Diaphragmatic stimulation by a pacemaker.
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Aged↗
Biomedical subjects
J R Hedges
Publications and source records attributed to J R Hedges.
Pharyngeal gram stains in the treatment of sore throats.
The use of the direct pharyngeal Gram stain for diagnosis of group A beta-hemolytic streptococcal pharyngitis was evaluated. Seventy-five consecutive out-patients presented with pharyngitis (or high fever in infants) were studied with pharyngeal cultures and Gram stains. Gram stains were read as either positive, negative, or indeterminate for streptococcal pharyngitis. When these predictions were correlated with the resulting culture growth of group A beta-hemolytic streptococci, the predictive value of a throat smear Gram stain was found to be significant (p less than 0.005). There were two false positives and three false negatives. Approximately one third of the smears were in the indeterminate category. Although the Gram stain of a pharyngeal smear was found to be less sensitive than the routine throat culture, the ability to obtain inexpensive rapid microbiological information suggests that the Gram stain can be used as a quick screening procedure.
Adolescent↗
Morphological and functional effects of bile salts on rat colon.
By correlating morphological observations with quantitative measurements of net water transport, we determined whether bile salts altered colonic absorptive cells. Epithelial alteration was equivocal and water absorption was uninhibited during infusions of 1 mM deoxycholate or of concentrations of taurocholate less than 10 mM. In contrast, 3 mM deoxycholate and greater than 10 mM taurocholate caused severe altertion of colonic epithelium and inhibited water absorption. These studies suggest that bile salts in the low concentrations normally found within the colon have little effect on colonic structure or water absorption. On the other hand, abnormally high concentrations of bile salts do alter colonic mucosal structure and function.
Animals↗
The effect of carcinogens on immune responses in the guinea-pig.
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Animals↗
Outcome of hospitalized injured patients after institution of a trauma system in an urban area.
OBJECTIVE: To determine if risk of death for hospitalized injured patients changes when an urban trauma system is implemented. DESIGN: An analysis of the risk of death in hospitalized injured patients in 1984 and 1985 (pretrauma system), 1986 and 1987 (early trauma system), and 1990 and 1991 (established trauma system) using hospital discharge abstract data. SETTING: A total of 18 acute care hospitals in the four-county area encompassing Portland, Ore. PATIENTS: A cohort of 70,350 hospitalized patients with at least one discharge diagnosis indicating injury. MAIN OUTCOME MEASURE: Death during hospitalization. RESULTS: After the trauma system was established, 77% of patients in the region with an Injury Severity Score (ISS) of 16 or greater were admitted to level I trauma centers. More than 72% of patients with an ISS less than 16 were hospitalized in nontrauma centers. Risk of death for injured patients hospitalized at level I trauma centers declined after the trauma system was established (odds ratio, 0.65; 95% confidence interval, 0.51 to 0.81). Patients who died in trauma centers after institution of the trauma system were younger and had more severe injuries, and the majority died within 1 day of admission, whereas patients who died in nontrauma centers died a median of 5 days after admission. CONCLUSION: Establishment of a trauma system shifted the more seriously injured patients to level I trauma centers, where there was a significant reduction in the adjusted death rate.
Adolescent↗
Comparison of prehospital trauma triage instruments in a semirural population.
An essential feature of the trauma center concept is the rapid delivery of patients with complicated injuries to a regional trauma center directly from the site of injury. A variety of triage instruments have been proposed to aid the prehospital personnel in making this difficult triage decision. We used a combination of prospective and retrospective analysis to evaluate and compare the performance of 11 recommended triage instruments on the same trauma population. Of the 130 patients evaluated by paramedics in a semirural area, 41 patients were considered desirable for trauma center triage. These patients were identified by either the absence of vital signs in the prehospital setting, death in the emergency department, immediate surgery other than for orthopedic extremity injury, or immediate admission to the intensive care unit. All subsequent in-hospital deaths occurred in the group of patients identified as deserving trauma center triage. Of the triage instruments, the Kane's "revised" checklist provided the largest improvement in odds against needing a trauma center when the triage instrument is negative. Of the triage instruments with a sensitivity greater than 70%, the respiratory/systolic pressure/Glasgow Coma Scale (RSG) score provided the largest improvement in odds for needing a trauma center when the triage instrument is positive. Although no triage instrument performed ideally, the patients missed by the triage instruments having a sensitivity greater than 70% were hemodynamically stable. Transfer of such patients to a trauma center following determination of the extent of underlying injury at a referring emergency department should be possible.
