2004 CAEP/ACMU Scientific Abstracts - Oral Abstracts (#1 to #16)

CAEP Abstracts

CJEM 2004;6(3):173-212

abstracts:  001-016 | 017-032 | 033-052 | 053-075 | 076-092 | 093-111 | 112-132

001 A randomized controlled trial comparing safety and efficacy of rectilinear biphasic versus monophasic defibrillators in out-of-hospital cardiac arrest: 'ORBIT'.

Morrison LJ, Dorian P, Long J, Vermeulen MJ, Schwartz B, Sawadsky B, Frank J, Cameron B, Burgess R, Shield J, Bagley P, Mausz V, Brewer J, Lerman B. Prehospital & Transport Medicine Research Program, Sunnybrook and Women's College Health Sciences Centre, University of Toronto, Toronto, ON

INTRODUCTION: The objective of this study was to compare the safety and efficacy of ascending rectilinear biphasic defibrillation (120J, 150J, 200J) with conventional monophasic defibrillation (200J, 300J, 360J) in the termination of ventricular fibrillation (VF) and pulseless ventricular tachycardia (VT) in patients with out-of-hospital cardiac arrest (OHCA) treated by EMT-P paramedics. METHODS: This was a randomized controlled trial employing block randomization. A blinded Outcome Validation Committee adjudicated all end points. RESULTS: There were 4532 OHCA and 540 with presumed VT or VF at some point during resuscitation. The station randomization compliance was 95%. The data entry error rate was <1%. The loss to follow-up rate for monophasic vs. biphasic (n = 217 vs 219) was 2% vs 3%. The patients in the 2 groups respectively (blinded analysis) were similar for age, gender, EMS response interval; 7.7 (4.1) vs 7.7 (3.7), down time; 10.6 (4.4) vs 10.9 (4.9), bystander witnessed; 144 vs 146 (67%: 67%), EMS witnessed; 19 vs 20 (9%: 9%), amiodarone; 96 vs 86 (44%: 39%), and different for prior defibrillation; 49 vs 34 (23%:16%), p = 0.05. Conversion to organized electrical activity after one shock was 55 vs. 67 (26%:3 2%), p = 0.2 and after 1-3 shocks was 98 vs 119 (45%: 54%), p = 0.06. Conversion for first highest energy setting shock was 30 vs 49 (14%: 23%), p = 0.02. The rate of return of spontaneous circulation was the same in both groups 88 vs 90 (41%: 41%). Survival outcomes were; alive to emergency department 123 vs 125 (57%: 57%), at 24 hours; 46 vs 50 (22%: 23%), and at 30 days; 14 vs15 (7%: 7%). Cerebral Performance Category scores were; "Good" 11 vs 16 (9%:13%), and "Moderate to Coma" 7 vs 3 (6%: 2%), p = 0.29 with no adverse events. CONCLUSIONS: Biphasic is not superior to monophasic waveform in the conversion of ventricular arrhythmias during OHCA. This study is not generalizable to all biphasic defibrillators and defibrillation protocols as it uses the rectilinear waveform in an ascending protocol.

Key words: resuscitation, defibrillation, cardiac arrest

002 The epidemiology of cardiac arrest in schools: Limited potential for PAD in a low risk setting.

De Maio VJ, Stiell IG, Vaillancourt C, Wells GA, Nesbitt L, Beaudoin T, Spaite DW. Department of Emergency Medicine, University of North Carolina, Chapel Hill, NC

