This article, the first in a series, is written to clarify the process of weaning from mechanical ventilation and to promote the development of a common language for understanding the complex weaning process. The Third National Study Group on Weaning From Mechanical Ventilation proposes a conceptual model and definitions that will provide a framework for future research on this important topic. This conceptual framework describes the preweaning phase, the weaning process, and the outcome phase of mechanical ventilation. Potential outcomes are completion of weaning, lack of completion, and terminal weaning. The weaning decision continuum incorporates: (1) when and how to begin the weaning process, (2) how to select therapies to assist with difficult weaning and chart progress during weaning, and (3) when to stop weaning if progress is no longer being made. An inherent assumption of this model is that each patient will display unique responses to the weaning process. The proposed conceptual framework and definitions provide a foundation for developing clinical practice guidelines and for guiding future ventilator weaning research.
The purposes of this article are to: identify gaps in the research literature on weaning adult patients from short-term mechanical ventilation, highlight the scientific base for practice guidelines, and suggest future research directions. Data bases from 1989 through June 1993 were reviewed, and relevant research articles were extracted, analyzed, and synthesized within the AACN Third National Study Group framework. Seminal work and other supportive literature also were used in this review. Despite considerable research on predictors and patient responses to weaning from short-term mechanical ventilation, few of the findings can be applied to clinical practice at this time. Less research is available on weaning modes and therapies that facilitate weaning from short-term mechanical ventilation; fruitful research in these areas depends in part on a better understanding of patient responses and accurate weaning predictors.