Adolescent↗
Limitations of chest pain follow-up from an urban teaching hospital emergency department.
Close outpatient follow-up of chest pain patients released from the emergency department (ED) has been suggested as an important means of detecting atypical presentations of cardiac ischemia. Urban teaching hospital patient populations often have limited private physician follow-up options and rely upon standard teaching hospital clinic systems. We analyzed the follow-up of 318 patients 30 or more years of age with nontraumatic chest pain released from the ED of a large urban teaching hospital. The planned disposition of the released patients was as follows: a medical clinic (136), another clinic or a private physician (76), or ED "as needed" (98); in addition, some patients left against medical advice (AMA) (8). The medical clinics received only 38% (51/136) of planned referrals. No subsequent record could be found for 13% (17/136) of referred patients. Only 17% (23/136) of referred patients were reevaluated within seven days. Two of the patients referred to medical clinics were admitted to the hospital within 24 hours for unstable angina and another was admitted from a medical clinic 16 days after ED evaluation with an acute myocardial infarction. Of patients with ED follow-up "as needed," one patient required admission for unstable angina 27 days after ED evaluation. Of the patients who left AMA, only two were reevaluated within 30 days. These findings suggest that specific measures to enhance follow-up must be instituted at urban teaching hospitals if chest pain patients are to be closely followed after ED release.
Adult↗
Threshold, enzymatic, and pathologic changes associated with prolonged transcutaneous pacing in a chronic heart block model.
Previous studies have shown that 30 minutes of transcutaneous cardiac pacing (TCP) can induce mild, clinically insignificant myocardial damage. Longer use of TCP may cause more severe cardiac damage which might result in an increase in the capture threshold for subsequent transvenous cardiac pacing (TVP). To assess this possibility, we examined changes induced by TCP in a canine chronic heart block model. Heart block was induced in conditioned dogs (n = 8) by His bundle ablation. Seven to 10 days after induction of heart block, six animals were paced. Cardiac enzymes were drawn before pacing and at 4, 24, 48, and 72 hours after pacing. Although there was a significant rise in CK at 4 and 24 hours (P less than 0.05), there was no detectable rise in the MB fraction in any of the paced animals. There was no elevation of LDH after pacing, although three animals did develop an LDH1/LDH2 isoenzyme flip indicative of myocardial damage. Animals were sacrificed 72 hours after pacing and their hearts were examined for gross and microscopic changes. The hearts of the paced animals revealed subendocardial, subepicardial, and perivascular areas of basophilic degeneration involving less than 1% of the myocardium in four of six animals. No evidence of such damage was seen in two heart-blocked control animals not undergoing pacing. TVP and TCP capture thresholds assessed before and after a 60-minute TCP pacing period showed no significant change. Hence, use of TCP for a 60-minute period prior to TVP appears to be a safe emergency pacing technique.
Animals↗
Analysis of base station morphine orders: assessment of supervising physician consistency.
Paramedic contact with a base station should gemerate consistent recommendations reflecting a consensus of base station physician care. In our urban EMS system, paramedics must contact a single base station to provide morphine sulfate (MS) for a patient with chest pain. We performed a retrospective cohort analysis of all prehospital MS requests for chest pain to determine the consistency of the circumstances for which the paramedic team was refused MS. These MS requests represented 123 of the 1,715 (7%) on-line physician consultations during the 6-month study. Only 15 of the 123 (12%) MS requests were refused. Neither the mean patient age, sex distribution, or presenting vital signs correlated with MS refusal. A maximum estimate of transport time to the hospital of less than or equal to 5 minutes was noted for 7 of 15 (47%) medication refusals compared to only 11 of 96 (11%) approvals with documented estimated transport times (P less than or equal to 0.005). A simultaneous request for nitroglycerin (NTG) was noted for 6 of the 15 (40%) medication refusals and 15 of the 108 (14%) approvals (P less than 0.05). We found refusal of MS administration to be uncommon. Supervising physicians tended to refuse MS when the transport time was short and when NTG was requested for concomitant administration. We also noted physician inconsistencies in refusal scenarios. These findings can guide physician consensus development to avoid sending mixed messages to paramedics.
