Optimal management improves asthma morbidity and mortality

Is non-invasive ventilation safe in acute severe asthma?

BACKGROUND AND OBJECTIVE

The effect of non-invasive ventilation (NIV) in acute severe asthma is unclear and there are concerns regarding its safety.

METHODS

We undertook a 5-year case-control review of mortality and morbidity associated with NIV use in acute severe asthma and compared this with asthma requiring invasive mechanical ventilation (IMV) and a control group with less severe asthma without ventilatory support.

RESULTS

Eight hundred seventy-three patients had acute severe asthma of whom 30 were treated with NIV, 17 with IMV and 90 served as controls. The mean duration of NIV was 9.5 ± 7.3 h with inspiratory positive airway pressure and expiratory positive airway pressure of 11.9 ± 1.4 and 5.8 ± 1.2 cmH2 O respectively. Mortality was zero in the NIV and control groups, compared with 41% in the IMV group. None of the NIV or control groups required escalation to invasive ventilation. There were no instances of haemodynamic compromise in the NIV or control groups. Length of hospital stay was 121 ± 96 h in the NIV group and similar to the severe IMV group (136 ± 99 h, P > 0.05) and significantly longer than the control group (42 ± 40 h, P < 0.05).

CONCLUSIONS

NIV can be safely used in acute severe asthma although further work is needed to delineate the precise patient selection process.

Noninvasive ventilation in acute asthma

Noninvasive ventilation (NIV) has well-recognized benefits in acute exacerbation of chronic obstructive pulmonary disease and pulmonary edema. Its utilization in acute asthma, however, remains controversial. In this review, we describe the physiological basis to justify NIV use in acute asthma and contribute a critical appraisal of the available literature relating to this practice. A discussion of some of the more pertinent, clinically relevant practicalities is also provided. Original research articles were identified using the electronic PubMed database. Randomized controlled trials of NIV in the setting of acute asthma were selected. Retrospective observational studies were also included if they were considered to contribute to the literature review. The use of NIV in the acute asthma setting has been shown to be associated with improvements in important physiological variables including measures of airflow and respiratory rate, and lends support to further study in this field. Improvements in airflow may be a direct effect of applied positive airway pressure or an indirect effect secondary to better dispersal of aerosolized medication. Reductions observed in respiratory rate and dyspnea are likely influenced by the amount of pressure support provided. Evidence suggestive of any improvement in mortality, intubation rate, or hospital/intensive care unit length of stay, however, is lacking. Studies to date have been hampered by small numbers and a lack of demonstrable meaningful clinical outcomes. Data relating to mortality, endotracheal intubation rates, and hospital length of stay/admission should be sought in future large clinical trials.

Asthma mortality among Swedish children and young adults, a 10-year study

BACKGROUND

Previous reports indicate that morbidity and mortality from asthma have increased during the past decades. Here, the mortality rate associated with asthma and possible risk factors in children and young adults in Sweden during the period 1994-2003 were evaluated.

METHODS

The medical profession was asked to report suspected cases of death from asthma in individuals 1-34 years of age. All death certificates containing relevant ICD codes were reviewed. Medical records and autopsy reports were assessed and telephone interviews with next-of-kin performed.

RESULTS

During the 10-year period 37 deaths due to asthma were identified. The median age at the time of death was 27 years and 6 of the deceased were younger than 15. The overall incidence of death from asthma decreased from 1.54 deaths per million in 1994 to 0.53 per million in 2003. Common risk factors were under-treatment (23/37), poor adherence to prescribed treatment (17/37) and adverse psychosocial situation (19/37). An alarming finding was that 11 of the 37 deaths were probably caused by food allergy and for 8 subjects death was associated with exposure to pet dander. The death certificates were found to contain inaccuracies with 30% of those for whom asthma was reported as the underlying cause having died from other causes.

CONCLUSION

Asthma mortality in children and young adults in Sweden decreased between 1994 and 2003. Food allergy and inadequate treatment were the major risk factors for such a death. Recognition and special care of patients with asthma who have shown signs of non-compliance, denial or severe food allergy must be encouraged.

