Airwaves
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《胸》
WEANING/LONG TERM VENTILATOR UNITS
As Simonds points out in an accompanying editorial to the paper by Pilcher and colleagues in this month’s Thorax, around 3–6% of patients admitted to the intensive care unit (ICU) require a prolonged course of mechanical ventilation and 2.5% of ICU admissions are weaning failures. In the USA, Simonds writes that there are 11 000 ventilator dependent patients in acute care facilities costing over $9 million a day. The outcome of weaning units is therefore an important topic, and Pilcher and colleagues describe the results of a 4 year follow up study from a regional weaning unit in South London, UK. They found that 38% of patients admitted to the unit were fully weaned, 27% died, and 35% required ventilatory support at discharge from hospital. Overall survival at 3 years from admission was 47%; patients with neuromuscular and chest wall conditions had the best outcomes and those with COPD had the lowest survival rate. Factors associated with increased mortality were increasing age and length of ICU stay, APACHE score, and a surgical cause for admission. Simonds also discusses some advantages and disadvantages of weaning or long term ventilator units and provides some suggestions for bed numbers and location for this important facility.
See 175 and 187
Long term survival in patients who left hospital alive according to diagnostic group
AIRWAY SMOOTH MUSCLE IN CF
Patients with cystic fibrosis (CF) often have chronic airways obstruction which may be reversible with bronchial hyperresponsiveness. Those with severe CF have previously been shown to have increased airway smooth muscle content. In this month’s Thorax Hays and colleagues describe, for the first time, increased smooth muscle content in CF patients with mild to moderate disease—as seen also in patients with asthma. The study showed hyperplasia of the airway smooth muscle without hypertrophy and reported that smooth muscle cell proliferation is characteristic of airway remodelling in CF. In an accompanying editorial, Sutcliffe and Knox suggest that these changes may provide a mechanism for the airway obstruction and hyperresponsiveness seen in CF and conclude that further studies of this finding are warranted.
See 181 and 226
ASTHMA AND SICKLE CELL DISEASE
Although respiratory complications and the acute chest syndrome are important in the management of sickle cell disease, there is little information on the relation between sickle cell disease and asthma. In this month’s Thorax Knight-Madden and colleagues describe a study of 80 children with sickle cell disease and 80 matched controls. Asthma and bronchial hyperreactivity were more common in children with sickle cell disease than in controls, although atopy was not more common. However, atopy and asthma were more common in children with sickle cell disease who had previously had recurrent episodes of acute chest syndrome. The authors conclude by speculating that early intervention with treatment for asthma may considerably reduce the pulmonary morbidity associated with sickle cell disease.
See page 206
VEGF AND ARDS
The acute respiratory distress syndrome (ARDS) is still associated with a significant mortality and non-cardiogenic pulmonary oedema is a characteristic feature. As vascular endothelial growth factor (VEGF) can cause vascular permeability, it is an obvious candidate for the study of the pathogenesis of ARDS, and low VEGF levels have been linked with a specific polymorphism (VEGF+936 CT). Medford and colleagues have studied this polymorphism in patients with ARDS and found that CT and TT genotype frequencies were increased compared with normal subjects and those "at risk" of ARDS. These genotypes were also associated with a higher mean APACHE III score. The results suggest a role for VEGF gene polymorphism in the development of ARDS and may have an important therapeutic application for the management of this difficult condition.
See page 244
EOSINOPHILS, INHALED STEROIDS AND COPD
Brightling and colleagues have previously reported that COPD patients with sputum eosinophilia have a greater improvement in FEV1 after a short course of oral prednisolone. In this issue of Thorax the same group report a study of the short term response to the inhaled steroid mometasone in COPD and the relationship with sputum markers. The results showed a small but significant improvement in FEV1 with inhaled steroids in patients with a higher sputum eosinophil count. However, in contrast to their earlier findings, there was no fall in the sputum eosinophil count or any other sputum inflammatory marker. This is an interesting observation and suggests that oral prednisolone has a greater effect on inflammation in the smaller airways than inhaled steroids.
