CAEP/ACMU 2001 Scientific Abstracts - Poster Presentations: 45-59

CAEP Abstracts

CJEM 2001;3(2):135-149

| 001-014 | 015-029 | 030-044 | 045-059 | 060-074 | 075-093 |

Poster Presentations

045 Attitude of emergency department patients with minor problems towards being treated by a nurse practitioner.
Moser MS, Abu-Laban RB, van Bee CA. University of British Columbia, Vancouver, British Columbia.

OBJECTIVES: Recently there has been increasing interest in alternate methods of health care delivery, including a possible role for nurse practitioners (NPs) in emergency departments (EDs). We sought to determine the attitude of ED patients with minor problems towards being treated by a NP and the characteristics of this population. METHODS: The study operated weekdays between 8am and 4pm from April 4, 2000, to July 13, 2000. Adults presenting to a tertiary ED with 1 or more of the following were eligible unless precluded by pain or language barriers: minor abrasion, laceration, bite, burn or extremity trauma; cast check; earache; superficial foreign body; lice/pinworms; morning after pill request; body fluid exposure; prescription refill; puncture wound; sore throat; subconjunctival hemorrhage; suture removal/check; tetanus immunization request; toothache; or female urinary tract infection (UTI). Consenting patients were provided background information and completed a brief survey prior to physician assessment. RESULTS: 213 patients were enrolled (86% of those eligible) and 6 surveys were excluded due to coding errors. The mean age of those studied was 34 years, and 58% were male. When asked about willingness to be treated by a NP for their problem, 72.5% of patients selected "Yes" (150/207: 95% confidence interval [CI] 65.8%-78.4%), 15.5% "uncertain" (32/207: 95% CI 10.8%-21.1%) and 12.1% "No" (25/207: 95% CI 8.0%-17.3%). Of those who selected "Yes," 21% indicated they would also still expect to see an emergency physician during their ED visit, while 67% indicated this was not essential. A logistic regression analysis run for secondary purposes found that willingness to be treated by a NP was independent of age, gender, or educational status. CONCLUSIONS: The majority of ED patients with minor problems indicate a willingness to be treated by a NP, often without any superimposed physician assessment. Whether this should lead to policy recommendations requires evaluation of many other factors including impact, logistics, cost and quality of care.
Key words: nurse practitioner

046 Comparison of pediatric triage assessment between registered nurses and emergency physicians.
Bergeron S, Gouin SS, Bailey B, Patel H. Hôpital Sainte-Justine, Montréal, Québec.

OBJECTIVES: To compare triage level assignment, using case scenarios, in a pediatric emergency department (ED) between registered nurses (RNs) and pediatric emergency physicians (PEPs). To compare triage level assignment by RNs and the PEPs to a consensus agreement gold standard. METHODS: Cross-sectional questionnaire survey sent to all RNs and PEPs working in the ED. The survey included 55 case scenarios providing details of the patient's symptoms, signs and mode of arrival. Participants were instructed to assign triage level on each case, using the following scale: resuscitation/emergent, urgent, less urgent, non-urgent. A priori, all cases were assigned a triage level by a consensus agreement using established triage guidelines. Kappa statistics and the mean number (±1 standard deviation [SD]) of correct responses were calculated. RESULTS: A response rate of 100% was
achieved (39 RNs, 24 PEPs). The kappa level of agreement (± 1 SD) amongst the RNs was 0.445 ± 0.003 and amongst the PEPs was 0.419 ± 0.005 (p < 0.0001). The mean number of correct responses (± 1 SD) for the RNs was 64.2% ± 8.0% and for the PEPs was 53.5% ± 8.1% (p < 0.0001). There were no significant differences by stratifying the RNs and the PEPs by experience level (<10 vs. >10 years) or by the type of shift work (day vs. evening vs. overnight). CONCLUSIONS: The level of agreement and accuracy of triage categorization was only moderate for both RNs and PEPs. Triage, a crucial step in emergency care, requires improved measurement.
Key words: triage, reliability

047 Paramedic rationale for non-compliance with peak expiratory flow measurements.
Millard W, Anton A. City of Calgary Emergency Medical Services and University of Calgary, Calgary, Alberta.

