Biomedical subjects

M Copass

Publications and source records attributed to M Copass.

17 recordsLinked to original sources

PubMed1999

Ten-year trend in survival and resource utilization at a level I trauma center.

OBJECTIVE: To determine the impact of increasing trauma center experience over time on survival and resource utilization. METHODS: The authors studied a retrospective cohort at a single level I trauma center over a 10-year period, from 1986 to 1995. Patients included all hospital admissions and emergency department deaths. The main outcome measures were the case-fatality rate adjusted for injury severity, hospital length of stay, and costs. RESULTS: A total of 25,979 patients were admitted or died. The number of patients per year increased, from 2063 in 1986 to 3313 in 1995. The proportion of patients transferred from another institution increased from 16.2% to 34.4%. Although mean length of stay declined by 28.4%, from 9.5 to 6.8 days, costs increased by 16.7%, from $14,174 to $16,547. The use of specific radiologic investigations increased; the frequency of operative procedures either remained unchanged (craniotomy, fracture fixation) or decreased (celiotomy). After adjusting for injury severity and demographic factors, the mortality rate decreased over 10 years. The improvement in survival was confined to patients with an injury severity score > or =16. CONCLUSION: Over a 10-year period, the case-fatality rate declined in patients with severe injuries. Overall acute care costs increased, partially because of the increased use of radiologic investigations. Even in otherwise established trauma centers, increasing cumulative experience results in improved survival rates in the most severely injured patients. These data suggest that experience contributes to a decrease in mortality rate after severe trauma and that developing trauma systems should consider this factor and limit the number of designated centers to maximize cumulative experience at individual centers.

Adult↗

PubMed1998

Human immunodeficiency virus seroprevalence among adults treated for out-of-hospital cardiac arrest in Seattle, Washington, 1989-1993.

STUDY OBJECTIVE: To estimate the potential risk of HIV exposure for those providing emergency care for out-of-hospital cardiac arrest in Seattle, Washington, by surveying the seroprevalence of HIV in the patient population. METHODS: We surveyed the seroprevalence of HIV among 1,474 persons treated for out-of-hospital cardiac arrest by paramedics during the years 1989 through 1993. Blood specimens were obtained at the site of cardiac arrest, stripped of personal identifiers, and tested for HIV-1 and HIV-2 by enzyme immunoassay and Western blot. RESULTS: Among the 1,011 men, 8 (.8%, 95 percent confidence interval .3% to 1.4%) were seropositive for HIV-1 during this 5-year period; all 8 were younger than age 55. No serologic evidence of HIV infection was detected among the 463 women. CONCLUSION: The seroprevalence of HIV in this population was relatively low. Risk of possible HIV transmission during paramedic treatment was remote.

Adult↗

PubMed1997

Introduction of unmarked mutations in the Helicobacter pylori vacA gene with a sucrose sensitivity marker.

Research on Helicobacter pylori has been hindered by the lack of useful genetic tools. Using the sacB gene of Bacillus subtilis, we developed a sucrose-based counterselection system that allows introduction of unmarked mutations in H. pylori. A kan-sacB cassette, consisting of the sacB gene expressed from the H. pylori flagellin promoter and the kanamycin resistance module, was introduced by homologous recombination into a target H. pylori gene. The resultant strains were sucrose sensitive and kanamycin resistant. Following transformation with a mutated allele, growth in sucrose-containing medium allowed the selection of strains that had lost the kan-sacB module and had integrated the unmarked allele. We have used this cassette to perform a site-directed modification of two histidine residues encoded by the vacA gene in a two-step procedure. This system should prove useful in the site-directed mutagenesis of H. pylori genes.

Alleles↗

PubMed1996

Prehospital endotracheal intubation of children by paramedics.

STUDY OBJECTIVE: To describe the experience of an emergency medical services system with the use of liberal indications for prehospital pediatric endotracheal intubation. METHODS: We performed a retrospective review of prehospital and hospital patient records in an urban and suburban prehospital care system. The study included all children aged 15 years or younger who were intubated in the prehospital setting by King County paramedics from January 1, 1984, to December 31, 1990. RESULTS: During the 7-year study period, 654 children were intubated, of which 355 (54%) were study patients. The median age of the patients was 3 years; 60% had an injury diagnosis. On arrival of the paramedics, 60% of the patients were in sinus rhythm, 62% had a systolic blood pressure of 70 mm Hg or greater, and 56% had a respiratory rate of 10 breaths per minute or greater. The Glasgow Coma Scale score was 8 or lower in 83% of the patients. Succinylcholine was used to facilitate intubation in 47% of patients. On arrival at the emergency department, 79% of the patients were in sinus rhythm; 75% had an adequate blood pressure (70 mm Hg or greater); 86% had a PaO2 value of 100 mm Hg or greater; and 74% had a PaCO2 value of 45 mm Hg or lower. Complications of intubation, more than half of which were classified as minor, were noted in 22.6% of patients. We were unable to determine the number of failed intubation attempts. Most of the patients (58%) survived to hospital discharge. Among cardiac arrest victims, only 12% survived. CONCLUSION: In a setting where paramedics practice with close medical direction, applying liberal indications for pediatric intubation and permitting the use of succinylcholine allowed paramedics to intubate children of different ages and diagnoses.

