Quantifying patient centered outcomes associated with the use of bilateral endobronchial coil treatment in patients with severe emphysema.

OBJECTIVE: To determine the impact of endobronchial coils on health-related quality-of-life (HRQoL). This paper utilizes trial data to identify the predictors of HRQoL in patients with severe emphysema, and subsequently estimates the impact of a new treatment on HRQoL (measured by utilities). These utility estimates are used to generate indicative long-term QALY estimates for a range of clinically plausible scenarios as a precursor to cost-effectiveness analyses. METHODS: Patient level HRQoL data from RENEW and the National Emphysema Treatment Trial (NETT) were combined and mapped to generic EuroQol 5-dimension health utility questionnaire (EQ-5D) values using a published algorithm. Multilevel statistical models were developed using treatment, time, response, and baseline characteristics (EQ-5D, age, gender, FEV1, lung RV) to predict EQ-5D over time. Lifetime QALY estimates were generated using published survival data from NETT (assuming no impact of treatment on mortality) and four clinically plausible response profiles. Each response profile was combined with assumptions around treatment impact (constant or time varying). RESULTS: After controlling for baseline characteristics, both treatment and response had a statistically significant impact (p < .001) on utility (+0.101 and +0.061, respectively). When combined with selected baseline characteristics and time, Coils and Standard of Care (SoC) generated more QALYs than SoC alone in all scenarios, with incremental lifetime benefit ranging from 0.29-0.55 QALYs. CONCLUSIONS: Coils and SoC resulted in statistically significant improvements in HRQoL compared to SoC alone in patients with severe emphysema.

Computed tomography assessment of lung volume changes after bronchial valve treatment.

The aim of the present study was to correlate clinical outcome measures following treatment with bronchial valves with regional lung volume. Computed tomography (CT) scan data from 57 subjects with severe emphysema were obtained from nine North American clinical trial sites. IBV(R) Valves (Spiration, Inc., Redmond, WA, USA) were placed to occlude segmental and subsegmental bronchi in right and left upper lobes using a flexible bronchoscope. Subjects completed a St George's Respiratory Questionnaire (SGRQ), pulmonary function test (PFT) and exercise capacity test. CT scans were analysed at baseline and at 1, 3 or 6 months after treatment to measure total and lobar lung density, volume and mass. Total lung volumes measured using CT were strongly correlated with PFT and did not change with treatment. However, the treated upper lobes significantly decreased in volume in 88% of the observations, by mean+/-sd 335+/-444 mL, or a decrease of 10.2% in the 6 month data. The untreated lobes had an 11.6% increase in volume. Changes in regional lung volume were associated with clinically meaningful improvements in SGRQ (-8.95+/-16.22), but not clinically meaningful PFT changes. The significant health status improvements reported by subjects following bilateral bronchial valve treatment are associated with regional lung volume changes and interlobar shift measured using computed tomography.

The role of apoptosis in respiratory diseases.

PURPOSE: The purpose of this article is to define apoptosis and describe how this cellular pathway is relevant to the pathogenesis of different respiratory diseases. This will assist clinical nurse specialists in understanding how new drugs and therapies inhibit and stimulate apoptotic pathways. BACKGROUND: Clinical nurse specialists need to expand their knowledge concerning the role of apoptosis so that they can better expand their spheres of influence. The 4 stages of apoptosis are discussed, as well as the various apoptotic pathways involved with asthma, emphysema, and acute respiratory distress syndrome that promote and inhibit apoptosis in patients. CONCLUSION: It is crucial for clinical nurse specialists to know what apoptosis is and how it relates to different pathophysiologic states. The challenge facing clinical nurse specialists is how to be kept informed and current concerning molecular and cellular mechanisms that are important in the practice setting. Strategies needed to maintain expertise include acquiring new knowledge, developing new skills, and changing attitudes about molecular biology. Apoptosis must become a significant part of any health professionals' continuing educational program because it has been recognized as the pathway to most any disease. Clinical nurse specialists who understand apoptosis and its pathways can use this knowledge to aid in the prevention and treatment of respiratory diseases.

Assessment and management of dyspnoea.

The terms 'dyspnoea' or 'breathlessness' refer to an individual's subjective awareness of discomfort related to the act of breathing. Elevations in CO2 above normal levels have been shown to cause breathlessness although it is unlikely to be the sole cause of breathlessness in a clinical setting. Several studies suggest that supplemental O2 during exercise will diminish the sensation of breathlessness although not all work has confirmed this finding. Much about the role of gas exchange in dyspnogenesis remains controversial. Phrenic blockade can abolish dyspnoea in response to breath-holding, while work in quadriplegics suggests that the intercostal muscles are not involved. A separate and direct pathway from the respiratory centre to the sensory cortex has also be implicated. Threshold discrimination has established that patients with chronic airflow limitation (CAL) have a blunted response to the addition of resistive loads to breathing, while category scaling methods (e.g. the Borg scale) have added descriptive terms to these physiological measures. Questionnaires often appear limited by their subjectivity and lack of correlation with physiological changes, but remain a useful tool in the clinical setting. In regard to therapy of dyspnoea high fat diets have a theoretical advantage in the CAL group but are generally not well tolerated. Resistive training devices and exercise training in CAL have been widely researched but in general, measures of lung remain unaltered and many of the studies would suggest that they have little, if any, inpact on functional status. Beta-agonists have been widely shown to be useful in CAL patients, despite the fact that bronchodilatation is not always demonstrable. Anticholinergics have be shown to be effective bronchodilators, but whether there is an improvement in dyspnoea above that expected from improvement in lung function is unclear. Animal studies and work in normal individuals would suggest that methylxanthines have a theoretical role in CAL possibly by increasing diaphragmatic muscle strength and decaying fatigue, but toxicity and lack of clear benefit in this group suggest that they should not be used as monotherapy. There is little evidence to support the use of opioids in chronic CAL although their role in the acute dyspnoea of end-stage CAL remains defined. The use of benzodiazepines has also been disappointing. Bullectomy remains widely accepted in clinical practice. New techniques such as 'reduction surgery' for diffuse emphysema are showing promise, although still in need of further testing and validation.

Relative risk and economic consequences of inpatient care among patients with renal failure.

During the final phases of chronic renal disease, inpatient care comprises an enormous share of morbidity and direct medical costs. Using an attributable risk methodology, this study calculated inpatient resource utilization and associated costs for chronic renal failure (CRF) and ESRD. A national hospital survey was used to identify the 348,962 hospitalizations for patients with renal failure in 1991. Among persons under the age of 65, pre-ESRD CRF patients had the same number of hospitalizations (nearly 75,000) as ESRD patients. Age-adjusted relative risk calculations indicate that patients with renal failure experience greater inpatient morbidity compared with other populations with chronic, progressive diseases. For example, compared with persons with diabetes, ischemic heart disease, hypertension, and emphysema, renal patients were at significantly higher risk of hospitalization for congestive heart failure, pneumonia, sepsis, electrolyte disorders, and gastrointestinal hemorrhage. Overall, renal failure patients were ten times more likely to be hospitalized (relative risk, 10.0; 95% confidence interval, 10.00 to 10.04) and, on average, were hospitalized nearly 1 day longer (P < 0.01) compared with the non-renal failure population in 1991. As a result, the economic consequences of inpatient care for the treatment of renal failure were enormous. In 1991, 222,827 hospitalizations, 1.5 million days of inpatient care, and $2.2 billion were attributable to renal failure. Further studies that examine other components of direct medical costs (e.g., long-term care, outpatient care, and pharmaceuticals) as well as indirect costs associated with the treatment and care of renal failure patients are warranted.