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Biomedical subjects

J M Dean

Publications and source records attributed to J M Dean.

At least 37 records · Page 2Linked to original sources
PubMed1999

Priorities for research in emergency medical services for children: results of a consensus conference.

OBJECTIVE: To arrive at a consensus on the priorities for future research in emergency medical services for children. METHODS: A consensus group was convened using the Rand-UCLA Consensus Process. The group took part in a 3-phase process. Round I involved reviewing a compendium of relevant research articles and answering a mailed questionnaire. Panel members were asked to prioritize topics on the basis of the 1993 Institute of Medicine Report on Emergency Medical Services for Children. Participants were asked to rate each topic based on the significance of the research, and whether the topic would (1) improve general knowledge (2), change behavior (3), improve health (4), decrease the cost of care, or (5) change public policy. A 4-point Likert scale was used. Participants were also asked if the research would require a multicenter study and if the research were feasible. Round II of the study involved a meeting of the panel, where the results of Round I were discussed and the topics were reprioritized. The topics were given a rank order and a final ranking was done in Round III. RESULTS: The panel considered a list of 32 topics; these were combined and reworded to give them more precise meaning. Several new topics were also added. Fifteen topics were given a rank order and placed within the 7 broad categories of the Institute of Medicine report. Clinical aspects of emergency care, systems organization, configuration, and operation and injury prevention were given high priority rankings. The first 5 topics were very close in point-rank order. CONCLUSION: The panel was able to develop a list of important topics for future research in emergency medical services for children that can be used by foundations, governmental agencies, and others in setting research agenda for such services.

Child↗
PubMed1999

Distinctive emergency department usage for injury for workers' compensation cases in Utah in 1996.

To compare emergency department services paid by worker's compensation (WC) with services paid by other payers, a state database of 72,747 emergency department visits for injured adults (ages 21 to 54) in 1996 in Utah was analyzed. WC visits accounted for 21.6% (15,704) of all adult injury visits. The mean emergency department charge for WC visits was $282, and the admission rate was 17 per 1000 visits. The mean charge for other payers was $334, and the admission rate was 43 per 1000 visits. Differences were also found between these groups for Injury Severity Scores and diagnoses. In summary, WC emergency department usage was associated with less severe injuries than was emergency department usage for other payers in Utah in 1996.

Accidents, Occupational↗
PubMed1999

Pre-hospital emergency medical services: a population based study of pediatric utilization.

OBJECTIVES: To examine emergency medical services (EMS) usage by children in one state. METHODS: Dispatch of an EMS vehicle in response to a call in the US is referred to as a "run". Runs for Utah for 1991-92 were linked to corresponding hospital records. Abbreviated injury severity scores (AISs) were assigned using ICDMAP-90 software. RESULTS: For the two year period there were at least 15 EMS runs per 100 children per year, with incomplete reporting from rural areas. EMS response and scene times were similar for all age groups, but interventions were less frequent for children under 5 years of age. When the principal AIS region of injury was the head, neck, or face, cervical immobilization was less frequent for children less than 5 years of age (54%) than for older children (76%) and immobilization was associated with improved outcome, using the crude measure of lower hospital charges. There was a similar association between splinting of upper extremity fractures and reduced hospital charges. Both associations did not appear to be due to differences in injury severity. CONCLUSIONS: The majority of EMS use by children is for trauma. Children less than 5 years of age are less likely to have an EMS intervention than older children. Whether the lower frequency of interventions is due to the lack of properly sized equipment on the vehicle, or to other factors, is undetermined.

Adolescent↗
PubMed1999

Effect of a pediatric trauma response team on emergency department treatment time and mortality of pediatric trauma victims.

