Invasive Mechanical Ventilation in Acute Exacerbation of COPD: Prognostic Indicators to Support Clinical Decision Making

Abstract

Although non-invasive ventilation is the mainstay of management for patients with hypercapnic acute exacerbation of COPD, invasive mechanical ventilation (IMV) still has an important role to play. IMV can be used successfully to reduce mortality and still maintain quality of life in a subset of patients. Despite this, the evidence to support which patients will benefit from IMV is limited. This article reviews the literature available to guide clinician decision-making. Age is not a reliable independent predictor of survival for COPD patients receiving IMV, nor are levels of PaO2, PCO2, or use of long-term oxygen therapy. Body composition and nutritional status are independent predictors of survival and the presence of co-morbidities, such as cor pulmonale, cardiovascular disease and diabetes mellitus are negative prognostic indicators. Length of time in hospital prior to ICU admission also is an adverse prognostic factor. Although scoring systems exist, their ability to predict outcome for individual patients has limitations. Work needs to be done to improve end-of-life planning in COPD with the encouragement of discussion about advance directives when patients are reaching advanced stage of the disease.