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1.
Front Med (Lausanne) ; 11: 1330457, 2024.
Article in English | MEDLINE | ID: mdl-38572162

ABSTRACT

Introduction: Vacuum extraction is generally considered an operator-dependent task, with most attention directed toward the obstetrician's technical abilities (1-3). Little is known about the effect of the team and non-technical skills on clinical outcomes in vacuum-assisted delivery. This study aimed to investigate whether the non-technical skills of obstetricians were correlated with their level of clinical performance via the analysis of video recordings of teams conducting actual vacuum extractions. Methods: We installed between two or three video cameras in each delivery room at Aarhus University Hospital and Horsens Regional Hospital and obtained 60 videos of teams managing vacuum extraction. Appropriate consent was obtained. Two raters carefully reviewed the videos and assessed the teams' non-technical skills using the Assessment of Obstetric Team Performance (AOTP) checklist, rating all items on a Likert scale score from 1 to 5 (1 = poor; 3 = average; and 5 = excellent). This resulted in a total score ranging from 18 to 90. Two different raters independently assessed the teams' clinical performance (adherence to clinical guidelines) using the TeamOBS-Vacuum-Assisted Delivery (VAD) checklist, rating each item (0 = not done, 1 = done incorrectly; and 2 = done correctly). This resulted in a total score with the following ranges (low clinical performance: 0-59; average: 60-84; and high: 85-100). Interrater agreement was analyzed using intraclass correlation (ICC), and the risk of high or low clinical performance was analyzed on a logit scale to meet the assumption of normality. Results: Teams that received excellent non-technical scores had an 81% probability of achieving high clinical performance, whereas this probability was only 12% among teams with average non-technical scores (p < 0.001). Teams with a high clinical performance often had excellent behavior in the non-technical items of "team interaction," "anticipation," "avoidance fixation," and "focused communication." Teams with a low or average clinical performance often neglected to consider analgesia, had delayed abandonment of the attempted vaginal delivery and insufficient use of appropriate fetal monitoring. Interrater reliability was high for both rater-teams, with an ICC for the non-technical skills of 0.83 (95% confidence interval [CI]: 0.71-0.88) and 0.84 for the clinical performance (95% CI: 0.74-0.90). Conclusion: Although assisted vaginal delivery by vacuum extraction is generally considered to be an operator-dependent task, our findings suggest that teamwork and effective team interaction play crucial roles in achieving high clinical performance. Teamwork helped the consultant anticipate the next step, avoid fixation, ensure adequate analgesia, and maintain thorough fetal monitoring during delivery.

2.
BJOG ; 128(9): 1534-1545, 2021 08.
Article in English | MEDLINE | ID: mdl-33969614

ABSTRACT

OBJECTIVE: To assess the cost-effectiveness of mifepristone and misoprostol (MifeMiso) compared with misoprostol only for the medical management of a missed miscarriage. DESIGN: Within-trial economic evaluation and model-based analysis to set the findings in the context of the wider economic evidence for a range of comparators. Incremental costs and outcomes were calculated using nonparametric bootstrapping and reported using cost-effectiveness acceptability curves. Analyses were performed from the perspective of the UK's National Health Service (NHS). SETTING: Twenty-eight UK NHS early pregnancy units. SAMPLE: A cohort of 711 women aged 16-39 years with ultrasound evidence of a missed miscarriage. METHODS: Treatment with mifepristone and misoprostol or with matched placebo and misoprostol tablets. MAIN OUTCOME MEASURES: Cost per additional successfully managed miscarriage and quality-adjusted life years (QALYs). RESULTS: For the within-trial analysis, MifeMiso intervention resulted in an absolute effect difference of 6.6% (95% CI 0.7-12.5%) per successfully managed miscarriage and a QALYs difference of 0.04% (95% CI -0.01 to 0.1%). The average cost per successfully managed miscarriage was lower in the MifeMiso arm than in the placebo and misoprostol arm, with a cost saving of £182 (95% CI £26-£338). Hence, the MifeMiso intervention dominated the use of misoprostol alone. The model-based analysis showed that the MifeMiso intervention is preferable, compared with expectant management, and this is the current medical management strategy. However, the model-based evidence suggests that the intervention is a less effective but less costly strategy than surgical management. CONCLUSIONS: The within-trial analysis found that based on cost-effectiveness grounds, the MifeMiso intervention is likely to be recommended by decision makers for the medical management of women presenting with a missed miscarriage. TWEETABLE ABSTRACT: The combination of mifepristone and misoprostol is more effective and less costly than misoprostol alone for the management of missed miscarriages.