OBJECTIVES: Paramedics function on ambulance runs without direct medical supervision and therefore, compliance to medical protocols and standing orders is essential. A focused audit of paramedic compliance to peak expiratory flow (PEF) collection in a dyspnea protocol revealed compliance persistently below 20%. The objective for this study was to determine paramedic rationale for non-compliance. METHODS: A brief survey was developed and administered to paramedics in an urban Advanced Life Support service. The survey included paramedic demographics, questions to establish level of compliance to PEF collection and beliefs toward the impact of PEF collection on patient care, hypothesized rationale for non-compliance to PEF collection, and a section for additional comments. RESULTS: All mean scores were independent of age, gender and years of experience. The majority of respondents answered they "never" or "seldom" collected PEF pretreatment or post-treatment. Over 65% believed PEF "never" or "seldom" influenced field treatment. When paramedics chose not to collect PEF, the majority stated they "agreed" or "strongly agreed" it aggravated the patient's shortness of breath, it delayed treatment, and did not influence field treatment. Close to 80% "disagreed" or "strongly disagreed" with the statement "I am not properly trained" and equally disagreed with "the equipment is too complicated for patient and/or paramedic." CONCLUSIONS: The study results supported the hypothesis that paramedics did not believe PEF influenced patient treatment and delayed treatment and were therefore unwilling to collect PEF measurements from dyspnea patients. Without evidence to support the use of PEF as a better tool than those traditionally used by paramedics, it is unlikely PEF will be collected.
Key words: asthma, emergency medical services

048 Assessment of decision-making capacity: implications for refusal of care in the emergency department.
Gillis AE, Pauls M. Dalhousie University, Halifax, Nova Scotia.

OBJECTIVES: An elderly, homeless patient presents to the emergency department with an acute exacerbation of chronic obstructive pulmonary disease (COPD). She demands to leave before receiving treatment and the attending physician must decide if she should be permitted to leave. Emergency physicians need to respect patient autonomy but still provide an ethically and legally appropriate standard of care. They must understand the concepts of informed consent and decision-making capacity (DMC) and be able to determine when a patient's DMC is impaired. Various approaches have been proposed to aid physicians in this task, but currently, no standardized method exists. Moreover, it is unclear how useful these approaches are in the emergency setting. METHODS: A MEDLINE search was conducted and a literature review performed to identify the available tools for assessment of DMC and to establish the relevance of these tools to the emergency medicine setting. RESULTS: The approaches of Applebaum and Grisso (1990, 1998) and Thewes, Fitzgerald and Sulmasy (1996) are the most widely accepted. Both encourage a global assessment of DMC, including complete physical and psychiatric assessment, and offer a concise series of questions to guide the clinician in an objective assessment of DMC. No tools designed specifically for the emergency medicine setting were found. CONCLUSIONS: Emergency physicians must be able to assess a patient's DMC in an effective and efficient manner. Good assessment tools exist, although each one has its limitations and none has been designed specifically with the time restraints or acute nature of the emergency department in mind. These tools offer a strong framework for objective measure of DMC that may be adapted to different clinical scenarios. A need exists to formulate a standardized assessment tool specifically for emergency physicians.
Key words: ethics, refusal of care

049 Patients who leave without being seen in the emergency department.
Bullard M, Holroyd B, Craig W, Klassen T, Yiannakoulias N, Johnson D, et al. University of Alberta, Edmonton, Alberta.