OBJECTIVE: Delay in the provision of definitive care for critically injured children may adversely effect outcome. We sought to speed care in the emergency department (ED) for trauma victims by organizing a formal trauma response system. DESIGN: A case-control study of severely injured children, comparing those who received treatment before and after the creation of a formal trauma response team. SETTING: A tertiary pediatric referral hospital that is a locally designated pediatric trauma center, and also receives trauma victims from a geographically large area of the Western United States. SUBJECTS: Pediatric trauma victims identified as critically injured (designated as "trauma one") and treated by a hospital trauma response team during the first year of its existence. Control patients were matched with subjects by probability of survival scores, and were chosen from pediatric trauma victims treated at the same hospital during the year preceding the creation of the trauma team. INTERVENTIONS: A trauma response team was organized to respond to pediatric trauma victims seen in the ED. The decision to activate the trauma team (designation of patient as "trauma one") is made by the pediatric emergency medicine (PEM) physician before patient arrival in the ED, based on data received from prehospital care providers. Activation results in the notification and immediate travel to the ED of a pediatric surgeon, neurosurgeon, emergency physician, intensivist, pharmacist, radiology technician, phlebotomist, and intensive care unit nurse, and mobilization of an operating room team. Most trauma one patients arrived by helicopter directly from accident scenes. OUTCOME MEASURES: Data recorded included identifying information, diagnosis, time to head computerized tomography, time required for ED treatment, admission Revised Trauma Score, discharge Injury Severity Score, surgical procedures performed, and mortality outcome. Trauma Injury Severity Score methodology was used to calculate the probability of survival and mortality compared with the reference patients of the Major Trauma Outcome Study, by calculation of z score. RESULTS: Patients treated in the ED after trauma team initiation had statistically shorter times from arrival to computerized tomography scanning (27 +/- 2 vs 21 +/- 4 minutes), operating room (63 +/- 16 vs 623 +/- 27 minutes) and total time in the ED (85 +/- 8 vs 821 +/- 9 minutes). Calculation of z score showed that survival for the control group was not different from the reference population (z = -0.8068), although survival for trauma-one patients was significantly better than the reference population (z = 2.102). CONCLUSION: Before creation of the trauma team, relevant specialists were individually called to the ED for patient evaluation. When a formal trauma response team was organized, time required for ED treatment of severe trauma was decreased, and survival was better than predicted compared with the reference Major Trauma Outcome Study population.

Case-Control Studies↗
PubMed1999

Critical pathways for postoperative care after simple congenital heart surgery.

OBJECTIVE: To evaluate the clinical, financial, and parent/patient satisfaction impact of critical pathways on the postoperative care of pediatric cardiothoracic patients with simple congenital heart lesions. STUDY DESIGN: Critical pathways were developed by pediatric intensive care nurses and implemented under the direction of pediatric cardiothoracic surgeons. PATIENTS AND METHODS: Critical pathways were used during a 12-month study on 46 postoperative patients with simple repair of atrial septal defect (ASD), coarctation of the aorta (CoA), and patent ductus arteriosus (PDA). Using the study criteria, a control group of 58 patients was chosen from 1993. Prospective and control group data collected included postoperative intubation time, total laboratory tests, arterial blood gas utilization, morphine utilization, time in the pediatric intensive care unit, total hospital stay, total hospital charges, total hospital cost, and complications. Variances from the critical pathway and satisfaction data were also recorded for study patients. RESULTS: Resource utilization was reduced after implementation of critical pathways. Significant reductions were seen in total hours in the pediatric intensive care unit, total number of laboratory tests, postoperative intubation times, arterial blood gas utilization, morphine utilization, length of hospitalization (ASD, 4.9 to 3.1 days; CoA, 5.2 to 3.2 days; and PDA, 4.1 to 1.4 days; all P < 0.05), total hospital charges (ASD, $16,633 to $13,627; CoA, $14,292 to $8319; and PDA, $8249 to $4216; all P < 0.05), and total hospital costs. There was no increase in respiratory complications or other complications. Patients and families were generally satisfied with their hospital experience, including analgesia and length of hospitalization. CONCLUSIONS: Implementation of critical pathways reduced resource utilization and costs after repair of three simple congenital heart lesions, without obvious complications or patient dissatisfaction.

