In vivo detection of acinar microstructural changes in early emphysema with (3)He lung morphometry.

Purpose: To quantitatively characterize early emphysematous changes in the lung microstructure of current and former smokers with noninvasive helium 3 ((3)He) lung morphometry and to compare these results with the clinical standards, pulmonary function testing (PFT) and low-dose computed tomography (CT).

Materials And Methods: This study was approved by the local institutional review board, and all subjects provided informed consent. Thirty current and former smokers, each with a minimum 30-pack-year smoking history and mild or no abnormalities at PFT, underwent (3)He lung morphometry.

Accuracy of emphysema quantification performed with reduced numbers of CT sections.

Objective: The purpose of this study was to assess the accuracy of emphysema measurements obtained from systematic samples of evenly spaced CT images compared with measurements obtained from the entire scan.

Materials And Methods: Evenly spaced transverse sections from the CT studies of 136 heavy smokers who underwent screening for lung cancer in the National Lung Screening Trial and of 112 subjects who underwent imaging before lung volume reduction surgery were sampled retrospectively. The samples were acquired both by selection of specific numbers of evenly spaced images and by selection of images at specific distance intervals.

Hyperpolarized 3He MR imaging: physiologic monitoring observations and safety considerations in 100 consecutive subjects.

Purpose: To evaluate the safety of hyperpolarized helium 3 ((3)He) magnetic resonance (MR) imaging.

Materials And Methods: Local institutional review board approval and informed consent were obtained. Physiologic monitoring data were obtained before, during, and after hyperpolarized (3)He MR imaging in 100 consecutive subjects (57 men, 43 women; mean age, 52 years +/- 14 [standard deviation]).

Outcomes after unilateral lung volume reduction.

Background: For patients with end-stage emphysema undergoing lung volume reduction surgery (LVRS), we have preferred a bilateral (BLVRS) approach to achieve maximum benefit with a single procedure. A unilateral (ULVRS) approach has been used in certain patients in whom BLVRS is contraindicated.

Methods: Between January 1993 and December 2006, 43 consecutive patients underwent ULVRS.

Transpleural ventilation of explanted human lungs.

Background: The hypothesis that ventilation of emphysematous lungs would be enhanced by communication with the parenchyma through holes in the pleural surface was tested.

Methods: Fresh human lungs were obtained from patients with emphysema undergoing lung transplantation. Control human lungs were obtained from organ donors whose lungs, for technical reasons, were not considered suitable for implantation.

Cost of Gram-negative resistance.

Objective: It is unclear that infections with Gram-negative rods resistant to at least one major class of antibiotics (rGNR) have a greater effect on patient morbidity than infections caused by sensitive strains (sGNR). We wished to test the hypothesis that rGNR infections are associated with higher resource utilization.

Design: Retrospective observational cohort study of prospectively collected data.

3He diffusion MRI of the lung.

Rationale And Objectives: MR imaging of the restricted diffusion of laser-polarized 3He gas provides unique insights into the changes in lung microstructure in emphysema.

Results: We discuss measurements of ventilation (spin density), mean diffusivity, and the anisotropy of diffusion, which yields the mean acinar airway radius. In addition, the use of spatially modulated longitudinal magnetization allows diffusion to be measured over longer distances and times, with sensitivity to collateral ventilation paths.

The night float system: ensuring educational benefit.

Background: The ACGME mandated a change in resident work hours effective July 2003. We postulated that taking a block of night call would provide an opportunity for residents to improve clinical decision-making without detracting from operative experience.

Methods: The educational benefit of the Night Float model was evaluated weekly by anonymous questionnaires that assessed resident conference attendance, operative experience, attending teaching interactions, and consultations for the previous seven days.

Integrating social and ethics-based aspects of medicine into physician education.

Ethics plays an important, formative role in medical education, stimulating the transformation of a physiologist-scientist into a compassionate and competent clinician. Our clinical ethics program challenges students to observe and recognize inherent value conflicts and understand how such issues must be resolved in their day-to-day work. Advances in biomedical research that hold potential to enhance human health and treat disease are provoking controversial questions of current practices in medical ethics and spawning new, unprecedented ethical dilemmas.

Results of lung volume reduction surgery in patients meeting a national emphysema treatment trial high-risk criterion.

Objectives: A report from the National Emphysema Treatment Trial indicated that lung volume reduction candidates with a forced expiratory volume in 1 second and a diffusing capacity of carbon monoxide of 20% or less of predicted value were at high risk for mortality and were unlikely to benefit from surgical intervention. This article examines the applicability of the National Emphysema Treatment Trial findings to our own patients.

