Intensification strategies for temperate hot-summer grazing dairy systems in South America: Effects of feeding strategy and cow genotype.

Pasture-based dairy systems present the opportunity to increase productivity per hectare through increasing stocking rate and forage utilization. However, in the temperate hot-summer region of South America, different productive strategies are being adopted by farmers. The aim of this study was to quantify the effect of feeding strategy (FS) and cow genotype (G) on individual animal and whole-farm biophysical performance. A design with 2 × 2 levels of intensification aiming to increase home-grown forage utilization and milk output per hectare was evaluated. The experiment was a randomized complete block design with a 2 × 2 factorial arrangement of treatments, combining 2 feeding strategies with varying proportions of grazing in the annual feeding budget [grass fixed (GFix) and grass maximum (GMax)] and 2 Holstein Friesian cow genotypes [New Zealand (NZHF) or North American Holstein Friesian (NAHF)]. The effects of FS, G, and their interaction were analyzed using mixed models. New Zealand Holstein Friesian cows presented lower individual milk yield and higher milk component concentrations, maintained higher average body condition score, and increased body weight (BW) throughout the experiment, while presenting a better reproductive performance compared with the NAHF cows. Although all farmlets were planned at the same stocking rate on a per kilogram of BW basis, the current stocking rate changed as a result of animal performance and grass utilization resulting in NZHF cows achieving greater BW per hectare. The superior stocking rate led to greater milk solids production and feed consumption per hectare for the systems with NZHF cows. The GFix feeding strategy resulted in greater total home-grown forage harvest and conserved forage surplus than GMax. Overall, it was feasible to increase stocking rate and increase milk production per hectare from home-grown forage with differing feeding strategies and Holstein Friesian cow genotypes within grazing systems located in the temperate hot-summer climate region of South America. The interactions reported between FS × G highlight the superior productivity per hectare of NZHF cows within the GMax feeding strategy based on maximizing grazed pasture, which could represent a competitive intensification strategy in terms of cost of production for this region.

Extracorporeal carbon dioxide removal to "protect" the lung.

The case histories are presented of three adults who had severe hypercapnic acidosis despite mechanical ventilation with what were considered to be injurious tidal volumes and airway pressures. The use of a percutaneously inserted arteriovenous extracorporeal carbon dioxide removal (AV-ECCO(2)R) device facilitated a dramatic reduction in the amount of ventilatory support required, achieving a "lung-protective" level. Two patients survived to hospital discharge. One patient died after it became apparent that her late-stage interstitial lung disease was unresponsive to immunosuppression. AV-ECCO(2)R may be a useful strategy in facilitating lung-protective ventilation.

Citation classics in patient safety research: an invitation to contribute to an online bibliography.

BACKGROUND: There has been a documented massive increase in published papers on patient safety over the past 20 years or so. AIMS: To ascertain the most influential papers over these last two decades. METHOD: We obtained citation counts on papers which seemed to have been the most important in influencing opinion and practice. Our original source of papers were based on a systematic review of patient safety literature carried out by Shojania and colleagues and supplemented by other papers that we had come across in the course of our work directing the Department of Health Patient Safety Research Programme. RESULTS: We have listed 62 papers on our full report found on our website (http://www.pcpoh.bham.ac.uk/publichealth/psrp/PS_review.htm) and present the top 10 most highly cited papers here. CONCLUSION: We are aware that the results were influenced by our subjective assessment and therefore invite readers to send us their favourite papers so we can include them in our interactive bibliography.

Prevalence of visual impairment in people aged 75 years and older in Britain: results from the MRC trial of assessment and management of older people in the community.

