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Biomedical subjects

J J Cottrell

Publications and source records attributed to J J Cottrell.

11 recordsLinked to original sources
PubMed1992

Is loss of body weight in chronic obstructive pulmonary disease patients with emphysema secondary to low tissue oxygenation?

The available clinical information to date does not support the hypothesis that tissue oxygen debt is the primary cause of the wasting process in the chronic obstructive pulmonary disease (COPD) patient population. However, this should not deter the 'believers' of the hypothesis from further investigation. The information outlined above supports the need for reconsideration of this clinical problem. Tissue oxygen requirements and utilization is a complex interplay of multiple variables. Likewise, the assessment of nutritional status in the setting of oxygen therapy is complicated by shifts in body fluid compartments independent of changes in the fat-free mass (FFM). Utilization of newer techniques will be required to resolve the contribution of low tissue oxygenation to the wasting process. The continued development of noninvasive methods for the assessment of tissue metabolism, cardiac function, and tissue energy requirements will allow investigators to further clarify the relationship between tissue oxygenation and metabolism in patients with COPD. Clinical trials designed to examine this issue must recognize the multiple effects of oxygen on all aspects of nutrient utilization, including caloric intake, needs, and tissue delivery. Failure to address all aspects of this system will lead to continued debate regarding the etiology of weight loss in the COPD patient population.

Clinical Trials as Topic↗
PubMed1992

Preoperative assessment of the thoracic surgical patient.

The preoperative assessment before pulmonary resection is both important and difficult. Pulmonary function testing is imperative to assess pulmonary reserve. If the FEV1 is less than 2 L, differential perfusion lung scans are used for a more accurate assessment. Exercise testing may also be used as an adjunct for high-risk patients or procedures. Although a predicted postoperative FEV1 of 800 mL is a widely accepted minimum for resection, it has not been scientifically validated. Lesser procedures (segmentectomy and wedge resection) may be performed with acceptable mortality in patients who were previously not considered surgical candidates.

Exercise Test↗
PubMed1989

Emergency transport by aeromedical blimp.

Recently there has been an explosive growth in the use of helicopters and fixed wing aircraft for the transportation of patients who are ill and injured. Although using such methods of transport may result in faster access to health care centres, their ultimate role for the civilian population is unclear. Unfortunately, there are many problems associated with aeromedical transport, particularly with rotary wing aircraft, which have shown an alarming tendency to crash. The use of lighter than air vehicles (blimps, hot air balloons) might offer most of the advantages of conventional aieromedical transport, with an appreciable improvement in safety.

Aircraft↗
PubMed1988

Altitude exposures during aircraft flight. Flying higher.

Commercial aircraft flight represents a highly variable altitude exposure that may result in significant hypoxemia for patients with cardiac or pulmonary disease. To develop better guidelines for travel by patients with cardiopulmonary disease, we measured inflight cabin altitude on 204 regularly scheduled commercial aircraft flights. Measurements were carried out on 16 different types of aircraft, operated by 28 airlines. The median altitude exposure for all flights was 6,214 feet (1894 m). Cabin altitudes ranged from sea level to 8,915 feet (2717 m). Inspired partial pressure of oxygen falls from 159 mm Hg at sea level to 127 mm Hg at 6,200 feet and further declines to 113 mm Hg at 9,000 ft. There was no significant difference between domestic and international flights. New generation aircraft fly at higher altitudes than older aircraft and are associated with greater altitude exposures to passengers (p = 0.002). The risk of hypoxemia may increase as newer model aircraft replace older ones.

Air Pressure↗
PubMed1983

A simplified computer report. Towards an understandable pulmonary function test.

We have developed a graphic format for the display of pulmonary function test results. Patient test results appear as a series of horizontal bar graphs. Each bar length is proportional to the test result and is printed over the normal ranges. This format allows rapid recognition of individually abnormal values. We have also grouped bars to create distinctive patterns characteristic of obstructive or restrictive lung disease. A computer program generates a custom form for each patient, displaying the results and ranges only for the specific test performed on that individual. No preprinting of forms is required. Written in the BASIC computer language, this program was designed to be flexible. A change of program parameters requires only minor program modification. In addition, because of its simplicity, our program can be implemented on almost any computer printer.

Computers↗
PubMed1983

Pulmonary function in progressive systemic sclerosis. Comparison of CREST syndrome variant with diffuse scleroderma.

The pulmonary function and chest roentgenograms were evaluated in 88 patients with the CREST syndrome variant of progressive systemic sclerosis (PSS or scleroderma). Seventy-two percent of the patients had abnormal pulmonary function. An isolated decrease in diffusing capacity was the most common abnormality noted, followed by restrictive abnormalities and airway obstruction. Chest roentgenograms revealed interstitial infiltrates consistent with pulmonary fibrosis in 33 percent. When compared to a contemporaneous group of 77 patients with PSS and diffuse scleroderma, patients with the CREST syndrome had similar abnormalities on pulmonary function testing and chest roentgenogram. However, patients with the CREST syndrome had a lower mean diffusing capacity despite a higher mean vital capacity; this combination of findings suggests primary pulmonary vascular disease. Calcified granulomata were identified significantly more often in PSS-CREST patients, while superior rib notching occurred exclusively in patients with PSS and diffuse scleroderma. The CREST variant of PSS is associated with frequent roentgenographic and pulmonary function abnormalities similar to those seen in PSS with diffuse scleroderma.

Adult↗
PubMed1983

Pulmonary function testing. What is 'normal'?

For many years, confusion has existed concerning the normal range for pulmonary function test results. Using statistical guidelines that have been traditionally applied to the interpretation of measured forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1), we have redefined normal limits for the most common pulmonary function test values, including those for FVC, FEV1, mean forced expiratory flow during the middle half of the FVC, FEV1 as a proportion of FVC, residual volume, functional residual capacity, total lung capacity, diffusion capacity, maximum voluntary ventilation, and peak expiratory flow. Our goal is to provide a simple and consistent scheme for interpretation of pulmonary function test data. We consider the assumptions used to achieve this simplification to be reasonable, as long as their limitations are understood.

Humans↗
PubMed1982

Office spirometry.

Explore the source record for details and available documents.

Ambulatory Care↗
PubMedDate not supplied

In-flight medical emergencies. One year of experience with the enhanced medical kit.

Recent regulations require commercial US aircraft to carry an enhanced medical kit. We reviewed kit use on United Airlines during the initial year of the regulations. We also surveyed passengers who became ill during flight and health care providers who used the new kit. The medical kit was used 362 times on 361 flights (once in every 1900 flights or one use for every 150,000 air travelers). Health care providers indicated that the kit was useful in more than 80% of emergencies and was occasionally lifesaving. In the emergencies in which the kit was used, 70% fell into one of seven major diagnostic groupings, including syncope/near syncope (29%), cardiac/chest pain (16%), asthma/lung disease/shortness of breath (10%), and allergic reactions (5%). With 450 million domestic air travelers per year, we would expect 3000 in-flight medical emergencies annually, and conclude that the enhanced medical kit is beneficial and propose that its effectiveness would be improved by the addition of a bronchodilator for inhalation.

Adult↗