Measurement of cardiac troponin I levels in the emergency department: predictive value for cardiac and all-cause mortality.

OBJECTIVE: To assess the predictive value of cardiac troponin I levels in cardiac and all-cause mortality in patients presenting to an emergency department. DESIGN: A prospective cohort study. SETTING: The emergency department of a major tertiary teaching hospital in metropolitan Melbourne over a six-week period in 1998. PATIENTS: All patients with requests for cardiac enzyme level measurement. MAIN OUTCOME MEASURES: Cardiac and all-cause mortality within 30 days of presentation. RESULTS: 424 patients (232 men, 192 women; age range, 16-93 years) were reviewed. The 30-day mortality rate was 7.3% (31/424); in patients with raised levels of both creatine kinase (CK)-MB isoenzyme and troponin I this rate was 27% (7/26; 95% CI, 13%-44%); and in those with troponin I levels above 2 microg/L, but normal CK-MB values, it was 24% (5/21; 95% CI, 5%-43%). The mortality rate in the group with normal results of cardiac markers was 4.3% (14/328; 95% CI, 2.1%-6.5%). Patients with minor increases in troponin I levels (minimal myocardial damage) showed an intermediate 30-day mortality rate (13%, 5/39; 95% CI, 2%-24%). Other predictors of 30-day mortality included age, presentation with shortness of breath, and electrocardiography (ECG) changes diagnostic of acute myocardial infarction or consistent with ischaemia. Cardiovascular causes were responsible for most of the deaths in patients with raised troponin I levels. Multivariate logistic regression analysis showed that raised levels of troponin (> 2.0 microg/L), but not of CK-MB, predict 30-day mortality rate. CONCLUSIONS: Compared with CK-MB, cardiac troponin I more accurately predicts 30-day mortality rates in patients presenting to the emergency department. Moreover, troponin I levels identify additional groups of patients at increased risk of death not so identified by measuring CK-MB values.

Aortic transection.

BACKGROUND: Traumatic aortic transection is uncommon in those trauma patients reaching hospital alive. METHODS: The Victorian Major Trauma Study (VMTS) received data from 25 hospitals in Victoria, a State of 4.4 million people, and identified 1874 patients with blunt trauma and Injury Severity Score (ISS) greater than 15 over a 2-year period (1 March 1992-28 February 1993 and 1 May 1994-30 April 1995). The Federal Office of Road Safety (FORS) examined coronial data from 1 January 1992 to 31 December 1992. These studies allowed a retrospective, population-based review of experience with aortic transection. RESULTS: The VMTS identified 19 patients who reached hospital, with signs of life at the scene of the accident, during a 2-year period. Of these, 8 left hospital alive: 4 without disability and 4 with disability related to non-thoracic injury. The annual incidence of aortic transection for the State, based on FORS data, was 13 per 1000000, lower than other reported studies. Review of the management of patients in hospital confirmed the usefulness of initial chest X-ray in diagnosis and the high incidence of associated injury. CONCLUSIONS: The study raises a number of issues, including the question of direct referral of patients with severe chest injury to hospitals with cardiothoracic facilities, increased use of transoesophageal echocardiography in diagnosis and increased use of immediate laparotomy and thoracotomy in certain patients.

Rib fractures in major trauma.

BACKGROUND: To determine the mortality, hospital and intensive care unit (ICU) stay of rib fractures in patients admitted to Victorian hospitals for more than 1 day. METHODS: All patients fitting the entry criteria for the Victorian Major Trauma Study with fractured ribs were identified between 1 March 1992 and 28 February 1993. Aetiology, age, sex, associated injury and outcome were analysed. RESULTS: Patients with rib fractures had a higher mortality and length of hospital stay, but this was not significantly different from other trauma. A significantly higher percentage of patients required ICU care for rib fractures (44%) compared with the total group with blunt injury (24%). The majority of rib fractures resulted from motor vehicle accidents 361/541 (67%). Injuries occurring on the street/highway resulting in rib fractures were more likely to be major; 62% had Injury Severity Score (ISS) > 15. Fractured ribs occurred more commonly with increased age. Mortality for patients with fractured ribs versus total trauma group was higher in elderly patients. Univariate analysis showed rib fractures were a positive predictor of death but when adjusted for ISS and age, rib fractures became a negative predictor. Rib fractures were not predictors for length of ICU or hospital stay. CONCLUSION: The sample of rib fractures collected in this study underestimates the overall incidence. For those patients admitted to hospital with identified rib fractures, there is a trend towards higher mortality and morbidity. However, this association is better predicted by ISS and age.

Failure to agree on the electrocardiographic diagnosis of ventricular tachycardia.

