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Biomedical subjects

K R Cooper

Publications and source records attributed to K R Cooper.

46 records · Page 3Linked to original sources
PubMed1984

Effect of kerosene heater emissions on indoor air quality and pulmonary function.

We monitored sulfur dioxide (SO2) and carbon monoxide (CO) concentrations in 14 suburban homes while modern kerosene heaters were operating. Mean concentrations were 7 parts per million (PPM) CO and 0.4 PPM SO2. Carboxyhemoglobin levels were significantly increased (p less than 0.0001), but performance on spirometric tests was not worsened by exposure to heater emissions in the 29 healthy residents of these homes. Our monitoring data agrees closely with predictions based on computer modeling and data from an environmental chamber study. Although we found no definite hazard for normal individuals, the concentration of either SO2 or CO exceeded standards for outdoor air quality in 8 of the 14 homes. Moreover, the SO2 concentrations we measured are sufficient to induce bronchospasm in some asthmatics. People with asthma should be informed of this risk.

Air Pollutants↗
PubMed1983

Effect of bronchoscopy on localization of gallium-67 citrate.

Bronchoscopy, bronchoalveolar lavage (BAL), and 67Ga lung scans are frequently performed for diagnosis or follow-up of patients with sarcoidosis, interstitial pneumonitis, lymphoma, infections, and bronchogenic carcinoma. Because many patients undergo all 3 of these procedures, it is important to determine what effects bronchoscopy and/or BAL may have on gallium imaging. Because 67Ga accumulates in neutrophils at the site of an inflammatory lesion as well as in those circulating in the vascular compartment, it seems reasonable to postulate that bronchoscopy could cause migration of labeled neutrophils into the lung, resulting in false positive gallium scans. To test this hypothesis, we studied 5 patients with varying chronologic relationships of 67Ga injection, gallium scanning, and bronchoscopy with BAL. In all patients, the repeat 67Ga lung scans remained normal or showed no change after bronchoscopy and BAL. We conclude that bronchoscopy with or without BAL does not cause increased 67Ga uptake by the lung.

Adult↗
PubMed1983

Accurate measurement of functional residual capacity and oxygen consumption of patients on mechanical ventilation.

We developed an apparatus and technique for the simultaneous measurement of functional residual capacity and oxygen uptake (VO2) for use in intensive care unit (ICU) patients. The accuracy of the functional residual capacity measurement was proven using an in vitro lung model and the reproducibility of this measurement was established by use in ICU patients. We tested the accuracy of the VO2 measurement in comparison with two other methods in common use among ICU patients and our method proved accurate. We conclude that this technique for measurement of functional residual capacity and VO2 is highly accurate and easily applied to patients on any mode of mechanical ventilation.

Functional Residual Capacity↗
PubMed1983

Reduced functional residual capacity and abnormal oxygenation in patients with severe head injury.

Severe head injury often results in hypoxemia, but the pathophysiology of this phenomenon is unclear. We studied 24 patients hospitalized after severe head injury to determine whether the abnormality of oxygen transfer as measured by venous admixture (Qs/Qt) was associated with a reduction in functional residual capacity (FRC) and also what changes in these variables could be induced by positive end-expiratory pressure (PEEP). Mean FRC was 68 percent of the value predicted for the upright position, and mean Qs/Qt was 0.196. The FRC and Qs/Qt were significantly related so that patients with the lowest FRC had the highest Qs/Qt (p less than 0.001). The FRC was small enough to expect closure of small airways in many of these patients. The addition of 10 cm H2O of PEEP resulted in an increase in FRC of 28 percent (+/- 15 percent [SD] of the value predicted for upright posture; Qs/Qt declined by 0.05 (+/- 0.05 [SD] ). Most of these patients had no spontaneous breathing due either to the severity of the brain injury or to the therapeutic hyperventilation and muscular paralysis employed to control intracranial pressure. We conclude that FRC is often reduced in patients hospitalized after severe head injury and that associated abnormalities of ventilation-perfusion matching often lead to an elevated Qs/Qt. Therapy with PEEP in the range of 10 to 15 cm H2O was well tolerated by our patients and can be used safely to reduce Qs/Qt.

