Determination of resonance frequency of the respiratory system in respiratory distress syndrome

AIM

To measure tidal volume delivery produced by high frequency oscillation (HFO) at a range of frequencies including the resonance frequency.

METHODS

Eighteen infants with respiratory distress syndrome were recruited (median gestation 28.7 weeks). Each was ventilated at frequencies between 8 and 30 Hertz. Phase analysis was performed at various points of the respiratory cycle. HFO was provided by a variable speed piston device. Resonance frequency was determined from the phase relation between the cyclical movements of the piston and pressure changes at the airway opening. Tidal volume was measured using a jacket plethysmograph.

RESULTS

The results were most reproducible when analysis was performed at the end of inspiration (within 1 Hz in nine out of 10 cases). Comparison between tidal volume delivery at 10 Hz and resonance frequency was made in 10 subjects. Delivery was significantly higher at resonance than at 10 Hertz (mean percentage increase 92%, range 9-222%).

CONCLUSIONS

These preliminary findings suggest that there is improved volume delivery at resonance frequency.

Assessment of effect of nasal continuous positive pressure on laryngeal opening using fibre optic laryngoscopy

AIM

To assess the effect of nasal continuous positive airways pressure (CPAP) on the dimensions of the laryngeal opening.

METHODS

Nine preterm infants who had previously received ventilatory support for respiratory distress syndrome (RDS) were studied. All were receiving nasal CPAP. The laryngeal opening was visualised using a fibre optic video camera system. The ratio of width to length of the opening was measured on and off CPAP.

RESULTS

In eight of the infants the width: length ratio increased on CPAP; mean change for group +24.4% (95% CI +11.9 to +37.9).

CONCLUSIONS

Nasal CPAP seems to dilate the larynx. This may explain the selective beneficial effects of CPAP on mixed and obstructive apnoea.

A randomized comparison of home uterine activity monitoring in the outpatient management of women treated for preterm labor

OBJECTIVE

The aim of the study was to evaluate home uterine activity monitoring as an intervention in reducing the rate of preterm birth among women treated for preterm labor.

STUDY DESIGN

A total of 186 women were treated in the hospital with magnesium sulfate for preterm labor and were prospectively randomly assigned to study groups; among these, 162 were ultimately eligible for comparison. Eighty-two of these women were assigned to the monitored group and 80 were assigned to an unmonitored control group. Other than monitoring, all women received identical prenatal follow-up, including daily perinatal telephone contact and oral terbutaline therapy. Outcome comparisons were primarily directed toward evaluation of preterm birth at <35 weeks' gestation. Readmissions for recurrent preterm labor and observations lasting <24 hours were evaluated in monitored and unmonitored groups. Compliance with monitoring was also evaluated in the monitored group.

RESULTS

The monitored and control groups were demographically similar. According to a multivariate logistic regression model, women with cervical dilatation of >/=2 cm were 4 times more likely to be delivered at <35 weeks' gestation (P <.05). Gestational ages at delivery were similar in the monitored and control groups. There was no significant difference in the overall rate of preterm delivery at <35 weeks' gestation between the monitored group (10.9%) and the control group (15.0%). The overall rates of delivery at <37 weeks' gestation were high (48.8% and 60.0% for monitored and control groups, respectively), and the difference was not significant. The numbers of women with >/=1 instance of readmission and treatment for recurrent preterm labor were equal in the monitored and control groups. The numbers of women with >/=1 hospital observation lasting <24 hours were not different between the groups. Compliance with monitoring did not significantly differ for women who were delivered at <35 weeks' gestation, women with >/=2 cm cervical dilatation at enrollment, or for African American women.

CONCLUSION

A reduction in the likelihood of preterm delivery at <35 weeks' gestation was not further enhanced by the addition of home uterine monitoring to the outpatient management regimens of women treated for preterm labor.

Defensive mothering in HIV-positive mothers

The grounded theory study discussed in this article provides an explanatory schema that illuminates the mothering experiences of women living with HIV infection. Eighteen HIV-positive mothers provided 24 in-depth interviews. The grounded theory method was used for data analysis. Defensive mothering was the basic social psychological process that these HIV-positive mothers used in response to their diagnosis and the inherent stigma. Their defensive posture afforded these mothers and their children some degree of psychological protection. Defensive mothering involved much mental work and included three subprocesses: preventing the spread of HIV, preparing the children for a motherless future, and protecting themselves through thought control.