STUDY OBJECTIVE: To determine the extent of interobserver agreement in the ECG diagnosis of ventricular tachycardia (VT) by using a four-step algorithm and three observers. METHODS: Simulated emergency department setting from records of an urban university teaching hospital. All ECGs taken in the ED during a 2-year period that showed a QRS duration of more than 120 msec and a heart rate faster than 110 beats per minute were reviewed. ECGs were categorized as demonstrating sinus rhythm (SR), irregular broad-complex tachycardia (I-BCT), or regular broad-complex tachycardia (BCT). Copies of the BCT ECGs and short clinical histories were given to each of three emergency physicians, who used a published, four-step algorithm (the Brugada algorithm) to categorize the BCT ECGs as indicating VT, indicating supraventricular tachycardia with aberrancy (SVT-A), or indeterminate. Interobserver agreement was assessed with the K-statistic. RESULTS: The records contained 178 ECGs, 88 of which were SR, 63 I-BCT, and 27 BCT. The 27 BCT ECGs were selected for review. The emergency physicians disagreed with each other 22% of the time in differentiating VT from SVT-A (K = .58). CONCLUSION: Application of the algorithm to actual clinical practice in the ED would probably result in the misdiagnosis of a substantial minority of patients having BCT, with potentially serious adverse consequences.

Patterns of injury from major trauma in Victoria.

Basic demographic and injury data were collected on all major trauma patients (ISS > 15) presenting to 25 Victorian hospitals over a 1 year period (March 1992-February 1993). A total of 1076 patients were identified with an Injury Severity Score (ISS) > 15. Of these, 957 resulted from blunt trauma, 68 from penetrating trauma and 51 from burns. Most serious blunt injury was transport-related (n = 652) but falls made up a significant proportion (n = 206). The pattern of injury in blunt trauma demonstrated in this study showed a preponderance of serious head, thoracic and limb injuries with less frequent occurrences of abdominal, spine and facial injuries. In major penetrating trauma, serious injuries of the thorax and abdomen were more frequent. Head injury is the most common cause of morbidity in major trauma patients. Motor vehicle accidents caused the majority of head injuries but, proportionately, head injury was more common in pedal cycle, pedestrian, motorcycle injuries and falls. The low frequency of major abdominal trauma has important implications for surgical training and resource allocation. In Victoria, various injury prevention interventions have been introduced such as compulsory wearing of bicycle helmets, a safer home environment and behavioral modifications through advertising. Injury prevention strategies must continue to target the populations at risk and assess the impact of interventions by accurate injury surveillance.

Major trauma in Australia: a regional analysis.

This study was undertaken to evaluate the frequency, distribution, cause, pattern, and outcome of patients suffering from major trauma in the State of Victoria over a 1-year period. No previous study in Australia has attempted a comprehensive regional analysis of major trauma. All major trauma admissions resulting from blunt, penetrating, and burns injury were identified, and data collected from emergency departments and intensive care log books at 25 major metropolitan and rural hospitals from the January 3, 1992 to February 28, 1993 by onsite data collectors. The total number of patients admitted into the study was 2,944. There were 1,076 major trauma cases with an Injury Severity Score greater than 15 in a population of 4.2 million people. The type of injury was predominantly blunt (87.5%), with only a small percentage of penetrating injuries (6.4%) and burns (6%). Major trauma in pediatric cases is less common (132 cases). The most common causes of injury were road transport (56%) and falls (22%). The overall outcome of the group was favorable when compared with the Major Trauma Outcome Study group (Z = 1.4, M = 0.93, W = 0.52). There was an unexpectedly low number of patients suffering from major trauma. Outcome using Trauma and Injury Severity Score methodology was favorable when compared with North America.

Allergies, upper respiratory tract infections, and asthma.

The aims of this study were (1) to quantify the prevalence of aeroallergen hypersensitivity in presentations for emergency treatment of asthma and (2) to determine the strength of association between viral upper respiratory tract infections (URTIs) and admission for treatment of asthma. A series of 209 asthmatic patients presenting to the Emergency Department (ED) of the Alfred Hospital over 6 months underwent skin prick testing and venipuncture for serum IgE and rye grass pollen (RGP) RAST. A case-control study of 38 asthmatic inpatients and 90 controls admitted for road trauma or endoscopy underwent nasopharyngeal aspiration for viral culture and immunofluorescence (IF). Eighty-four percent of ED asthmatic patients had one or more positive skin tests to common aeroallergens, 57% had a positive skin test, and 45% had a positive RAST to RGP. Viral cultures or IF studies were positive in 8 asthmatic patients and 2 controls. Asthmatic inpatients were 6 times more likely to have a viral URTI than were controls. It is concluded that aeroallergen hypersensitivity is present in most asthmatic patients presenting to the ED, and that there is a strong association between viral URTIs and admission for asthma.

Helicopter retrieval of primary trauma patients by a paramedic helicopter service.