OBJECTIVES: Patients who leave without being seen (LWBS) constitute a problem for emergency departments (EDs) due to their potential for increased morbidity and dissatisfaction. Few jurisdictions can accurately evaluate the pattern of LWBS for a large population; this study examines this ED subgroup using a provincial database. METHODS: All patients presenting to Alberta EDs were eligible for inclusion. Data were derived from a sample of ED patients treated in 17 health regions over 1 year (fiscal 98/99) with a specific disposition code of LWBS. Data were extracted from the Ambulatory Care Classification System (ACCS) database, computerized abstracts coded similarly across all regions. Diagnostic categories were recorded using ICD-9 coding by medical record nosologists and represented the primary physician discharge diagnostic code. Descriptive statistics and crude presentation rates are reported. RESULTS: Over 1 year, 1,493,659 ED visits were recorded; LWBS cases represented 18,672 (1.3%) cases during that period. Young children (ages: <5; 14%) and adults (ages: 20-29; 23%) represent the largest percentage of cases. The elderly (>64 years) represent <5% of the overall LWBS sample. Males (9,332; 50%) and females are similarly represented. Wide seasonal variation (34%) was observed, and December rates were highest (9.7%). LWBS occur most frequently on Mondays (18%) and hourly trends demonstrate a bimodal pattern (peaks in the late morning and early evening hours). Most (16,460 [95%]) patients who LWBS do not repeat this behaviour, but 0.5% of individuals in the province have up to 4 LWBS events per year. The crude rates provincially are 5.7/1000 ED visits; higher than average rates occurred in 1 of the 2 largest urban areas (population >500,000). CONCLUSIONS: This study characterizes annual LWBS cases across a large population. These data suggest further detailed evaluation of LWBS may be fruitful, especially using linkages to other databases to determine eventual outcomes and subsequent health services utilization.
Key words: refusal of care, emergency

050 Compliance with discharge instructions in patients discharged from the emergency department after presenting with chest pain or shortness of breath.
Perng J, Leach J, Ackroyd S, Campbell SG, Smith D. Dalhousie University, Halifax, Nova Scotia.

OBJECTIVES: To assess the follow-up compliance of patients discharged from the emergency department after presenting with the complaint of chest pain or shortness of breath and to assess the agreement between initial diagnosis and follow-up diagnosis. METHODS: A retrospective chart review was performed for patients presenting with chest pain or shortness of breath in the months of February 1998 and 1999. Of 420 patients identified, consent could be obtained for interview in 213 (50.7%). Patients were questioned with regard to initial diagnosis, follow-up instructions and compliance therewith, and diagnosis at follow-up visit. These data were compared to those obtained at chart review. RESULTS: Of the patients that completed follow-up visits 17/89 (19%) reported that a different diagnosis had been made at a subsequent visit. 89/115 (77%) of the patients that reported being told to follow-up with another doctor had done so. 102/213 (48%) records showed documentation of instructions for follow-up. 67/115 (58%) of patients that had reported receiving follow-up instructions had instructions documented in the charts. 43/102 (42%) of patients that reported receiving no instructions had follow-up instructions documented in the charts. CONCLUSIONS: Considerable inconsistencies exist between what a patient perceives as discharge instructions and actual documentation in the chart records. Discharge instructions are complied with in the majority of cases. Initial emergency department diagnoses of patients presenting with chest pain or shortness of breath is commonly in disagreement with subsequent diagnoses.
Key words: compliance, discharge instructions

051 Refusal of transport by hypoglycemic patients following prehospital intravenous dextrose.
Carter AJE, Keane PS, Dreyer JF. University of Western Ontario, London, Ontario.

OBJECTIVES: The prehospital administration of intravenous (IV) dextrose to hypoglycemic patients is one of the advanced life support skills delegated to advanced care paramedics in Ontario. Following a quality assurance review which revealed that 47% of patients were refusing transport after receiving IV dextrose, we conducted a telephone survey to determine if patients had sought additional care in the 2-week period after their refusal of transport. We also questioned all those contacted regarding their level of satisfaction with the care provided by paramedics. METHODS: We reviewed ambulance call report forms of 157 sequential patients who met emergency medical services (EMS) criteria for on-scene treatment of hypoglycemia and attempted to contact all who met study inclusion criteria. Those contacted were asked a standard set of questions regarding the incident. RESULTS: 100 patient follow-up contacts were made over a 12-month period, from April 1999 to March 2000. The population receiving IV dextrose ranged in age from 11 to 93, with a mean of 54.5. Average score on the Glasgow Coma Scale on presentation was 8.96 +/- 3.24, and average blood glucose before dextrose was 2.14 +/- 0.71. Eighty-eight of 157 (56.05%) patients refused transport. Significant differences between the transported group and the refusal group were age (transported 63.5, refused 47.6, p < 0.001), and blood glucose (transported 2.34, refused 1.96, p = 0.001). There was no difference between the 2 groups in terms of repeat access to the health care system (6 in each group), or in satisfaction with the care provided by paramedics. CONCLUSIONS: We concluded that the practice of treating patients for symptomatic hypoglycemia, and leaving them at the scene, appears to be safe. All patients treated were satisfied with the treatment they received. Further study of this group of patients is required to be certain that leaving patients at the scene is a safe procedure.
Key words: emergency medical services, hypoglycemia

