Missed intracranial injuries are rare in emergency departments using the PECARN head injury decision rules.

PURPOSE: The PECARN head trauma (HT) prediction rules have been developed to guide computed tomography-related decision-making for children with minor HT (mHT). There are currently limited data on the rate of unscheduled revisits to emergency departments (EDs), and initially missed intracranial injuries, in children with mHT initially assessed using the PECARN rules. This study aimed to fill this gap in knowledge. METHODS: Clinical charts of children assessed for mHT over a 5-year period at two EDs that implemented the PECARN rules in Italy and France were reviewed retrospectively. Children who returned to EDs for mHT-related, or potentially related complaints, within 1 month of initial assessment were included. RESULTS: The total number of children with mHT presenting for the first time to the EDs of both sites was 11,749. Overall, 180 (1.5%) unscheduled revisits to the EDs occurred for mHT-related or potentially related complaints. Twenty-three of these 180 patients underwent neuroimaging, and seven had an intracranial injury (including one ischemic stroke). Of these, three were hospitalized and none needed neurosurgery or intensive care. CONCLUSION: Unscheduled revisits for mHT in EDs using the PECARN rules were very uncommon. Initially missed intracranial injuries were rare, and none needed neurosurgery or intensive care.

The effect of in situ simulation training on the performance of tasks related to patient safety during sedation.

In many countries, procedural sedation outside of the operating room is performed by pediatricians. We examined if in situ sedation simulation training (SST) of pediatricians improves the performance of tasks related to patient safety during sedation in the Emergency Department (ED). We performed a single-center, quasi-experimental, study evaluating the performance of sedation, before-and-after SST. Sixteen pediatricians were evaluated during sedation as part of their usual practice, using the previously validated Sedation-Performance-Score (SPS). This tool evaluates physician behaviors during sedation that are conducive to safe patient outcomes. Following the sedation, providers completed SST, followed by a structured debriefing. They were then re-evaluated with the SPS during a subsequent patient sedation in the ED. Using multivariate regression, odds ratios were calculated for each SPS component, and were compared before and after the SST. Thirty-two sedations were performed, 16 before and 16 after SST. SPS scores improved from a median of 4 (IQR 2-5) to 6 (IQR 4-7) following SST (p < 0.0009, median difference 2, 95% CI 1-3). SST was associated with improved performance in four SPS components. The findings of this pilot study suggest that sedation simulation training of pediatricians improves several tasks related to patient safety during sedation.

Emergency Department Pain Management in Pediatric Patients With Fracture or Dislocation in a Bi-Ethnic Population.

STUDY OBJECTIVE: We determine whether ethnicity in a bi-ethnic population of northern Israel is associated with disparities in pediatric emergency department (ED) opioid analgesia in patients with fracture or dislocation. METHODS: A retrospective cohort study was conducted. All records of patients aged 3 to 15 years and receiving a diagnosis of a limb fracture or dislocation were extracted. Data on demographics, including ethnicity, nurse ethnicity, pain level, and pain medication, were collected. Medications were administered according to a nurse-driven pain protocol. RESULTS: During the nearly 4-year study period, 3,782 children with fractures visited the ED, 1,245 Arabs and 2,537 Jews. Of these, 315 Arabic patients and 543 Jewish patients had a pain score of 7 to 10. The proportion of Arabic and Jewish children who received opioid therapy was 312 of 315 (99.05%) and 538 of 543 (99.08%), respectively (difference 0.03%; 95% confidence interval -0.13% to 0.19%). Of the 315 Arabic children, 99 were approached by Arabic nurses (31.4%), and 98 of those received opioids (98.9%); 216 were approached by Jewish nurses (68.6%), and 214 of those received opioids (99%). Of the 543 Jewish children, 351 were approached by Jewish nurses (64.6%), and 348 of those received opioids (98.9%); 192 were approached by Arab nurses (35.4%), and 190 of those received opioids (98.9%). During the 2014 11-week Israeli-Palestinian armed conflict, 232 children with fractures visited the ED, 87 Arabs and 145 Jews, of whom 16 and 27 had pain scores of 7 to 10. The proportion of Arabic and Jewish children who received opioid medication was 16 of 16 (100%) and 26 of 27 (96%), respectively (difference 4%; 95% confidence interval -16% to 18%). CONCLUSION: Findings suggest that ethnic differences, including during periods of conflicts, have no effect on opioid analgesia in this ED.

