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Biomedical subjects

K O'Mara

Publications and source records attributed to K O'Mara.

9 recordsLinked to original sources
PubMed1998

Near-fatal heat stroke during the 1995 heat wave in Chicago.

BACKGROUND: In July 1995, Chicago sustained a heat wave that resulted in more than 600 excess deaths, 3300 excess emergency department visits, and a substantial number of intensive care unit admissions for near-fatal heat stroke. OBJECTIVE: To describe the clinical features of patients admitted to an intensive care unit with near-fatal classic heat stroke. Patients were followed for 1 year to assess delayed functional outcome and mortality. DESIGN: Observational study. SETTING: Intensive care units in the Chicago area. PATIENTS: 58 patients admitted to the hospital from 12 July to 20 July 1995 who met the case definition of classic heat stroke. MEASUREMENTS: The data collection tool was designed to compile demographic and survival data and to permit analysis of organ system function by abstracting data on physical examination findings, electrocardiography and echocardiography results, fluid resuscitation, radiography results, and laboratory findings. Data on functional status at discharge and at 1 year were collected by using a modified Stanford Health Assessment Questionnaire. RESULTS: Patients experienced multiorgan dysfunction with neurologic impairment (100%), moderate to severe renal insufficiency (53%), disseminated intravascular coagulation (45%), and the acute respiratory distress syndrome (10%). Fifty-seven percent of patients had evidence of infection on admission. In-hospital mortality was 21%. Most survivors recovered near-normal renal, hematologic, and respiratory status, but disability persisted, resulting in moderate to severe functional impairment in 33% of patients at hospital discharge. At 1 year, no patient had improved functional status, and an additional 28% of patients had died. CONCLUSIONS: Near-fatal classic heat stroke is associated with multiorgan dysfunction. A high percentage of patients had infection at presentation. A high mortality rate was observed during acute hospitalization and at 1 year. In addition, substantial functional impairment at discharge persisted 1 year. The degree of functional disability correlated highly with survival at 1 year.

Adult↗
PubMed1998

Effect of standard and high dose ranitidine on [13C]urea breath test results.

OBJECTIVE: It has been suggested that standard dose H2 blockers will affect the [14-C]urea breath test. The aim of this study was to evaluate the effect of standard and high dose ranitidine on the [13C]urea breath test in a prospective cross-over study. METHODS: Volunteers found to be positive for H. pylori by IgG serology and [13C]urea breath test were given either ranitidine 150 mg b.i.d. or 300 mg b.i.d. for 14 days. Repeat breath tests were completed on the last day of antisecretory dosing and study patients were immediately crossed over to the other ranitidine dose. The third breath test was performed at 14 days after initiation of the new dose. RESULTS: A total of 20 volunteers were enrolled. Using the established cut-off of 2.4% for the commercial breath test, only one patient developed negative results on H2 blockers. This patient had negative breath tests on both ranitidine doses and remained test-negative off all medications 6 wk after study completion, suggesting either a false positive baseline test or an unexpected bacterial eradication. No specific trend in breath test results was observed for the group (p=NS). On ranitidine 300 mg, six of 19 patients elevated their breath results from 23% to 112% (mean 76%) above baseline. CONCLUSION: Ranitidine at standard or high doses did not generate a reproducible decline in breath test results. Histamine 2 blockers do not need to be discontinued before urea breath testing.

Anti-Ulcer Agents↗
PubMed1996

Changes in apical organization of choroidal cells in rats adapted to spaceflight or head-down tilt.

Structural changes observed in choroid plexuses from rats dissected aboard a space shuttle, on day 13 of an orbital flight (NASA STS-58 mission, SLS-2 Experiments) demonstrated that choroidal epithelial cells display a modified organization in a microgravitational environment. Results were compared with ultrastructural observations of choroid plexus from rats maintained under anti-orthostatic restraint (head-down tilt) for 14 days. In both experiment types, the main alterations observed by transmission electron microscopy, at the level of choroidal epithelial cells from the third and fourth ventricles, concerned the formation and the organization of apical microvilli, whereas pseudopod-like structures appeared. Immunocytochemical distribution of ezrin, a cytoskeletal protein involved in apical cell differentiation in choroid plexus, confirmed the structural alteration of microvilli in head-down tilted rats, Kinocilia tended to disappear from the apical surface, suggesting a partial loss of cell polarization. In addition, large amounts of clear vesicles were gathered in the apical cytoplasm of choroidal epithelial cells. Disorganization of apical microvilli accumulations of apical vesicles and partial loss of cell polarity showed that long-stays in weightlessness induced alterations in the fine structure of choroid plexus, consistent with a marked reduction of cerebrospinal fluid production.

Adaptation, Physiological↗
PubMed1985

Enhanced X-ray imaging of spheroids: an O(n) algorithm for characterizing convex blobs.

A simple O(n) algorithm to find the least squares circular fit of a tabulated function is presented. A demonstration of the algorithm's utility is provided by the analysis of a set of digitized band-filtered images of a radiograph of a common grapefruit. The application of this method of image understanding to the early radiographic detection and analysis of cancer (coin lesions) is proposed.

Computers↗
PubMed1983

Trauma and oral anticoagulants.

Patients on oral anticoagulants who present to the emergency department following trauma pose a special problem. Careful attention must be given to exclude any sites of overt or occult bleeding, particularly in the CNS, where there may be no external evidence of injury. A PT or thrombotest should be obtained as minimum laboratory workup in all cases. In specific situations, emergency reversal of anticoagulation must be undertaken.

Anticoagulants↗
PubMed1982

Tricyclic antidepressant overdose.

Overdose from tricyclic antidepressants (TCAs) is increasing. TCAs are well absorbed orally, highly protein bound, and highly lipid soluble. Clinical features of poisoning with TCAs occur within 12 hours of ingestion, usually after a dose of 20 mg/kg or more. Clinical symptomatology involves various anticholinergic, central nervous system, and cardiovascular effects. Cardiovascular toxicity accounts for the majority of the fatalities and may include a hyperdynamic response, various arrhythmias and heart blocks, or severe hypotension. Prolongation of the QRS interval of 10 msec or more implies severe toxicity. Many factors limit the usefulness of drug levels in the overdosed patient. Treatment revolves around good supportive care and general poisoning management. The physician should no longer use physostigmine precipitously. Sodium bicarbonate is effective in treating many of the cardiovascular complications. Other cardiac drugs are used but with varying efficacy. Patients with significant signs or symptoms of toxicity require monitored hospitalization until clinically free of manifestations for 24 to 48 hours.

Antidepressive Agents, Tricyclic↗