052 Air medical transport of non-traumatic aortic disasters.
Mitchell A, Tallon J. Dalhousie University, Halifax, Nova Scotia.

OBJECTIVES: To review and describe 4 years of experience with non-traumatic aortic disasters (dissections/ruptures) transported by a new rotor wing, provincially dedicated air medical program. METHODS: Retrospective 4-year review of air medical programs mission records, and review of related hospital records. Patients listed as suspected aortic disaster (non-traumatic) in the air medical records were included. Mission records were reviewed for emergency medical services (EMS) diagnosis, blood pressures pre/post transport, transport times, and mortality. Hospital records were reviewed for diagnosis, interventions/treatment, and mortality. Blood pressures below 80 mm Hg systolic are considered hemodynamically unstable. RESULTS: A cohort of 34 patients were identified. Three deaths occurred within the transport period, 31 (91%) patients arrived at hospital alive. Twenty-five patients (73.5%) arrived at hospital hemodynamically stable, mean out of hospital time was 60 minutes. Nine patients (26.5%) arrived hemodynamically unstable, mean out of hospital time was 54 minutes. There was no significant difference in times between these 2 groups (p = 0.16). Overall mortality was 53% (18). Differences in transport time between survivors and deaths was not statistically significant (p = 0.93). The diagnoses on admission to hospital: 14 (41%) were RAAA, 5 (15%) AAA no rupture, 8 (24%) aortic dissections, and 4 (12%) had no aortic pathology. Fourteen patients (41%) received emergent surgical intervention. The EMS diagnosis contained the correct diagnosis in 76% of cases. CONCLUSIONS: Our program transported 34 suspected aortic disasters of which 14 were immediate surgical candidates upon arrival. Aortic disaster is not infrequent within our air medical program. There were several patients who did not warrant transport under the context of aortic disaster. Specific policies and procedures based on continuing quality review should be in place to optimize the transport and care of these patients.
Key words: aortic aneurysm, aortic dissection, emergency medical services

053 The pre-hospital use of adenosine for the treatment of supraventricular tachycardia.
Rabin EA, Sosnowski T, Antoniuk J, Rowe BH. University of Alberta, Edmonton, Alberta.

OBJECTIVES: Adenosine is an accepted therapy to abort supraventricular tachycardia (SVT) in the emergency department. Given its ease of use and excellent safety profile, the pre-hospital use of adenosine seems reasonable. This project is the first known report of adenosine use by emergency medical services (EMS) in Canada. METHODS: An SVT protocol incorporating adenosine was developed, implemented and evaluated during 1998-99 in a large Canadian EMS system. Recorded cases of adenosine use were obtained from the records management system, a computerized database of all the patient care reports maintained by this EMS program. Cases from Jan. 1, 1999, to Dec. 12, 1999, were examined in this retrospective chart audit of patients with SVT who received adenosine. RESULTS: Of 57 charts initially identified, 13 were miscoded and adenosine was not actually given, leaving 44 (77%) for full review. In 40 (91%) cases, paramedics followed the SVT treatment protocol for the administration of adenosine. Of the 4 (9%) cases where the protocol was not followed, 2 had tachycardia secondary to an underlying drug overdose and 2 had SVT with vital signs outside of the protocol's definitions. Adenosine was successful in converting the SVT in 33 (75%) cases and was well tolerated by the patients. One (2%) patient deteriorated after administration of adenosine; upon review, this patient had evidence of a more complex underlying cardiac problem. CONCLUSIONS: The administration of adenosine appears safe in the pre-hospital setting. Adenosine was administered by EMS appropriately in most patients and was successful in converting the majority of SVT cases. Adenosine was well tolerated by the patients. Further evaluation is required to determine the accuracy of emergency medical responders' ECG skills to diagnose SVT and to investigate secondary clinical benefits to patients as a result of prompt SVT cessation.
Key words: supraventricular tachycardia, adenosine, emergency medical services

054 Use of Rh prophylaxis in the emergency department for first trimester bleeding: a retrospective review.
Allan RJ, Regan K. University of Western Ontario, London, Ontario.