INTRODUCTION: Many U.S. school boards have been legislated to provide public access defibrillation (PAD) programs in elementary and secondary schools despite a lack of data on cardiac arrests in this setting. We evaluated the incidence and epidemiology of cardiac arrests occurring in schools to encourage thoughtful policy making by Canadian leaders. METHODS: This cohort study includes all prospectively collected, non-traumatic, out-of-hospital cardiac arrests, regardless of age, in the 21 communities of the Ontario Prehospital Advanced Life Support (OPALS) Study. Case and survival definitions followed the Utstein style. Cardiac arrests occurring in schools were identified by linking dispatch address data to the regional property assessment roll. The property roll also provided the total number of school sites within the study boundary. Analyses were descriptive. RESULTS: From 1995-1999, there were 8731 cardiac arrests including 192 pediatric cases <16 years. Overall, 36 arrests occurred in a school setting; 23 in elementary/secondary schools and 13 in post-secondary institutions. Patient characteristics for all school arrests included (95% confidence interval): mean age 57 years (51-62); male gender 92% (79-98); bystander witnessed 63% (45-79); bystander CPR 54% (37-71); initial rhythm VF 76% (58-89); mean response interval 5.0 minutes (4.2-5.7); and survival to hospital discharge 5.6% (0.7-18.7). Only two arrests occurred in school aged children (ages 11 and 15) and both occurred during exercise. On average, one cardiac arrest can be expected per school every 357 years in the 1641 elementary/secondary schools and every 55 years in the 142 post-secondary institutions. CONCLUSIONS: Very few arrests occur in the school setting; even fewer in school-aged children. Widespread deployment of PAD programs in elementary and secondary schools in the OPALS communities is a potentially costly initiative, which is unlikely to lead to important survival benefits for children or adults.

Key words: cardiac arrest, public access defibrillation

003 Are any advanced life support treatments associated with better survival in out-of-hospital cardiac arrest?

Stiell IG, Nesbitt L, Wells GA, Nichol G, Cousineau D, for the OPALS Study Group. Department of Emergency Medicine, University of Ottawa, Ottawa, ON

INTRODUCTION: In the Ontario Prehospital Advanced Life Support (OPALS) Study Phase III, we demonstrated that an ALS program did not improve cardiac arrest survival in a rapid defibrillation EMS system. In this study, we sought to determine if specific ALS treatments are associated with better survival. METHODS: This multicenter clinical trial was conducted in 17 communities and enrolled all adult out-of-hospital cardiac arrest patients during the 12-month BLS-D rapid defibrillation and the 36-month ALS phases. Paramedics were trained to ALS standards including endotracheal intubation IV drug use. The primary outcome was survival to discharge. Chi-square and stepwise logistic regression analyses were performed. RESULTS: The 5,637 patients enrolled had these characteristics: mean age 69.2 (range 16-102), male 66.7%, witnessed 51.7%, bystander CPR 14.7%, initial rhythm VF/VT 32.3%, defibrillator <8 minutes 93.3%; survival 5.1%. During the ALS phase, success rates were intubation 93.7% and IV insertion 89.0%. This Table compares survivors (N = 286) and non-survivors (N = 5,351), giving adjusted odds ratios and 95% CIs for factors associated with survival. CONCLUSIONS: This study further confirms the importance of bystander CPR and early defibrillation. Among ALS interventions, intubation, atropine, and epinephrine had a negative association and only lidocaine had a positive association with survival. Randomized trials are required to further evaluate the value of ALS interventions.

Key words: cardiac arrest, advanced life support, resuscitation

004 Socioeconomic status and survival after prehospital cardiac arrest.

Denny CJ, Schull MJ, Szalai JP, Stiell IG. Division of Emergency Medicine, University of Toronto, Toronto, ON

INTRODUCTION: Baseline survival from prehospital cardiac arrest is poor. Low socioeconomic status (SES) is associated with higher mortality among patients with acute myocardial infarction treated in-hospital, where discretion exists in treatment decisions. We evaluated whether SES is associated with survival after prehospital cardiac arrest, where treatments are standardized. METHODS: This historical cohort study included all cardiac arrest patients with an initial rhythm of ventricular fibrillation or ventricular tachycardia from 1991-2002 in 20 communities (population 20,000-750,000) across the province of Ontario enrolled in the Ontario Prehospital Advanced Life Support (OPALS) Study. OPALS data was linked to 1996 Canadian Census data using the location of the cardiac arrest to impute the median neighbourhood income (a validated proxy measure for SES). The primary outcome was survival to hospital admission. Multivariable logistic regression analyses were performed. Covariates included age, gender, witnessed arrest (yes/no), bystander CPR (yes/no), and response interval. RESULTS: 3387 patients had these characteristics: mean age 68.6 years, 66.4% male, 53% witnessed arrest, 19% bystander CPR, mean response interval 7 minutes, median neighbourhood income $21,062 (range $17,629-$24,443). 86% of cardiac arrests occurred in the place of residence. 22.3% of patients survived to hospital admission. 11.8% of patients survived to hospital discharge. In multivariable analyses, median neighbourhood income (SES) was not associated with survival (OR 0.84; 95%CI 0.67-1.06). Younger age (OR 1.07; 95% CI 1.01-1.14), witnessed arrest (OR 1.58; 95% CI 1.29-1.93), and bystander CPR (OR 1.67; 95% CI 1.41-1.99) were associated with improved survival. Longer response interval (OR 0.92; 95% CI 0.90-0.95) was associated with decreased survival. CONCLUSIONS: Unlike in studies of hospitalized patients, socioeconomic status is not a predictor of survival after prehospital cardiac arrest.

