Biomedical subjects
Publications and source records attributed to T Farrell.
We report a case of eight year old child who developed severe subcutaneous emphysema, bilateral pneumothorax, pneumomediastinum and pneumoperitonium in recovery room after apparently uneventful general anaesthesia for eight primary teeth extractions. Causes and treatment of these complications are discussed.
OBJECTIVES: To evaluate the performances of estimated fetal weight (EFW) and fetal growth velocity (FGV) in the prediction of birth weight>95th centile amongst women with impaired glucose tolerance (IGT); the prediction of neonatal hypoglycaemia was a secondary endpoint. STUDY DESIGN: Two hundred and forty-two consecutive women (61 type 1 diabetes mellitus, 14 type 2 diabetes mellitus, 49 gestational diabetics and 118 with impaired glucose tolerance) receiving routine care at the combined diabetes/antenatal clinic, Jessop Hospital for Women, Sheffield. EFW was routinely calculated at approximately two-week intervals in the third trimester with the last EFW prior to delivery used in the analysis. FGV was calculated from two estimates of fetal weight between 21 and 35 days apart. EFW and FGV were both expressed as standard deviation (Z) scores. RESULTS: The mean gestational age at delivery was 37 weeks (range 26-40 weeks). Sixty-five (27%) infants were of birth weight>95th centile. Mean EFW Z scores were 2.7 and 0.99 for >95th and <95th centile, respectively (p<0.001). Receiver operator characteristics (ROC) curve analysis gave area under the curve 0.8; using a cut-off Z score of 1.7 (=95.5 centile), EFW has sensitivity 80% and specificity 72% in predicting an LGA neonate (likelihood ratios 2.8 and 0.27 for positive and negative test). Mean FGV Z scores were 0.85 and 0.4 for >95th and <95th centile, respectively (p>0.05); ROC curve analysis indicated no discriminatory capacity. Estimates of fetal size and growth performed poorly in the prediction of neonatal hypoglycaemia. CONCLUSION: In routine clinical practice, EFW has limited utility in the prediction of the LGA infant. FGV does not identify the LGA infant. EFW and FGV do not predict neonatal hypoglycaemia.
The photophysical and spectroscopic properties of a new class of oligothiophene derivatives, designated as cruciform oligomers, have been investigated in solution (room and low temperature) and in the solid state (as thin films in Zeonex matrixes). The study comprises absorption, emission, and triplet-triplet absorption spectra, together with quantitative measurements of quantum yields (fluorescence, intersystem crossing, internal conversion, and singlet oxygen formation) and lifetimes. The overall data allow the determination of the rate constants for all decay processes. From these, several conclusions are drawn. First, in solution, the main deactivation channels for the compounds are the radiationless processes: S(1) --> S(0) internal conversion and S(1) --> T(1) intersystem crossing. Second, in general, in the solid state, the fluorescence quantum yields decrease relative to solution. A comparison is made with the analogous linear alpha-oligothiophenes, revealing a lower fluorescence quantum efficiency and, in contrast to the normal oligothiophenes, that internal conversion is an important channel for the deactivation of the singlet excited state. Replacement of thiophene by 1,4-phenylene units in the longer-sized cruciform oligomer increases the fluorescence efficiency. The highly efficient generation of singlet oxygen through energy transfer from the triplet state (S(Delta) approximately 1) provides support for the measured intersystem crossing quantum yields and suggests that reaction with this may be an important pathway to consider for degradation of devices produced with these compounds.
It is demonstrated using reflection anisotropy spectroscopy that the adsorption of cytosine and cytidine -monophosphate at the Au(110) 1 x 2/electrolyte interface gives rise to ordered structures in which the base is oriented vertical to the surface and parallel to the [110] axis of the Au(110) plane.
