Hypoxic challenge flight assessments in patients with severe chest wall deformity or neuromuscular disease at risk for nocturnal hypoventilation.

BACKGROUND: The British Thoracic Society (BTS) recommendations for patients with respiratory disease planning air travel suggest that an oxygen saturation (SaO(2)) >95% precludes the need for any further assessment of the need for supplemental oxygen during flight. A hypoxic challenge test (HCT) is recommended for patients with a resting SaO(2) between 92% and 95% with an additional risk factor, including kyphoscoliosis (KS) or neuromuscular disease (NMD). However, this recommendation was based on very few data. PATIENTS AND METHODS: HCTs were performed on 19 adult patients with KS and/or NMD (age 22-73 years, forced expiratory volume in 1 s (FEV(1)) 0.76, forced vital capacity (FVC) 0.92, SaO(2) 95%, partial pressure of arterial CO(2) (PaCO(2)) 5.7 kPa) who were at risk for nocturnal hypoventilation. 15 were home ventilator users. Arterial blood gas measurements were made before and at the end of the hypoxic challenge. RESULTS: The results of HCTs show that the majority (15 of 19) of this cohort of patients met the criteria suggested by the BTS Standards of Care Committee for in-flight oxygen regardless of baseline SaO(2). CONCLUSIONS: This finding suggests that all patients with severe extrapulmonary restrictive lung disease should undergo assessment with HCT prior to air travel. The study confirms that even patients with a resting saturation of >95% can desaturate significantly during hypoxic challenge. This study does not address the question of whether desaturation at altitude has any adverse consequences for patients. A decision as to whether it is safe for a patient to fly should be made by an experienced clinician and based on a number of factors, which should include previous travel experience, the patient's overall condition and the results of an HCT.

Randomised crossover study of pressure and volume non-invasive ventilation in chest wall deformity.

BACKGROUND: Non-invasive ventilation is an established treatment for chronic respiratory failure due to chest wall deformity. There are few data available to inform the choice between volume and pressure ventilators. The aim of this study was to compare pressure and volume targeted ventilation in terms of diurnal arterial blood gas tensions, lung volumes, hypercapnic ventilatory responses, sleep quality, and effect on daytime function and health status when ventilators were carefully set to provide the same minute ventilation. METHODS: Thirteen patients with chest wall deformity underwent a 4 week single blind randomised crossover study using the Breas PV403 ventilator in either pressure or volume mode with assessments made at the end of each 4 week period. RESULTS: Minute ventilation at night was less than that set during the day with greater leakage for both modes of ventilation. There was more leakage with pressure than volume ventilation (13.8 (1.9) v 5.9 (1.0) l/min, p = 0.01). There were no significant differences in sleep quality, daytime arterial blood gas tensions, lung mechanics, ventilatory drive, health status or daytime functioning. CONCLUSIONS: These data suggest that pressure and volume ventilation are equivalent in terms of the effect on nocturnal and daytime physiology, and resulting daytime function and health status.

Domiciliary non-invasive ventilation for recurrent acidotic exacerbations of COPD: an economic analysis.

BACKGROUND: Patients with chronic obstructive pulmonary disease (COPD) pose a significant burden to healthcare providers with frequent exacerbations necessitating hospital admission. Randomised controlled data exist supporting the use of acute non-invasive ventilation (NIV) in patients with exacerbations of COPD with mild to moderate acidosis. The use of NIV is also described in chronic stable COPD, with evidence suggesting a reduction in hospital admissions and general practitioner care. We present economic data on the impact of domiciliary NIV on the need for admission to hospital and its attendant costs. METHODS: A cost and consequences analysis of domiciliary NIV based on a before and after case note audit was performed in patients with recurrent acidotic exacerbations of COPD who tolerated and responded well to NIV. The primary outcome measure was the total cost incurred per patient per year from the perspective of the acute hospital. Effectiveness outcomes were total days in hospital and in intensive care. RESULTS: Thirteen patients were identified. Provision of a home NIV service resulted in a mean (95% CI) saving of pound sterling 8254 (pound sterling 4013 to pound sterling 12,495) (Euro 11,720; Euro 5698 to Euro 17,743) per patient per year. Total days in hospital fell from a mean (SD) of 78 (51) to 25 (25) (p=0.004), number of admissions from 5 (3) to 2 (2) (p=0.007), and ICU days fell from a total of 25 to 4 (p=0.24). Outpatient visits fell from a mean of 5 (3) to 4 (2) (p=0.14). CONCLUSIONS: This study suggests that domiciliary NIV for a highly selected group of COPD patients with recurrent admissions requiring NIV is effective at reducing admissions and minimises costs from the perspective of the acute hospital. Such evidence is important in obtaining financial support for providing such a service.

Primary pulmonary botryomycosis: a late complication of foreign body aspiration.

Primary pulmonary botryomycosis is a rare cause of haemoptysis and can enter the differential diagnosis of a mass on the plain chest radiograph. The case history is presented of a 63 year old man with botryomycosis which was initially thought to be a bronchial carcinoma. When the diagnosis was made several years later it was found to be secondary to persisting vegetable material in the bronchial tree following previous aspiration.

Churg-Strauss syndrome associated with montelukast therapy.

Churg-Strauss syndrome is a rare form of eosinophilic vasculitis associated with asthma. There have been several recent case reports of the condition in association with leukotriene antagonists and it has been speculated that the Churg-Strauss syndrome was unmasked when oral corticosteroids were withdrawn. We report a case of Churg-Strauss syndrome associated with montelukast therapy in an asthmatic patient in whom there had been no recent oral corticosteroid use. We believe that this is the first such reported case and would suggest that clinicians need to be vigilant in all patients who develop systemic symptoms when starting treatment with leukotriene antagonists.