Breath ethane as a marker of reactive oxygen species during manipulation of diet and oxygen tension in rats

Breath ethane, O2 consumption, and CO2 production were analyzed in 24-mo-old female Fischer 344 rats that had been fed continuously ad libitum (AL) or restricted 30% of AL level (DR) diets since 6 wk of age. Rats were placed in a glass chamber that was first flushed with air, then with a gas mixture containing 12% O2. After equilibration, a sample of the outflow was collected in gas sampling bags for subsequent analyses of ethane and CO2. The O2 and CO2 levels were also directly monitored in the outflow of the chamber. O2 consumption and CO2 production increased for DR rats. Hypoxia decreased O2 consumption and CO2 production for the AL-fed and DR rats. These changes reflect changes in metabolic rate due to diet and PO2. A significant decrease in ethane generation was found in DR rats compared with AL-fed rats. Under normoxic conditions, breath ethane decreased from 2.20 to 1.61 pmol ethane/ml CO2. During hypoxia the levels of ethane generation increased, resulting in a DR-associated decrease in ethane from 2.60 to 1.90 pmol ethane/ml CO2. These results support the hypothesis that DR reduces the level of oxidative stress.

HIV-positive mothers and stigma

Our purpose in this paper is to demonstrate how stigma pervades the lives of human immunodeficiency virus (HIV)-positive mothers and their children. Data from a grounded theory study on HIV-positive mothers are used to illustrate Goffman's theory of stigma. This research is an example of "emergent fit," where extant theory is discovered by the interpretive researchers to fit much of the data. The sample included 18 HIV-positive mothers who participated in in-depth interviews. The HIV-positive mothers valued being perceived as normal but acknowledged that normalcy was lost for them because of the stigma of HIV. Consequently, they tried to pass as normal by managing information and manipulating their environment. They attempted to cover up their illness by lying and pretending. Health care professionals can provide quality, client-centered care when they understand the power that stigma holds over these women and the strategies that effectively mitigate the stigma.

A prospective study of microvascular free-flap surgery and outcome

Over a 6-month period, 23 members of the International Microvascular Research Group participated in a prospective survey of their microvascular free-flap practice. Data were recorded with each case for 60 variables covering patient characteristics, surgical technique, pharmacologic treatment, and postoperative outcome. A total of 493 free flaps were reported with a representative demographic distribution for age, sex, indications for surgery, risk factors, flap type, surgical technique, and pharmacologic intervention. Mixed effects logistic regression modeling was used to determine predictors of flap failure and associated complications. The overall incidence of flap failure was 4.1 percent (20 of 493). Reconstruction of an irradiated recipient site and the use of a skin-grafted muscle flap were the only statistically significant predictors of flap failure, with increased odds of failure of 4.2 (p = 0.01) and 11.1 (p = 0.03), respectively. A postoperative thrombosis requiring re-exploration surgery occurred in 9.9 percent of the flaps. The incidence of this complication was significantly higher when the flap was transferred to a chronic wound and when vein grafts were needed, with increased odds of failure of 2.9 (p = 0.02) and 2.5 (p = 0.02), respectively. There was a lower incidence of postoperative thrombosis when rectus/transverse rectus abdominis muscle (TRAM) flaps were used, where odds of failure decreased by 0.36 (p = 0.04), and when subcutaneous heparin was administered in the postoperative period, where odds decreased by 0.27 (p = 0.04). There was an overall 69-percent salvage rate for flaps identified with a postoperative thrombosis. Intraoperative thrombosis occurred in 41 cases (8.3 percent) and was observed more frequently in myocutaneous flaps or when vein grafts were needed (5.5 and 5.0 greater odds, respectively; p < 0.001) but was not associated with higher flap failure (2 of 41 cases; 4.9-percent failure rate). The incidence of a hematoma and/or hemorrhage was increased in obese patients and when vein grafts were needed [2.7 (p = 0.02) and 2.6 (p = 0.03) greater odds, respectively], whereas this complication was significantly decreased in muscle flaps (myocutaneous or skin-grafted muscle), in tobacco users, when a heparinized solution was used for general wound irrigation, and when the attending surgeon performed the arterial anastomosis (in contrast to the resident or fellow on staff) (p < 0.05 for each factor). With the multivariable analysis, many factors were found not to have a significant effect on flap outcome, including the recipient site (e.g., head/neck, breast, lower limb, etc.); indications for surgery (trauma, cancer, etc.); flap transfer in extremes of age, smokers, or diabetics; arterial anastomosis with an end-to-end versus end-to-side technique; irrigation of the vessel without or with heparin added to the irrigation solution; and a wide spectrum of antithrombotic drug therapies. These results present a current baseline for free-flap surgery to which future advances and improvements in technique and practice may be compared.