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OBJECTIVES: To determine if cervical length obtained with three-dimensional ultrasound correlated with the 'true cervical volume' and to evaluate the reliability and validity of transabdominal and transvaginal three-dimensional cervical volume measurement. METHODS: This was a prospective observational study. Three-dimensional cervical volume measurements were made prior to hysterectomy in 28 women. Following hysterectomy the amputated cervical volume was calculated using water displacement. For the assessment of intra- and interobserver reliability, the intraclass correlation coefficient (ICC) was used. The index of concordance between the sonographic cervical volumes and those obtained by the reference standard (true cervical volume) was assessed with the limits of agreement method and the ICC. RESULTS: Transabdominal cervical length and transvaginal cervical length correlated moderately with actual cervical volume; correlation coefficients were 0.64 and 0.57 (P < 0.05), respectively. Intraobserver reliability for both transabdominal and transvaginal cervical volume assessment was good (> 0.75). Interobserver reliability for transvaginal cervical volumes was similarly good (ICC = 0.90). However, for transabdominal measurements the interobserver reliability was poor (ICC = 0.51). The validity of both methods of three-dimensional volume assessment was poor (ICC < 0.75). This was reflected in the wide limits of agreement, which ranged from approximately - 25 mL to + 30 mL. CONCLUSION: The reliability and validity of three-dimensional cervical volume measurement are poor. Clinical introduction of cervical volume measurement should be avoided at this time.
OBJECTIVE: To establish whether there is a relationship between estimated fetal weight (EFW) and umbilical artery Doppler waveform impedance indices in the third trimester. METHODS: The pulsatility index (PI) and S/D (systolic/diastolic) ratio were obtained together with the EFW from 274 low-risk pregnancies. Measurements were made at fortnightly intervals from 30 weeks' gestation until delivery. A relationship between the two impedance indices and EFW was sought at gestational age ranges of 30-32, 33-35, 36-38 and 39-41 weeks. RESULTS: There were 918 pairs of PI (with S/D) and EFW available for analysis. The mean of the impedance indices decreased with advancing gestational age as expected. There was no clinically relevant correlation between impedance indices and EFW within any of the gestational age ranges. CONCLUSION: Impedance indices from the umbilical artery Doppler waveform decrease with advancing gestational age due, at least partially, to expansion of the placental vascular tree. Within narrow gestational age ranges in the third trimester, there is no meaningful correlation between fetal weight and impedance indices. It is therefore not necessary to adjust umbilical artery Doppler impedance indices to account for fetal size.
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Proteinuria is one of the fundamental criteria for the diagnosis of pre-eclampsia with quantitative assessment based on the 24-hour urine protein estimation as the gold standard. This study was undertaken to determine whether a 2-hour protein estimation correlated with that of a formal 24-hour collection. Thirty women with proteinuric hypertension were recruited. There was significant correlation between the 2-hour and 24-hour urine protein levels (Pearson's correlation coefficient 0.76 (P 0.000). A positive 2-hour test was associated more closely with significant levels of 24-hour proteinuria than dipstick analysis alone. We conclude from this study that a random 2-hour sample could be used for the initial assessment of proteinuria and so avoid the delay associated with 24-hour quantification of urinary protein.
AIM: To determine the frequency of major congenital anomalies in the offspring of women with gestational diabetes (GDM), classified according to their postpartum glucose tolerance status. METHODS: A prospective study of pregnancies in women with Type 1 diabetes (n = 221), Type 2 diabetes (n = 317) and GDM (n = 1822) between 1985 and 2000 (15 years). Congenital anomalies were detected by antenatal ultrasound or postnatal examination. RESULTS: The frequency of major congenital anomalies in the offspring was 5.9% (95% confidence interval (CI) 3.2-9.8) for women with Type 1 diabetes; 4.4% (95% CI 2.4-7.3) for women with Type 2 diabetes; and 1.4% (95% CI 0.9-2.0) for women with GDM. Two hundred and thirty-seven women with GDM (13%) had diabetes diagnosed on early (6-week) postpartum glucose tolerance testing. The frequency of major congenital anomalies in their offspring was 4.6% (95% CI 2.3-8.2), compared with 0.9% (95% CI 0.5-1.5) for the remainder of the GDM group (P < 0.0001). CONCLUSIONS: GDM is not a homogeneous group with regard to the risk of major congenital anomalies. In those with diabetes on early postpartum testing, who are likely to have had unrecognized Type 2 diabetes antedating their pregnancy, the rate of major congenital anomalies is the same as for women with established Type 1 or Type 2 diabetes. In the remainder of the GDM group, the rate does not differ from the non-diabetic background rate.
