Biomedical subjects

John Hansen-Flaschen

Publications and source records attributed to John Hansen-Flaschen.

3 recordsLinked to original sources

PubMed2002

Pulmonary ventilation and perfusion scanning using hyperpolarized helium-3 MRI and arterial spin tagging in healthy normal subjects and in pulmonary embolism and orthotopic lung transplant patients.

Conventional nuclear ventilation/perfusion (V/Q) scanning is limited in spatial resolution and requires exposure to radioactivity. The acquisition of pulmonary V/Q images using MRI overcomes these difficulties. When inhaled, hyperpolarized helium-3 ((3)He) permits MRI of gas distribution. Magnetic labeling of blood (arterial spin-tagging (AST)) provides images of pulmonary perfusion. Three normal subjects, two patients who had undergone single lung transplantation for emphysema, and one subject with pulmonary embolism (PE), were imaged. (3)He distribution and blood perfusion appeared uniform in the normal subjects and throughout the lung allografts. Gas distribution and perfusion in the emphysematous lungs were non-uniform and paralleled radiographic abnormalities. AST imaging alone revealed a lower-lobe wedge-shaped perfusion defect in the patient with PE that corresponded to computed tomography (CT) imaging. Hyperpolarized (3)He gas is demonstrated to provide ventilation images of the lung. Blood perfusion information may be obtained during the same examination using the AST technique. The sequential application of these imaging methods provides a novel tool for studying V/Q relationships.

Helium↗

PubMed2002

Hospice care for patients with advanced lung disease.

Hospices are organized programs of support services for patients in the advanced stages of a terminal illness and their families. Although hospices serve dying patients regardless of diagnosis, limited available evidence suggests that these programs are relatively underutilized by patients dying of nonmalignant lung diseases. One explanation may be a lower awareness of hospice eligibility criteria and services among pulmonologists than oncologists. The unpredictability of death from advanced lung disease is another likely reason. Certain limitations on federal and private insurance coverage for patients with advanced lung disease probably contribute as well. For those patients who do enroll, hospice offers expert palliation of physical, psychological, social, and spiritual distress, as well as practical support for home care needs, hospitalization for short-term control of symptoms, and inpatient respite care for relief of home caregivers. Hospice workers view dying as an active phase of life filled with the pursuit of goals that patients and family members wish to complete before or shortly after the end of life. This article reviews hospice care in the United States with particular attention to eligibility criteria and services available for patients who are dying of an advanced lung disease. Specific recommendations are offered for referring respiratory disease patients to hospice programs.

Combined Modality Therapy↗

PubMed2002

Validating a dipstick method for detecting recent smoking.

This report evaluates the validity of a new method for verifying self-reported smoking status in patients presenting for pulmonary medicine treatment. A prospective comparison was made between self-reports of smoking status and a new semiquantitative, enzyme-linked, immunosorbent assay-based method testing for the presence of a prime nicotine metabolite, cotinine. Results were validated by gas chromatography/mass spectrometry. Data were collected in an urban, academic, tertiary health care setting. The study included 76 consecutive new patients presenting to participating clinical practices at the Pulmonology or Thoracic Surgery Services. Before taking a smoking history, patients were informed that their urine would be tested onsite for the presence of nicotine using a new method, the NicoMeter, for determining tobacco product exposure, followed by more standard laboratory testing. The level of agreement between the biochemical measurement types was excellent, kappa = 0.777. The new biochemical measurement type used was easy to use. Self-reported smoking status corresponded closely to biochemical testing. However, there was a 5.3-9.5% misclassification of smoking status among the group studied, depending upon the measurement type used. Among 32 lung cancer patients, 15.6%, most likely misrepresented their current smoking status. The NicoMeter appears to be a valid and useful method for confirming self-reported smoking status. Lung cancer patients had a higher rate of inaccurate nonsmoking compared with patients with nonmalignant pulmonary disease. The findings have implications for investigators who accept self-reported smoking status without biochemical verification.

Aged↗