Subject(s)
Abortifacient Agents/administration & dosage , Abortion, Missed/drug therapy , Mifepristone/administration & dosage , Misoprostol/administration & dosage , Abortifacient Agents/economics , Abortion, Missed/economics , Adolescent , Adult , Cost-Benefit Analysis , Double-Blind Method , Drug Therapy, Combination , Female , Humans , Mifepristone/economics , Misoprostol/economics , Pregnancy , Young Adult
3.
BJOG ; 127(6): 757-767, 2020 05.
Article in English | MEDLINE | ID: mdl-32003141

ABSTRACT

OBJECTIVES: To assess the cost-effectiveness of progesterone compared with placebo in preventing pregnancy loss in women with early pregnancy vaginal bleeding. DESIGN: Economic evaluation alongside a large multi-centre randomised placebo-controlled trial. SETTING: Forty-eight UK NHS early pregnancy units. POPULATION: Four thousand one hundred and fifty-three women aged 16-39 years with bleeding in early pregnancy and ultrasound evidence of an intrauterine sac. METHODS: An incremental cost-effectiveness analysis was performed from National Health Service (NHS) and NHS and Personal Social Services perspectives. Subgroup analyses were carried out on women with one or more and three or more previous miscarriages. MAIN OUTCOME MEASURES: Cost per additional live birth at ≥34 weeks of gestation. RESULTS: Progesterone intervention led to an effect difference of 0.022 (95% CI -0.004 to 0.050) in the trial. The mean cost per woman in the progesterone group was £76 (95% CI -£559 to £711) more than the mean cost in the placebo group. The incremental cost-effectiveness ratio for progesterone compared with placebo was £3305 per additional live birth. For women with at least one previous miscarriage, progesterone was more effective than placebo with an effect difference of 0.055 (95% CI 0.014-0.096) and this was associated with a cost saving of £322 (95% CI -£1318 to £673). CONCLUSIONS: The results suggest that progesterone is associated with a small positive impact and a small additional cost. Both subgroup analyses were more favourable, especially for women who had one or more previous miscarriages. Given available evidence, progesterone is likely to be a cost-effective intervention, particularly for women with previous miscarriage(s). TWEETABLE ABSTRACT: Progesterone treatment is likely to be cost-effective in women with early pregnancy bleeding and a history of miscarriage.


Subject(s)
Abortion, Spontaneous/economics , Abortion, Spontaneous/prevention & control , Progesterone/economics , Progestins/economics , Uterine Hemorrhage/drug therapy , Abortion, Spontaneous/etiology , Adolescent , Adult , Cost-Benefit Analysis , Double-Blind Method , Female , Humans , Live Birth/economics , Pregnancy , Progesterone/therapeutic use , Progestins/therapeutic use , Randomized Controlled Trials as Topic , State Medicine , Treatment Outcome , United Kingdom , Uterine Hemorrhage/complications , Uterine Hemorrhage/economics , Young Adult
4.
Eur J Obstet Gynecol Reprod Biol ; 228: 209-214, 2018 Sep.
Article in English | MEDLINE | ID: mdl-30007248