All trauma cases flown over a 3.5 year period by the Metropolitan Helicopter Ambulance (MHA) from the accident scene to the Alfred Hospital were analysed. The MHA carries paramedics trained in advanced life support and is not under direct medical control. There were 254 patients (226 males, 28 females, mean age 34 years) of whom 242 had sustained blunt trauma. The mean distance from the accident scene to hospital was 28 nautical miles. The mean time from dispatch of the MHA to arrival at the Alfred was 82 min. The mean ground time at the scene was 32 min. Major trauma (an injury severity score (ISS) of 15 or more) was present in 62% of patients, and the mean ISS was 22.4. The major treatments at the accident scene by the paramedics were insertion of an intravenous (i.v.) cannula (242 cases), application of splints (197 cases), endotracheal intubation (35 patients) and needle thoracostomy to exclude tension pneumothorax (18 cases). There were 25 patients with a Glasgow Coma Score (GCS) less than 8 who were not intubated at the scene. Review of paramedic management identified four cases where prehospital care could have been improved but it is unlikely the final outcome would have changed: delay in transport (1 case), inadequate i.v. fluid resuscitation (2 cases) and delay in intubation (1 case). There was 1 case of undiagnosed tension pneumothorax that contributed to the patient's death and 1 case of non-intubation where the outcome may have been altered. Overall there were 38 deaths (14% mortality), which was not significantly different from the predicted mortality of 17%.(ABSTRACT TRUNCATED AT 250 WORDS)

Drug overdose--reducing the load.

OBJECTIVE: To review available information about various methods for reducing gastrointestinal absorption of a poison or drug. DATA SOURCES: Articles on overdose and accidental poisoning generated by the Australian Medlars Service and concentrating on the period between 1985 and 1990 were surveyed. Earlier studies were included if relevant. STUDY SELECTION AND DATA EXTRACTION: English language articles with an emphasis on studies using objective methods to measure individual and comparative efficacy of gastrointestinal decontamination techniques were selected. A total of 65 articles were reviewed. DATA SYNTHESIS: Gastric emptying procedures (gastric lavage or emesis caused by syrup of ipecac) are only effective if performed within one hour of drug ingestion. Gastric lavage is superior to syrup of ipecac. Oral administration of activated charcoal is more effective than either gastric emptying procedure, and is recommended for most cases of poisoning. Cathartics (sorbitol) can be used with activated charcoal. Whole bowel lavage with polyethylene glycol is indicated in selected cases of potentially lethal overdose where the toxic substance cannot be absorbed by charcoal and has passed the pylorus. CONCLUSIONS: Children--syrup of ipecac can be given at home to children older than 12 months. Most children who reach hospital can be treated by charcoal alone. ADULTS--Most patients are managed with supportive care and, in the absence of contraindications, a single dose of activated charcoal if seen within four hours of ingestion of the poison or drug. Gastric lavage is used if the patient presents within one hour of ingestion and has clinical features of toxicity.

Tension pneumoperitoneum after cardiopulmonary resuscitation.

OBJECTIVE: To increase awareness of the unusual complication of pneumoperitoneum after cardiopulmonary resuscitation. CLINICAL FEATURES: A 57-year-old male farmer with a history of chronic renal failure and heart disease, as well as severe oesophageal reflux for which fundoplication had been performed, developed a tension pneumoperitoneum after cardiopulmonary resuscitation. This resulted in lower limb cyanosis and an erection, a previously unreported complication. INTERVENTION AND OUTCOME: The tension was relieved by uncapping a peritoneal dialysis catheter that was in situ. The cyanosis and erection resolved immediately, suggesting that the tension pneumoperitoneum had caused significant venous obstruction. A 3 cm defect in the posterior wall of the stomach was repaired. CONCLUSION: The likelihood of pneumoperitoneum is reduced if standard guidelines for cardiopulmonary resuscitation are adhered to.

Tricyclic antidepressant poisoning.

OBJECTIVE: To review poisoning with tricyclic antidepressants. DATA SOURCE: English language literature search using Australian Medlars Service (1977-1989), manual search of journals and review of bibliographies in identified articles. STUDY SELECTION: Approximately 250 articles, abstracts and book chapters were selected for analysis. DATA EXTRACTION: The literature was reviewed and 93 articles were selected as representative of important advances. DATA SYNTHESIS: The major features of overdose are neurological, cardiac, respiratory and anticholinergic. Life-threatening complications develop within six hours of overdose or not at all. All patients seen within six hours of overdose should have their stomachs emptied. All patients should receive activated charcoal. Coma, convulsions, respiratory depression and hypotension are treated with standard resuscitation techniques and drugs. Treat patients with significant cardiotoxicity or cardiac arrest with alkalinisation by sodium bicarbonate or hyperventilation, aiming for an arterial pH of 7.45-7.55. Lignocaine is used for ventricular arrhythmias. Other antiarrhythmic drugs are contraindicated (Class 1A, Class 1C), potentially lethal (Class II), of no benefit (phenytoin) or of unproven efficacy (Class III and Class IV). Physostigmine has no role at all. Haemodialysis and haemoperfusion are of no benefit. CONCLUSION: The death rate of those who reach hospital is 2%-3%. Most of these deaths are cardiac in origin, and are caused by direct depression of myocardial function rather than cardiac arrhythmias.