AIMS: To measure the prevalence of visual impairment in a large representative sample of people aged 75 years and over participating in the MRC trial of assessment and management of older people in the community. METHODS: 53 practices in the MRC general practice research framework. Data were obtained from 14 600 participants aged 75 years and older. Prevalence of visual impairment overall (binocular visual acuity <6/18) which was categorised separately into low vision (binocular visual acuity <6/18-3/60) or blindness (binocular visual acuity of <3/60). The prevalence of binocular acuity <6/12 was presented for comparison with other studies. Visual acuity was measured using Glasgow acuity charts; glasses, if worn, were not removed. RESULTS: Visual acuity was available for 14 600 people out of 21 241 invited (69%). Among people with visual acuity data, 12.4% overall (1803) were visually impaired (95% confidence intervals 10.8% to 13.9%); 1501 (10.3%) were categorised as having low vision (8.7% to 11.8%), and 302 (2.1%) were blind (1.8% to 2.4%). At ages 75-79, 6.2% of the cohort were visually impaired (5.1% to 7.3%) with 36.9% at age 90+ (32.5% to 41.3%). At ages 75-79, 0.6% (0.4% to 0.8%) of the study population were blind, with 6.9% (4.8% to 9.0%) at age 90+. In multivariate regression, controlling for age, women had significant excess risk of visual impairment (odds ratio 1.43, 95% confidence interval 1.29 to 1.58). Overall, 19.9% of study participants had a binocular acuity of less than 6/12 (17.8% to 22.0%). CONCLUSION: The results from this large study show that visual impairment is common in the older population and that this risk increases rapidly with advancing age, especially for women. A relatively conservative measure of visual impairment was used. If visual impairment had been defined as visual acuity of <6/12 (American definition of visual impairment), the age specific prevalence estimates would have increased by 60%.

Randomised comparison of three methods of administering a screening questionnaire to elderly people: findings from the MRC trial of the assessment and management of older people in the community.

OBJECTIVE: To compare three different methods of administering a brief screening questionnaire to elderly people: post, interview by lay interviewer, and interview by nurse. DESIGN: Randomised comparison of methods within a cluster randomised trial. SETTING: 106 general practices in the United Kingdom. PARTICIPANTS: 32 990 people aged 75 years or over registered with participating practices. MAIN OUTCOME MEASURES: Response rates, proportion of missing values, prevalence of self reported morbidity, and sensitivity and specificity of self reported measures by method of administration of questionnaire for four domains. RESULTS: The response rate was higher for the postal questionnaire than for the two interview methods combined (83.5% v 74.9%; difference 8.5%, 95% confidence interval 4.4% to 12.7%, P<0.001). The proportion of missing or invalid responses was low overall (mean 2.1%) but was greater for the postal method than for the interview methods combined (4.1% v 0.9%; difference 3.2%, 2.7% to 3.6%, P<0.001). With a few exceptions, levels of self reported morbidity were lower in the interview groups, particularly for interviews by nurses. The sensitivity of the self reported measures was lower in the nurse interview group for three out of four domains, but 95% confidence intervals for the estimates overlapped. Specificity of the self reported measures varied little by method of administration. CONCLUSIONS: Postal questionnaires were associated with higher response rates but also higher proportions of missing values than were interview methods. Lower estimates of self reported morbidity were obtained with the nurse interview method and to a lesser extent with the lay interview method than with postal questionnaires.

Impact of prematurity on admissions to the neonatal nursery of a rural South African district hospital.

The objectives of this study were to determine causes of admission to a district hospital neonatal nursery; to describe outcomes; and to determine risk factors for these outcomes. The study was based at the neonatal nursery of Hlabisa hospital, KwaZulu/Natal; 149 consecutive admissions to the nursery between May and November 1995 were audited. The main outcome measures were diagnosis, gestational age, birthweight, critical event during admission (sepsis, severe vomiting, diarrhoea, jaundice, fits, apnoea), and outcome (discharged alive, death, discharged with deficit). Most admitted neonates (73; 54 per cent) were aged less than 37 weeks at birth, and 123 (84 per cent) weighed less than 2.5 kg. Prematurity and low birthweight accounted for 114 (81 per cent) admissions. In all, 58 (39 per cent) neonates experienced a total of 72 critical events, the most frequent being sepsis (39; 54 per cent). Although most (114; 77 per cent) were discharged well, 20 (15 per cent) died and three (3 per cent) were discharged with a significant deficit. Sepsis and apnoea were most frequent among the lightest and most immature babies, while fits were more frequent among heavier, mature babies. In a multivariate model, experiencing any critical event (odds ratio [OR] 15.6; 95 per cent CI 3.0-82.6, p = 0.001) was the only significant independent risk factor for mortality, although birthweight (p = 0.068) and gestational age (26-30 vs. > or = 37 weeks; OR 5.6, 95 per cent confidence internal [CI] 0.3-95.7, p = 0.23), further contributed to risk of death. We conclude that a substantial proportion (around 27 per cent) of district perinatal mortality occurs in the neonatal nursery. Several simple and effective interventions exist to minimize neonatal loss in district hospitals in South Africa.

