End-of-life issues in AIDS: the research perspective.
Explore the source record for details and available documents.
Acquired Immunodeficiency Syndrome↗
Biomedical subjects
A R Knebel
Publications and source records attributed to A R Knebel.
Health related quality of life and disease severity in patients with alpha-1 antitrypsin deficiency.
STUDY QUESTION: To describe health-related quality of life (HRQL) in individuals with alpha-1 antitrypsin (AAT) deficiency, examine the cross-sectional relationship between disease severity and HRQL, and explore changes in lung function and HRQL over time in a subset of these individuals. MATERIAL/METHODS: Forty-five adults with AAT deficiency and moderate to severe emphysema completed the Chronic Respiratory Disease Questionnaire (CRQ), six-minute walk distance (6-MWD) and pulmonary function tests (PFTs). Twenty of the 45 were followed for two additional years with repeated measurements of CRQ and PFTs. RESULTS: The mean +/- SD age was 49 +/- 8 years. Initial CRQ subscale scores were: dyspnea 17.5 +/- 4.3; fatigue 17.0 +/- 5.46; emotional function 33.1 +/- 8.67; and mastery 21.7 +/- 4.65. No relationship was found between percent predicted forced expiratory volume in one second (FEV1%) and CRQ score; 6 MWD and fatigue correlated significantly (r = 0.32, p < 0.05). Repeated PFT and CRQ measurements in 20 subjects showed statistically significant declines in FEV1 and slow vital capacity (SVC), but no change in CRQ scores. CONCLUSIONS: Results suggest persons with AAT deficiency face challenges to HRQL that are similar to older adults with chronic pulmonary disease. Further research is needed on the nature of the relationship between disease severity and HRQL in this population.
Adult↗
Clinical evaluation of noninvasive monitoring of oxygen saturation in critically ill patients.
OBJECTIVE: To examine the effect of abnormal cardiac index on the accuracy of measurement of oxygen saturation by pulse oximetry. METHODS: Forty-six patients (mean age, 49 years) in a 9-bed medical ICU were studied. Measurements of oxygen saturation obtained with pulse oximeters and with a functional cooximeter were collected at baseline and 4, 8, 16, 24, 32, 40, and 48 hours later. Hemodynamic and cardiopulmonary parameters were recorded. RESULTS: The Bland-Altman technique yielded upper and lower limits of agreement of 2.53% and -7.11%. Most (95.7%) of the differences between the measurements of oxygen saturation obtained with the 2 methods were within these limits, although some of these differences may be clinically unacceptable. The bias was -2.29%, and the precision was 2.41%. The clinical conditions associated with inaccurate tracking of saturation by pulse oximetry across the range of actual arterial oxygen saturation values were abnormal cardiac index, partial pressure of carbon dioxide, heart rate, and pulmonary capillary wedge pressure. CONCLUSIONS: In patients with abnormal cardiac index, the pulse oximeter measurements exceeded the actual oxygen saturation by up to 7%. Pending prospective studies, clinicians should be aware that when certain cardiopulmonary parameters are abnormal, the margin of error in measurements of oxygen saturation obtained with a pulse oximeter may be greater than when those parameters are normal.
Adult↗
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↗
Dyspnea management in alpha-1 antitrypsin deficiency: effect of oxygen administration.
BACKGROUND: A deficiency of alpha-1 antitrypsin (AAT) can lead to pulmonary disease in middle-aged adults in whom dyspnea management can be a significant issue. OBJECTIVE: The research addressed whether short-term oxygen (O2) administration during activities might decrease dyspnea and improve exercise performance in nonhypoxemic patients with emphysema caused by a deficiency of alpha-1 antitrypsin. METHOD: This was a double-blind, randomized crossover study of 31 subjects with a deficiency of AAT (mean + SD, age = 47 +/- 7), moderate emphysema and a resting PaO2 > 70 mm Hg. Oxygen saturation (SpO2), 6-minute walk distance, and end of walk dyspnea were measured during three practice walks and during walks with nasal cannula administration of O2 (intervention) and compressed air (control). RESULTS: Repeated measures analysis of variance (ANOVA) showed significant differences across the walks for SpO (F= 18.9, p = 0.0001), 6-minute walk distance (F= 6.07, p = 0.004), and dyspnea (F= 4.44, p = 0.016). Using post hoc contrasts, SpO2 was the only variable that differed between 20, and compressed air (p < 0.0001). There was, however, an interaction effect of gender with O2 for dyspnea (F= 9.85, p = 0.004). Mean values showed that men did not benefit from O2 (p = 0.87). However, women experienced less dyspnea when receiving O2 as compared with compressed air (p = 0.0025), and although not statistically significant, the lower dyspnea with O2 corresponded with an increased walk distance of 79 feet. CONCLUSIONS: O2 administration may be useful for reducing dyspnea during exercise in selected populations.
Adult↗