Aged↗
Inability to validate a predictive score for infective endocarditis in intravenous drug users.
We sought to identify presenting features that should increase the accuracy of diagnosis of endocarditis in symptomatic intravenous drug use (IVDU) patients. We used two data sets of IVDU patients to develop and validate a score for endocarditis. A retrospective analysis of admitted IVDU patients was conducted with subsequent validation of endocarditis score on consecutive admitted IVDU patients at the same urban teaching hospital emergency department. Statistical comparison was made of presenting clinical features in patients with and without positive blood cultures or vegetation on their echocardiogram. Multivariable analysis of significant features was carried out. A clinical score was developed using a likelihood ratio to determine weighting. Validation of the score was tested by application to a second set of admitted symptomatic IVDU patients. The performance of the score was assessed by comparison of receiver operating characteristic curves for the two data sets. Factors associated with endocarditis on multivariable analysis were past history of endocarditis (negative correlation), total white blood cell (WBC) count, percentage neutrophils and bands on differential WBC count, infiltrate on chest x-ray, and arterial oxygenation (negative correlation). Prospective validation showed poor predictive performance of the endocarditis score. Presenting clinical, radiographic, and laboratory features do not appear helpful in estimating the clinical likelihood of endocarditis in symptomatic IVDU patients.
Adult↗
ExacTech blood glucose meter clinical trial.
INTRODUCTION: Current prehospital protocols for the management of patients with altered mental status include the empiric administration of hypertonic glucose, naloxone, and thiamine. The injudicious use of 50% dextrose (D50W) may result in hyperosmolarity, a worsening of hypokalemia, and unwarranted additional health-care costs for the patient. The administration of D50W also may worsen the neurological outcome of patients with local or generalized ischemia. OBJECTIVE: To evaluate the ExacTech blood glucose meter's ability to estimate blood glucose levels accurately and rapidly. METHODS: Emergency medical technicians (EMTs) from selected advanced life support (ALS) units in the Portland, Ore., metropolitan area participated in a prospective clinical trial of the ExacTech blood glucose meter. A convenience sample was drawn from emergency medical services (EMS) patients with suspected diabetic emergencies, altered mental status, and other neurological deficits. Venous blood samples were drawn from these populations at the same time as the ExacTech readings were obtained. The venous blood was submitted to the receiving hospitals for laboratory analysis of blood glucose levels, and a comparison was made between the results of the two methods. RESULTS: A total of 80 matched sets of data were obtained from 1 April 1990 through 6 May 1991. The hospital blood glucose values ranged from 8 to 1233 mg/dl. Sixteen (20%) of the patients were hypoglycemic (&.lt.60 mg/dl) and 23 (28.8%) were hyperglycemic ( greater than 180 mg/dl). The ExacTech device sensitivity and specificity for hypoglycemia using venous samples were 94.6% and 89.2%, respectively. For hyperglycemia, these same parameters were 87.5% and 97.1%. Pearson's r over the range of the instrument (40-450 mg/dl) was 0.8656 (p less than .001). If the prehospital "definition" of hypoglycemia (for threshold-to-treat) is raised to 65 mg/dl, the device has 100% sensitivity in the sample population. CONCLUSION: The device functioned accurately and consistently in the prehospital environment over a wide range of temperatures, and in the hands of many different individuals.
Adolescent↗
Emergent intubation and CT scan pathology of blunt trauma patients with Glasgow Coma Scale scores of 3-13.
