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Oxygen therapy in acute exacerbations of chronic obstructive pulmonary disease.

Brill SE, Wedzicha JA - Int J Chron Obstruct Pulmon Dis (2014)

Bottom Line: Associated health care utilization and morbidity are high, and many patients require supplemental oxygen or ventilatory support.The last 2 decades have seen a substantial increase in our understanding of the best way to manage the respiratory failure suffered by many patients during this high-risk period.We also review current recommendations for best practice, including methods for improving oxygen provision in the future.

View Article: PubMed Central - PubMed

Affiliation: Airway Disease Section, National Heart and Lung Institute, Imperial College, London, UK.

ABSTRACT
Acute exacerbations of chronic obstructive pulmonary disease (COPD) are important events in the history of this debilitating lung condition. Associated health care utilization and morbidity are high, and many patients require supplemental oxygen or ventilatory support. The last 2 decades have seen a substantial increase in our understanding of the best way to manage the respiratory failure suffered by many patients during this high-risk period. This review article examines the evidence underlying supplemental oxygen therapy during exacerbations of COPD. We first discuss the epidemiology and pathophysiology of respiratory failure in COPD during exacerbations. The rationale and evidence underlying oxygen therapy, including the risks when administered inappropriately, are then discussed, along with further strategies for ventilatory support. We also review current recommendations for best practice, including methods for improving oxygen provision in the future.

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Pathological processes underlying the worsening of respiratory failure at COPD exacerbation.Abbreviations: COPD, chronic obstructive pulmonary disease; V/Q, ventilation–perfusion ratio.
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f1-copd-9-1241: Pathological processes underlying the worsening of respiratory failure at COPD exacerbation.Abbreviations: COPD, chronic obstructive pulmonary disease; V/Q, ventilation–perfusion ratio.

Mentions: A complex series of events occurs at COPD exacerbation, worsening V/Q mismatch and oxygenation. Consequent to an exacerbation trigger, usually viral or bacterial,20 airway inflammation increases rapidly,21 causing increased mucus secretion, mucosal edema, and bronchospasm.22 This causes acute worsening of expiratory airflow limitation, which, combined with tachypnea, leads to a damaging cycle of dynamic hyperinflation and abnormal breathing.23 These, along with other factors discussed below, markedly reduce alveolar ventilation. Changes within the pulmonary vasculature compound the situation. Pulmonary vascular resistance and pulmonary arterial pressure rise acutely at exacerbation24 and this, combined with cardiac dysfunction,25 reduces blood flow to the alveolar capillary bed. Despite this, perfusion appears to be disproportionately increased through poorly ventilated lung units,8 and this worsens systemic hypoxemia still further. These processes are summarized in Figure 1.


Oxygen therapy in acute exacerbations of chronic obstructive pulmonary disease.

Brill SE, Wedzicha JA - Int J Chron Obstruct Pulmon Dis (2014)

Pathological processes underlying the worsening of respiratory failure at COPD exacerbation.Abbreviations: COPD, chronic obstructive pulmonary disease; V/Q, ventilation–perfusion ratio.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4230177&req=5

f1-copd-9-1241: Pathological processes underlying the worsening of respiratory failure at COPD exacerbation.Abbreviations: COPD, chronic obstructive pulmonary disease; V/Q, ventilation–perfusion ratio.
Mentions: A complex series of events occurs at COPD exacerbation, worsening V/Q mismatch and oxygenation. Consequent to an exacerbation trigger, usually viral or bacterial,20 airway inflammation increases rapidly,21 causing increased mucus secretion, mucosal edema, and bronchospasm.22 This causes acute worsening of expiratory airflow limitation, which, combined with tachypnea, leads to a damaging cycle of dynamic hyperinflation and abnormal breathing.23 These, along with other factors discussed below, markedly reduce alveolar ventilation. Changes within the pulmonary vasculature compound the situation. Pulmonary vascular resistance and pulmonary arterial pressure rise acutely at exacerbation24 and this, combined with cardiac dysfunction,25 reduces blood flow to the alveolar capillary bed. Despite this, perfusion appears to be disproportionately increased through poorly ventilated lung units,8 and this worsens systemic hypoxemia still further. These processes are summarized in Figure 1.

Bottom Line: Associated health care utilization and morbidity are high, and many patients require supplemental oxygen or ventilatory support.The last 2 decades have seen a substantial increase in our understanding of the best way to manage the respiratory failure suffered by many patients during this high-risk period.We also review current recommendations for best practice, including methods for improving oxygen provision in the future.

View Article: PubMed Central - PubMed

Affiliation: Airway Disease Section, National Heart and Lung Institute, Imperial College, London, UK.

ABSTRACT
Acute exacerbations of chronic obstructive pulmonary disease (COPD) are important events in the history of this debilitating lung condition. Associated health care utilization and morbidity are high, and many patients require supplemental oxygen or ventilatory support. The last 2 decades have seen a substantial increase in our understanding of the best way to manage the respiratory failure suffered by many patients during this high-risk period. This review article examines the evidence underlying supplemental oxygen therapy during exacerbations of COPD. We first discuss the epidemiology and pathophysiology of respiratory failure in COPD during exacerbations. The rationale and evidence underlying oxygen therapy, including the risks when administered inappropriately, are then discussed, along with further strategies for ventilatory support. We also review current recommendations for best practice, including methods for improving oxygen provision in the future.

Show MeSH
Related in: MedlinePlus