See page 193(Wisia Wedzicha, Editor in)
As Simonds points out in an accompanying editorial to the paper by Pilcher and colleagues in this month’s Thorax, around 3–6% of patients admitted to the intensive care unit (ICU) require a prolonged course of mechanical ventilation and 2.5% of ICU admissions are weaning failures. In the USA, Simonds writes that there are 11 000 ventilator dependent patients in acute care facilities costing over $9 million a day. The outcome of weaning units is therefore an important topic, and Pilcher and colleagues describe the results of a 4 year follow up study from a regional weaning unit in South London, UK. They found that 38% of patients admitted to the unit were fully weaned, 27% died, and 35% required ventilatory support at discharge from hospital. Overall survival at 3 years from admission was 47%; patients with neuromuscular and chest wall conditions had the best outcomes and those with COPD had the lowest survival rate. Factors associated with increased mortality were increasing age and length of ICU stay, APACHE score, and a surgical cause for admission. Simonds also discusses some advantages and disadvantages of weaning or long term ventilator units and provides some suggestions for bed numbers and location for this important facility.
See 175 and 187
Long term survival in patients who left hospital alive according to diagnostic group
AIRWAY SMOOTH MUSCLE IN CF
Patients with cystic fibrosis (CF) often have chronic airways obstruction which may be reversible with bronchial hyperresponsiveness. Those with severe CF have previously been shown to have increased airway smooth muscle content. In this month’s Thorax Hays and colleagues describe, for the first time, increased smooth muscle content in CF patients with mild to moderate disease—as seen also in patients with asthma. The study showed hyperplasia of the airway smooth muscle without hypertrophy and reported that smooth muscle cell proliferation is characteristic of airway remodelling in CF. In an accompanying editorial, Sutcliffe and Knox suggest that these changes may provide a mechanism for the airway obstruction and hyperresponsiveness seen in CF and conclude that further studies of this finding are warranted.
See 181 and 226
ASTHMA AND SICKLE CELL DISEASE
Although respiratory complications and the acute chest syndrome are important in the management of sickle cell disease, there is little information on the relation between sickle cell disease and asthma. In this month’s Thorax Knight-Madden and colleagues describe a study of 80 children with sickle cell disease and 80 matched controls. Asthma and bronchial hyperreactivity were more common in children with sickle cell disease than in controls, although atopy was not more common. However, atopy and asthma were more common in children with sickle cell disease who had previously had recurrent episodes of acute chest syndrome. The authors conclude by speculating that early intervention with treatment for asthma may considerably reduce the pulmonary morbidity associated with sickle cell disease.
See page 206
VEGF AND ARDS
The acute respiratory distress syndrome (ARDS) is still associated with a significant mortality and non-cardiogenic pulmonary oedema is a characteristic feature. As vascular endothelial growth factor (VEGF) can cause vascular permeability, it is an obvious candidate for the study of the pathogenesis of ARDS, and low VEGF levels have been linked with a specific polymorphism (VEGF+936 CT). Medford and colleagues have studied this polymorphism in patients with ARDS and found that CT and TT genotype frequencies were increased compared with normal subjects and those "at risk" of ARDS. These genotypes were also associated with a higher mean APACHE III score. The results suggest a role for VEGF gene polymorphism in the development of ARDS and may have an important therapeutic application for the management of this difficult condition.
See page 244
EOSINOPHILS, INHALED STEROIDS AND COPD
Brightling and colleagues have previously reported that COPD patients with sputum eosinophilia have a greater improvement in FEV1 after a short course of oral prednisolone. In this issue of Thorax the same group report a study of the short term response to the inhaled steroid mometasone in COPD and the relationship with sputum markers. The results showed a small but significant improvement in FEV1 with inhaled steroids in patients with a higher sputum eosinophil count. However, in contrast to their earlier findings, there was no fall in the sputum eosinophil count or any other sputum inflammatory marker. This is an interesting observation and suggests that oral prednisolone has a greater effect on inflammation in the smaller airways than inhaled steroids.
See page 193(Wisia Wedzicha, Editor in)