Aortic Coarctation↗
PubMed1998

Innovation in the assessment of nursing theory and its evaluation: a team approach.

In response to recent national changes in United Kingdom (UK) nurse education (e.g. devolution of assessment, moves to higher education, revision of the aims) and to local concerns (e.g. fairness to students, validity and reliability of written assessments, helping staff with less experience of assessment, student learning) an initiative has been developed at Southampton based on a team approach to marking and moderating. A five-stage evaluation was designed to accompany implementation of the initiative. The evaluation, carried out by a lecturer and an independent educational evaluator, involved both tutors/lecturers and students. Interviews, questionnaires and observation methods were used. Benefits of the initiative and of the particular model of evaluation included: increased knowledge and confidence in the validity and reliability of the marking and moderating process undertaken by tutor-teams; increased fairness to students; in-service tutor training related to student assessment; knowledge that assessment-promoted learning was taking place. A review of the total assessment programme was an unexpected outcome, including a review of the frequency and timing of assessments and of the written guidelines. The five-stage evaluation developed a feeling of involvement and heightened self-knowledge. Curricular understanding also increased; this helped to achieve the initiative as designed and intended. We recommend this model of evaluation; it promotes involvement of all concerned, students as well as staff, and generates valuable process-knowledge. It can be used in pre- and post-registration nurse education.

Attitude of Health Personnel↗
PubMed1997

Characterization of recombinant soybean leghemoglobin a and apolar distal histidine mutants.

The cDNA for soybean leghemoglobin a (Lba) was cloned from a root nodule cDNA library and expressed in Escherichia coli. The crystal structure of the ferric acetate complex of recombinant wild-type Lba was determined at a resolution of 2.2 A. Rate constants for O2, CO and NO binding to recombinant Lba are identical with those of native soybean Lba. Rate constants for hemin dissociation and auto-oxidation of wild-type Lba were compared with those of sperm whale myoglobin. At 37 degrees C and pH 7, soybean Lba is much less stable than sperm whale myoglobin due both to a fourfold higher rate of auto-oxidation and to a approximately 600-fold lower affinity for hemin. The role of His61(E7) in regulating oxygen binding was examined by site-directed mutagenesis. Replacement of His(E7) with Ala, Val or Leu causes little change in the equilibrium constant for O2 binding to soybean Lba, whereas the same mutations in sperm whale myoglobin cause 50 to 100-fold decreases in K(O2). These results show that, at neutral pH, hydrogen bonding with His(E7) is much less important in regulating O2 binding to the soybean protein. The His(E7) to Phe mutation does cause a significant decrease in K(O2) for Lba, apparently due to steric hindrance of the bound ligand. The rate constants for O2 dissociation from wild-type and native Lba decrease significantly with decreasing pH. In contrast, the O2 dissociation rate constants for mutants with apolar E7 residues are independent of pH, suggesting that hydrogen bonding to the distal histidine residue in the native protein is enhanced under acid conditions. All of these results support the hypothesis that the high affinity of Lba for oxygen and other ligands is determined primarily by enhanced accessibility and reactivity of the heme group.

Amino Acid Sequence↗
PubMed1997

Comparison of simultaneously obtained arterial and capillary blood gases in pediatric intensive care unit patients.