Near drowning.

A doctor may be asked at any time to render first aid to an apparently drowned person, often when there is little or no medical equipment available and no trained persons present to assist with the resuscitation. This article concentrates on the pathophysiology of drowning, and how it influences the treatment (especially in the prehospital phase).

A randomized controlled clinical trial of pharmacokinetic theophylline dosing.

Ninety-one patients admitted to hospital with acute air-flow obstruction and requiring theophylline therapy were randomly assigned to either a monitored or a control group. Intravenously administered and subsequent orally administered theophylline dosages for patients in the monitored group were adjusted daily on the basis of each patients's estimated theophylline clearance; dosages for control patients were determined by attending physicians, using knowledge of theophylline serum concentrations. During intravenous therapy, fewer monitored than control patients had serum theophylline concentrations in the toxic range (18.9 versus 37.8%, p = 0.04), and during subsequent oral therapy more monitored than control patients had serum theophylline concentrations in the therapeutic range (71.1 versus 44.4%, p = 0.018). There was a trend for peak expiratory flow rates to normalize more quickly in monitored patients, and their mean duration of hospital stay was shorter (6.3 versus 8.7 days, p = 0.029). Two patients in the control group died; both had theophylline concentrations above 25 micrograms/ml and clinical toxicity. No serious side effects were observed in the monitored group. With pharmacokinetic individualization of theophylline dosage, more patients achieved serum concentrations in the therapeutic range, and there was a tendency for more rapid clinical improvement.

Renal localization of Tamm-horsfall protein in unilateral obstructive uropathy in rats.

The distribution of Tamm-horsfall protein (THP) within nephrons and in the renal interstitium of the kidney was examined in rats after unilateral ureteral ligation. Urinary casts containing THP were detected not only distal to the site of THP synthesis in cells of the ascending limbs of the loop of Henle, but also in more proximal portions of the nephron, suggesting retrograde intratubular movement of urine. THP-positive casts within Bowman's space of glomeruli were found by 6 hours and were maximal at 2 weeks after obstruction. At this time, THP was present in 25 per cent of all glomeruli, predominantly in central zones of the outer cortex. No morphologic evidence suggesting passage of THP across Bowman's capsule of these glomeruli was found. By contrast, interstitial THP aggregates resulting from urinary extravasation from tubules were detected throughout the study. These occurred earlier and were more numerous, albeit smaller, in the cortex where they were concentrated in periarterial and periglomerular sites. Multiple pathways for escape of urinary THP from tubules were demonstrated and included tubular ruptures and necrosis, forniceal tears, and venous polyps. Although occasional masses of THP in the interstitium were surrounded by inflammatory cells, the overall time course and distribution of interstitial THP deposits did not correlate closely with the development of widespread interstitial hypercellularity and scarring after obstruction. Although not directly linked to the pathogenesis of tissue injury in obstructive uropathy, THP provides an excellent marker of urinary extravasation and of the pathways of urine flow within the kidney under pathologic conditions.

Renal infection with Mycobacterium chelonei.

A case of renal infection with Mycobacterium chelonei is described. The infection probably occurred via haematogenous spread from an infected arteriovenous shunt in a uraemic woman. Prolonged treatment with intravenous cefoxitin combined with oral erythromycin and rifampicin eradicated the organism from the urine. Although renal function stabilised for one year, gradual deterioration to end-stage renal failure occurred.

Evaluation of the Gambro Lundia Major 1.36 m2 disposable parallel plate dialyzer.

The Gambro Lundia Major 1.36 m2 dialyzer was assessed in vivo in ten hemodialysis patients. Urea and creatinine clearances (measured as whole blood values at 60 minutes with a blood flow rate of 200 ml/minute) were 166 +/- 8 m/minute (mean +/- standard error of the mean, n = 9) and 115 +/- 4 ml/minute (n = 11). The creatinine clearance is 15% lower than in vitro data. There was a marked decrease in urea and creatinine clearance with third use of the dialyzer. The ultrafiltration rate was 490 ml/hour/100 mmHg. The priming volume was 125 ml (at a transmembrane pressure of 100 mmHg) and residual blood volume in the dialyzer was 0.57 +/- 0.11 ml (n = 5). The handling, storage and ease of disposal of the dialyzer is better than previous models and its performance characteristics are clinically acceptable.