipulated by the AAMI may not be applicable to a pregnancy population.

Blood Pressure↗

Can 24-hour ambulatory blood pressure measurement predict the development of hypertension in primigravidae?

OBJECTIVE: To assess the role of 24-hour ambulatory blood pressure measurement in the mid-second trimester as a predictive test for the development of hypertension in pregnancy. DESIGN: Prospective intervention. SETTING: The Rotunda Hospital, Dublin. PARTICIPANTS: One thousand one hundred and two healthy primigravid women. INTERVENTION: 24-hour ambulatory blood pressure measurement at 18 to 24 weeks of gestation. MAIN OUTCOME MEASURES: The development of pre-eclampsia or gestational hypertension. RESULTS: A total of 1048 women had sufficient readings to be included in the final analysis. Of these, 23 (2.2%) developed pre-eclampsia, 64 (6.1%) developed gestational hypertension and 961 (91.7%) remained normotensive. Significantly higher ambulatory blood pressures were recorded in both the pre-eclamptic and gestational hypertensive group compared with the normotensive group. In addition, the gestational hypertensive group had significantly higher clinically measured blood pressure compared with the normotensive group. There were no differences between the pre-eclamptic and the gestational hypertensive group for any of the blood pressure parameters analysed. The best overall predictor for pre-eclampsia was 24-hour mean diastolic pressure which using a cutoff level of 71 mmHg gave a test with a sensitivity of only 22% and a positive predictive value of 15%. CONCLUSION: Because the absolute differences are small and the overlap between the hypertensive and normotensive groups large, ambulatory blood pressure measurement, in a healthy primigravid population, between 18 and 24 weeks of gestation is not a useful predictor of hypertension.

Adult↗

Lack of reproducibility in pregnancy of Korotkoff phase IV as measured by mercury sphygmomanometry.

BACKGROUND: Since hypertensive disorders of pregnancy are common, blood pressure is frequently measured in all pregnant women. Many authorities recommend that Korotkoff phase IV (K4, muffling of sound) is taken as the diastolic identification point measured on mercury sphygmomanometry in pregnancy because of reports that phase V (K5, disappearance of sound) is at or near to zero cuff pressure in some pregnant women. We compared the identification and reproducibility of K4 and K5 by observers unaware of each other's results. METHODS: In the first part of the study, two pairs of observers each took 340 measurements in 85 pregnant women. The second part of the study consisted of 1120 measurements in 80 pregnant and 80 non-pregnant women by five pairs of observers. Measurements were taken simultaneously by sphygmomanometry with a shared cuff and diaphragm; the observers were in separate booths. FINDINGS: K5 was identified in all measurements by both observers and never approached zero. K4 was heard in only 52% of measurements; in 33% of cases it was heard by only one of the pair of observers, so the pair agreed on its detection in only 19% of readings. Visual analogue scores used to assess Korotkoff sound quality indicated that systolic blood pressure was perceived significantly more clearly than diastolic blood pressure (K4 or K5). Even when K4 was heard by both observers, agreement on its value was poor (78% within 5 mm Hg vs 86% for K5, p < 0.05). K4 was heard significantly less often in non-pregnant women (32% of measurements). There was also no consistency in the identification of K4 within individual women. INTERPRETATION: K4 has little value in clinical management because it cannot be reproduced accurately. We recommend that K4 should be replaced by K5 as the measure of diastolic blood pressure in pregnancy.

Blood Pressure↗

Diurnal blood pressure difference in the assessment of preeclampsia.

OBJECTIVE: To evaluate diurnal variation in blood pressure (BP) in normal gravidas and those with preeclampsia, using ambulatory BP monitoring. METHODS: A cross-sectional comparative observational study was performed in three teaching hospital maternity units. Twenty-four normotensive and 24 preeclamptic women who were similar in age, weight, and mean duration of gestation (35 weeks) were studied. Diurnal variation and BP measurement were assessed using ambulatory BP monitors validated for use in pregnancy and for which normal reference ranges for pregnancy have been derived. RESULTS: At night, the BP fall was less in preeclamptic women than in normotensive women. The day-night BP difference decreased as average BP rose (diastolic gradient = -0.54 [95% confidence interval (CI) -0.77 to -0.31], systolic gradient = -0.36 [95% CI -0.58 to -0.14], where gradient denotes a unit increase in BP leading to an increase or decrease in the day-night difference). CONCLUSION: The decrease in day-night BP difference observed in preeclampsia is inversely related to average BP. This blunting of the day-night BP difference may be a useful adjunctive measure of disease severity in preeclampsia.

Adolescent↗

Hypertension in pregnancy: which method of blood pressure measurement is most predictive of outcome?

OBJECTIVE: To determine the clinical effectiveness of blood pressure (BP) measurement using conventional sphygmomanometry in the antenatal clinic and obstetric day unit compared with automated BP monitoring at home. METHODS: The study population consisted of 109 nulliparous white women with BPs of at least 140 or 90 mmHg at the antenatal clinic after 20 weeks' gestation, who underwent obstetric day unit and 24-hour automated BP monitoring on the same day. Automated measurement was obtained every half hour for 24 hours using a commercially available device that had been previously validated in pregnancy. RESULTS: At the traditional BP cutoff point (140/90 mmHg), the relative risk for subsequent development of adverse obstetric outcome was greatest for automated BP measurement: The relationships between outcome and automated diastolic BP were all statistically significant: proteinuria (P = .034), preterm delivery (P < .001), birth weight below the tenth percentile (P = .001), admission to the special care neonatal unit (P = .001), and cesarean delivery (P = .007). CONCLUSION: Automated BP measurement appears to improve the identification of patients who are at high risk of poor obstetric outcome. Automated BP measurement is worthy of further evaluation as an antenatal screening and diagnostic test.

Adolescent↗