ABSTRACT

O-ring retractors (Alexis/Mobius) have been shown to reduce the risk of Surgical site infection (SSI) following general abdominal surgery. The benefit at caesarean section (CS) remains to be established given the relatively high cost. OBJECTIVES: To assess the efficacy of O-ring retractors when used at CS. STUDY DESIGN: Systematic review and meta-analysis. Electronic databases were searched from inception of each database until January 2018. No language restrictions were applied. All randomised controlled trials (RCTs) which compared the use of an O-ring retractor to routine care at CS were included. Primary outcome was SSI. Secondary outcomes were operating time, estimated blood loss, need for blood transfusion, need to exteriorise the uterus, requirement for additional postoperative analgesia and adequate operative field visualisation. Analysis was performed using Revman 5.3. RESULTS: 6 RCTs were included in the qualitative synthesis and the meta-analysis. This included 1669 women. The use of O-ring retractors did not reduce the risk of SSI when used at CS RR 0.76 (95% CI 0.34-1.70). Nor did the use of O-ring retractors reduce the operating time, estimated blood loss, the need for blood transfusion or the need for additional postoperative analgesia. The use O-ring retractors did reduce the need for exteriorisation of the uterus RR 0.48 (95% CI 0.33-0.69), and did increase the rate of adequate visualisation of the operative field RR 1.05 (95% CI 1.00-1.10). In a planned subgroup analysis there was a reduction in the rate of SSI with the use of O-ring retractors in women with a BMI < 35 RR 0.34(95% CI 0.12-0.98). CONCLUSION: This review has shown that O-ring retractors do not reduce the incidence of the common measurable complications of CS; SSI, blood loss, need for blood transfusion and need for additional postoperative analgesia. There may be a subgroup where these retractors are useful, but present evidence does not justify their routine use at CS.


Subject(s)
Cesarean Section/instrumentation , Blood Loss, Surgical , Cesarean Section/adverse effects , Female , Humans , Operative Time , Pregnancy , Surgical Wound Infection/etiology
5.
BJOG ; 125(8): 965-971, 2018 Jul.
Article in English | MEDLINE | ID: mdl-29193647

ABSTRACT

OBJECTIVE: The aim of this study was to estimate the incidence of anaphylaxis in pregnancy and describe the management and outcomes in the UK. DESIGN: A population-based descriptive study using the UK Obstetric Surveillance System (UKOSS). SETTING: All consultant-led maternity units in the UK. POPULATION: All pregnant women who had anaphylaxis between 1 October 2012 and 30 September 2015. Anaphylaxis was defined as a severe, life-threatening generalised or systemic hypersensitivity reaction. METHODS: Prospective case notification using UKOSS. MAIN OUTCOME MEASURES: Maternal mortality, severe maternal morbidity, neonatal mortality and severe neonatal morbidity. RESULTS: There were 37 confirmed cases of anaphylaxis in pregnancy, giving an estimated incidence of 1.6 (95% CI: 1.1-2.2) per 100 000 maternities. Four cases of anaphylaxis were in women with known penicillin allergies: two received co-amoxiclav and two cephalosporins. Twelve women had anaphylaxis following prophylactic use of antibiotics at the time of a caesarean delivery. Prophylactic use of antibiotics for Group B streptococcal infection accounted for anaphylaxis in one woman. Two women died (5%), 14 (38%) women were admitted to intensive care and seven women (19%) had one or more additional severe maternal morbidities, which included three haemorrhagic events, two cardiac arrests, one thrombotic event and one pneumonia. No infants died; however, in those infants whose mother had anaphylaxis before delivery (n = 18) there were seven (41%) neonatal intensive care unit admissions, three preterm births and one baby was cooled for neonatal encephalopathy. CONCLUSIONS: Anaphylaxis is a rare severe complication of pregnancy and frequently the result of a reaction to antibiotic administration. This study highlights the seriousness of the outcomes of this condition for the mother. The low incidence is reassuring given the large proportion of the pregnant population that receive prophylactic antibiotics during delivery. TWEETABLE ABSTRACT: Anaphylaxis is a rare severe complication of pregnancy and frequently the result of a reaction to antibiotic administration.


Subject(s)
Anaphylaxis/mortality , Population Surveillance , Pregnancy Complications/mortality , Adult , Female , Humans , Incidence , Infant, Newborn , Maternal Mortality , Perinatal Mortality , Pregnancy , Pregnancy Complications/immunology , Pregnancy Outcome , Prospective Studies , United Kingdom/epidemiology , Young Adult
6.
Eur J Obstet Gynecol Reprod Biol ; 192: 54-60, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26151240

