Management of COPD Exacerbation

Background

Patients with acute COPD exacerbations are seen frequently in the emergency department (ED). Acute exacerbations are associated with significant morbidity, mortality and health care expenditures. Although systemic corticosteroids, antibiotics and noninvasive positive pressure ventilation (NPPV) are recommended interventions for patients with acute COPD exacerbations, their benefits are not clearcut. The authors performed a systematic review and meta analysis to evaluate the effectiveness of these therapies on treatment failures, need for intubation, in hospital mortality, and length of stay (LOS).[1]
Methods

For each of the therapies MEDLINE and EMBASE were searched from 1968-2006 for English-language articles. Studies were limited to acute COPD exacerbations, as defined by worsening cough or dyspnea or increased sputum production. Only randomized, controlled trials were included and data was abstracted utilizing a standardized form. Treatment failures were defined as unchanged or worsening symptoms requiring additional treatment during the follow up period.
Results

( Table 1 )

Systemic Corticosteroids. Ten studies involving 959 patients were identified but not all studies were included in the analyses. Average patient age was 67 years and most patients had a history of cigarette smoking. On average, pH was 7.40 and PaCO2 was 42 mm Hg. The use of systemic corticosteroids during exacerbation decreased treatment failure rate by 46% and was associated with a mean decrease in hospital length of stay by 1.42 days when compared with placebo. The only consistently reported adverse effect was hyperglycemia.

Antibiotics. Five studies involving 557 patients evaluated the use of antibiotics during COPD exacerbation.[2] The use of antibiotics reduced the rate of total treatment failures by 46% over placebo. However, while antibiotics significantly reduced treatment failures when administered to patients who were hospitalized (RR, 0.34), no such reduction was noted in ambulatory patients (RR 0.88). Three clinical trials involving 181 hospitalized patients also demonstrated a 78% decrease in in-hospital mortality. These results were based on small underpowered studies and a larger clinical trial is needed to confirm these results. No difference was noted between classes of antibiotics. Antibiotics did not affect lung function, blood gas measurements or LOS compared to placebo.

Noninvasive Positive Pressure Ventilation. Twelve randomized controlled studies involving 959 patients demonstrated a 65% reduction in the need for intubation when NPPV was used instead of standard therapy. There was also a decrease in overall mortality and decreased LOS. The mean pH at the time of study entry was 7.31. The benefits of NPPV increased as pH decreased. In addition, the in-hospital mortality rate was reduced by 55% and hospital length of stay was shortened by a mean of 1.94 days.
Authors Conclusions

Patients with acute COPD exacerbation should be treated with systemic corticosteroids, antibiotics and NPPV. Systemic corticosteroids reduce treatment failures in both in-hospital and outpatient settings, while antibiotics appear more effective in patients requiring hospitalization. NPPV should be considered in patients with arterial respiratory acidosis.
Relevance to Emergency Medicine

The results of this meta-analysis support current guidelines.[3] Systemic corticosteroids should be prescribed for all patients with COPD exacerbation and antibiotics should be administered to sicker patients with COPD exacerbation, especially those who require hospitalization. Consider obtaining arterial blood gases early in patients with severe COPD exacerbation to determine who is most likely to benefit from NPPV.

Source :http://www.medscape.com/viewarticle/583568