Case-control study of phyto-oestrogens and breast cancer

BACKGROUND

Phyto-oestrogens are a group of naturally occurring chemicals derived from plants; they have a structure similar to oestrogen, and form part of our diet. They also have potentially anticarcinogenic biological activity. We did a case-control study to assess the association between phyto-oestrogen intake (as measured by urinary excretion) and the risk of breast cancer.

METHODS

Women with newly diagnosed early breast cancer were interviewed by means of questionnaires, and a 72 h urine collection and blood sample were taken before any treatment started. Controls were randomly selected from the electoral roll after matching for age and area of residence. 144 pairs were included for analysis. The urine samples were assayed for the isoflavonic phyto-oestrogens daidzein, genistein, and equol, and the lignans enterodiol, enterolactone, and matairesinol.

FINDINGS

After adjustment for age at menarche, parity, alcohol intake, and total fat intake, high excretion of both equol and enterolactone was associated with a substantial reduction in breast-cancer risk, with significant trends through the quartiles: equol odds ratios were 1.00, 0.45 (95% CI 0.20, 1.02), 0.52 (0.23, 1.17), and 0.27 (0.10, 0.69)--trend p = 0.009--and enterolactone odds ratios were 1.00, 0.91 (0.41, 1.98), 0.65 (0.29, 1.44), 0.36 (0.15, 0.86)--trend p = 0.013. For most other phytoestrogens there was a reduction in risk, but it did not reach significance. Difficulties with the genistein assay precluded analysis of that substance.

INTERPRETATION

There is a substantial reduction in breast-cancer risk among women with a high intake (as measured by excretion) of phyto-oestrogens-particularly the isoflavonic phyto-oestrogen equol and the lignan enterolactone. These findings could be important in the prevention of breast cancer.

An audit of 267 consecutively excised mammographically detected breast lesions 1989-1993

Pathology reports and slides were reviewed from 267 mammographically detected impalpable breast lesions, excised after hookwire localisation. There were 182 benign and 85 malignant lesions (benign to malignant ratio of 2.1:1). The invasive cancers tended to be small (mean 13 mm; 50% < or = 10 mm), of low histologic grade (38% Grade I), with a low incidence of lymph node metastases (15%). A high proportion of pure duct carcinoma in situ (DCIS) lesions (21%) was found, and an unusually high proportion of invasive lobular carcinoma (17%). Preoperative fine needle aspiration (FNA) was performed in 95 (36%) cases, including 47 (18%) sampled using sterotactic guidance and 48 (18%) sampled by palpation. The absolute sensitivity of diagnosis of malignancy was 32% and 5% respectively. In 79% of carcinomas further operation was performed, for axillary clearance or re-excision of incompletely excised tumor; this high rate was largely a result of a decision not to use frozen section diagnosis for impalpable lesions and because of the early stages of the development of preoperative needle diagnosis. 58% of invasive cancers, including seven of eight (87.5%) carcinomas with an extensive intraduct component (EIC + ve), and 72% of DCIS were incompletely excised at the first operation. Residual tumor was found in the re-excisions in 26% of EIC - ve invasive carcinomas, 71% of the EIC + ve cases and 56% of DCIS lesions. The malignant lesions had highly favourable prognostic indices. The need for concentration of experience with pre-operative FNA was highlighted. Positive excision margins were a good predictor for residual malignancy, particularly for EIC + ve cases and for DCIS lesions.

Opinions of physical therapy education program directors on essential functions

BACKGROUND AND PURPOSE

The purpose of this study was to determine the opinions of directors of physical therapy education programs concerning the essential functions physical therapist students must be able to complete, with or without reasonable accommodation.

SUBJECTS

Fifty-eight physical therapy education program directors participated.

METHODS

Participants completed surveys as part of a three-round Delphi technique. They had the opportunity to modify or make additions to the initial list in the first round and rate the items in the last two rounds using an ordinal scale.

RESULTS

All participants rated communication skills and practicing in a safe, ethical, and legal manner as definitely essential functions. Nearly universal agreement (95%-99%) was present for determining physical therapy needs of patients with movement dysfunction and demonstrating the ability to apply universal precautions. Performance of treatment procedures and performance of assessment procedures were rated essential by 90% to 95% of the participants. The least agreement was found for participation in the process of scientific inquiry.