OBJECTIVES: The use of Rh prophylaxis in the first trimester remains a controversial issue. To date, there has been little published comparing the rate of transplacental hemorrhage in threatened abortion versus a control group; however, it has been shown that completed spontaneous abortion carries an increased rate of sensitization compared to normal pregnancies. Several prominent authorities suggest the use of prophylaxis regardless of gestational age; however, others have argued that the amount of transplacental hemorrhage only becomes a risk at greater than 10-12 weeks. METHODS: This study retrospectively reviews emergency department visits in London, Ontario, during the period of 1990 to the present day, in order to assess current investigation and management of vaginal bleeding in the first trimester. Inclusions were women presenting to the emergency department during the first trimester with vaginal bleeding or abdominal trauma. RESULTS: A total of 408 visits were reviewed, with 297 inclusions. Discharge diagnoses included threatened abortions in 178 (60%), ectopic pregnancy in 40 (13%), and first trimester trauma in 2 (<1%). Of 275 women with Rh status documented on the hospital chart, only 176 (64%) had Rh status documented on the emergency chart. Using hospital chart data, 43 of 275 (14%) with documented blood type were Rh negative. Out of 43 Rh negative females, 25 (58%) cases resulted in loss of the pregnancy. Of these 25, 11 (44%) received Rhogam in the emergency department, leaving 14 (56%) potential isoimmunizing events untreated. Of the 11 treated with Rhogam, 6 were greater than or equal to 10 weeks gestational age, while 5 were less. Using hospital chart data, 43 of 275 (14%) were Rh negative. The number of Rh negative females whose final outcome was spontaneous abortion or ectopic pregnancy was 25 of 43 (58%). Of these 25, 11 (44%) received Rhogam in the emergency department, leaving 14 (56%) potential isoimmunizing events untreated. CONCLUSIONS: The results of this review suggest the need for consensus and a physician education initiative on the management of first trimester vaginal bleeding.
Key words: threatened abortion, ectopic pregnancy

055 Evaluation of controlled-release oxycodone (OxyContin) q12h in the treatment of acute traumatic pain.
Ducharme J, Eisenhoffer J, Quigley P, Harsanyi Z, Darke AC. Saint John Regional Hospital, Saint John, New Brunswick.

OBJECTIVES: Pain is the most common presenting complaint in emergency departments (EDs) but may be under-evaluated and under-treated. The purpose of this study was to evaluate controlled-release (CR) oxycodone (OxyContin, Purdue Pharma) in the control of pain following acute trauma, using a fixed or variable 12 hourly dose for 5 days. METHODS: Eighteen evaluable patients presented in the ED within 48 hours of sustaining a single impact injury caused by acute deceleration or flexion. Patients were given an initial dose of 20 mg and then randomly assigned to take CR oxycodone 20 mg q12h or 10-30 mg q12h for the next 5 days. Since the mean doses (40.0 ± 0.00 and 40.1 ± 9.7 mg/day) and pain scores (p = 0.3393) across 5 days were not different between the treatments, the groups were combined. RESULTS: The mean baseline pain score was 64.7 ± 24.0 mm (100 mm VAS). Pain scores decreased to 50.0 ± 25.5 (p = 0.0344) and 31.6 ± 25.6 mm (p = 0.0003) during the first 30 minutes and 7 hours, respectively. The average daily pain score decreased to 20.0 ± 24.6 (p < 0.0001) by day 5. Difficulty in falling asleep (100 mm VAS) and nighttime and morning awakening (100 mm VAS) due to pain, improved throughout the study period (18.1 to 8.0, p = 0.0180; 17.7 to 3.8, p = 0.2249; and 19.5 to 6.1 p = 0.3479; respectively). Average nausea and drowsiness scores (100 mm VAS) were 10.23 ± 12.60 and 18.87 ± 15.40 respectively. CR oxycodone was rated moderately or highly effective by 94% of patients. The most commonly reported adverse events were somnolence, nausea, and constipation. CONCLUSIONS: Oxycodone is an effective and rapidly acting agent for the treatment of pain following acute traumatic injury. A 12 hourly dosing schedule, using a fixed or patient-determined dose is feasible for the treatment of acute traumatic pain.
Key words: pain, analgesia, oxycodone

