ASPIRE registry: assessing the Spectrum of Pulmonary hypertension Identified at a REferral centre.

Pulmonary hypertension (PH) is a heterogeneous condition. To date, no registry data exists reflecting the spectrum of disease across the five diagnostic groups encountered in a specialist referral centre. Data was retrieved for consecutive, treatment-naïve cases diagnosed between 2001 and 2010 using a catheter-based approach. 1,344 patients were enrolled, with a mean follow-up of 2.9 yrs. The 3-yr survival was 68% for pulmonary arterial hypertension (PAH), 73% for PH associated with left heart disease, 44% for PH associated with lung disease (PH-lung), 71% for chronic thromboembolic PH (CTEPH) and 59% for miscellaneous PH. Compared with PAH, survival was inferior in PH-lung and superior in CTEPH (p<0.05). Multivariate analysis demonstrated that diagnostic group independently predicted survival. Within PAH, Eisenmenger's survival was superior to idiopathic PAH, which was superior to PAH associated with systemic sclerosis (p<0.005). Within PH-lung, 3-yr survival in sleep disorders/alveolar hypoventilation (90%) was superior to PH-lung with chronic obstructive pulmonary disease (41%) and interstitial lung disease (16%) (p<0.05). In CTEPH, long-term survival was best in patients with surgically accessible disease undergoing pulmonary endarterectomy. In this large registry of consecutive, treatment-naïve patients identified at a specialist PH centre, outcomes and characteristics differed between and within PH groups. The current system of classification of PH has prognostic value even when adjusted for age and disease severity, emphasising the importance of systematic evaluation and precise classification.

Mercury emissions from coal combustion.

Mercury liberated during coal combustion can be either discharged as vapor in the flue as or retained in the furnace ash. About 90 percent (by weight) of the mercury released from a furnace fired with pulverized coal appears to be in the vapor phase, and 10 percent remains with the furnace residual ash. For a 700-megawatt unit, approximately 2.5 kilograms of mercury per day are released.

Challenges and successes of HIV voluntary counselling and testing programme in antenatal clinics in greater Kingston, Jamaica.

ISSUES: Voluntary counselling and testing (VCT) is a critical issue impacting HIV disease management from a national and global perspective. In Jamaica (population 2.6 million), 2% of women in antenatal clinics are HIV-positive and mother-to-child-transmission (MTCT) accounted for 7% of all reported cases in 2002. Notwithstanding this, VCT was ad hoc and not standardized. In 2003, a structured VCT programme was developed islandwide with over 300 VCT service providers and 16 qualified trainers. DESCRIPTION: We describe the challenges and successes of VCT provided by five trained research nurses in the Perinatal HIV/AIDS Programme in Kingston which services 19,000 pregnant women per year in three major maternity centres and their 42 feeder antenatal clinics. LESSONS LEARNED: The VCT model used was group education, opt-out individual testing, individual post-test counselling for seropositives and informing seronegatives of their negative status. Major challenges encountered included lack of quality control of the counselling process and lost opportunities for un-booked women who presented in labour However successes enjoyed included client assessment of risk behaviours with appropriate lifestyle changes, increased uptake of HIV testing and adherence to care for themselves and their infants, as well as reduction in stigma. RECOMMENDATIONS: VCT has proven to be an important intervention that enabled improvement in the awareness, prevention and control of HIV in Jamaican pregnant women. Nurses who are appropriately trained in VCT can play a pivotal role in successful provision of VCT services.

Evolving care of HIV-infected pregnant women in Jamaica--from nevirapine to HAART.

BACKGROUND: The Ministry of Health, Jamaica, is scaling-up programmes to improve the health of HIV-positive pregnant women according to the modified WHO recommended preventative mother to child transmission (pMTCT) regimens of therapy based upon the mother's clinical and immunological status. Highly-active antiretroviral drugs (HAART) can result in successful pMTCT to < 1%. We report the clinical and immunological characteristics of HIV/AIDS in an era of evolving treatment and care of HIV-infected pregnant Jamaican women. SUBJECTS AND METHOD: Clinical records were reviewed of patients registered in antenatal clinics in Greater Kingston and St. Catherine, Jamaica (annual birth cohort--20,000) between September 2002 and August 2006. Disease status was determined using the Centers for Disease Control and Prevention (CDC) classification system for adult HIV/AIDS. Demographic, clinical and laboratory data were documented and analyzed. RESULTS: During the four-year period, 571 HIV-infected women were enrolled; 62% from Victoria Jubilee Hospital, 25% from Spanish Town Hospital and 13% from the University Hospital of the West Indies. Mean age was 27-29 (range 15-41) years, median parity was 2 (range 0-9) and 68-70% were unemployed. Ninety-five per cent had live births. CDC categories of illnesses were A--mild disease in 82% (n=473), B--moderate disease in 4.4% (n=24) and C--severe disease in 1.4% (n=8) while 12% (n=66) had insufficient data. During the first three years, CD4+ cell counts were evaluated in only 2.5% (10 of 406) of patients with median of 344 cells/microL, compared to CD4 evaluation in 50% (83 of 165 women) in the last year with median of573 cells/uL. Antiretroviral (ARV) medications primarily for pMTCT were given to 89% (n=506) ofwomen. Of these, uptake of HAART increased during years 1-3 from 2-3% to 62% in year four Within two years post-partum, 24 women died, 92% (n=22)from the direct complications of HIV/AIDS. CONCLUSION: A comprehensive system of care of HIV in the peripartum period has been developed in Jamaica. Detailed medical evaluation during pregnancy is performed with modern guidelines and increasing laboratory availability of CD4+ cell counts and viral loads. We believe declining HIV infection rates in Jamaican infants and healthier mothers are a direct consequence of increased testing in pregnancy with early diagnosis and initiation of HAART-based pMTCT regimens in pregnant women.