CONCLUSION AND DISCUSSION

There is agreement among the physical therapy education program directors concerning the essential functions that should be required of students. The results of this study should serve as a reference for physical therapy education programs for developing the essential functions required of students.

Life events and the risk of breast cancer: a case-control study

A case-control study was undertaken to investigate the possibility of an association between stressful life events and the development of breast cancer. Ninety-nine breast cancer cases, and 99 controls matched by age and area of residence, completed a life events inventory to measure life change and distress scores over a 2-year and a 10-year period. Study subjects were also interviewed to establish potential breast cancer risk factors; their height and weight were measured; they completed a food frequency questionnaire and provided a fasting blood sample for hormonal assay. After adjusting for potential confounders, women with a 10-year life change score greater than 210 (i.e. the highest quartile) had 4.67 times the risk of developing breast cancer, compared with those in the lowest quartile (P < 0.05).

Stereotactic 14 gauge core-biopsy of the breast: results from 101 patients

BACKGROUND

Along with fine needle aspiration (FNA) cytology, core-biopsy has become an integral part of the assessment of mammographically detected breast lesions.

METHODS

A series of stereotactic large-core-biopsies of mammographically detected breast lesions was studied to assess the accuracy and limitations of the technique in diagnosing malignancy and in giving specific benign diagnoses, and its use in determining surgical management.

RESULTS

Eighty per cent of carcinomas were diagnosed as malignant (absolute sensitivity). In 88.8% of the cancers, the core-biopsy was classified as malignant, suspicious or atypical/indeterminate (complete sensitivity), and in 72% of the invasive carcinomas, invasive tumour was present in the core. The technique was more successful for invasive carcinomas than for ductal carcinoma in situ (DCIS) (absolute sensitivity 86.1 and 55.5, respectively; P = 0.28) and for malignant mass lesions than for a mass with associated microcalcifications or for pure microcalcifications (absolute sensitivity 91, 71 and 66.6%, respectively; P = 0.19). In five of the 45 cancers (11.1%), no tumour tissue was present in the core, but all were excised after mammographic review and no delays in diagnosis have been experienced to date. The benign to malignant ratio for excised lesions was 0.11:1. Of the benign lesions, a specific diagnosis was given in 49% (calcifications in the core in a background of fibrocystic change, or postoperative scarring, or fibro-adenoma); the remainder showed non-specific benign findings. All patients where invasive carcinoma was diagnosed in the core underwent axillary clearance and wide local excision or mastectomy at their first operation.

CONCLUSIONS

This technique can markedly reduce the number of benign lesions needing open biopsy, and provide information allowing definitive management of most carcinomas at the first operation. The accuracy of core-biopsy was lower in DCIS/microcalcification lesions; extra core samples or a combination of FNA and core-biopsy may be of value in these cases.

Integrating Informatics into the Undergraduate Curriculum: A Report on a Pilot Project

Previous case reports in this series on Education and Training have looked at specialist courses for postgraduate students seeking an in-depth know ledge of informatics and a career in the field. By contrast, this review describes a project designed to pilot a series of learning opportunities for undergraduate medical students. Although some UK medical colleges have opted to introduce informatics into the curriculum as a discipline in its own right, the Informatics Department at St Bartholomew’s Hospital Medical College chose a different approach. When a new curriculum was introduced at St Bartholomew’s and at The London Hospital Medical College, the Head of the Informatics Department saw this as an ideal opportunity to explore ways of integrating informatics into the curriculum. The initiatives described in this paper were made possible as a result of an award from the UK government Department of Employment. Money from an Enterprise in Higher Education grant funded a range of programmes, one of which was designed to introduce students to selected aspects of informatics and to demonstrate what is feasible in the undergraduate curriculum. The work carried out over a period of three and a half years was intended to provide the basis for the next phase of curriculum development. However, in the wake of the restructuring which has taken place in London medical colleges, the Informatics Department at what was St Bartholomew’s has relocated to University College London Medical School, and is now called The Centre for Health Informatics and Multi professional Education (CHIME). University College is designing a new medical curriculum and CHIME is drawing on the experience gained through the Enterprise Project to find the best way to integrate informatics into this curriculum.