Adolescent↗

PubMed1995

Cyclodextrins for growth of Helicobacter pylori and production of vacuolating cytotoxin.

Growth of Helicobacter pylori in liquid culture requires the addition of media supplements that often interfere with subsequent purification of bacterial antigens. In order to determine whether cyclodextrins can substitute for conventional H. pylori growth supplements, we cultured H. pylori in the presence of five commercially available cyclodextrins. The effect of these compounds on the production of the vacuolating cytotoxin antigen was evaluated. Several cyclodextrins supported flourishing growth and permitted the consistent production of vacuolating cytotoxin. These data suggest that Brucella broth supplemented with cyclodextrins is an improved medium for bacterial culture and industrial production of H. pylori antigens.

Antigens, Bacterial↗

PubMed1993

The effect of acute alcohol intoxication and chronic alcohol abuse on outcome from trauma.

OBJECTIVE: To determine the effect of acute alcohol intoxication and chronic alcohol abuse on morbidity and mortality from trauma. DESIGN: Prospective cohort study. PATIENTS: Blunt or penetrating trauma patients at least 18 years of age admitted to one trauma center or dying at the injury scene. MAIN OUTCOME MEASURES: Mortality, complications (infection, pneumonia, respiratory failure, or multiple organ failure), and length of hospital stay. RESULTS: Acute intoxication had no effect on risk of dying--at the injury scene, within the first 24 hours of hospitalization, after the first 24 hours, or overall. Acute intoxication also did not increase the risk of complications and was associated with shorter lengths of stay. Patients with both biochemical and behavioral evidence of chronic alcohol abuse had a twofold increased risk of complications, particularly pneumonia and any infection, compared with those with no evidence of chronic alcohol abuse. CONCLUSIONS: Chronic, but not acute, alcohol abuse adversely affects outcome from trauma. Attention to the problem of chronic alcohol abuse in trauma patients is necessary, and screening trauma patients for chronic alcohol abuse appears to be warranted.

Adult↗

PubMed1993

The magnitude of acute and chronic alcohol abuse in trauma patients.

OBJECTIVE: To assess the incidence of acute alcohol intoxication and the proportion of trauma patients with evidence of chronic alcohol abuse. DESIGN: Prospective cohort study. SETTING: Regional level I trauma center. PARTICIPANTS: Patients aged 18 years and older admitted with blunt or penetrating trauma. MAIN OUTCOME MEASURES: Admission blood alcohol concentrations (BACs), the Short Michigan Alcohol Screening Test (SMAST), and biochemical markers for chronic alcohol abuse. RESULTS: Of the 2657 patients enrolled, 47.0% had a positive BAC and 35.8% were intoxicated (BAC > or = 100 mg/dL) on admission to the emergency department. Intoxicated patients were more likely to be 25 to 34 years old, male, and nonwhite; the highest proportion of intoxicated patients was among victims of stab wounds. Three fourths of acutely intoxicated patients had evidence of chronic alcoholism as indicated by a positive SMAST, and 25% to 35% of acutely intoxicated patients had biochemical evidence of chronic alcohol abuse. CONCLUSIONS: The high prevalence of both acute intoxication and chronic alcoholism in trauma patients indicates the need to diagnose and appropriately treat this pervasive problem in trauma victims.

Adolescent↗

PubMed1993

Stroke following rottweiler attack.

A previously healthy 50-year-old man suffered a major right cerebral infarction shortly after receiving head and neck bites in an attack by two rottweilers. Arteriography revealed occlusion of the right middle cerebral artery, an intimal flap and pseudoaneurysm in the high right internal carotid artery just proximal to the skull base, and an obstructed right vertebral artery. The powerful jaw mechanism of rottweilers and other large mastiff-type dogs makes their bites particularly destructive. The predilection of these animals for attacking the head and upper body makes occult crush injury to the extracranial cerebral vessels an important diagnostic consideration following such attacks.