OBJECTIVE: To determine whether capillary blood gas measurements provide a clinically acceptable estimate of arterial pH, PCO2, and PO2. DESIGN: Prospective convenience sample. SETTING: Pediatric intensive care unit at a referral children's hospital. PATIENTS: Fifty children > 1 month of age with indwelling arterial catheters. INTERVENTIONS: A local anesthetic was applied to the third finger of the hand contralateral to a radial artery catheter. After 90 mins, simultaneous arterial and capillary blood gases were drawn. MEASUREMENTS AND MAIN RESULTS: Arterial and capillary pH, PcO2, and PO2 were measured. Heart rate and Wong/Baker faces score were noted before and during capillary blood gas collection to assess discomfort associated with blood collection. There was a strong correlation between capillary and arterial pH (r2 = .903, p < .0001). The relative average bias of the capillary pH was 0.009, with capillary lower than arterial and 95% limits of agreement of +/- 0.032. In all patients, the absolute value of the difference between arterial and capillary pH was < or = 0.05. There was a strong correlation between arterial and capillary PCO2 (r2 = .955, p < .0001). The relative average bias of the capillary PCO2 was 1.6 torr (0.21 kPa), with capillary higher than arterial and 95% limits of agreement of +/- 4.5 torr (+/- 0.6 kPa). In two of 50 patients, the absolute value of the difference between arterial and capillary PCO2 was > 6.5 torr (> 0.87 kPa). Despite a statistically significant correlation between capillary and arterial PO2 (r2 = .358, p < .0001), the absolute value of the difference between arterial and capillary PO2 was > 6.5 torr (> 0.87 kPa) in 42 of 50 patients. Pain, endotracheal intubation, vasoactive drips, or pharmacologic paralysis did not affect accuracy of the capillary pH or PCO2. CONCLUSIONS: Capillary blood gases accurately reflect arterial pH and PCO2 in most pediatric intensive care unit patients. Capillary samples did not significantly underestimate arterial hypercarbia or acidosis. This conservative reflection of metabolic status may be particularly useful in hemodynamically stable patients with mild-to-moderate lung disease.

Acidosis↗
PubMed1997

Nonradiographic assessment of enteral feeding tube position.

OBJECTIVE: To determine whether a clinical, nonradiographic criterion can be used to predict when the tip of a blindly placed feeding tube is in the small intestine. DESIGN: Prospective sample. SETTING: Pediatric intensive care unit at a tertiary care children's hospital. PATIENTS: Critically ill children requiring transpyloric feeding. INTERVENTIONS: The small bowel was intubated, using a blind, bedside transpyloric feeding tube placement protocol. The feeding tube was considered to be in the small bowel when <2 mL of a 10- mL aliquot of insufflated air could be aspirated from the feeding tube. This clinical criterion was confirmed with an abdominal radiograph. MEASUREMENTS AND MAIN RESULTS: Patient age ranged from 1 month to 19 yrs (median 6 months). Weight ranged from 2.2 to 60 kg (median 4.9). Median time to feeding tube placement was 10 mins (range 5 to 60). Eighty-nine percent of the patients were mechanically ventilated, while 28% of these patients were pharmacologically paralyzed. Seventy-five feeding tubes were inserted. There were no known complications. Ninety-nine (74/75) percent of the feeding tubes were positioned in the small bowel. The inability to aspirate insufflated air correctly predicted small bowel intubation with 99% certainty (Sequential Probability Ratio Test, p = .05 and power = .80). This test incorrectly predicted the position of only one feeding tube, the 26th, which was in the stomach. Of the 74 feeding tubes positioned in the small bowel, 13 feeding tubes were in the duodenum and 61 were in the jejunum. CONCLUSIONS: The inability to aspirate insufflated air confirms the transpyloric position of a feeding tube. Other clinical criteria did not successfully predict small bowel intubation. Use of this single test may obviate confirmatory abdominal radiographs in carefully selected patients and may lead to more cost-effective and timely initiation of enteral feedings.

Adolescent↗
PubMed1996

Ecstasy intoxication: an overlap between serotonin syndrome and neuroleptic malignant syndrome.

3,4-Methylenedioxymethamphetamine (MDMA), also known as "ecstasy" is a popular recreational drug with potential for abuse. Although its neurotoxic effects have been established in animal studies, the acute and long-term effects of this serotonergic agent in humans are still unknown. We describe a 19-year-old woman with overlapping symptoms of neuroleptic malignant syndrome and serotonin syndrome after a single exposure to MDMA. We also review 15 other cases reported in the literature to draw attention to the serious neurotoxicity, including fatal outcomes, caused by the use of this increasingly popular, illicit drug.