Key words: cardiac arrest, resuscitation

005 Derivation of a termination-of-resuscitation guideline for emergency medical technician-paramedics and comparison with a published emergency medical technician-defibrillator guideline.

Morrison LJ, Vermeulen MJ, Kiss A, Nesbitt L, Steill IG, Verbeek PR. Sunnybrook and Women's College Health Sciences Centre, University of Toronto, Toronto, ON

INTRODUCTION: We sought to identify characteristics associated with survival of out-of-hospital cardiac arrest attended by advanced paramedics (EMT-P) and compare them with a published out-of-hospital termination of resuscitation (TOR) guideline previously derived in cardiac arrests treated by EMT-Defibrillation (EMT-D) attendants. METHODS: Retrospective analysis of adult cardiac arrests treated by EMT-Ps in rural and urban EMS systems participating in the OPALS study. The EMT-D guideline proposed termination of resuscitation if the patient had no return of spontaneous circulation (ROSC), no shock administered, and EMS personnel did not witness the arrest. Multivariate logistic regression was used to examine the relationship between these variables, as well as bystander witness and bystander CPR, and survival to hospital discharge. Sensitivity and negative predictive value were calculated for the combination of predictive characteristics and the original rule. RESULTS: 4673 cardiac arrest patients were included; 3098 (62%) were male, mean (SD) age was 66 (15), and 239 (5.1%; 95% CI 4.5-5.8) survived to hospital discharge. Among those with ROSC (3841, 82%), only 3 survived (0.08%; 95% CI 0.02-0.23). Multivariate analysis showed that ROSC (OR 745; 95% CI 101.9->999.9) bystander witness (OR 2.1; 95% CI 1.3-3.3), bystander CPR (OR 2.9; 95% CI 1.8-4.5), and shock prior to transport (OR 4.6; 95% CI 2.6-8.2) were associated with survival. A TOR guideline based on these variables was 100% sensitive (95% CI 98-100) for survival and had 100% negative predictive value (95% CI 100-100) for death. For the EMT-D rule, these values were 100% (95% CI 99.3-100) and 100% (95% CI 100-100) respectively. CONCLUSIONS: In the OPALS EMS systems, cardiac arrest patients may be considered for prehospital TOR after EMT-P resuscitation when there is no ROSC, no shock administered, no bystander CPR and the arrest was unwitnessed by bystanders. The EMT-D TOR guideline appears equally sensitive. Both require prospective validation.

Key words: cardiac arrest, resuscitation, emergency medical services

006 Locations of pediatric cardiac arrest: Implications for public access defibrillation.

De Maio VJ, Stiell IG, Vaillancourt C, Wells GA, Spaite DW, Nesbitt L. Department of Emergency Medicine, University of North Carolina, Chapel Hill, NC