INTRODUCTION: Widely accepted guidelines for use of pharmacologic agents for prehospital intubation have not been fully developed. Toward the goal of formulating specific guidelines, this study sought to determine how well the Glasgow Coma Scale (GCS) score stratifies the need for emergent intubation (within 30 minutes of emergency department arrival or in the prehospital setting). METHODS: A one-year, retrospective review of the charts of blunt trauma patients with presumed head injury who presented to the emergency department of a Level 1 trauma center with a GCS score of less than or equal to 13 was performed. A total of 120 patients met the inclusion and exclusion criteria. RESULTS: A significant number of patients presenting with a GCS score of less than or equal to 9 required emergent intubation. A significant minority of patients presenting with a GCS score of 10-13 required emergent intubation (20%) or had intracranial pathology on head CT scan (23%), and the majority of patients from this subgroup did not require subsequent intubation. Alcohol or substance intoxication and communication barriers such as deafness and language difficulties limited the clinical examination. CONCLUSIONS: Patients with a presenting GCS score of less than or equal to 9 represent candidates for the use of pharmacologic agents to facilitate aggressive airway control by well-trained and supervised emergency medical technicians (EMTs). Emergent intubation of patients with a GCS score of 10-13 is problematic. Patients with a presenting GCS score of 10-13 must be evaluated individually and closely monitored.(ABSTRACT TRUNCATED AT 250 WORDS)
Adolescent↗
Use of resuscitation skills by paramedics caring for critically injured children in Oregon.
OBJECTIVES: 1) To perform a statewide analysis of the frequency of major pediatric trauma cases and the use of resuscitation skills by paramedics (EMT-Ps). 2) To determine whether EMT-Ps use resuscitation skills less frequently for injured children than for older patients. METHODS STUDY DESIGN: Retrospective, database analysis of major trauma cases. SETTING AND POPULATION: 1995 statewide trauma registry data for patients with EMT-P scene care. OBSERVATIONS: The database included patient demographics, field vital signs, field procedures [e.g., intravenous (i.v.) line placement, chest compressions, needle thoracostomy, endotracheal intubation], field medication, and vital signs at ED presentation. DATA ANALYSIS: Patients aged < or = 12 years ("pediatric") were compared with those aged > 12 years ("older"). Analyses of patients with tachycardia, hypotension, and obtundation were performed using chi 2 analysis (alpha = 0.05). RESULTS: Of 3,502 trauma patients managed by an EMT-P, only 297 (8%) were aged < or = 12 years. Fewer pediatric patients (18%) than adults (27%) had an injury severity scale score > or = 16, p < 0.005. The frequency of most resuscitation skills and the administration of medications were not statistically different between patient groups. However, i.v.s were four times more likely to be placed in adults (76%) than in pediatric patients (42%), p < 0.001. Subanalyses indicated fewer pediatric patients with tachycardia (p = 0.02) or hypotension (p = 0.02) received an i.v., compared with adults who had similar physiologic parameters. Obtunded patients were equally likely to receive endotracheal intubation, although the procedure was rarely used (20%). CONCLUSIONS: EMT-Ps infrequently manage seriously injured children. i.v.s are less frequently placed in pediatric trauma patients, even in the setting of physiologic abnormalities. The contributions of these field procedures to patient outcomes should be evaluated further.
Adolescent↗
Evaluation of Syva EMIT Toxicological Serum Tricyclic Antidepressant Assay.
Tricyclic antidepressant (TCA) overdose is a common, potentially life-threatening finding in patients seen in emergency departments. There is a need to rapidly differentiate the TCA overdose from others in the emergency unit population. The Syva EMIT Toxicological Serum Tricyclic Antidepressant Assay for serum tricyclic antidepressant levels on 87 patients being evaluated for possible TCA overdose in the emergency department of the University of Cincinnati Hospital was examined. Serum tricyclic antidepressant concentrations were also determined by high performance liquid chromatography (HPLC), and comprehensive urine drug screening was performed by several methods. The EMIT assay correctly identified all 53 negative patients whose TCA levels were less than 300 ng/mL. The remaining 34 patients had positive TCA levels greater than 300 ng/mL by EMIT; however, 22 were confirmed by HPLC. Phenothiazines and phenothiazine metabolites were present in the remaining 12 unconfirmed patients, indicating a cross reaction with this class of drugs. It was concluded that the assay is useful to exclude the presence of serious TCA ingestion when a result of less than 300 ng/mL is obtained. However, a result of greater than 300 ng/mL is not specific for TCAs only, as evidenced by the cross reactions obtained with phenothiazines.
