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Biomedical subjects

A R Knebel

Publications and source records attributed to A R Knebel.

9 recordsLinked to original sources

A volunteers in participatory sampling survey of weaning practices. The Third National Study Group on Weaning from Mechanical Ventilation.

The survey results of the VIPs membership described in this article add qualitative information to the growing body of scientific knowledge on weaning patients off ventilators. Clearly, quantitative studies exploring the efficacy of different weaning practices across the continuum must be done if we are to accurately compare practices and prescribe the "when" and "how" of weaning. To this end, the Third National Study Group is revising the proposed weaning model and model in order to further elucidate the state of the art and science of weaning.

Adult

Ventilator weaning protocols and techniques: getting the job done.

Various protocols and techniques used to facilitate the weaning process are herein summarized. The protocols were derived from the literature, a survey of critical care nurses, and personal communications with individuals who use innovative methods to expedite the weaning process and reduce costs. The protocols provide a guideline for standardizing the weaning process, but they do not negate the importance of having skilled clinicians who provide continuity in implementing the protocols. The nursing profession has the opportunity to provide leadership in reducing health care costs through implementation of standardized approaches to weaning patients from mechanical ventilatory support.

Clinical Protocols

Weaning from long-term mechanical ventilation.

Although many investigators have attempted to identify weaning predictors and weaning modes for use in long-term mechanically ventilated patients, none has emerged as superior. Furthermore, few investigators have viewed the process of weaning as a dynamic continuum; thus, guidelines for care of these patients have yet to be developed. Facilitative methods and therapies to enhance weaning potential, although attractive, have little scientific basis for application. Care delivery systems, which focus on systematic, comprehensive and coordinated care, are promising because outcomes demonstrate that they are economical, safe, and effective. This article reviews the research on weaning adult, long-term mechanically ventilated patients, suggests future research directions, and highlights the scientific basis for practice guidelines.

Adult

Terminal weaning from mechanical ventilation: a review.

Terminal weaning is a clinical intervention for withdrawing mechanical ventilatory support when such support is an unacceptable outcome for a patient. Withdrawal of life support must be done in a humane manner for the patient, the family, and the patient's care providers. Research-based directions for clinical practice are limited because of the paucity of research in this area. Recommendations for future study are related to methods, facilitative therapy, patient, family, and caregiver responses, and care delivery models.

Family

Comparison of breathing comfort during weaning with two ventilatory modes.

In twenty-one patients ventilated for > or = 3 days, we compared similar levels of partial support provided by synchronized intermittent mandatory ventilation (SIMV) and pressure support ventilation (PSV) in terms of breathing comfort. On a single day, eligible subjects experienced, in random order, both SIMV and PSV weaning protocols (sequential 20% reductions in support at timed intervals) separated by a 1 to 3 h rest. Breathing comfort was defined by subjective ratings of dyspnea and anxiety. Subjects reported significant levels of preweaning dyspnea and anxiety despite resting for at least 6 h. Dyspnea and anxiety were not significantly different between the two methods at any level of support. Our findings suggest that dyspnea and anxiety are higher than expected on "full" ventilator support, and that comfort may not differ between PSV and SIMV during active withdrawal of machine support.

Adult

Weaning from mechanical ventilation: concept development.

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.

Decision Making

Weaning from short-term mechanical ventilation: a review.

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.

Dyspnea

When weaning from mechanical ventilation fails.

OBJECTIVE: To describe the etiologies and indicators of weaning failure and to provide a framework for planning interventions to facilitate weaning of long-term ventilation patients. DATA SOURCE: A Medline search of human studies in English on weaning from mechanical ventilation. ARTICLE SELECTION: Articles were selected if they pertained to the assessment and management of weaning failure. Both research and review articles were included. DATA EXTRACTION: All pertinent articles were described, along with their limitations. DATA SYNTHESIS: Weaning from mechanical ventilation is an emerging science. Caring for patients who are difficult to wean requires expert clinical decision making so patients do not feel defeated and have the best chances for success. Combining the limited research on weaning intervention with clinical expertise helps to build a scientific basis for care and can assist clinicians in tailoring interventions to specific problems that precipitate weaning failure. CONCLUSION: A scientific approach to care may promote weaning in difficult cases and provide directions for future research into the etiologies of weaning failure.

Attitude to Health

Weaning from mechanical ventilation: current controversies.

As an acute episode of respiratory failure resolves for the patient who is receiving mechanical ventilation, the sometimes difficult task of resuming spontaneous ventilation begins. The resumption of spontaneous ventilation, commonly referred to as weaning, is often difficult for the patient with preexisting lung disease. The purpose of this article is to explore the current controversies related to weaning patients from mechanical ventilation. Patients with chronic obstructive pulmonary disease are used as examples, providing the background for understanding weaning in difficult cases. Weaning is conceptualized as a process of three phases: preweaning, weaning, and extubation. Important considerations during each phase are examined.

Education, Nursing, Continuing