Paediatric admissions to a rural South African hospital: value of hospital data in helping to define intervention priorities and allocate district resources.

OBJECTIVE: To audit paediatric medical admissions to a rural district hospital in order to help define intervention priorities and allocate district resources. DESIGN: Prospective audit of consecutive admissions to the paediatric medical service of Hlabisa Hospital, KwaZulu-Natal, between March 1995 and February 1996. MAIN OUTCOME MEASURES: Number of admissions, month of admission, age, sex, diagnosis, nutritional status, HIV status, outcome and length of stay. RESULTS: Of 1,364 children admitted, 995 (73%) were aged under 24 months and 584 (43%) were either underweight for age or severely malnourished. Acute respiratory tract infection (384, 28%), acute diarrhoea (200, 15%), dysentery (168, 12%) and severe malnutrition (149, 11%) were the major causes for admission and were responsible for most deaths (113, 75%). The overall case fatality rate was 11% and most (90, 60%) died within 48 hours of admission. Forty-five per cent of the 332 children tested were HIV-positive. CONCLUSION: Most severe morbidity and mortality result from four common conditions, reflecting poor socioeconomic conditions in the area. Opportunities for clincial intervention to reduce their impact include identification of 'at risk' children, focusing care early in admissions, use of standardised protocols of care, and integrated management of the sick child.

Paediatric burns in a rural South African district hospital.

OBJECTIVES: To describe the epidemiology, clinical features, management and outcome of children with burns admitted to a rural district hospital. DESIGN: A retrospective analysis of the case notes of consecutive cases of paediatric burns. SETTING: Hlabisa Hospital, KwaZulu-Natal-a 450-bed rural district hospital serving approximately 200,000 people. SUBJECTS: All cases of paediatric burns (age < 12 years) admitted to Hlabisa Hospital in 1994. MAIN OUTCOME MEASURES: Number of admissions, month of admission, age, sex, time to presentation, site of burn, complications, number of surgical procedures, adherence to management protocol and outcome. RESULTS: One hundred and forty-nine children presented to the outpatient department in 1994 and 88 (59%) were admitted. The median age of those admitted was 36 months with 66 (75%) aged less than 5 years; 42 (48%) were boys. Thirty-nine children (44%) were admitted during the four winter months of May to August. The average interval from the time of the burn to presentation at hospital was 42 hours (range 1-120). Sixty-eight burns (77%) were due to hot fluid or food burning the legs, trunk or arms. There was a high level of morbidity. Nineteen (22%) children developed wound infections, 5 (6%) developed contractures and 20 (23%) required a total of 32 surgical procedures. There was 1 death. Burns were responsible for more paediatric patient days spent in hospital than any condition other than malnutrition, and a longer length of stay was associated with delay in presentation. Children presenting within 24 hours of the burn had a mean length of stay of 12.8 days, compared with 25.2 days (P = 0.03) for children presenting 24 hours or more after the burn. Twenty of the 22 children who stayed for longer than 3 weeks or who required transfer were judged to have been managed inadequately in at least one respect compared with 3 of 48 who were discharged within 2 weeks or not transferred (P < 0.001). CONCLUSION: This study shows that paediatric burns are an important cause of morbidity and contribute significantly to inpatient stay in this rural setting. The lengthy delay from time of burn to presentation at hospital is of serious concern and our results show that this delay is associated with increased hospital stay. As most burns were due to spillage of hot fluids or food there seems to be significant potential for preventive interventions. Community-based studies would help to estimate the true incidence of burns and would contribute to an understanding of the reasons for delay in presentation. The information gathered is being used to inform the development of a burns prevention programme.

Epidemic shigella dysentery in children in northern KwaZulu-Natal.