The development of a clinical skills centre

Guidelines produced by the General Medical Council of Great Britain have emphasised the importance of the development of the skills and attitudes appropriate for a junior doctor. Medical schools are in the process of reforming their curricula accordingly. The development of these skills is made increasingly difficult by changes such as short admissions to hospital, increased care in the community, and reduced resources. This article outlines the development of a clinical skills centre as a multidisciplinary unit to improve clinical skills teaching with the aid of up-to-date technology and educational practices. By sharing our experience we aim to provide a practical guide for the development of such units in other medical and nursing colleges.

Integrating Informatics into the Undergraduate Curriculum: A Report on a Pilot Project

Previous case reports in this series on Education and Training have looked at specialist courses for postgraduate students seeking an in-depth knowledge of informatics and a career in the field. By contrast, this review describes a project designed to pilot a series of learning opportunities for undergraduate medical students. Although some UK medical colleges have opted to introduce informatics into the curriculum as a discipline in its own right, the Informatics Department at St Bartholomew's Hospital Medical College chose a different approach. When a new curriculum was introduced at St Bartholomew's and at The London Hospital Medical College, the Head of the Informatics Department saw this as an ideal opportunity to explore ways of integrating informatics into the curriculum. The initiatives described in this paper were made possible as a result of an award from the UK government Department of Employment. Money from an Enterprise in Higher Education grant funded a range of programmes, one of which was designed to introduce students to selected aspects of informatics and to demonstrate what is feasible in the undergraduate curriculum. The work carried out over a period of three and a half years was intended to provide the basis for the next phase of curriculum development. However, in the wake of the restructuring which has taken place in London medical colleges, the Informatics Department at what was St Bartholomew's has relocated to University College London Medical School, and is now called The Centre for Health Informatics and Multiprofessional Education (CHIME). University College is designing a new medical curriculum and CHIME is drawing on the experience gained through the Enterprise Project to find the best way to integrate informatics into this curriculum.

The cultural basis of prosodic modifications to infants and children: a response to Fernald's universalist theory

Fernald and her colleagues have argued for the universality of prosodic modifications in speech addressed to infants (e.g. Fernald, 1987; Fernald, Taeschner, Dunn, Papousek, de Boysson-Bardies & Fukui, 1989). An alternative proposal in Bernstein-Ratner & Pye (1984) and Pye (1986) argues that speech modifications to children are the result of a set of conventions that may vary from culture to culture. This note presents arguments against Fernald and in support of the cultural account of prosodic modifications to infants and children. First, in response to criticisms in Fernald et al., data are presented which defend the conclusion in Bernstein-Ratner & Pye that Quiché mothers show less prosodic modification to children than do mothers in other cultures studied to date. Second, data used to support the universal position in Fernald (1987) on adult identification of infant affective states are reinterpreted and shown to be equally interpretable as the result of a set of culturally transmitted rules.

A portable communicative architecture for electronic healthcare records: the Good European Healthcare Record project (Aim project A2014)

The European Union is supporting research into medical informatics via its Advanced Informatics in Medicine (AIM) program. One of the current AIM projects is the Good European Healthcare Record (GEHR) project. Its objective is to devise an architecture for electronic healthcare records that will enable them to be comprehensive, communicative, and portable to different systems. The work was funded from January 1992 to December 1994. The project team consisted of over 50 personnel representing clinicians, computer scientists, and computer programmers in eight European countries. The partner organizations are Health Data Management Partners (Belgium), Croix Rouge Francaise (France), France Telecom, Association des Medecins et Medicins Dentistes (Luxembourg), Instituto Clinica Geral Zona Norte (Portugal), Medical College of St Bartholomew's Hospital (UK), and SmithKline Beecham (UK). The work of the project has been carried out by three subgroups covering clinical, architecture, and systems aspects. One of the strengths of the project has been that most of the work has been done as collaborations between members of different groups. This has meant that there has been very close contact between clinicians and computer experts. The GEHR project is providing important input into the standardization process in Europe via, for example, PT011 of Working Group 1 of CEN TC/251 (the developing standards for the architecture of healthcare records).

Using adverse events in health-care quality improvement: results from a British acute hospital

Adverse event monitoring is a problem-oriented approach to clinical audit and health-care quality improvement, which was developed and has been widely used in the USA. Briefly explores the technique itself and its evolution. Presents experience gained from the widespread use of the approach in a British acute hospital, and results from one specialty--ophthalmology. Suggests that the study of adverse events in patient care can produce significant improvements in patients' care, that it is particularly suited to some specialties, and that it should be used alongside other techniques in hospital clinical audit programmes. Concludes that, as the demand for quality-monitoring information from purchasers and within providers grows, adverse event monitoring may become one of the key techniques for quality assessment and improvement.