INTRODUCTION: The trend for widespread deployment of PAD programs continues despite a lack of evidence indicating the effectiveness of this modality. We identified the location of pediatric cardiac arrest to determine the potential value of PAD in the younger population. METHODS: This cohort study includes all prospectively collected out-of-hospital cardiac arrests in children <16 years, regardless of etiology, in the Ontario Prehospital Advanced Life Support (OPALS) Study. Overall population in the 21 communities was 2.8 million with almost 600,000 less than 16 years. The regional property assessment roll identified the specific property type for each cardiac arrest address and the total number of sites, per location type, within the study boundary. Analyses were descriptive. RESULTS: From 1994-2001, there were 291 pediatric cardiac arrests, representing an annual incidence of 6.3 per 100,000 at risk. Patient characteristics included: male gender 56%, age ¾12 months 46%; bystander witnessed 24%, bystander CPR 18%, median response interval 5.9 minutes, survival to hospital discharge 3.3%. Of the 268 cases with available addresses, 236 (88%) occurred in a residential setting. The remaining 32 cases occurred in public locations: street/road/highway 8, water/boat/marina 5, school 3, single store/strip mall 3, stadium/fairground 2, indoor mall 2, hotel 2, office building 2, farm 2, daycare 1, recreation/community facility 1, sports field/park 1. Placing AEDs in the 1641 elementary and secondary schools in the 21 OPALS communities would potentially treat only 3 arrests during an 8 year period. CONCLUSIONS: Pediatric cardiac arrest is a relatively rare problem; even rarer are instances where this occurs in a public setting. It is highly unlikely that widespread implementation of PAD would lead to important survival benefits for children. Public health planners should direct resources toward improving the traditional EMS response and management of pediatric cardiac arrest patients.

Key words: cardiac arrest, resuscitation, public access defibrillation

007 The role of the mental status examination in assessment of minor head injury.

Stiell IG, DreyerJ, Clement C, Holroyd B, Lee J, Wells GA, MacPhail I, Brison R, McKnight RD, Rowe B, Schull M, Eisenhauer M, for the CCC Study Group. Department of Emergency Medicine, University of Ottawa, Ottawa, ON

INTRODUCTION: Minor head injury is a common ED problem and the relative value of clinical assessment and CT remains controversial. This study evaluated the accuracy and reliability of the mental status exam in the ED. METHODS: This prospective cohort study was conducted in 9 tertiary care EDs and enrolled adult minor head injury patients with loss of consciousness, amnesia, or confusion and a GCS score of 13-15. Physicians conducted standardized patient assessments and completed data forms prior to imaging. In some cases 2nd physicians performed interobserver assessments. The outcome was clinically important brain injury on CT. Analyses included univariate association, kappa, unadjusted odds ratio. RESULTS: The 2,706 patients had these characteristics: mean age 38.7, GCS score-15 79.8%, important brain injury 8.1%, required neurological intervention 1.4%, death 0.2%. The Table (next column) shows % brain injury (N = 229) and non-injury (N = 2,477) patients with the findings, odds ratios for injury, kappa. CONCLUSIONS: All mental status assessments are strongly associated with brain injury in minor head injury. The most reliable and discriminating findings are Amnesia 30 minutes before injury, Object recall test 3/3, Initial GCS 13, Any drop in GCS, and Failure to reach GCS 15 by 2 hours.

Key words: minor head injury, diagnosis

008 Interobserver agreement in the assessment of children with minor head injury.

Osmond MH, Klassen TP, Stiell IG, Correll R, Aronyk K, Reed M, Joubert G, Nijssen-Jordan C, Jarvis A, Pusic M, Kimoff L, Silver N, McConnell D, Bailey B, Hamilton M, Vassilyadi M, Moher D, for the CATCH Study Group. Department of Pediatrics, University of Ottawa, Ottawa, ON

INTRODUCTION: To determine interobserver agreement in the MD assessment of clinical findings in children with minor head injury. This methodological sub-study was an important component in the derivation of a clinical decision rule for the Canadian Assessment of Tomography for Childhood Head Injury (CATCH) Study. METHODS: This prospective cohort study was conducted in 9 Canadian pediatric teaching hospital EDs and involved children (0-16 years) with documented loss of consciousness, amnesia, disorientation, persistent vomiting (>=2 times) or irritability (children < 2) and a GCS score of 13-15. MDs evaluated patients for 28 standardized clinical findings before imaging and performed blinded interobserver assessments when feasible. Analyses included the simple or weighted kappa coefficient with 95% CIs. RESULTS: 384 assessments were conducted on 192 patients who were similar to the study population: mean age 9.6 (range 0-16); male 61.0%; mechanisms: fall 42.2%, sports 20.8%, bicycle 9.4%, MVC 4.7%; admitted 14.1%; brain injury on CT 4.7%. The Table (next page) shows kappa values for clinical findings. CONCLUSIONS: "Pallor" had poor agreement. Findings with moderate agreement were "possible depressed skull fracture", "lethargy" and "initial GCS score". Substantial agreement was found for most elements of the CATCH CT Head Rule, suggesting that physicians should be able to consistently interpret the overall rule. This reliability will be explicitly and prospectively evaluated in ongoing studies.