ABSTRACT

OBJECTIVE: The number of caesarean sections at maternal request without medical indication is increasing. We aimed to explore the views of pregnant women, midwives and doctors using six hypothetical clinical scenarios and compare group views on: (a) perceived appropriateness of requests for caesarean section and (b) the reasons underlying these requests. STUDY DESIGN: A questionnaire was distributed to 166 pregnant women, 31 midwives and 52 doctors within maternity units at two hospitals in the North East region of England. Six hypothetical clinical scenarios for maternal requests were used: (1) uncomplicated first pregnancy, (2) one previous normal delivery, (3) one previous instrumental delivery, (4) one previous caesarean section, (5) one previous caesarean section with vaginal delivery since and (6) uncomplicated twin pregnancy. To highlight the differences in group responses, two main questions were asked for each scenario: 1. Should women be able to request a caesarean section? 2. What do you feel are the reasons for requesting a caesarean section? Data was analysed using Chi-squared or likelihood ratio as appropriate. RESULTS: In scenarios 1-3, professional groups were 'less likely' than pregnant women to always support a request (2.4% vs. 19.4%), (2.6% vs. 15.6%), (4.6% vs. 22%), (p<0.001). No significant differences were shown between doctors and midwives except for scenario 6 (twins), where midwives more often felt maternal requests should be declined (26.1% vs. 1.9%) (p=0.001). Multiparous women (n=95) were more likely to agree 'sometimes' to maternal requests in scenarios 1, compared to nulliparous women (n=71) (21.1% vs. 4.2%) (p=0.04). 'Safety of the baby' was ranked highly with pregnant women in scenarios 1-3 (mean 24.4%, range [15.8-38%]) compared with healthcare professionals (7.6% [3.4-12.8%]). However in scenario 3, healthcare professionals attributed 'fear of injury to self' (29.6%) as the most likely reason compared to 14.6% of pregnant women. CONCLUSION: Healthcare professionals and pregnant women's views differ significantly. Multiparous patients' views differ from those who have not had children before. We should provide clearer information on risks and benefits which encompass areas that concern women most.


Subject(s)
Attitude of Health Personnel , Cesarean Section/psychology , Elective Surgical Procedures/psychology , Midwifery , Obstetrics , Patient Preference/psychology , Adolescent , Adult , Decision Making , Delivery, Obstetric/psychology , Fear , Female , Humans , Middle Aged , Parity , Pregnancy , Surveys and Questionnaires , Young Adult
7.
Ultrasound Obstet Gynecol ; 46(2): 182-90, 2015 Aug.
Article in English | MEDLINE | ID: mdl-25826778

ABSTRACT

OBJECTIVES: To assess the diagnostic accuracy of placental growth factor (PlGF) and ultrasound parameters to predict delivery of a small-for-gestational-age (SGA) infant in women presenting with reduced symphysis-fundus height (SFH). METHODS: This was a multicenter prospective observational study recruiting 601 women with a singleton pregnancy and reduced SFH between 24 and 37 weeks' gestation across 11 sites in the UK and Canada. Plasma PlGF concentration < 5(th) centile, estimated fetal weight (EFW) < 10(th) centile, umbilical artery Doppler pulsatility index > 95(th) centile and oligohydramnios (amniotic fluid index < 5 cm) were compared as predictors for a SGA infant < 3(rd) customized birth-weight centile and adverse perinatal outcome. Test performance statistics were calculated for all parameters in isolation and in combination. RESULTS: Of the 601 women recruited, 592 were analyzed. For predicting delivery of SGA < 3(rd) centile (n = 78), EFW < 10(th) centile had 58% sensitivity (95% CI, 46-69%) and 93% negative predictive value (NPV) (95% CI, 90-95%), PlGF had 37% sensitivity (95% CI, 27-49%) and 90% NPV (95% CI, 87-93%); in combination, PlGF and EFW < 10(th) centile had 69% sensitivity (95% CI, 55-81%) and 93% NPV (95% CI, 89-96%). The equivalent receiver-operating characteristics (ROC) curve areas were 0.79 (95% CI, 0.74-0.84) for EFW < 10(th) centile, 0.70 (95% CI, 0.63-0.77) for low PlGF and 0.82 (95% CI, 0.77-0.86) in combination. CONCLUSIONS: For women presenting with reduced SFH, ultrasound parameters had modest test performance for predicting delivery of SGA < 3(rd) centile. PlGF performed no better than EFW < 10(th) centile in determining delivery of a SGA infant.