Methods: We reviewed 280 patients who underwent bilateral lung volume reduction surgery at our institution between January 1993 and December 2001.

A prospective evaluation of lung volume reduction surgery in 200 consecutive patients.

Objectives: Though numerous studies have demonstrated the short-term efficacy of lung volume reduction surgery (LVRS) in select patients with emphysema, the longer-term follow-up studies are just being reported. The primary objectives of this study were to assess long-term health-related quality of life, satisfaction, physiologic status, and survival of patients following LVRS.

Design: We used a prospective cohort study design to assess the first 200 patients undergoing bilateral LVRS (from 1993 to 1998), with follow-up through the year 2000.

Long-term outcome of bilateral lung volume reduction in 250 consecutive patients with emphysema.

Objective: Numerous reports have confirmed the early benefits of lung volume reduction surgery for selected patients with emphysema. This report documents the long-term survival and functional results after lung volume reduction surgery.

Methods: Between January 1993 and June 2000, a total of 250 consecutive patients underwent bilateral lung volume reduction surgery through median sternotomy at our institution.

Quantitative in vivo assessment of lung microstructure at the alveolar level with hyperpolarized 3He diffusion MRI.

The study of lung emphysema dates back to the beginning of the 17th century. Nevertheless, a number of important questions remain unanswered because a quantitative localized characterization of emphysema requires knowledge of lung structure at the alveolar level in the intact living lung. This information is not available from traditional imaging modalities and pulmonary function tests.

Repeatability of quantitative CT indexes of emphysema in patients evaluated for lung volume reduction surgery.

Purpose: To evaluate the repeatability of quantitative computed tomographic (CT) indexes of emphysema and the effect of spirometric gating of lung volume during CT in candidates for lung volume reduction surgery (LVRS).

Materials And Methods: Initial and same-day repeat routine inspiratory spiral chest CT studies were performed in 29 LVRS candidates (group 1, routine study vs repeat study). In a separate cohort of 29 LVRS candidates, spiral chest CT studies were performed both without and with spirometric gating by using a spirometer to trigger scanning at 90% of vital capacity (group 2, spirometric gating study).

Outcome of bilateral lung volume reduction in patients with emphysema potentially eligible for lung transplantation.

Objective: Between January 1993 and May 1998, we performed 200 consecutive bilateral lung volume reduction operations. After initial assessment, 99 of these patients were eligible for lung volume reduction and potentially eligible for immediate or eventual lung transplantation on the basis of age and absence of contraindications. All chose to proceed with lung volume reduction surgery.

MR imaging of diffusion of (3)He gas in healthy and diseased lungs.

Hyperpolarized (3)He gas MRI was used to form maps of the effective diffusivity of gas in human lungs. Images of diffusion as well as spin density are presented from a study of 11 healthy volunteers and 5 patients with severe emphysema. The effective rate of diffusion, D(e), of the gas is reduced by the alveolar walls; tissue destruction in emphysema is hypothesized to result in larger D(e).

Dynamic echo planar MR imaging of lung ventilation with hyperpolarized (3)He in normal subjects and patients with severe emphysema.

We applied the rapid imaging capability of echo planar MR pulse sequences and hyperpolarized (3)He ventilation imaging to observe the dynamic distribution of gas in the lungs during breathing. Findings in five normal volunteers (age 19-53 years) and four patients with severe smoking-related emphysema (age 56-71 years) were compared. All studies were performed on a 1.

Patient selection for lung volume reduction surgery: An objective model based on prior clinical decisions and quantitative CT analysis.

Objectives: We used whole-lung quantitative CT analysis (QCT)-an objective method of evaluating emphysema severity and distribution based on measurement of lung density-to determine whether subjective selection criteria for lung volume reduction surgery are applied consistently and to model the patient selection process, and assessed the relationship of the model to postoperative outcome.

Design: Logistic regression analysis using QCT indexes of emphysema and preoperative physiologic test results as the independent variables, and the decision to operate as the dependent variable.

Setting: University hospital.

Outcome of Medicare patients with emphysema selected for, but denied, a lung volume reduction operation.

Background: Lung volume reduction operation shows promise in relieving symptoms and improving function in highly selected patients with emphysema. Withdrawal of Medicare funding for patients selected for operation by standard criteria created a matched control group with which to compare lung volume reduction recipients.

Methods: A retrospective study was done comparing 22 volume reduction candidates denied operation with 65 contemporaneous and comparable volume reduction recipients.