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.

Outcomes of patients presenting to a dedicated rapid access lung cancer clinic.

We examined the outcomes of the first 500 patients referred to a dedicated Rapid Access Lung Cancer Clinic. A total of 206 patients (41.2%) were diagnosed with a thoracic malignancy; 179 had primary lung cancer and 27 had secondary or other thoracic cancers. Pulmonary nodules requiring ongoing surveillance were found in a further 79 patients (15.8%). Of those patients found to have primary lung cancer, 24 (13.4%) had Small Cell and 145 (81%) had Non Small Cell Lung Cancer. In patients with Non small cell tumours, 26 (21.1%) were stage 1, 14 (11.4%) stage II, 37 (30.1%) stage III and 46 (37.4%) stage IV at diagnosis. For the 129 patients (72%) in whom the thoracic MDT recommended active treatment, primary therapy was surgical resection in 44 (24.6%), combined chemoradiation in 31 patients (17.3%), chemotherapy alone in 39 (21.8%) and radiation in 15 (8.4%).

Responses to a questionnaire on networking between OIE Reference Laboratories and OIE Collaborating Centres.

Two separate questionnaires were distributed to 20 OIE Collaborating Centres and 160 OIE Reference Laboratories to assess the current status of networking and collaboration among OIE Reference Laboratories and between OIE Reference Laboratories and OIE Collaborating Centres. The questionnaire for the OIE Reference Laboratories contained 7 sections with questions on networking between laboratories, reporting of information, biosecurity quality control, and financing. Emphasis was placed in obtaining information on inter-laboratory relationships and exchange of expertise, training needs and sharing of data and information. The questionnaire for the OIE Collaborating Centres contained six sections with the emphasis on aspects related to awareness of services that can be provided, expertise that could be made available, sharing of information and the relationship with the national veterinary services of the countries concerned. The responses to the questionnaires were collated, categorised and statistically evaluated to allow for tentative inferences on the data provided. Valuable information emanated from the data identifying the current status of networking and indicating possible shortcomings that could be addressed to improve networking.

Small cell lung cancer treated in southeast Wales.

AIMS: In small cell lung cancer (SCLC), consolidation thoracic irradiation (CTI) increases 3-year absolute survival by 5.4% in patients with limited disease and a complete response to chemotherapy. Early concurrent thoracic radiotherapy has been shown to improve local control and prolong survival compared with CTI in some trials. The standard management of patients with SCLC in southeast Wales is CTI in individuals with limited disease and a complete response to chemotherapy. A review of patients with SCLC was carried out to establish whether survival locally is comparable with that reported in published studies, and if patients given CTI have survival comparable with that reported in studies where early concurrent thoracic radiotherapy was used. MATERIALS AND METHODS: Between January 2000 and December 2002, 303 patients were registered with SCLC in southeast Wales. One hundred and fifteen (47%) patients had limited disease and 60/115 (52%) received CTI. RESULTS: Patients with limited disease receiving CTI had a median survival of 17.7 months (95% confidence interval: 15-27.9 months). The 2- and 5-year survivals were 38 and 13%, respectively. CONCLUSIONS: These results compare favourably with previously published studies on SCLC. There are no plans to change our current treatment policy for SCLC in southeast Wales.

Making do not attempt resuscitation decisions: do doctors follow the guidelines?

When do not attempt resuscitation orders are contemplated, guidelines exist to outline standards for planning patient care and decision making. These guidelines may not always be fully followed as ethical issues arise which may prevent doctors from doing so.

Global detection and identification of Campylobacter fetus subsp. venerealis.

Bovine genital campylobacteriosis caused by Campylobacter fetus subsp. venerealis (Cfv) is a genital infection that threatens the cattle industry. Detection and identification of Cfv are key factors in control programmes. Trade regulations should be based on scientifically and internationally accepted methods of detection and identification of Cfv. Such methods are described in the World Organisation for Animal Health (OIE) Manual of Diagnostic Tests and Vaccines for Terrestrial Animals. A study was conducted to determine which methods are in use in OIE Member Countries and to get an overview of new or improved tests. A questionnaire was sent to OIE Member Countries, and 26 out of 166 were returned. Globally, a diversity of methods for the detection and identification of Cfv are in use. The authors conclude that there is a lack of harmonisation that may have consequences for the description of the health status of countries and may lead to disputes with respect to trade regulations.

Gonococcal endocarditis: a rare complication of a common disease.

This report describes a case of gonococcal endocarditis in a 28 year old male patient with no history of previous valvular heart disease. More cases of gonococcal endocarditis (a rare complication of gonorrhoea) may occur with the increase in the incidence of gonorrhoea and the increase in resistance to ciprofloxacin, which is currently used as the first line agent for the treatment of gonorrhoea in 75% of genitourinary medicine clinics.