OBJECTIVE: To establish whether there is a relationship between the amniotic fluid index and estimated fetal weight in the third trimester. The presence of a relationship would require adjustment of amniotic fluid index to take account of estimated fetal weight with potential improvement in its prediction of adverse perinatal outcomes. METHODS: Paired measurements of amniotic fluid index and estimated fetal weight from 274 low-risk pregnancies enrolled in a longitudinal study of fetal growth. Measurements were made at fortnightly intervals from 30 weeks' gestation until delivery. A relationship between amniotic fluid index and estimated fetal weight was sought at gestational age week intervals of 30-32, 33-35, 36-38 and 39-41. RESULTS: One thousand and three pairs of measurements of amniotic fluid index and estimated fetal weight were available for analysis. Mean amniotic fluid index decreased towards term as expected. There was no correlation between amniotic fluid index and estimated fetal weight. Furthermore, there was no correlation between amniotic fluid index and estimated fetal weight at any of the gestational age intervals. CONCLUSIONS: There is no clinically relevant correlation between amniotic fluid index and estimated fetal weight. It should remain clinical practice to take account of gestational age when interpreting amniotic fluid index but it is not necessary to make adjustments for estimated fetal weight.
Immunoglobulin A (IgA) deficiency is 10 to 15 times more common in patients with celiac disease (CD) than in healthy subjects. Serological tests have become the preferred methods of diagnosing CD in both symptomatic and asymptomatic patients. However, commercially available serological methods are limited in that they detect only the IgA isotype of antibodies (with the exception of IgG gliadin assays); hence, IgA-deficient patients with CD may yield false-negative serology. Fifteen pediatric patients with CD and 10 IgA-deficient pediatric patients without CD were examined for IgA and IgG antibodies to endomysium, gliadin, and tissue transglutaminase. Twenty-five specimens from patients with IgA deficiency were examined. Fifteen were from patients with CD, and 10 were patients without CD. All 15 IgA-deficient patients with CD were positive for endomysium antibodies of the IgG isotype and for IgG gliadin antibodies. All but one of the IgA-deficient patients with CD were also positive for IgG tissue transglutaminase antibodies. None of the IgA-deficient patients without CD were positive for any of the antibody markers. All the specimens examined were also negative for IgA-specific antibodies to endomysium, gliadin, and tissue transglutaminase. IgG-specific antibody tests for endomysium, gliadin, and tissue transglutaminase are useful for the identification of IgA-deficient patients with CD. IgG antibody tests along with tests routinely being used in clinical laboratories can reliably detect all active patients with CD. In addition, the levels of these CD-specific IgG antibodies could be used to monitor patient dietary compliance.
First-year medical students were surveyed by questionnaire to assess levels of stress and physical symptoms resulting from their experience of the anatomy room. There was a 100% response rate from the 188 students. Most students (95%) found the prospect of their first visit to the anatomy room exciting. A small number initially experienced physical symptoms, but these had improved significantly 10 weeks later. Most students suffered very little or no stress (80%) on their first visit with only 2% of respondents rating their stress levels as high. Ten weeks later, 87% experienced little or no stress with only 1% stating that they had high stress levels. The anatomy room was rated to be less stressful than workload and assessments. Students reported that the anatomy room provoked thoughts of mortality, and 27% suggested that there should be more preparation before the first visit to the anatomy room. Our findings support previous studies suggesting that American/Canadian students in particular find anatomy stressful. However, the wisdom of interpreting adverse reactions as symptomatic of post-traumatic stress disorder is questioned. This study shows the anatomy room to be a positive learning experience for the students of the Royal College of Surgeons in Ireland.
Hypertensive disorders are the most common medical problems encountered by women during pregnancy and remain a major cause of maternal and fetal mortality and morbidity throughout the world. This article provides an update on the definition and classifications of hypertension in pregnancy and discusses the recent consensus statement from the Australasian Society into the Study of Hypertension in Pregnancy (ASSHP). A review of the relevance of the traditional triad of symptoms in the assessment of women for hypertensive disorders in pregnancy is also presented. An understanding of these issues will help midwives accurately assess women and ensure that appropriate management of pregnancies complicated by hypertensive disorders occurs.