Key words: minor head injury, diagnosis, reliability

009 Development of a prediction rule for the early discharge of patients with chest discomfort.

Christenson J, Innes G, McKnight D, Thompson C, Wong H, Yu E, Boychuk B, Grafstein E, Rosenberg F, Gin K, Singer J, Anis A. Providence Health Care, Vancouver, BC

OBJECTIVE: Rule out protocols for patients with chest discomfort of uncertain etiology are expensive to apply to all patients. No tool exists to guide safe early discharge of very low risk patients. We sought to construct a clinical prediction rule to define patients presenting with chest discomfort who are safe to discharge after 2 hours of ED observation. METHODS: This prospective, cohort study enrolled consenting subjects > = 25 years old with chest discomfort and no traumatic or x-ray cause. At 30 days, investigators assigned a diagnosis of ACS or no ACS according to explicit definitions. Predictor variables included characteristics of presenting pain, physical findings, risk factors, medications, vital signs, and ECGs and serum cardiac markers at 0 and 2 hours. A modified classification and regression tree analysis with clinical input provided the best combination of predictors. RESULTS: Of 769 patients, 10.0% had AMI, 12.5% definite UA, 2.7% possible UA and 74.8% no ACS. The early discharge prediction rule has 3 steps. 1. Patients (n = 356) whose initial ECG has ST-T wave abnormality other than T-wave flattening or whose pain is similar to previous cardiac pain are at high risk. 2. Other patients without prior coronary disease who are < 40 y/o or are > = 40 y/o with a 0 hour CKMB of < 3.0 micrograms/L and atypical pain (either chest tenderness reproducing the pain or no radiation of pain to neck, jaw or left arm) are very low risk (n = 159). 3. Additional patients with pain that increases on breathing and have no rise in CKMB or TnI and no ischemic ECG changes over 2 hours are also very low risk (n = 35). The sensitivity of this definition of very low risk patients is 99.4%. It identifies 31.3% of patients without disease who can be safely discharged with information available within 2 hours. CONCLUSION: This prediction rule defines a group of chest pain patients who can be safely discharged without an expensive rule out protocol. It requires validation in an independent cohort.

Key words: chest pain, acute coronary syndrome, clinical prediction rule

010 Comparison of the performance of the components of the Canadian CT head rule and the New Orleans criteria.

Stiell IG, Clement C, Wells GA, Eisenhauer M, Schull M, Holroyd B, MacPhail I, Dreyer J, Lee J, Rowe B, McKnight RD, Brison R, for the CCC Study Group. Department of Emergency Medicine, University of Ottawa, Ottawa, ON

INTRODUCTION: Both the Canadian CT Head Rule (CCHR) and the New Orleans Criteria (NOC) are very sensitive for brain injury but are comprised of different variables. We sought to assess the accuracy and reliability of these components. METHODS: This prospective cohort study was conducted in 9 tertiary care EDs and enrolled adult minor head injury patients with loss of consciousness, amnesia, or confusion and GCS score of 13-15. Physicians performed standardized assessments and completed data forms. Patients then underwent CT to determine clinically important brain injury. We conducted chi-square, kappa, and unadjusted odds ratio analyses. RESULTS: The 2,706 patients had these characteristics: mean age 38.4, important brain injury 8.5%, neurological intervention 1.5%. The Table shows % of brain injury (N = 229) and non-injury (N = 2,477) patients with the findings, p-value, kappa, odds ratio.CONCLUSIONS: 6 of the 7 CCHR components but only 3 of the 7 NOC components showed both good kappa values and strong association with brain injury. The superior specificity of the CCHR likely relates to more reliable and accurate component variables.