Antidepressive Agents, Tricyclic↗
Oregon trauma system: change in initial admission site and post- admission transfer of injured patients.
OBJECTIVE: Associate statewide trauma system development with a change in the percentage of injured patients initially hospitalized at Levels I and II categorized trauma hospitals and a change in the length of stay (LOS) prior to arrival at a Level I or II hospital (PRE-LOS) and total LOS (T-LOS) for post-admission transfer patients. METHODS: A retrospective analysis was performed using a hospital discharge database of 235,395 discharges with codes for acute injury managed at 74 acute care hospitals in Oregon State from 1983 to 1991. Primary outcome measures were admission site and transfer patient PRE-LOS and T-LOS. Predicator variables included category of initial hospital admission site, injury severity scale (ISS) score, head injury, age, and status of trauma system (pre-system, 1983 to 1987; transitional, 1988 to 1989; and post-system, 1991 to 1992). RESULTS: There was a significant increase in the percentage of initial admissions to hospitals with Level I and II categorization (17.6%, 26.2%, and 27.6% for the three periods of development, respectively; p < 0.00001). The percentage of patients with ISS scores greater than 15 admitted initially to Level I or II hospitals increased from 33.4% to 52.6% and 57.3%; p < 0.00001). Only 1,059 0.57%) of 185,321 patients initially admitted to Level III, Level IV, or noncategorized hospitals were transferred to a Level I or II hospital. Mean PRE-LOS for 1.059 transferred patients showed a significant decrease with system development (2.3, 1.9, and 1.8 days, respectively; p < 0.02). When adjusted for age, ISS score, and head injury effects, mean T-LOS was significantly reduced for the transitional and post-system periods (p < 0.05). CONCLUSIONS: In Oregon, development of a statewide trauma system was associated with increased initial admissions to Level I and II trauma hospitals. For those patients transferred to higher levels of care post- admission, hospital LOSs were decreased with trauma system development.
Adolescent↗
Pearls for the teaching of procedural skills at the bedside.
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Clinical Competence↗
Birth, or benchmark of evolution?
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Emergency Medicine↗
Early CK-MB elevations predict ischemic events in stable chest pain patients.
OBJECTIVE: To demonstrate that creatine kinase-MB fraction (CK-MB) elevations within three hours of presentation in the emergency department (ED) are associated with subsequent ischemic events in clinically stable chest pain patients. METHODS: Prospective cohort study at two university- affiliated teaching hospitals. Participants were consenting ED chest pain patients 25 years old or older without evidence of rhythm or hemodynamic instability (n = 449). Exclusions included ST-segment elevation > or = 0.1 mV in > or = 2 electrocardiogram leads, chest wall trauma, abnormal x-ray studies, and incomplete data collection. Measurements included presenting and three-hour CK-MB levels, presenting ECG, initial clinical impression of coronary care unit need, and clinical follow up. Monitored adverse events included myocardial ischemia necessitating coronary angioplasty or cardiac bypass surgery, recurrent in-hospital myocardial infarction, bradycardia requiring pacing, emergent cardioversion, cardiogenic shock, ventricular fibrillation, and death. RESULTS: Overall, nine (2%) of 449 patients experienced an ischemic event within the first 48 hours. All nine patients required either coronary angioplasty or bypass surgery. Four (44%) of the nine patients with 48-hour ischemic events had elevated CK-MB levels. Of 23 patients who had complications within one week of ED presentation, seven (30%) had elevated ED CK-MB levels. An elevated CK-MB level was associated with an ischemic event both within 48 hours (risk ratio 9.5; 95% CI 2.7-33.7) and within one week (risk ration 5.2; 95% CI 2.3-11.7). CONCLUSIONS: An elevated CK-MB level within three hours of ED presentation is associated with a subsequent ischemic event in the clinically stable chest pain patient without ST-segment elevation. However, the ED CK-MB identifies only a minority or otherwise low-risk patients who develop ischemic events; other markers for diagnosing myocardial ischemia in the ED are needed.
Adult↗