Animals↗

PubMed1993

Hyperemic receptive aphasia on neuroSPECT.

NeuroSPECT of regional cerebral blood flow (rCBF) with Tc-99m HMPAO demonstrated left temporoparietal hyperemia in two patients with acute receptive aphasia. This finding prompted further testing with electroencephalography that added to the impression of ictal dysphasia. The differential diagnosis in one case included complicated migraine. NeuroSPECT depicts blood flow abnormalities in acute aphasic disorders, either due to ischemia, which is most commonly the cause, or due to hyperemia secondary to migraine or epilepsy. The treatment and prognosis of these latter conditions differ from stroke, and thus SPECT plays a role in patient management.

Adult↗

PubMed1992

Effects of alcohol intoxication on the initial assessment of trauma patients.

STUDY OBJECTIVES: To evaluate the influence of alcohol intoxication on the initial assessment and treatment of trauma patients. DESIGN: A prospective study of 2,237 trauma patients 18 years of age or older admitted to a Level I trauma center over a 19-month period. RESULTS: The study population was primarily male (78%) and white (73%) and had sustained blunt trauma (79%). One thousand fifty-three patients (47.1%) had positive blood alcohol concentration (BAC); median BAC in patients with any detectable alcohol was 179 mg/dL. When stratified by injury severity categories and compared with nonintoxicated (BAC less than 100 mg/dL) patients, intoxicated patients with an Injury Severity Score (ISS) of 1 to 15 were more likely to undergo the following: field and/or ED intubation (relative risk [RR], 2.22; 95% confidence interval [CI], 1.7 to 2.7); diagnostic peritoneal lavage (RR, 1.83; CI, 1.43 to 2.3); head computed tomography scanning (RR, 1.18; CI, 1.0 to 1.4); and intracranial pressure monitoring (RR, 1.41; CI, 0.74 to 2.7). The effects were less pronounced for those patients with an ISS of more than 15, except for intracranial pressure monitoring where patients with an ISS of more than 15 were 47% more likely to have intracranial pressure monitoring if intoxicated (RR, 1.47; CI, 1.2 to 1.9). CONCLUSION: Acute intoxication appears to alter the initial assessment of injury severity, resulting in an increased use of invasive diagnostic and therapeutic procedures.

Adolescent↗

PubMed1991

Non-invasive vascular tests reliably exclude occult arterial trauma in injured extremities.

We evaluated the ability of noninvasive vascular tests to exclude clinically significant occult arterial damage in injured extremities. In a preliminary study, a Doppler arterial pressure index (API) (the systolic AP in the injured extremity divided by the AP in an uninvolved arm) of less than 0.90 was found to have sensitivity and specificity of 95% and 97%, respectively, for major arterial injury. The negative predictive value for an API greater than 0.90 was 99%. Because these values suggested that noninvasive vascular tests might effectively be substituted for "exclusion" arteriography in patients at risk for silent extremity arterial injuries, we then conducted a trail in which arteriography was performed in extremity trauma victims only when the API was less than 0.90. Among 100 traumatized limbs (84 penetrating, 16 blunt) in 96 consecutive patients, 16 of 17 limbs (94%) with an API less than 0.90 had positive arteriographic findings, and seven underwent arterial reconstruction. Among 83 limbs with an API greater than 0.90, followup (including duplex scanning in 64 limbs) revealed five minor arterial lesions (four pseudoaneurysms, one arteriovenous fistula) but no major injuries. Arteriograms for extremity trauma fell from 14% to 5.2% of all angiographic studies performed (p less than 0.001, Chi-square). These studies suggest that noninvasive vascular tests can reliably exclude major occult arterial damage in injured extremities. Screening for such injuries with Doppler arterial pressure measurements, reserving arteriography for limbs in which the API is less than 0.90, is safe, accurate, and cost effective.

Adolescent↗

PubMed1990

Rapid diagnosis of thoracic aortic transection using intravenous digital subtraction angiography.

Rupture of the thoracic aorta associated with blunt trauma remains a frequently lethal injury. Although increasing numbers of patients with ruptured aortas are surviving to reach the hospital, the in-hospital mortality attending this injury remains high. Death due to transected aorta has been related to a delay in diagnosis. In an attempt to decrease the time necessary for diagnosis of this injury, we studied 50 patients using intravenous digital subtraction angiography (IVDSA) and conventional biplane angiography. We found that IVDSA was significantly faster than conventional biplane angiography, and that when IVDSA films are of diagnostic quality, they are sufficient to reliably demonstrate the presence of traumatic aortic transection. Our study was too small to establish whether IVDSA is a sufficiently sensitive test to exclude aortic injury. Further studies in this area need to be performed.