Adolescent↗
PubMed1996

Inhaled nitric oxide in children with severe lung disease: results of acute and prolonged therapy with two concentrations.

OBJECTIVES: To evaluate the acute effects of 11 and 60 parts per million (ppm) inhaled nitric oxide on the pulmonary vascular resistance and systemic oxygenation of children with severe lung disease, and to compare the outcome of prolonged therapy with approximately 10 and 40 ppm inhaled nitric oxide. DESIGN: Prospective, randomized study. SETTING: A 26-bed pediatric intensive care unit in a tertiary children's hospital. PATIENTS: Nineteen patients (median age 11 yrs, range 7 months to 16 yrs) with acute bilateral lung disease requiring a positive end-expiratory pressure (PEEP) of > 6 cm H2O and an FIO2 of > 0.5 for > 12 hrs were treated with inhaled nitric oxide. One patient was treated twice during the same hospitalization. INTERVENTIONS: Acute hemodynamic and blood gas effects of 11 and 60 ppm inhaled nitric oxide were studied, while delivering these concentrations in random order for intervals of 20 to 30 mins. Each interval was preceded by an interval of 20 to 30 mins without nitric oxide. Patients were then randomized and treated for a prolonged period with approximately 10 or 40 ppm inhaled nitric oxide independent of their initial acute responses to 11 and 60 ppm. Nitric oxide was discontinued when ventilatory support was decreased to a PEEP of < or = 6 cm H2O and an FIO2 of < or = 0.5. MEASUREMENTS AND MAIN RESULTS: Inhaled nitric oxide selectively decreased pulmonary vascular resistance and improved systemic oxygenation. Acute hemodynamic and blood gas effects of 11 and 60 ppm nitric oxide were similar. Systemic oxygenation improved to a greater extent in patients with radiographic evidence of residual aerated lung regions than in patients with diffuse bilateral lung disease. Maximum methemoglobin concentrations were greater in patients treated for a prolonged period with 40 ppm nitric oxide. The mortality and duration of therapy were similar for patients treated with 10 and 40 ppm inhaled nitric oxide. CONCLUSIONS: Pulmonary vascular resistance and systemic oxygenation are acutely improved to a similar extent by 11 and 60 ppm inhaled nitric oxide, and concentrations in excess of 10 ppm are probably not needed for prolonged therapy of children with severe lung disease.

Administration, Inhalation↗
PubMed1996

Tumor detachments of the retinal pigment epithelium in ocular/ central nervous system lymphoma.

BACKGROUND: Ocular/central nervous system (CNS) lymphoma is a B-lymphocyte-derived tumor that characteristically involves the retina, optic nerve head, vitreous, and subretinal pigment epithelial areas of the eye. METHOD: A retrospective analysis of clinical history and photography fluorescein angiography, histopathology, and immunocytochemistry of an untreated patient with ocular/CNS lymphoma was performed. RESULTS: Tumor detachments of the retinal pigment epithelium (RPE) evolved into areas of RPE atrophy and depigmentation and disciform scars. Histopathologic studies disclosed foci of tumor cells in the wall of and around blood vessels and between the RPE and Bruch's membrane. Immunocytochemistry identified the malignant cells as B-lymphocytes. CONCLUSIONS: The clinicopathologic features of a patient with ocular/CNS B-cell lymphoma are presented. Retinal pigment epithelium tumor detachments evolved to areas of RPE atrophy and depigmentation and disciform scars.

Aged↗
PubMed1996

Home mechanical ventilation of children.

The medical records of 89 ventilator-assisted children followed at the University of Michigan Medical Center from 1978 to 1993 were reviewed. The status of these children was remarkably stable. Parameters of communication, nutrition, education, and mobility changed very little over time, and fewer than half had to be re-admitted. Children aged 9 to 12 years had the most nursing hours; in terms of diagnosis, those with spinal cord injury and bronchopulmonary dysplasia had the most. The younger children had the longest initial hospital stay and the most re-admissions. The authors conclude that appropriate rehabilitation during the initial hospitalization can minimize later changes, instability and rehospitalizations, and that careful follow-up and periodic evaluation can improve the patients' health and function.