Adolescent↗
PubMed1982

Effect of short-term sleep loss on breathing.

Loss of sleep is common among patients with respiratory disorders. We studied ventilatory performance in 15 normal subjects to determine whether a single night of sleep loss would have any detectable effect on breathing. Spirometry and hypercapnic ventilatory response testing were performed daily for 3 consecutive days with no sleep permitted between testing on days 1 and 2. We found a small but significant decline in forced vital capacity and maximal voluntary ventilation and a 20% decrease in hypercapnic ventilatory response slope after sleep loss (P less than 0.05). We conclude that sleep loss results in a significant deterioration in ventilatory performance, which may be clinically important to patients with respiratory diseases.

Adult↗
PubMed1980

Hepatoma presenting as a single cavitary lung mass.

A patient who had had a lobectomy for a large cavitary lung mass died one month later. An autopsy was performed and pathologic review of surgical and postmortem specimens confirmed that the original lung lesion was metastatic hepatoma. Excavating solitary metastases from primary adenocarcinomas represent the rarest form of cavitary metastatic lesion, and this is the first report of hepatocellular carcinoma presenting as a single cavitary lung mass.

Carcinoma, Hepatocellular↗
PubMedDate not supplied

Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/PCDF) in food samples collected in southern Mississippi, USA.

In 1994, we analyzed 43 foodstuff samples from local supermarkets in southern Mississippi, USA, for PCDD/PCDF. 2,3,7,8-Cl4DD could be quantified in 31 of these samples. On a lipid basis, levels in meat (0.53-1.10 pg I-TEQ/g) and dairy products (0.42-1.10 pg I-TEQ/g) were slightly lower than those reported from other industrialized countries. While levels in dairy samples from the United States and Europe are comparable, there is a difference in the contribution of individual congeners to the I-TEQ: for example, in milk samples from Germany approximately 40% of the I-TEQ is due to the presence of 2,3, 4,7,8-Cl5DF while in the Mississippi samples this congener only contributes 16%. The highest concentrations of PCDD/PCDF in our study were detected in the farm-raised catfish (10.2-27.8 pg I-TEQ/g). A unique finding was that in addition to the 2,3,7,8-substituted PCDD/PCDF the catfish samples contained many non-2,3,7,8-substituted congeners. This is unusual because vertebrate animals selectively eliminate or metabolize the non-2,3,7,8-substituted congeners.

Benzofurans↗
PubMedDate not supplied

Severe central nervous system damage and profound acidosis in persons exposed to pentaborane.

Three cases of pentaborane intoxication resulting from a common exposure are presented. These cases were characterized by the rapid onset of seizures and opisthotonic spasms accompanied by severe metabolic acidosis without respiratory compensation. Rhabdomyolysis occurred, serum transaminase levels were elevated, and liver damage was demonstrated histologically. One patient died and another sustained severe neurologic damage. These poisonings are unique with respect to the rapid and devastating neurologic consequences. Pentaborane is an extremely toxic compound and a major hazard not only to exposed workers but also to the medical personnel dealing with them.

Acidosis↗
PubMedDate not supplied

Prospective study of the pulmonary toxicity of continuously infused bleomycin.

Bleomycin is an effective antitumor drug but must be used cautiously because of its pulmonary toxicity. We performed a prospective study of the effects on pulmonary function when bleomycin was given as a continuous iv infusion over a 7-day period. Bleomycin was administered at a dose of 15 units/m2 as an iv push followed by 15 units /m2/day as a continuous iv drip. Thirteen previously untreated patients completed the study after receiving a mean total dose of 228 units. Pulmonary function tests were performed before bleomycin treatment and periodically during the subsequent 6 months. There was a small mean increase in both vital and diffusing capacities after 6 months, which was not statistically significant. No patient had a serious loss in pulmonary function. We conclude that the risk of bleomycin toxicity is low when the drug is given at this dose by continuous infusion. The risk may be less than the risk of toxicity from bolus injection in this dose range.

Aged↗