Angiography, Digital Subtraction↗

PubMed1990

Southeast Alaska to Seattle emergency medical air transports: demographics, stabilization, and outcomes.

Most rural EMS aeromedical transport studies have been based on distances of less than 100 miles. No current published studies exist evaluating long-distance transports. A retrospective chart review was conducted of all patients transported from southeast Alaska to Seattle, Washington, by an intensive care air ambulance over a five-year period (1982-1986). During the study period, 442 patients were transported an average one-way distance of 703 +/- 58.9 miles. Of these, 134 had a diagnosis of major or multiple trauma and were the focus of the study. Patient demographics and medical stabilization by Alaskan physicians, the flight team, and the receiving hospital were analyzed. Injury severity and outcomes also were evaluated. Of the study group, 31% required air transport within Alaska before being seen by a physician. The flight team provided major stabilization for 11% of the trauma victims, minor stabilization for 42%, and no further stabilization for 47%. Patient flights were categorized using previously published criteria as "essential" to survival in 27% of the cases, "helpful" in 55%, and "noncontributory" in 18%. This study presents a profile of patients injured in remote areas who require stabilization by rural, often nonsurgical physicians and face long-distance transfers before reaching definitive care. Health-care systems in sparsely populated areas may use this study as a reference for comparing trauma outcomes and quality of care in long-distance air transport.

Adolescent↗

PubMed1989

Empyema thoracis in patients undergoing emergent closed tube thoracostomy for thoracic trauma.

The vast majority of thoracic trauma victims require only observation or tube thoracostomy for definitive treatment of their thoracic injury. Although tube thoracostomy is generally considered a limited intervention, 2 to 25 percent of patients who undergo this procedure develop infectious complications. To determine the incidence and risk factors for the development of empyema thoracis after tube thoracostomy, a retrospective study was undertaken. We found that the development of empyema thoracis was increased in patients whose pleural space was incompletely drained and whose thoracic catheters were in place for a prolonged period.

Adolescent↗

PubMed1989

The sensitivity of vital signs in identifying major thoracoabdominal hemorrhage.

Prehospital and emergency room recordings of hemodynamic vital signs frequently play a major role in the evaluation and treatment of trauma victims. Guidelines for resuscitation and treatment are affected by absolute cutoffs in hemodynamic parameters. To determine the sensitivity of various strata of systolic blood pressure and heart rate in identifying patients with major thoracoabdominal hemorrhage, a 1-year retrospective review was conducted. A third of all patients presented to the emergency department with a normal blood pressure and over three-quarters attained a normal blood pressure during the emergency department evaluation. Although the sensitivity of vital signs in identifying this group of patients improved as the variance from normal increased, standard cutoffs were relatively insensitive. We conclude that normal postinjury vital signs do not predict the absence of potentially life-threatening hemorrhage and abnormal vital signs at any point after injury require investigation to rule out significant blood loss.

Abdominal Injuries↗

PubMed1989

Drug use in trauma victims.

We examined the prevalence and characteristics of drug use in a large sample of fatally and nonfatally injured trauma victims. Routinely collected urine specimens from 452 emergency room patients and 160 persons autopsied at the Medical Examiner's Office (MEO) were analyzed for the presence of marijuana, cocaine, opiates and benzodiazepines using EMIT enzyme immunoassays. Blood alcohol levels were also measured. Tests were positive for at least one drug in 40.3% of the ER and 18.7% of the MEO samples. Marijuana was the most commonly detected drug in both groups. Specimens were more likely to be positive in younger persons and in males, and in victims of assaults and traffic accidents. Alcohol was present in the blood in more than one third of ER and MEO samples. Only 39.8% of ER samples and 52.3% of MEO samples were negative for both alcohol and drugs.

Adolescent↗

PubMed1988

The medical and social impact of nonaccidental injury.

To determine the medical and economic impact of nonaccidental trauma at a regional trauma and emergency care facility, a prospective patient database was used to follow up all victims of intentional injury admitted during one year. Specific patient data were combined with financial data to determine the medical outcome, expenditure, and hospital reimbursement. We found that 17% of the 2451 trauma patients admitted to our facility were victims of nonaccidental injury. The majority of these patients were severely injured, with an average hospital stay of six days. Hospital charges averaged $13,000 per patient. Three fourths of these individuals required governmental funding for medical care. Six months after completion of the review, only two thirds of all expenditures had been reimbursed. These patients represent a high medical services use group and consume a disproportionately high percentage of medical resources.

Alcohol Drinking↗