OBJECTIVE: To evaluate the reliability and validity of two and three dimensional ultrasound volumetric measurements using balloon and uterine models. DESIGN: Prospetive observational study. SETTING: Obstetric ultrasound department at a university teaching hospital. METHOD: Two and three dimensional ultrasound volumetric measurements (with 5, 10 and 15 ultrasonic slices) were performed on 30 different sets of ultrasound images obtained from 15 water filled balloons with volumes ranging from 19 to 697mL. The measurements were performed independently by two observers who were blinded to the true volumes of the balloons. For the uterine model, only three dimensional ultrasonic volume measurements were performed independently on 16 uteri by two observers who were again unaware of the definitive uterine volumes. OUTCOME MEASURE: For the assessment of intra-and inter-rater reliability, the intraclass correlation coefficient was used. The index of concordance between the ultrasonic volumes and those obtained by the reference standard (validity) was assessed with the conventional Pearson's correlation coefficient, limits of agreement method and the intra-class correlation coefficient. RESULTS: High levels of reliability and validity were obtained for both two and three dimensional ultrasound balloon volume measurements. For two dimensional ultrasonic volume measurements, the intra-class correlation coefficient ranged from 0.992 to 0.998 for reliability and validity whereas the Pearson's correlation coefficient for validity was 0.996. With three dimensional ultrasonic volume measurements, the intra-class correlation coefficient ranged from 0.991 to 0.999 for reliability and validity whereas the Pearson's correlation coefficient for validity was 0.999. Both two and three dimensional ultrasonic measurements tended to underestimate the true balloon volume with the largest observed mean difference obtained with three dimensional ultrasound measurements using five ultrasonic slices and the smallest value obtained with three dimensional ultrasound measurements employing 15 ultrasonic slices. The mean difference in volume measurement for two dimensional ultrasound was intermediate between these two values. However, two dimensional ultrasound volume measurement generated the largest range between the limits of agreement whereas the smallest range was obtained with three dimensional ultrasound using 10 ultrasonic slices. The intra-class correlation coefficient for reliability and validity with three dimensional ultrasonic uterine volume estimation ranged from 0.956 to 0.996 whereas the Pearson's correlation coefficient for validity ranged from 0.993 to 0.999). The use of three dimensional ultrasound also consistently under-estimated the actual uterine volumes. The larger the number of ultrasonic slices employed for three dimensional ultrasound, the smaller was the mean difference between the ultrasonic and true uterine volume measurements and the smaller the limits of agreement. CONCLUSIONS: The reliability and validity of balloon and uterine volume measurement by three dimensional ultrasound is high. This allows further research on three dimensional ultrasound for measuring pelvic organ volumes in the prediction of pelvic pathology.
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OBJECTIVE: To develop and validate a computerised algorithm for the interpretation of the characteristics of fetal heart rate monitoring in labour. DESIGN: Prospective observational study. SETTING: Labour ward in a tertiary hospital. SAMPLE: Intrapartum cardiotocograms from 24 pregnancies. METHODS: A computerised algorithm was developed to assess the fetal heart baseline rate, variability, the number of accelerations and the number of decelerations. Twenty five minute segments of cardiotocograms were interpreted by the algorithm and also by seven expert reviewers independently. The reviewers were unaware of the outcome of labour. The reliability of the characteristics of cardiotocography and the validity of the computerised algorithm were assessed using the intraclass correlation coefficient and weighted kappa statistic for continuous and ordinal variables respectively. RESULTS: The inter rater reliability of the baseline fetal heart rate and the number and type of decelerations was good (intraclass correlation coefficient 0.93, 0.93 and 0.79, respectively). The reliability of baseline variability (kappa = 0.27) and accelerations (intraclass correlation coefficient = 0.27) was poor. The computerised algorithm had good agreement with the reviewers for the baseline fetal heart rate (intraclass correlation coefficient 0.91 to 0.98) and the number of decelerations (intraclass correlation coefficient 0.82 to 0.91), but was less valid as regards the number of late decelerations (intraclass correlation coefficient 0.68 to 0.85) and the number of accelerations (intraclass correlation coefficient 0.06 to 0.80), and was invalid as regards baseline variability (kappa 0.00 to 0.34). CONCLUSIONS: The high level of validity of the computerised algorithm for the estimation of the baseline fetal heart rate and the number of decelerations justifies its further technical development.