Paediatric and perinatal HIV/AIDS in Jamaica an international leadership initiative, 2002-2007.

BACKGROUND: Paediatric and Perinatal HIV/AIDS remain significant health challenges in the Caribbean where the HIV seroprevalence is second only to Sub-Saharan Africa. METHOD: We describe a collaborative approach to the prevention, treatment and care ofHIVin pregnant women, infants and children in Jamaica. A team of academic and government healthcare personnel collaborated to address the paediatric and perinatal HIV epidemic in Greater Kingston as a model for Jamaica (population 2.6 million, HIV seroprevalence 1.5%). A five-point plan was utilized and included leadership and training, preventing mother-to-child transmission (pMTCT), treatment and care of women, infants and children, outcomes-based research and local, regional and international outreach. RESULTS: A core group of paediatric/perinatal HIV professionals were trained, including paediatricians, obstetricians, public health practitioners, nurses, microbiologists, data managers, information technology personnel and students to serve Greater Kingston (birth cohort 20,000). During September 2002 to August 2007, over 69 793 pregnant women presented for antenatal care. During these five years, significant improvements occurred in uptake of voluntary counselling (40% to 91%) and HIV-testing (53% to 102%). Eight hundred and eighty-three women tested HIV-positive with seroprevalence rates of 1-2% each year The use of modified short course zidovudine or nevirapine in the first three years significantly reduced mother-to-child transmission (MTCT) of HIV from 29% to 6% (RR 0.27; 95%0 CI--0.10, 0.68). During 2005 to 2007 using maternal highly active antiretroviral therapy (HAART) with zidovudine and lamivudine with either nevirapine, nelfinavir or lopinavir/ritonavir and infant zidovudine and nevirapine, MTCT was further reduced to an estimated 1.6% in Greater Kingston and 4.75% islandwide. In five years, we evaluated 1570 children in four-weekly paediatric infectious diseases clinics in Kingston, St Andrew and St Catherine and in six rural outreach sites throughout Jamaica; 24% (377) had HIV/AIDS and 76% (1193) were HIV-exposed. Among the infected children, 79% (299 of 377) initiated HAART resulting in reduced HIV-attributable childhood morbidity and mortality islandwide. An outcomes-based research programme was successfully implemented. CONCLUSION: Working collaboratively, our mission of pMTCT of HIV and improving the quality of life for families living and affected by HIV/AIDS in Jamaica is being achieved.

Preoperative shuttle walking testing and outcome after oesophagogastrectomy.

BACKGROUND: Objective assessment of cardiorespiratory reserve has been recommended before major surgery to identify patients with impaired oxygen delivery who may be at increased operative risk. Access to formal cardiopulmonary exercise (CPX) testing is limited outside larger centres. Following a previous audit of morbidity and mortality after oesophagectomy, we decided to add a simpler form of exercise test to our preoperative screen and review the outcomes. METHODS: Fifty-one patients who had surgical resection of an oesophageal cancer in our unit between April 2002 and April 2005 carried out an incremental shuttle walk exercise test before operation. Thirty-day outcome data were collected for each patient. RESULTS: Overall mortality in the group was 10%. No patient who walked 350 m or more died within 30 days. Five of the eight patients who could not achieve this distance died and two others remained in the critical care unit at 30 days. CONCLUSION: Preoperative shuttle walk testing using a standard protocol appears to be a sensitive indicator of operative risk in this group of patients. The apparent threshold value of 350 m is consistent with previously reported measures of functional capacity obtained using formal CPX testing.

Quantitation of isoprenaline-induced changes in the ventricular myocardium.

