PubMed Health⌕ Search

Biomedical subjects

Aidan Halligan

Publications and source records attributed to Aidan Halligan.

8 recordsLinked to original sources
PubMed2005

Urine protein estimation in hypertensive pregnancy: which thresholds and laboratory assay best predict clinical outcome?

OBJECTIVE: To determine what threshold for proteinuria could best predict clinical outcome and whether this threshold could be applied universally to any biochemical assay. DESIGN: A prospective observational study of hypertensive pregnancies referred for further assessment after in a UK University hospital (n=197). Twenty-four hour urine protein was measured by two different assays [benzethonium chloride assay (BCA) and Bradford assay]. The differences between the two assays were calculated from Receiver Operating Characteristic (ROC) curves. Commonly used thresholds for defining preeclampsia (0.3 and 0.5 g/24 hours) were explored for both assays for the prediction of adverse clinical outcomes (severe hypertension, Birthweight<10th percentile, preterm delivery, and a composite biochemical/haematological derangement). RESULTS: The two assays are not equivalent. The prevalence of>300 mg/24 hour proteinuria and, hence, the prevalence of preeclampsia differed between the two assays. ROC curve analysis demonstrates that the two assays are similar in terms of overall performance as predictive tests. However the threshold of 300 mg/24 hours performs poorly as a predictor of clinical risk. Likelihood ratios (LR) for the BCA at the 300 mg/L threshold for each clinical outcome do not achieve statistical significance. At the 500 mg/L threshold, the LR+for the BCA assay does achieve statistical significance for severe hypertension (LR+:1.51 95% CI 0.99-2.28) and for birthweight<10th percentile (LR+:1.72 95% CI 1.11-2.66). For the Bradford assay at the 300 mg/24 hour threshold, the LR+does achieve statistical significance for birthweight<10th percentile (LR+:1.71 95% CI 1.41-4.31). However, at the 500 mg/24 hour threshold, the LR+is significant for severe hypertension (LR+:2.15 95% CI 1.07-4.34), birthweight<10th percentile (LR+:2.79 95% CI 1.4-5.54) and biochemical disease (LR+:2.47 95% CI 1.22-5.01). CONCLUSIONS: This study suggests that thresholds for proteinuria need to be higher (possibly>or=0.5 g/24 hours) and there is the need for a "gold standard" proteinuria assay against which all other measures of quantification can be assessed.

Adult↗
PubMed2004

Emergency care. From zero to hero.

Essex Ambulance Service trust has achieved a rapid transformation, having last year received the country's worst CHI report. The trust transformed itself through new roles, collaborative working and developing its own model for out-of-hours services. Staff have new confidence in the management team, led by young, relatively inexperienced chief executive Anthony Marsh.

Ambulances↗
PubMed2003

Urinary microalbumin/creatinine ratios: reference range in uncomplicated pregnancy.

During uncomplicated pregnancy, the development of proteinuria is accepted as a poor prognostic sign and is associated with increasing maternal and perinatal mortality and morbidity. Physiological proteinuria increases with increasing gestation and one of its largest constituents is albumin. The reference range for the (micro)albumin/creatinine ratio (ACR) has not been described for normal pregnancy. This prospective cross-sectional study describes the gestation-specific 95% reference ranges for urinary microalbumin concentration, creatinine concentration and ACR in uncomplicated pregnancy. There is a significant increase ( P =0.016) in the ACR in the third trimester. The mean difference is 0.091 mg of albumin/mmol of creatinine (95% confidence interval, 0.014-0.168). Our results describe the first well-defined gestation-specific 95% reference range for a point-of-care measurement of the ACR. These data are essential if such testing is to be employed in antenatal care.

Adolescent↗
PubMed2003

Validation of the DCA 2000 microalbumin:creatinine ratio urinanalyzer for its use in pregnancy and preeclampsia.

OBJECTIVE: To determine the accuracy of the DCA 2000 albumin/creatinine ratio urinanalyzer (Bayer Corp., Elkhart, IN) in uncomplicated pregnancy and preeclampsia. METHODS: This was a prospective observational study in a large teaching maternity hospital. Ninety one uncomplicated pregnant women and 100 women referred for assessment of de novo hypertension in pregnancy had albumin concentrations, creatinine concentrations, and albumin/creatinine ratios (ACR) compared between the DCA 2000 and the laboratory gold standard assays (Dade Dimension clinical chemistry autoanalyzer), for both early morning urines (EMU) and 24-hr urine collections. RESULTS: The interassay and intra-assay variability for the DCA 2000 were less than 5.1%. In uncomplicated pregnancy the mean difference in ACR between the DCA 2000 and the laboratory assay was 0.08 mg/mmol (SD 0.28; 95% limits of agreement, -0.47, 0.63) for EMU and 0.06 (SD 0.23; 95% limits of agreement, -0.39, 0.51) for 24-hr samples. In the hypertensive cohort the ACR mean differences were -0.82 (SD 7.13; 95% limits of agreement, -14.79, 13.15) for EMU and -0.76 (SD 4.14; 95% limits of agreement, -8.87, 7.35) for 24-hr samples. The mean differences between assays in the hypertensive group had broader 95% limits of agreement due to greater variability in the samples with high albumin concentrations (>40 mg/L). CONCLUSIONS: The DCA 2000 is accurate for the measurement of albumin creatinine ratios in the uncomplicated pregnant population. In the hypertensive population the DCA 2000 remains accurate though when the albumin concentration is greater than 40 mg/L the 95% limits of agreement are broader. We would recommend that all other automated urinalysis devices be validated by similar protocols to allow meaningful comparisons of accuracy.

Adolescent↗
PubMed2002

Hidden errors of aneroid sphygmomanometers.

BACKGROUND: Measurement of blood pressure remains the most commonly performed screening test in medical practice. With the likely removal of mercury sphygmomanometers from the workplace alternative devices are required. Of these the aneroid sphygmomanometer is popular both in the community and hospital setting. We investigated the accuracy of all the aneroid and mercury sphygmomanometers during dynamic calibration within a tertiary referral maternity hospital. METHODS: We compared the accuracy of 39 aneroid and 36 mercury sphygmomanometers to a recently calibrated and serviced mercury sphygmomanometer (the accepted gold standard). All devices were in current clinical use. Using three blinded, trained observers, 30 different pressures were checked throughout the pressure range following British Hypertension Society protocol guidelines. RESULTS: Only 31 (86%) of the mercury devices and 36 (92%) of the aneroid devices were in adequate working condition and suitable for analysis. Significantly more aneroid devices had systematic errors of > 5 mmHg (19 versus 3%, < 0.05). Fifty percent of aneroid devices had at least one reading > 10 mmHg out compared to only 10% of mercury devices (chi square programme). CONCLUSIONS: Aneroid sphygmomanometers in apparent good working order are inaccurate compared to mercury devices. Some of these faults can only be detected during dynamic testing. To minimize the risk of erroneous blood pressure recording, aneroid devices should be regularly checked for accuracy using dynamic calibration methods as recommended in validation protocols.

Adult↗