Subject(s)
Fetal Growth Retardation/blood , Fetal Growth Retardation/diagnostic imaging , Infant, Small for Gestational Age/blood , Pregnancy Proteins/blood , Pubic Symphysis/diagnostic imaging , Adult , Amniotic Fluid/diagnostic imaging , Female , Fetal Growth Retardation/physiopathology , Humans , Infant, Newborn , Intercellular Signaling Peptides and Proteins , Placenta Growth Factor , Predictive Value of Tests , Pregnancy , Pregnancy Trimester, Third , Pubic Symphysis/anatomy & histology , ROC Curve , Reproducibility of Results , Ultrasonography, Prenatal , Umbilical Arteries/diagnostic imaging , Uterus/diagnostic imaging
8.
BJOG ; 115(10): 1289-95; discussion 1295-6, 2008 Sep.
Article in English | MEDLINE | ID: mdl-18715415

ABSTRACT

BACKGROUND: Oxytocin is widely used to speed up slow labour, especially in nulliparous women, but randomised trials, apart from one reported only in abstract, have been too small to exclude important effects. OBJECTIVE: To test the hypothesis that early use of oxytocin reduces the need for caesarean delivery. DESIGN: A randomised controlled trial. SETTING: Twelve obstetric units within the Northern and Yorkshire regions in the North East of England. PARTICIPANTS: A total of 412 low-risk nulliparous women in spontaneous labour at term, who had been diagnosed with primary dysfunctional labour were recruited from January 1999 to December 2001. INTERVENTION: Immediate oxytocin administration (active group) or oxytocin withheld for up to 8 hours (conservative group). MAIN OUTCOME MEASURES: Caesarean section and operative vaginal delivery rates. The length of labour measured from the time of randomisation to delivery. The rate of maternal Edinburgh Postnatal Depression Scale (EPDS) greater than 12 (major depression) within 48 hours of delivery. RESULTS: The caesarean section rates were 13.5% active versus 13.7% controls (OR 0.98, 95% CI 0.6-1.7). Operative delivery, 24.5% versus 30.9% (OR 0.73, 95% CI 0.5-1.1). The median (interquartile range) randomisation to delivery interval in the active group was 5 hours 52 minutes (3:57-8:28) and in the conservative group 9 hours 8 minutes (5:06-13:16) (P < 0.001). The rate of EPDS >12 was 20% in the active arm versus 15% among controls (OR 1.26, 95% CI 0.7-2.2). There was one perinatal death in each group and no major differences in perinatal outcomes. CONCLUSIONS: Among nulliparous women with primary dysfunctional labour, early use of oxytocin does not reduce caesarean section or short-term postnatal depression. However, it shortens labour considerably and may reduce operative vaginal deliveries.


Subject(s)
Labor, Induced/methods , Obstetric Labor Complications/drug therapy , Oxytocics/administration & dosage , Oxytocin/administration & dosage , Adult , Cesarean Section/statistics & numerical data , Drug Administration Schedule , Female , Humans , Maternal Age , Parity , Postpartum Hemorrhage/etiology , Pregnancy , Pregnancy Outcome
9.
Neuroimage ; 10(5): 570-81, 1999 Nov.
Article in English | MEDLINE | ID: mdl-10547334

ABSTRACT

The importance of the left hemisphere in language function has been firmly established and current work strives to understand regional specializations within the perisylvian language areas. This paper reports a case study of a deaf user of American Sign Language undergoing an awake cortical stimulation mapping procedure. Patterns of sign errors accompanying electrical stimulation of Broca's area and the supramarginal gyrus (SMG) are reported. Our findings show Broca's area to be involved in the motor execution of sign language. These data demonstrate that the linguistic specificity of Broca's area is not limited to speech behavior. In addition, unusual semantic-phonological errors were observed with stimulation to the SMG; these data may implicate the SMG in the binding of linguistic features in the service of language production. Taken together, these findings provide important insight into the linguistic specificity of Broca's area and the functional role of the supramarginal gyrus in language processing.