Small doses of isoprenaline sulphate given intermittently produce a characteristic cardiopathy consisting of subendocardial scarring and myocardial hypertrophy. A morphometric technique was successfully applied to the quantitation of these changes. This technique improves the use of the isoprenaline model for the study of cardiac necrosis as statistical analysis can be applied and objective comparisons made. No hypertrophy was seen in the absence of myocardial necrosis which suggests that it is at least in part compensatory.

Human factors in aircraft incidents: results of a 7-year study.

Human error causes or contributes to considerably over half of all aviation mishaps. This report describes a 7-year study of aircraft incident data conducted in an attempt to further our understanding of the phenomenon of human error. The study of incidents as a surrogate for aircraft accidents is relevant only if incidents constitute a population or universe of which accidents are a subset. This assumption has been examined in a study of over 35,000 reports of aviation incidents collected from 1976-83 by the NASA Aviation Safety Reporting System. One-third of the reports involve conflicts among aircraft. The most common single-aircraft anomalies in flight involve altitude or track deviations. The most common controller errors involve failure to coordinate traffic with other elements of the air traffic control system. Analysis of these reports indicates that both human and system factors contributing to human errors can be identified. Many other incidents involve shortcomings specifically of the human, rather than of the system. Failures of control are rare in this series, but failures of decision-making and cockpit resource management are frequent. Boredom, complacency and ennui appear to underlie some failures, while very high workloads are associated with others. These data indicate that at least several categories of aircraft accidents involving operational and human factors are, in fact, subsets of populations of incidents containing the same elements. The environment in which an incident occurs is extremely important in determining its outcome. It is concluded that aviation incident reports are a necessary and important instrument in safety surveillance.

Comparisons of pilot performance in simulated and actual flight.

Five highly experienced professional pilots performed instrument landing system approaches under simulated instrument flight conditions in a Cessna 172 airplane and in a Link-Singer GAT-1 simulator while under the influence of orally administered secobarbital (0, 100, and 200 mg). Tracking performance in two axes and airspeed control were evaluated continuously during each approach. The data from the airplane and simulator were compared. Error and RMS variability were about half as large in the simulator as in the airplane. The observed data were more strongly associated with the drug level in the simulator than in the airplane. Further, the drug-related effects were more consistent in the simulator. Improvement in performance suggestive of learning effects were seen in the simulator, but not in actual flight. It is concluded that the GAT-1 simulator is a useful and sensitive device for studies of the effects of mild stress on pilot performance, but extrapolation of simulator data to the flight environment must be approached with considerable caution.

Effects of alcohol on pilot performance in simulated flight.

Ethyl alcohol's known ability to produce reliable decrements in pilot performance was used in a study designed to evaluate objective methods for assessing pilot performance. Four air carrier pilot volunteers were studied during eight simulated flights between San Francisco and Los Angeles in a Boeing 727-232 simulator. Two flights were conducted at each of four target blood alcohol levels, 0, 0.025, 0.050, and 0.075%. Each flight lasted about 1 h. Flights were conducted with full crews in a full simulated ATC environment. Data from direct observations and videotapes were used to examine discrete errors committed by the subjects. Total errors increased linearly and significantly with increasing blood alcohol. Planning and performance errors, procedural errors and failures of vigilance each increased significantly in one or more pilots and in the group as a whole. Failures of crew coordination were not associated with blood alcohol level. Serious errors increased significantly even at the lowest alcohol level studied, 0.025% (25 mg/dl), compared with control values.

Occupational siderosis and welders' lung: a review.

Siderosis of the lung is generally assumed to be a benign condition, not associated with respiratory symptoms. A review of the literature suggests that this assumption may be incorrect, and that siderosis may lead both to symptomatic and functional changes. It is known that iron ore miners have a raised lung cancer mortality, but this has been attributed to smoking, or exposure to tars or radon. Mortality studies among iron workers (haematite miners, welders, iron foundry and steel workers) show, however, that an association exists between working with iron and death, both from lung cancer and other respiratory causes. A number of surveys have examined respiratory function and symptoms among welders. These indicate that welding is associated with obstructive airways disease. The effect of the welding fume on respiratory function and symptoms can be as great as that of smoking. Iron has also been shown to cause fibrosis in some cases. Small functional changes of restriction and loss of lung compliance are often due to iron alone. The fibrosis may be enhanced by associated silica exposure. A number of constituents of welding fume could, along with iron, contribute to pulmonary changes. The presence of siderosis may act as a good marker of exposure to fume and any resulting disability.

Dynamics and clinical effects of nonferrous metals in the human body.

Pollution from toxic metal fumes and dusts occurs in many industrial situations. Exposed workers may experience occupational diseases directly related to poisoning from metallic elements. Studies have shown that the major route of absorption of metals is by inhalation. Once absorbed, distribution to various tissues and excretion from the body differ between metals. Multiphasic retention times have been described for many metals with a proportion of the body burden being eliminated very slowly. Biological half-lives range across many years. Whilst blood or urine levels of metals may reflect current exposure, once exposure ceases these levels may not be good indicators of remaining body burden. Acute and chronic health effects occur after exposure. A wide range of chronic disease including many respiratory diseases (emphysema, lung cancer, chronic obstructive pulmonary disease, fibrosis and asthma), together with neurological, haematological, hepatotoxic and nephrotoxic effects, has been reported.