056 Underdosing of acetaminophen by parents.
Goldman RD, Scolnik D. The Hospital for Sick Children, University of Toronto, Toronto, Ontario.

OBJECTIVES: Acetaminophen is widely used for antipyresis in pediatrics. We conducted this study to find the rate of underdosing of this drug in a pediatric emergency department (PED) and whether visits would have been avoided if fever had subsided at home after antipyretic treatment. METHODS: We interviewed 90 randomly selected parents of children >28 days old with fever >38ºC in the previous 24 hours and visiting the PED because of the fever. Parents were shown pictures of acetaminophen packages and were asked the dose of the medication given to their child and if they had checked the recommended dosage on the box before giving that dose. RESULTS: 80 questionnaires were suitable for enrollment. Mean age was 35 months (standard deviation [SD] 32) and 38.8% had had fever for less than 24 hours. Half (48.1%) of the parents administered an underdose of acetaminophen (<10 mg/kg), 35.4% gave the recommended dose (10-15 mg/kg) and 16.5% administered an ovedose. Almost all (96.3%) of the parents had read the package before administrating the medication. English was the language spoken at home in 64.5%. 58.2% of parents would not have come to the PED if fever had subsided at home. Parents underdosed significantly more in children over 2 years of age (p = 0.024). We found no correlation between dosage given and parental age, education, decision not to come to the PED if the fever declined or whether English was the primary language spoken at home. CONCLUSIONS: In our study population, many PED visits could have been prevented if optimal acetaminophen dosages had been administered. This was especially true in children >2 years old. Health care professionals should inquire about acetaminophen dosage given at home as part of their history taking, and efforts should be made to educate parents regarding the recommended dose of acetaminophen.
Key words: acetaminophen, fever, pediatric

057 Emergency department treatment of paroxysmal atrial fibrillation.
Kapur AK. University of Ottawa, Ottawa, Ontario.

OBJECTIVES: Atrial fibrillation is the most common arrhythmia managed in emergency departments. There is no consensus on the safest and most efficacious emergency department treatment of clinically stable paroxysmal atrial fibrillation: rate control only, pharmacologic cardioversion, or primary electrical cardioversion. METHODS: This prospective observational cohort study reviewed all adult patients with clinically stable paroxysmal atrial fibrillation presenting to an emergency department of either of the 2 participating hospitals. Patients with either new-onset or recurrent paroxysmal atrial fibrillation were eligible. Exclusion criteria included current episode of fibrillation lasting more than 48 hours or an unknown length of time, pregnancy, or previous inclusion in this study. Demographic information and medical history were collected on each patient, as well as information on the treatment received during the emergency department visit, including rate control medications, any attempts at cardioversion, their success rate, and any complications. Patients were contacted 4 weeks after their visit and interviewed regarding recurrence of atrial fibrillation and further medical treatment received. A quality of life survey (SF-36) was also administered. Data collection started in September 2000 and will continue until February 2001. RESULTS: Descriptive data will be presented on the outcomes of the different treatment approaches including success rate of cardioversion (proportion of patients in sinus rhythm at emergency department discharge and at 4-week follow-up), complication rate, recurrence of fibrillation, and patient preference as determined by the quality of life score. Comparisons will be made after controlling for variables other than treatment approach. CONCLUSIONS: This is the first prospective study of emergency department treatment of stable paroxysmal atrial fibrillation. The information provided on the outcome of the different treatment approaches and on patient preferences will be useful to guide physician practice and will allow determination of the feasibility of a randomized trial.
Key words: atrial fibrillation, therapy, emergency department

058 SLiC: Stat lactate in chest pain for the early detection of acute myocardial infarction.
Lee J, Gatien M, Stiell I, Ooi D, Wielgosz A. The Ottawa Hospital, Ottawa, Ontario.