Subject(s)
Arousal/physiology , Brain Mapping , Deafness/physiopathology , Frontal Lobe/physiopathology , Parietal Lobe/physiopathology , Sign Language , Anomia/physiopathology , Electric Stimulation , Epilepsy, Complex Partial/physiopathology , Gyrus Cinguli/physiopathology , Humans , Image Processing, Computer-Assisted , Language Tests , Male , Middle Aged , Phonetics , Semantics
10.
Proc AMIA Symp ; : 349-53, 1999.
Article in English | MEDLINE | ID: mdl-10566379

ABSTRACT

A goal of the University of Washington Brain Project is to develop software tools for processing, integrating and visualizing multimodality language data obtained at the time of neurosurgery, both for surgical planning and for the study of language organization in the brain. Data from a single patient consist of four magnetic resonance-based image volumes, showing anatomy, veins, arteries and functional activation (fMRI). The data also include the location, on the exposed cortical surface, of sites that were electrically stimulated for the presence of language. These five sources are mapped to a common MR-based neuroanatomical model, then visualized to gain a qualitative appreciation of their relationships, prior to quantitative analysis. These procedures are described and illustrated, with emphasis on the visualization of fMRI activation, which may be deep in the brain, with respect to surface-based stimulation sites.


Subject(s)
Brain Mapping , Cerebral Cortex/anatomy & histology , Language , Magnetic Resonance Imaging , Anatomy, Cross-Sectional , Cerebral Cortex/physiology , Epilepsy/surgery , Humans , Image Processing, Computer-Assisted , Models, Anatomic , Temporal Lobe/anatomy & histology , Temporal Lobe/physiology , Temporal Lobe/surgery
11.
J Am Med Inform Assoc ; 5(1): 17-40, 1998.
Article in English | MEDLINE | ID: mdl-9452983

ABSTRACT

OBJECTIVE: Conceptualization of the physical objects and spaces that constitute the human body at the macroscopic level of organization, specified as a machine-parseable ontology that, in its human-readable form, is comprehensible to both expert and novice users of anatomical information. DESIGN: Conceived as an anatomical enhancement of the UMLS Semantic Network and Metathesaurus, the anatomical ontology was formulated by specifying defining attributes and differentia for classes and subclasses of physical anatomical entities based on their partitive and spatial relationships. The validity of the classification was assessed by instantiating the ontology for the thorax. Several transitive relationships were used for symbolically modeling aspects of the physical organization of the thorax. RESULTS: By declaring Organ as the macroscopic organizational unit of the body, and defining the entities that constitute organs and higher level entities constituted by organs, all anatomical entities could be assigned to one of three top level classes (Anatomical structure, Anatomical spatial entity and Body substance). The ontology accommodates both the systemic and regional (topographical) views of anatomy, as well as diverse clinical naming conventions of anatomical entities. CONCLUSIONS: The ontology formulated for the thorax is extendible to microscopic and cellular levels, as well as to other body parts, in that its classes subsume essentially all anatomical entities that constitute the body. Explicit definitions of these entities and their relationships provide the first requirement for standards in anatomical concept representation. Conceived from an anatomical viewpoint, the ontology can be generalized and mapped to other biomedical domains and problem solving tasks that require anatomical knowledge.


Subject(s)
Anatomy/classification , Unified Medical Language System , Vocabulary, Controlled , Artificial Intelligence , Humans , Semantics , Terminology as Topic , Thorax/anatomy & histology
12.
Proc AMIA Symp ; : 921-5, 1998.
Article in English | MEDLINE | ID: mdl-9929353

ABSTRACT

Through intraoperative electrical stimulation mapping, it is possible to identify sites on the surface of the brain that are essential for language function. Interesting correlations have been found between the distribution of these sites and behavioral traits such as verbal IQ. In previous work, tools were developed for building a reconstruction of a patient's cortical surface and using it to recover coordinates of essential language sites. However, considerable expertise was required to produce good reconstructions. This paper describes an improved version of the mapping procedure, in which segmentation is driven by a 3-D shape model. The model-based approach provides more intuitive control over the system, allowing a trained user to complete a surface reconstruction and mapping in about two hours. This level of performance makes it feasible to gather language maps for a large number of patients, which hopefully will lead to significant new findings about language organization in the brain.