Asbestos exposure, lung cancer and asbestosis.

The relationship between asbestos exposure, lung cancer and asbestosis is reviewed. Studies have demonstrated the risk of lung cancer to be raised in asbestos-exposed workers whether asbestosis is present or not. Although increasing exposure increases the risk of disease, variability in estimation of fibre levels and in subject susceptibility should be borne in mind. Consensus opinion recommends that attribution of lung cancer to asbestos exposure should be based on clinical and occupational histories. The risk of lung cancer in those who both smoke and are exposed to asbestos is increased in a multiplicative way, putting subjects at very great risk.

Damp housing and asthma.

An allergic disposition has long been recognized as a risk factor for asthma. However, it has been suggested that, irrespective of genetic factors, exposure to environmental agents is of major importance in the development of asthma. In industrialized countries, people spend most of their time indoors and so environmental conditions inside the home may play an important role in asthma development. A review of studies examining the relationship between housing conditions and health in general or, more specifically, the relationship between respiratory symptoms/asthma and damp housing and mould has been carried out. These studies have shown that damp housing conditions are associated with increased prevalence of respiratory symptoms and asthma. The severity of asthma increases with an increasing quantity of dampness and mould in the home. It is suggested that damp conditions may, by a number of mechanisms, increase the allergenic burden so resulting in the development of asthma.

Nursing interventions in the Kingston Paediatric and Perinatal HIV/AIDS Programme in Jamaica.

BACKGROUND: Nursing care has been the "grass roots" of healthcare management even before nursing became a profession. Literature on the nursing experience with HIV is minimal and so it is challenging to comment on, or to compare experiences. PURPOSE: This paper highlights the nursing interventions as a key feature in the ongoing development and success of a prevention of mother-to-child HIV transmission (pMTCT) programme in a resource-limited setting. METHOD: In the Kingston Paediatric and Perinatal HIV/AIDS Programme, the nurses and midwives were carefully selected and then trained in the management of preventing mother-to-child transmission (pMTCT) of HIV/AIDS, voluntary counselling and testing and the identification and nursing management of paediatric and perinatal HIV/AIDS. The sites of the programme included three large maternity centres and four paediatric centres, with several feeder clinics for pregnant women. A nurse coordinator supervised the interventions at each site. A multidisciplinary team followed protocol-driven management for the care of pregnant HIV-positive women and children. There was strong collaboration with the Jamaican government and other agencies. RESULTS: The nursing interventions served to: sensitize and encourage other healthcare workers in the care of persons living with HIV/AIDS; sensitize persons in the community about the disease; improve the comfort level of women and families with accessing healthcare; enable prospective data collection for programme assessment and research purposes and to enhance multidisciplinary collaboration to widen the scope of patient care and prevent duplication of healthcare services. CONCLUSION: Nursing intervention is a vital part of a pMTCT HIV programme; however, ongoing education and training of the entire healthcare team needs to be continued in order to strengthen the programme. It is hoped that much of what is done in the Kingston Paediatric and Perinatal HIV/AIDS Programme will become integrated in the nursing management of maternal and child health nationally.

The prediction of in-flight hypoxaemia using non-linear equations.

BACKGROUND: Respiratory disease may cause profound hypoxaemia during flight. Previously derived linear equations poorly predict the need for supplemental oxygen during air travel. The current gold standard assessment is the hypoxic challenge test (HCT). Recent guidelines recommend HCT is performed for those patients with SpO2 < 95% at sea level. The HCT protocol is a costly and time consuming investigation. METHODS: Retrospective clinical and HCT data from 138 patients were applied to previous linear equations to assess predictive value. Novel non-linear predictive models (NLMs) were constructed from these data. The linear equations and the NLMs were then applied prospectively to 44 patients undergoing HCT. RESULTS: Overall, 39% of historic patients had a positive HCT (PaO2N2 <50 mmHg). Existing linear equations varied in sensitivity (52-87%) and specificity (40-74%) at predicting positive HCT results. Seven novel NLMs (NLM1 to NLM7) were developed from the historic dataset. All NLMs predicted PaO2N2 more accurately than the original linear equations when tested prospectively. The best fit was observed using NLM2 which uses PaO2RA and PaCO2RA as input terms. The NLMs are applicable to a broad range of conditions. CONCLUSIONS: The novel NLMs represent a low cost option for the prediction of significant hypoxia during flight and perform better than SpO2 in identifying those patients who require more formal assessment with HCT.