Glucocorticoid treatment reduces exhaled nitric oxide in cystic fibrosis patients.

In cystic fibrosis (CF), low concentrations of exhaled nitric oxide (NO) and reduced expression of inducible nitric oxide synthase (iNOS) in airway epithelium have been reported. However, abundant iNOS expression has been found in the subepithelial tissues and elevated concentrations of NO metabolites in breath condensate and sputum. These conflicting results may be explained by increased scavenging of NO by superoxide radicals, resulting in rapid conversion to peroxynitrite, so that only a small proportion of the NO produced in the lung tissue reaches the airway lumen. If iNOS were active in the CF lung, exhaled NO would be further reduced by glucocorticoid treatment. CF patients (n = 13) were recruited to a double-blind, placebo-controlled study with crossover. Treatment comprised prednisolone or placebo for 5 days with a 9 day washout. After each treatment, exhaled NO was measured, spirometry performed and blood collected for measurement of serum nitrogen dioxide/nitrous oxide (NO2/NO3). Ten patients (8 male) completed the study. Following prednisolone treatment (mean +/- SD) exhaled NO concentration (3.1 +/- 1.6 parts per billion (ppb)) was significantly reduced versus placebo treatment (4.9 +/- 4.2 ppb; p<0.05, Wilcoxon signed-rank test). Spirometric indices and serum NO2/NO3 concentration were unchanged. These findings support the hypothesis that glucocorticoids suppress nitric oxide production in cystic fibrosis airways by reducing inducible nitric oxide synthase expression or by inhibiting recruitment of neutrophils, cells which express inducible nitric oxide synthase.

Total sputum nitrate plus nitrite is raised during acute pulmonary infection in cystic fibrosis.

Nitric oxide (NO) can be detected in exhaled gas in human subjects. It is produced by nitric oxide synthase (NOS) and is rapidly metabolized to nitrite and nitrate (NO2/NO3). Exhaled NO is reported to be elevated in patients with asthma, bronchiectasis, or upper respiratory tract infection. Recent reports have shown no increase of exhaled NO in stable cystic fibrosis (CF). We hypothesized that NOS activity is increased in patients with acute pulmonary exacerbation of CF. We therefore measured exhaled NO and sputum NO2/NO3 in three subject categories: patients with acute pulmonary exacerbation of CF, patients with stable CF, and healthy control subjects. Mean +/- SD exhaled NO was significantly higher in control subjects (8.8 +/- 4.9 ppb) than in both acute (3.8 +/- 3.9 ppb) and stable (5.0 +/- 2.5 ppb) patients. Sputum NO2/NO3 was significantly higher in acute patients (774 +/- 307 micromol/L) when compared with both stable patients (387 +/- 203 micromol/L) and control (421 +/- 261 micromol/L) subjects. Sputum NO2/NO3 did not return to normal in a subgroup of patients assessed after 2 wk of intensive antibiotic and glucocorticoid treatment. These results confirm that exhaled NO is not a useful measure of airway inflammation in CF. Elevated levels of sputum NO2/NO3 suggest that NOS is activated during acute pulmonary exacerbations of CF.

Neutrophil adhesion molecule surface expression and responsiveness in cystic fibrosis.

The neutrophil-dominated inflammation of the lung in cystic fibrosis (CF) has traditionally been seen as a physiological response to continuous opportunistic infection. Recent studies suggest, however, that regulation of the inflammatory response itself may be altered in CF. Neutrophil migration from the bloodstream involves alterations in surface expression of the adhesion molecules L-selectin and Mac-1 (CD11b/CD18). The aim of this study was to assess neutrophil adhesion molecule expression and responsiveness in CF. Neutrophils from chronic (n = 16) and acutely infected (n = 13) CF patients and 15 normal control subjects were directly assessed by Fluorescence-activated cell sorter (FACS) analysis for surface expression of L-selectin and CD11b before and after stimulation with interleukin 8 (IL-8) or f-Met-Leu-Phe (fMLP). Neutrophils from stable (n = 5) and acutely infected (n = 5) non-CF bronchiectasis patients were also assessed. Surface upregulation of CD11b was similar in all groups. Basal levels of L-selectin were also comparable among all groups, however, when stimulated, neutrophils from both stable and acutely infected CF patients shed significantly less L-selectin than those from control subjects (p < 0.05 and p < 0.01, respectively). This decreased responsiveness was not observed in either stable or acutely infected non-CF bronchiectasis patients. These results add to the accumulating evidence suggestive of a defective inflammatory response in CF.