Subject(s)
Brain Mapping , Brain/anatomy & histology , Image Processing, Computer-Assisted , Magnetic Resonance Imaging , Models, Anatomic , Anatomy, Cross-Sectional , Humans
13.
Proc AMIA Annu Fall Symp ; : 469-73, 1997.
Article in English | MEDLINE | ID: mdl-9357670

ABSTRACT

Accurate segmentation of medical images poses one of the major challenges in computer vision. Approaches that rely solely on intensity information frequently fail because similar intensity values appear in multiple structures. This paper presents a method for using shape knowledge to guide the segmentation process, applying it to the task of finding the surface of the brain. A 3-D model that includes local shape constraints is fitted to an MR volume dataset. The resulting low-resolution surface is used to mask out regions far from the cortical surface, enabling an isosurface extraction algorithm to isolate a more detailed surface boundary. The surfaces generated by this technique are comparable to those achieved by other methods, without requiring user adjustment of a large number of ad hoc parameters.


Subject(s)
Brain/anatomy & histology , Image Processing, Computer-Assisted , Magnetic Resonance Imaging , Models, Anatomic , Anatomy, Cross-Sectional , Humans
14.
Br J Obstet Gynaecol ; 103(12): 1217-21, 1996 Dec.
Article in English | MEDLINE | ID: mdl-8968239

ABSTRACT

OBJECTIVES: To estimate and compare the costs of surgical and medical treatment of miscarriage to the National Health Service. DESIGN: A patient-centred, partially randomised trial. SETTING: A teaching hospital in Scotland. PARTICIPANTS: Four hundred and thirty-seven women with a proven first trimester miscarriage. MAIN OUTCOME MEASURES: The cost per patient of surgical and medical management of miscarriage plus the extra cost per patient of introducing medical management of miscarriage under three different scenarios are calculated. RESULTS: The average cost of surgical treatment was Pounds 397 compared with Pounds 347 for medical treatment. Sensitivity analysis showed that the extra cost of introducing the medical management of miscarriage ranged from a cost saving of Pounds 71 per patient to an additional cost of Pounds 47 per patient. CONCLUSIONS: Our analysis showed that it may be possible to generate cost savings by introducing medical methods in the management of early miscarriage. However, the savings assume that costs associated with theatre use can be fully realised.


Subject(s)
Abortion, Spontaneous/economics , Abortion, Induced/economics , Abortion, Induced/methods , Abortion, Spontaneous/metabolism , Cost Savings , Female , Health Care Costs , Humans , Patient-Centered Care , Pregnancy , Scotland
19.
Ophthalmic Surg ; 26(3): 194-9, 1995.
Article in English | MEDLINE | ID: mdl-7651682

ABSTRACT

Characteristics of alkalinized local anesthetics are poorly described with regard to stability and precipitation. Current fixed-volume methods of alkalinization often result in unstable, precipitated solutions of unpredictable pH. We determined a stable, nonprecipitating, anesthetic mixture and used it in a randomized double-blind crossover study of 21 patients to evaluate alkalinized anesthetic solutions in reducing pain on injection. Our solution significantly reduced pain associated with retrobulbar injection (analysis of variance, P = .0362) but not that associated with Nadbath injection. Fixed-volume alkalinization is not recommended because complications can result with the use of precipitated anesthetics.


Subject(s)
Anesthesia, Local/methods , Anesthetics, Local/chemistry , Anesthetics, Local/therapeutic use , Bupivacaine/chemistry , Bupivacaine/therapeutic use , Cataract Extraction , Chemical Precipitation , Cross-Over Studies , Double-Blind Method , Drug Stability , Drug Therapy, Combination , Epinephrine/chemistry , Epinephrine/therapeutic use , Humans , Hyaluronoglucosaminidase/chemistry , Hyaluronoglucosaminidase/therapeutic use , Hydrogen-Ion Concentration , Lidocaine/chemistry , Lidocaine/therapeutic use , Pain, Postoperative/prevention & control , Pilot Projects , Sodium Bicarbonate
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