Key words: clinical prediction rule, Canadian CT head rule

011 A prospective study to evaluate intubating conditions and hemodynamic effects of etomidate for rapid sequence intubation in the emergency department.

Zed PJ, Abu-Laban RB, Harrison DW. CSU Pharmaceutical Sciences, Vancouver General Hospital, Faculty of Pharmaceutical Sciences & Division of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, BC

INTRODUCTION: Etomidate is a non-barbituate induction agent approved for use under Health Canada restrictions. The purpose of this study was to evaluate intubating conditions and hemodynamic effects of etomidate in patients undergoing rapid sequence intubation (RSI) in a tertiary emergency department (ED). METHODS: All patients receiving etomidate for induction for ED RSI between 1/11/01 and 31/12/03 were prospectively evaluated. Intubating conditions were rated by the emergency physician using a 5-point Likert scale. Hemodynamics were recorded pre and for up to 15 minutes post RSI. Descriptive statistics were generated and pre/post hemodynamic responses were compared using paired T-tests. RESULTS: 336 patients were studied, 313 of whom had a clinical course or data capture appropriate for hemodynamic analysis. Trauma (39%), stroke (17%) and overdose (16%) were the top three indications for intubation. Lidocaine, fentanyl and succinylcholine were administered in 67%, 23%, and 95% of cases, respectively. Intubating conditions were rated as excellent or good in 88% and 9% of cases respectively. Mean baseline systolic and diastolic blood pressure (SBP/DBP) were 132.0 ± 32.4 mmHg and 68.6 ± 19.8 mm Hg, respectively, which was slightly increased within the 15 minutes following etomidate administration to 134.4 ± 30.1 mm Hg and 69.9 ± 18.7 mm Hg, respectively (p = 0.002 for SBP). The subgroup of 45 patients with a low mean SBP pre-etomidate had a significant increase in SBP from pre, to 5 minutes, to 15 minutes post etomidate at 82.6 ± 16.6 mm Hg, 91.4 ± 19.2 mm Hg (p < 0.001) and 98.5 ± 22.1 mm Hg (p < 0.001), respectively. CONCLUSIONS: Etomidate provides satisfactory intubating conditions in a heterogenous group of ED patients. Hemodynamics are not adversely effected following etomidate administration, however, the patient subgroup with low pre-RSI SBP appears to have a blood pressure increase post-RSI. This finding may be attributable to cointerventions and requires further evaluation.

Key words: airway management, rapid sequence intubation, etomidate

012 The impact of a severe acute respiratory syndrome (SARS) outbreak on emergency department utilization in Toronto, Canada.

Schull MJ, Stukel TS, Gunraj N, Woodward G, Vermeulen MJ, Laupacis A. Institute for Clinical Evaluative Sciences, Toronto, ON

OBJECTIVE: The largest outbreak of SARS outside of Asia occurred in Toronto with 247 probable cases and 43 deaths. To control the outbreak, severe restrictions were imposed on access to non-urgent hospital services in Toronto. Three EDs were also closed temporarily due to hospital-based SARS outbreaks. We sought to describe the effect of a SARS outbreak and related control measures on overall ED utilization. METHODS: We obtained fee-for-service claims for ED visits in Toronto and elsewhere in Ontario from January 2002 to September 2003. We compared average daily ED visits in two SARS affected months (April, May 2003) with corresponding months in 2002. The pre-SARS variation in monthly visits was expressed as the ratio of standard deviation to mean ED visits over all 15 pre-SARS months. RESULTS: During SARS months, overall utilization of EDs decreased by up to 25.3% in Toronto and 18.6% elsewhere in Ontario (see Table). These decreases were 6.0 times and 3.8 times greater, respectively, than the expected monthly fluctuations. Even larger relative decreases were seen for some minor conditions: among these, otitis media visits decreased the most, and respiratory infection visits the least.CONCLUSION: SARS was associated with a marked decrease in ED utilization in Toronto, in the absence of any restrictions on access to emergency care. Planning for outbreaks of SARS or similar illnesses should anticipate substantial reductions in overall ED utilization as opposed to surges in demand, even in areas not directly affected by the outbreak.