OBJECTIVES: Current biochemical markers are not sensitive for acute myocardial infarction (AMI) until 6 hours after the onset of chest pain. The objective of this study was to determine the sensitivity of venous lactate drawn at the time of presentation for AMI in ED chest pain patients. METHODS: We prospectively enrolled patients >25 years of age presenting with non-traumatic chest pain where the emergency physician (EP) ordered an electrocardiogram and any bloodwork as part of their investigation. A cutoff of >1.5 mmol/L was used for venous lactates. The charts of all admitted patients where reviewed at discharge to determine whether they met WHO criteria for AMI. Both the treating EPs and the investigator determining outcomes were blinded to lactate levels. Discharged patients were followed by telephone 3 to 4 weeks after discharge. RESULTS: We report the results of the first 299 patients enrolled. The mean age was 64 years, 160 patients (54%) were male, and 169 (57%) were discharged. No discharged patient reported a subsequent MI at phone follow-up, with 14 (4.7%) lost to follow-up. Serum lactates were elevated on presentation in 27/29 patients with AMI (sensitivity 93%, 95% confidence interval [CI] 90%-96%). Specificity was 45%, and the negative predictive value 98%. By comparison, the troponin (TnT) was positive at the time of presentation in only 12/29 patients (sensitivity 41%, 95% CI 34%-49%) with AMI. Although stat lactate missed 2 patients with AMI, 1 of these patients had no elevation in CK or TnT until 7 hours after presentation. CONCLUSIONS: Serum lactate shows promise as a rapidly available and inexpensive marker for AMI. Further study should be undertaken to define high risk groups based on clinical variables to maximize the sensitivity and specificity.
Key words: myocardial infarction, lactate

059 Atenolol overdose successfully treated with calcium chloride.
O'Grady JP, Anderson S, Pringle D. University of Western Ontario, London, Ontario.

OBJECTIVES: Atenolol, a selective beta1-adrenergic antagonist, as well as other beta blockers are used for their efficacy in the treatment of hypertension, ischemic heart disease and certain arrhythmias. Only a few severe atenolol intoxications have been reported and only 1 that we know of has used calcium chloride in its treatment. However, this was 48 hours post ingestion and levels of atenolol at that time where most likely negligible. Also, only 1 case of propranolol, a non-selective beta1-adrenergic antagonist, describes the use of calcium chloride as a possible treatment. METHODS: We present a case of atenolol overdose and successful treatment with calcium chloride in a 50-year-old woman. Upon arrival to the emergency department, the patient's blood pressure was in the 50-60 systolic range and her rhythm strip showed a first degree heart block. Conventional treatment proved unsuccessful and the patient was given calcium chloride to which she responded dramatically. RESULTS: A review of the literature using MEDLINE and the bibliographies of all journal articles found, as stated previously, that calcium chloride is not the usual agent of choice for the treatment of beta blocker overdoses. The pharmacokinetics of atenolol, the signs and symptoms of beta blocker overdosage as well as the main method of cardiotoxicity of beta1-adrenergic antagonists are discussed. Furthermore, the 2 reported cases of beta blocker overdoses treated with calcium chloride are reviewed. Finally, treatment options for atenolol and other beta blocker overdoses are presented and the scientific data supporting the treatment of atenolol intoxications with calcium chloride are examined. CONCLUSIONS: The results of our case, as well as the examination of other cases and the review of relevant literature, has led us to conclude that calcium chloride should be part of the arsenal of therapies used for treatment of beta blocker overdoses and, more specifically, atenolol. This being said, treatment of beta blocker overdoses and other drugs should be done in contact with the local poison control centre.
Key words: atenolol, beta blocker, intoxication

| 001-014 | 015-029 | 030-044 | 045-059 | 060-074 | 075-093 |