Adolescent↗
PubMed1996

Hemodynamic effects of N-acetylamrinone in a porcine model of group B streptococcal sepsis.

High plasma concentrations of N-acetylamrinone, a primary metabolite of amrinone, are measured in some children during prolonged amrinone infusion. The purpose of this investigation was to determine if N-acetylamrinone has direct hemodynamic effects independent of amrinone. Twenty neonatal piglets received an infusion of 6 x 10(9) colony-forming units/kg of group B Streptococcus to induce sepsis. Subsequently, they were divided into 1 of 3 groups and received a 1-hr infusion of either normal saline (N = 4); 8 mg/kg amrinone, followed by 20 micrograms/kg/min (N = 9); or 8 mg/kg N-acetylamrinone, followed by 20 micrograms/kg/min (N = 7). Hemodynamic measurements and arterial/venous blood-gas determinations were obtained every 30 min during the study. Systemic vascular resistance and pulmonary vascular resistance were calculated. One milliliter of blood was obtained every 30 min during drug administration to determine plasma amrinone and N-acetylamrinone concentrations. The mean amrinone plasma concentrations measured at 30 and 60 min during the infusion time in the group receiving amrinone were 8.8 +/- 1.1 and 6.9 +/- 0.7 micrograms/ml, respectively. These animals experienced a significant decrease in mean pulmonary artery pressure and pulmonary vascular resistance, compared with saline controls after a 30-min infusion of amrinone. The mean N-acetylamrinone plasma concentrations measured at 30 and 60 min during the N-acetylamrinone infusion were 7.3 +/- 0.8 and 5.7 +/- 0.6 micrograms/ml, respectively. There was no difference between any hemodynamic parameter measured in these animals, compared with saline controls at any time during the infusion. We conclude that amrinone, but not N-acetylamrinone, causes pulmonary vasodilation in a porcine model of sepsis and that the parent drug is the sole active component in amrinone.

Amrinone↗
PubMed1995

Difference between the measured and ordered dose of catecholamine infusions.

OBJECTIVE: To measure the actual concentrations of dopamine, dobutamine, and epinephrine in infusates prepared for patients, and to compare these concentrations with those of the dopamine HCl, dobutamine, and epinephrine HCl infusates that had been prescribed to evaluate drug preparation accuracy. DESIGN: Prospective, unblind study. SETTING: Pediatric intensive care unit in a tertiary-care teaching hospital. PARTICIPANTS: All dopamine, dobutamine, and epinephrine infusions ordered for patients during the 2-month study period were eligible for inclusion in the study. MEASUREMENTS: Daily samples of dopamine, dobutamine, and epinephrine infusates that were prepared for 41 pediatric patients were obtained; the infusate catecholamine concentration was measured by HPLC and compared with the ordered concentration. The concentration than was multiplied by the rate of infusion to determine the catecholamine dose. MAIN RESULTS: There were significant differences between the measured doses of dopamine, dobutamine, and epinephrine and the dopamine HCl, dobutamine, and epinephrine HCl doses (p = 0.0001, p = 0.039, and p = 0.0009, respectively) that had been ordered because of preparation inaccuracies. Failure to account for the HCl salt in the stock drug accounted for some, but not all, of the inaccuracy of the dopamine HCl and epinephrine HCl infusates. There was a wide interday variability in the measured catecholamine dosage in patients receiving the same dose for 3 days or more. CONCLUSIONS: There are daily fluctuations in the preparation of dopamine, dobutamine, and epinephrine infusates that could alter the amount of drug actually delivered to critically ill patients and potentially contribute to their hemodynamic instability.

Adolescent↗