Key words: SARS, emergency health services

013 Predicting functional impairment in patients with mild traumatic brain injury after emergency department discharge.

Papa Ricci L, Idris A, Demery J, Dede D, Heaton S, Efros D, Pineda J, Hayes RL. Department of Emergency Medicine, University of Florida, Gainesville, FL

INTRODUCTION: This study prospectively assessed clinically significant functional impairment (CSFI) in patients with mild traumatic brain injury (MTBI) after ED discharge. METHODS: This prospective cohort study enrolled consecutive adults with MTBI defined by loss of consciousness (LOC), amnesia, or disorientation and a GCS score of 13-15 with a normal CT scan of brain presenting to a tertiary care hospital ED. Patients had a 15-variable dataform completed by ED physicians and were followed for 3 months after discharge. Outcome was assessed using standardized neuropsychological tests and measures of daily functioning. Patients were classified as having CSFI if they had both: 1) performance on cognitive testing that was >1.5 standard deviations below the mean score of published normative samples and 2) evidence of functional impairment on measures of daily living compared to pre-injury levels. Categorical data were analyzed using Fisher's Exact test, continuous variables by independent sample 2-tailed t-test, and ordinal variables by Mann-Whitney U test. Those variables found to be associated with the outcome measure CSFI (p < 0.1) were combined using logistic regression analysis. RESULTS: Over a 6-month enrollment period, 101 patients were enrolled and 64 patients with MTBI were followed: mean age 36 years (range 18-85), 62% male, and 80% GCS = 15 on ED arrival. CSFI was present in 10% of patients. Three variables were significantly correlated with having CSFI: i) high school education or less (OR = 0.128, 95% CI 0.02-0.88), ii) witnessed LOC >5 minutes (OR = 5.79, 95% CI 1.0-33.3), and iii) persistent amnesia >1 hour of event (OR = 9.2, 95% CI 1.3-64.1). Hosmer-Lemeshow goodness-of-fit statistic was 1.9 for 4DF (p = 0.75). The sensitivity of the model was 80% and the specificity was 77%. The overall accuracy of this model was 77%. CONCLUSIONS: This study has identified factors that could be used to identify MTBI patients at risk for CSFI. Future studies will prospectively validate this model.

Key words: minor head injury, outcome

014 Non-steroidal anti-inflammatory and mydriatic in the treatment of traumatic corneal abrasion: a randomized clinical study.

Le Sage N, Rochette L, Verreault R. Division of Emergency Medicine, Dpt of Family Medicine, Laval University, Quebec City, PQ

INTRODUCTION: It has been demonstrated in the past that the eye patch is not beneficial in the treatment of traumatic corneal abrasions. Nevertheless, this painful condition requires treatment to reduce symptoms. The objective of this study is to determine the efficacy of a non-steroidal anti-inflammatory, with or without mydriatic, for the treatment of traumatic corneal abrasion. METHODS: 225 eligible patients with a corneal abrasion were included in this double-blind randomized study and were assigned to one of the three treatment groups: topical sodium diclofenac (NSAID, n = 75), topical sodium diclofenac and homatropine (NSAID-mydriatic, n = 73), or placebo (n = 77). No occlusive patch was applied. All patients were reexamined each day until healing, and the degree of discomfort was assessed using a 10 centimeter visual analog scale (VAS). RESULTS: At the first visit, the three treatment groups were comparable, and after 1, 2 and 3 days, cumulated incidence of healing was similar. For the 140 patients with initial moderate to severe discomfort (VAS >5 cm), significative differences were observed. There was a reduction of discomfort during the first 24 hours (2.0 cm for the NSAID-mydriatic group, 1.5 cm for the AINS group, and 0.7 cm for the placebo group (p = 0.05)), and at the time of the second visit (respectively 4,8 cm, 5.2 cm and 5.0 cm (p = 0.05)). There was also a reduction of pain between the second and third visits (respectively 5.5 cm, 4.5 cm and 2.5 cm (p = 0.03)), and at the time of the third visit (respectively 6.4 cm, 5.9 cm and 4.3 cm (p = 0.03)). CONCLUSIONS: The association diclofenac-homatropine seems to reduce discomfort in patients with traumatic corneal abrasion for whom initial discomfort is moderate to severe. This reduction is more important during the second day of treatment.

