Managing patients with stable respiratory disease planning air travel: a primary care summary of the British Thoracic Society recommendations.

Air travel poses medical challenges to passengers with respiratory disease, principally because of exposure to a hypobaric environment. In 2002 the British Thoracic Society published recommendations for adults and children with respiratory disease planning air travel, with a web update in 2004. New full recommendations and a summary were published in 2011, containing key recommendations for the assessment of high-risk patients and identification of those likely to require in-flight supplemental oxygen. This paper highlights the aspects of particular relevance to primary care practitioners with the following key points: (1) At cabin altitudes of 8000 feet (the usual upper limit of in-flight cabin pressure, equivalent to 0.75 atmospheres) the partial pressure of oxygen falls to the equivalent of breathing 15.1% oxygen at sea level. Arterial oxygen tension falls in all passengers; in patients with respiratory disease, altitude may worsen preexisting hypoxaemia. (2) Altitude exposure also influences the volume of any air in cavities, where pressure x volume remain constant (Boyle's law), so that a pneumothorax or closed lung bulla will expand and may cause respiratory distress. Similarly, barotrauma may affect the middle ear or sinuses if these cavities fail to equilibrate. (3) Patients with respiratory disease require clinical assessment and advice before air travel to: (a) optimise usual care; (b) consider contraindications to travel and possible need for in-flight oxygen; (c) consider the need for secondary care referral for further assessment; (d) discuss the risk of venous thromboembolism; and (e) discuss forward planning for the journey.

Seasonality, risk factors and burden of community-acquired pneumonia in COPD patients: a population database study using linked health care records.

BACKGROUND: Community-acquired pneumonia (CAP) is more common in patients with COPD than in the adult general population, with studies of hospitalized CAP patients consistently reporting COPD as a frequent comorbidity. However, despite an increasing recognition of its importance, large studies evaluating the incidence patterns over time, risk factors and burden of CAP in COPD are currently lacking. METHODS: A retrospective observational study using a large UK-based database of linked primary and secondary care records was conducted. Patients with a diagnosis of COPD aged ≥40 years were followed up for 5 years from January 1, 2010. CAP and exacerbation episodes were identified from hospital discharge data and primary care coding records, and rates were calculated per month, adjusting for mortality, and displayed over time. In addition, baseline factors predicting future risk of CAP and hospital admission with CAP were identified. RESULTS: A total of 14,513 COPD patients were identified: 13.4% (n=1,938) had ≥1 CAP episode, of whom 18.8% suffered from recurrent (≥2) CAP. Highest rates of both CAP and exacerbations were seen in winter. A greater proportion of frequent, compared to infrequent, exacerbators experienced recurrent CAP (5.1% versus 2.0%, respectively, P<0.001); 75.6% of CAP episodes were associated with hospital admission compared to 22.1% of exacerbations. Older age and increasing grade of airflow limitation were independently associated with increased odds of CAP and hospital admission with CAP. Other independent predictors of future CAP included lower body mass index, inhaled corticosteroid use, prior frequent exacerbations and comorbidities, including ischemic heart disease and diabetes. CONCLUSION: CAP in COPD demonstrates clear seasonal patterns, with patient characteristics predictive of the odds of future CAP and hospital admission with CAP. Highlighting this burden of COPD-associated CAP during the winter period informs us of the likely triggers and the need for more effective preventive strategies.

Identifying Risk of Future Asthma Attacks Using UK Medical Record Data: A Respiratory Effectiveness Group Initiative.

BACKGROUND: Asthma attacks are common, serious, and costly. Individual factors associated with attacks, such as poor symptom control, are not robust predictors. OBJECTIVE: We investigated whether the rich data available in UK electronic medical records could identify patients at risk of recurrent attacks. METHODS: We analyzed anonymized, longitudinal medical records of 118,981 patients with actively treated asthma (ages 12-80 years) and 3 or more years of data. Potential risk factors during 1 baseline year were evaluated using univariable (simple) logistic regression for outcomes of 2 or more and 4 or more attacks during the following 2-year period. Predictors with significant univariable association (P < .05) were entered into multiple logistic regression analysis with backward stepwise selection of the model including all significant independent predictors. The predictive accuracy of the multivariable models was assessed. RESULTS: Independent predictors associated with future attacks included baseline-year markers of attacks (acute oral corticosteroid courses, emergency visits), more frequent reliever use and health care utilization, worse lung function, current smoking, blood eosinophilia, rhinitis, nasal polyps, eczema, gastroesophageal reflux disease, obesity, older age, and being female. The number of oral corticosteroid courses had the strongest association. The final cross-validated models incorporated 19 and 16 risk factors for 2 or more and 4 or more attacks over 2 years, respectively, with areas under the curve of 0.785 (95% CI, 0.780-0.789) and 0.867 (95% CI, 0.860-0.873), respectively. CONCLUSIONS: Routinely collected data could be used proactively via automated searches to identify individuals at risk of recurrent asthma attacks. Further research is needed to assess the impact of such knowledge on clinical prognosis.