Role of airway epithelial cells in development of asthma and allergic rhinitis

Asthma and allergic rhinitis frequently coexist in the same patient. There is a similarity and variation as well as potential relationship between asthma and allergic rhinitis. There is an increasing evidence to suggest a major involvement of airway epithelial cells in the pathogenesis of asthma and allergic rhinitis. The present review describes the importance of the airway epithelial cell in the development of allergic airway diseases, its role as the primary airway defense against exposure of the airway and lung to inflammatory stimuli and antigens and as an important player through activation of epithelial Toll-like receptors (TLRs) to provide an important link between innate immunity and allergic disease. Additionally, airway epithelial cells can act as inflammatory promoters capable of directing dendritic cells (DCs) towards a T helper 2 (Th2) response, and as active producers of several inflammatory/anti-inflammatory mediators. It is hypothesized that airway epithelial cells may play as both inflammatory initiator and immuno-pathological feedback regulation between allergic rhinitis and asthma via release of systemic inflammatory mediators. Thus, airway epithelial cells may be valuable therapeutic targets for discovery and development of new drugs and/or new therapeutic strategies to treat asthma and allergic rhinitis.

Asthma mortality in southern Brazil: is there a changing trend?

BACKGROUND

Mortality from asthma increased during the last decades but is now declining in some countries. Little is known about this trend in Brazil.

OBJECTIVE

The objective of the study was to determine the trends in asthma mortality in Southern Brazil.

METHODS

We reviewed death certificates of 566 people in the state of Rio Grande do Sul, Brazil, between 5 and 39 years of age in whom asthma was reported to be the underlying cause of death during the period of 1981-2003. Population data were available in 5-year age groups. Mortality rates were submitted to linear and quadratic regression procedures.

RESULTS

Among children and teenagers (5-19 years), there were 170 asthma deaths, ranging from 4 to 13 deaths each year with rates of 0.154/100,000 to 0.481/100,000. In young adults (20-39 years), 396 asthma deaths occurred, ranging from 9 to 32 each year, with rates from 0.276/100,000 to 1.034/100,000. There was an initial increase in rates, with later stabilization, and then the start of a decline beginning in the late 1990s and the early part of this decade. This trend occurred in both age subgroups examined but was more evident in males.

CONCLUSIONS

Asthma mortality in southern Brazil remains low and appears to be decreasing after reaching a peak in the mid-1990s. The reason for these trends remains unknown.

Factors associated with mortality after an asthma admission: a national United Kingdom database analysis

BACKGROUND

Lack of a United Kingdom (UK) fatal asthma registry has resulted in few recent analyses regarding patient characteristics, co-morbidities, and admission type in relation to mortality post an asthma admission. This study aims to report these factors in addition to season of event for the years 2000-2005 to provide data regarding asthma burden in the in-patient hospital setting.

METHODS

Data were analysed from the CHKS database collated from UK National Health Service data providing 70% of in-patient coverage in the UK. Patients with admissions under ICD-10 codes J45 "Asthma" and J46 "acute severe asthma" were included. Codes for associated co-morbidity at time of admission were identified, as well as month of admission and death, age, gender and length of stay.

RESULTS

The mortality rate over the 5-year period was 1063 patients from 250,043 asthma admissions (0.43%). Critical care mortality was far higher and an annual rate indicated that for every 100,000 admissions 2878 (95% CI 2091;3857) patients died. Respiratory infection, cardiovascular disease and diabetes were common co-morbidities for all admissions. December and January had the peak number of deaths post asthma admission which were nearly all in adults, death being rarer in children. Women and those over 45 years had the highest rate of death which may reflect asthma prevalence.

CONCLUSIONS

Co-morbid conditions experienced by older asthma patients may contribute to mortality post an asthma admission and greater understanding of risk factors contributing to fatality are required.

Continuing decreases in asthma mortality in the United States

BACKGROUND

Rates of death from asthma in the United States increased after 1978 until 1988 and then tended to stabilize through 1997.

OBJECTIVE

To identify and evaluate subsequent trends in asthma mortality in the United States.

METHODS

Tabulation and graphing of data from the National Center for Health Statistics identifying asthma (International Classification of Diseases [ICD], Ninth Revision, code, 493; ICD-10 code, J45-J46) as the underlying cause of death in the 50 United States and the District of Columbia with rates of death from asthma by age, race, and sex and age-adjusted rates of death by race.

RESULTS

Rates of death from asthma in the United States increased from 0.8 per 100,000 general population in 1977 and 1978 to 2.0 in 1989 and 2.1 in 1994 through 1996 but have decreased to 1.6 in 2000, a decrease accounted for only partly by implementation in 1999 of the ICD-10. Rates have been higher for women than men but have decreased for both. Age-adjusted rates of death for asthma have been much higher for blacks than whites.

CONCLUSION

Asthma mortality has stabilized since 1988 and decreased since 1998. Improved management and recent decreases in prevalence are the most likely explanations for these recent trends.