Key words: corneal abrasion, diclofenac, homatropine

015 Concussion in children: Short term follow-up with psychological testing.

Ali S, Pusic MV, Friedman D, Chalut D. Departments of Paediatrics & Emergency Medicine, University of Alberta, Edmonton, AB

INTRODUCTION: To report the incidence of abnormal psychological testing within 6 weeks post-concussion in children who presented to the Emergency Dept (ED); to identify the incidence of persistent post-concussion symptoms. SETTING: The Montreal Children's Hospital (MCH) is an urban, tertiary care pediatric ED. The MCH Neurotrauma Program was developed to care for and prevent childhood head trauma. Our neurotrauma coordinator followed up on all children with concussion. Children with persistent symptoms (e.g. memory deficits, difficulty concentrating, persistent headaches) underwent psychological testing. METHODS: We performed a retrospective review of neurologically healthy children aged 8-18 years who presented with concussion, between Jan 1997- Apr 2001. We excluded children whose injury occurred >24 hours prior to the ED visit. We extracted the psychology test reports for all children who had had them done. Two of us independently examined each report and determined "normal" vs. "abnormal". Reports where a previously existing abnormality was unchanged were coded as "normal". We resolved discrepancies by consensus. RESULTS: 722 patients (8-18 years of age) were diagnosed with concussion during the study period. Of these 216 were referred for psychological testing. 18 did not appear for their appointments while reports were not available for 25. Seven had their assessments <10days post injury while 28 were >42 days post injury leaving 138 reports for analysis. The rate of abnormal psychological testing was 32/138 (23%; 95% CI: 16%-31%). 47 had a previously identified learning disability - 13 had post-concussion abnormalities beyond the existing problem. Post concussion syndrome (OR 4.7; 95% CI 2.0, 11) predicted abnormality whereas loss of consciousness (OR 0.9; 95% CI 0.4, 2.2) and a prior Learning Disability (OR 1.4 ; 95% CI 0.6, 3.3) did not. CONCLUSIONS: Systematic psychological testing of an at-risk population showed a low rate of abnormality overall.

Key words: minor head injury, pediatric

016 Use of protective equipment by skateboarders in public skateparks: An observational study.

Martin C, Joubert GI. Children Hospital of Western Ontario, University of Western Ontario, London, ON

INTRODUCTION: Skateboarding (SB) popularity continues to grow, involving the participation of millions of children in North America. In the USA over 50,000 Emergency Department (ED) visits/year result from SB activity. SB parks (SBP), designed specifically for SB, are rapidly growing in number with many requiring the use of protective equipment (PE). The objective of this study was to determine the use of PE (Helmet, knee pads, elbow pads and wrist pads) in a representative sample of public SBP users in Southwestern Ontario (SWO). METHODS: An observational survey was conducted at five public SBPs in SWO from June to August 2003. The number of male and female SB and their respective use and type of PE were recorded. The observational survey was done, using 2 of the SBPs in small towns, and 3 in cities > 300,000 people in order to provide a representative sample of skateboarders. RESULTS: A total of 572 observations of SB youths were made, consisting of 534 male and 38 female SB. The observed use of PE by both males and females was very low. 473 (88.6%) males wore no PE at all. 56 (10.5%) wore a helmet only, 4 (0.7%) wore helmet and knee pads, and 1 (0.2%) wore knee and elbow pads. 29 (76.3%) females wore no PE at all. 7 (18.4%) wore a helmet only, and 2 (5.3%) wore knee and elbow pads. All of the SBPs were unsupervised and four had signage indicating that protective equipment was "Recommended". One SBP had a sign indicating that the use of a helmet was "Mandatory". However, of the 31 males observed at this mandatory PE SBP, only 9 (29%) were wearing helmets. CONCLUSIONS: This study shows that there is a very low observed prevalence of skateboarding PE in public SBPs in SWO. This low use of PE is present even in "Helmet mandatory" SBPs. Future studies should focus on methods to enforce the use of PE in public SBPs, not only for the increased safety for SB, but also for the liability issues facing towns and cities that build them.