OBJECTIVES: To describe the epidemiology, clinical features, management and outcome of children with Shigella dysenteriae type I infection admitted to a rural district hospital. DESIGN: Prospective cohort study. SETTING: Hlabisa Hospital, KwaZulu-Natal. SUBJECTS: Children aged under 12 years admitted with a history of bloody mucoid diarrhoea between February and December 1995. MAIN OUTCOME MEASURES: Number of admissions, age, sex, clinical features, complications and outcome. RESULTS: Between February and December 1995, 158 cases of bloody diarrhoea were admitted, compared with 6 the previous year. Shigella dysenteriae type I, resistant to ampicillin, tetracycline, chloramphenicol, trimethoprim and sulphamethoxazole, but susceptible to nalidixic acid and ceftriaxone, was isolated. The mean age of patients was 30 months. Patients typically presented with frequent bloody mucoid diarrhoea, fever, abdominal pain and dehydration. One hundred and sixteen (73%) recovered, 17 (11%) were transferred for tertiary care, 4 (3%) absconded, and 21 died (case fatality rate = 13%; 95% confidence interval (CI) 8-20). Seventeen (11%) developed haemolytic uraemic syndrome and 4 (3%) a protein-losing enteropathy. The malnourished (adjusted relative risk (RR) 3.3, 95% CI 1.6-7.1; P < 0.01) and those aged less than 2 years (adjusted RR 4.2; 95% CI 1.0-17.2; P = 0.05) were more likely to die. Dysentery deaths accounted for 19% of total paediatric hospital mortality. CONCLUSION: A serious epidemic of shigella dysentery has established itself and is having a significant impact in this area. The virulence and drug resistance of the organism has resulted in high levels of morbidity and mortality. Broad public health measures will be needed to contain the epidemic. Further community-based surveillance is urgently needed, as is research to determine modes and risk factors for transmission.

Detection of microemboli by transcranial Doppler ultrasound.

Doppler ultrasound detection of abnormally high-pitched signals within the arterial waveform offers a new method for diagnosis, and potentially for prediction, of embolic complications in at-risk patients. The nature of Doppler "microembolic" signals is of particular interest in patients with prosthetic heart valves, where a high prevalence of these signals is observed. Monitoring the middle cerebral artery with 2-MHz transcranial Doppler ultrasound (TC-2000, Nicolet Biomedical; Warwick, UK), we looked for microemboli signals in 150 patients (95 women and 55 men), and found 1 or more signals during a 30-min recording in 89% of 70 patients with Bjork-Shiley valves (principally monostrut), 54% of 50 patients with Medtronic-Hall valves, and 50% of 30 patients with Carpentier-Edwards valves (p < 0.001, chi 2). In the patients with Bjork-Shiley valves, the mean number of signals per hour was 59 (range, 42-86; 95% confidence interval), which was significantly higher than the mean in patients with Medtronic-Hall and Carpentier-Edwards valves (1.5[range, 0.5-2.5] and 1 [range, 0-5.3], respectively; both p < 0.04, multiple comparisons. Bonferroni correction). In the patients undergoing serial pre- and postoperative studies, the causative role of the valve implant was emphasized. There was no correlation between the number of emboli signals and a prior history of neurologic deficit, cardiac rhythm, previous cardiac surgery, or the intensity of oral anticoagulation, in patients with prosthetic heart valves. In Bjork-Shiley patients, dual (mitral and aortic) valves were associated with more signals than were single valves. In Medtronic-Hall patients, the signal count was greater for valves in the aortic position than it was for valves in the mitral position. Comparative studies of Doppler emboli signals in other clinical settings suggest a difference in composition or size of the underlying maternal between prosthetic valve patients and patients with carotid stenosis. These studies also suggest that the signals are of gaseous origin in valve patients. The clinical significance of continuing microembolism remains to be determined.

Socioeconomic variation in admission for diseases of female genital system and breast in a national cohort aged 15-43.

OBJECTIVE: To investigate socioeconomic variation among young women in the risk of hospital admission for diseases (including neoplasms) of the female genital system and breast and for the common surgical procedures of dilatation and curettage and hysterectomy. DESIGN: Large nationally representative cohort study with individual records of confirmed admissions to NHS and private hospitals since birth and data on occupational and educational experience. SETTING: England, Scotland, and Wales. PATIENTS: General population sample of 1628 women, 1549 of whom had a complete admissions record for the ages of 15-43 years. MAIN OUTCOME MEASURES: The percentage of women admitted for neoplasms or other diseases of the female genital system and breast or who had dilatation and curettage or hysterectomy between the ages of 15 and 43 years. RESULTS: By the age of 43, 35% of women had been admitted, 17% had undergone dilatation and curettage at least once, and 10% had had a hysterectomy. There were significant inverse educational gradients, the risk of admission increasing more than twofold between the most and least educated women. The differential risk was most striking for disorders of menstruation, in which only 1% of those with the highest educational qualifications and 19% of those with minimal qualifications had been admitted to hospital. There was a significant educational gradient in the hysterectomy rate (from 1% to 15%) and a twofold difference in the risk of dilatation and curettage. There were also significant gradients in risk of admission and of hysterectomy according to partner's social class. CONCLUSIONS: Socioeconomic variations in the risk of dilatation and curettage and of hysterectomy were large. Lessening the socioeconomic gradient in risks of admissions and surgery for diseases of the female genital system and breast, particularly for menstrual disorders, could have important resource implications.

The changing pattern of in-patient care.

BACKGROUND: A nationally representative longitudinal study presented the opportunity to describe National Health Service (NHS) and private in-patient care used over seven years by a population of young adults in relation to known risk factors for admission and for future health. METHODS: Information on each hospital admission between ages 36 and 43 years, comprising length of admission and whether under NHS or private care, was collected from 1625 men and 1623 women, the population of the 1946 birth cohort study. Obstetric care was excluded from most analyses. RESULTS: From this population, 22 per cent of men and 39 per cent of women were admitted to hospital at least once during the seven-year period, for a total of 11,276 days, a mean of 3.5 days (SD 13.1) for each person in the study, and 11.6 (SD 21.9) days for those admitted. The proportion of admissions not under NHS care rose from 14 per cent of all admissions in 1982 to 23 per cent in 1989. Employers contributed to health insurance for 25 per cent of employed men and 7 per cent of employed women. Risk of admission was greater, and admissions were longer, in those least educated and from poorest circumstances; men with largest waist-hip ratios were admitted for longer than others. Private admissions were proportionately greater in nonmanual classes and among those from favourable social and educational backgrounds, that is, those known to be at least risk of serious and chronic illness. CONCLUSION: Heaviest users of in-patient care were those most likely to be at greatest health risk, who were least likely to have private health insurance. The rising mid-life uptake of private health insurance through employers (25 per cent of employed men by age 43 years) may foreshadow a future problem in a return to NHS care on retirement in this population, which represents the beginning of the future population bulge in the elderly.

Subclinical embolism in patients undergoing cardiac valve implantation and coronary artery bypass surgery.

Patients undergoing prosthetic valve insertion and coronary artery bypass surgery were examined with transcranial Doppler ultrasound, recently shown to be capable of detecting continuing subclinical emboli in patients with embolic sources. In 30 patients examined at least 1 year after valve surgery, and in whom warfarinisation was stable within defined limits, 20 of 24 patients (83%) with mechanical valves and 3 of 6 patients (50%) with porcine valves had embolic signals. In a serial preoperative and postoperative study in a further 30 patients, of whom 29 had native or bioprosthetic valves, only the one patient with a previous mechanical mitral valve prosthesis had embolic signals preoperatively. The incidence of embolic signals increased to 9 (30%) on the first postoperative day, and 20 (67%) on day 5. In a similar serial study in 25 patients undergoing coronary bypass surgery, 8 (32%) had preoperative embolic signals, which were explicable by cardiac and/or carotid disease in 6 cases. The embolus signal incidence and count did not increase postoperatively in this group. No embolic signals were found in 15 volunteer controls. The results indicate that prosthetic valves cause continuing microembolisation, detectable by transcranial Doppler; coronary artery bypass cases may have incidental embolic signals which are unaffected by cardiac surgery. This new application of Doppler ultrasound may improve the clinical assessment of embolic risk of new prosthetic valve types and deserves further examination.