Prehospital pain management of injured children: a systematic review of current evidence.

OBJECTIVES: Injury is a common cause of acute pain in children. The objective of this study was to analyze the available evidence in prehospital pain management of injured children. METHODS: The Patient/Population, Intervention, Comparator, and Outcome question was as follows: "In pediatric patients requiring prehospital analgesia for traumatic injuries, what is the level of evidence (LOE) available for the safety and efficacy of pharmacologic interventions?" The electronic databases MEDLINE/PUBMED, EMBASE, and Google Scholar were searched to identify all the relevant articles published in electronic journals, books, and scientific Web sites over the last 20 years. Studies were included if they reported on prehospital use of analgesics in injured children. Reviews, editorials, and surveys were excluded. RESULTS: Nineteen studies met the inclusion criteria. Thirteen were pediatric studies and 6 were studies of both adults and children. Nine were nonrandomized studies with concurrent controls (LOE-2), and 10 were retrospective case series and chart reviews (LOE-4). A measurable effect of analgesia was consistently found when analgesics were provided en route to the hospital; however, most studies reported a relatively low rate of analgesic use. CONCLUSIONS: Only a few studies examined the efficacy of pediatric prehospital analgesia. Fentanyl at a dose of 1 to 3 µg/mg seems to have an accepted efficacy. The current level of evidence is insufficient to assess the safety profile of analgesics. The findings of this study suggest that the analgesic treatment of injured children in the prehospital setting is suboptimal.

The Pediatric Emergency Care Applied Research Network intermediate-risk predictors were not associated with scanning decisions for minor head injuries.

AIM: This study determined the predictors associated with the decision to perform a computed tomography (CT) scan in children with a minor head injury (MHI). We focused on those facing an intermediate risk of clinically important traumatic brain injury (ciTBI), according to the Pediatric Emergency Care Applied Research Network (PECARN) prediction rule. METHODS: A 1-year, cross-sectional study was performed in an Italian paediatric emergency department, focusing on children presenting within 24 h of an MHI and meeting the PECARN intermediate-risk criteria. RESULTS: We included 308 children, and 47% were younger than 2 years of age. CT scans were carried out on 13%, 1.3% had a ciTBI and one was initially missed but did not need neurosurgery following diagnosis. Single and multiple PECARN intermediate-risk predictors were not associated with whether a CT scan was carried out. The only clinical variable associated with the decision to perform a CT scan was if the child was <3 months of age (OR 18.1, 95% CI, 4.91-66.61). CONCLUSION: The PECARN intermediate-risk predictors did not play a major role in the decision to perform a CT scan. The only factor significantly associated with the decision to perform a CT scan was when the patient was younger than 3 months of age.

The use of handheld near-infrared device (Infrascanner)for detecting intracranial haemorrhages in children with minor head injury.

OBJECTIVE: A handheld device using near-infrared technology(Infrascanner) has shown good accuracy for detection of traumatic intracranial haemorrhages in adults. This study aims to determine the feasibility of use of Infrascanner in children with minor head injury (MHI) in the Emergency Department(ED). Secondary aim was to assess its potential usefulness to reduce CT scan rate. METHODS: Prospective pilot study conducted in two paediatric EDs, including children at high or intermediate risk for clinically important traumatic brain injury (ciTBI) according to the adapted PECARN rule in use. Completion of Infrascanner measurements and time to completion were recorded. Decision on CT scan and CT scan reporting were performed independently and blinded to Infrascanner results. RESULTS: Completion of the Infrascanner measurement was successfully achieved in 103 (94 %) of 110 patients enrolled,after a mean of 4.4±2.9 min. A CT scan was performed in 18(17.5 %) children. Only one had an intracranial haemorrhage that was correctly identified by the Infrascanner. The exploratory analysis showed a specificity of 93 % (95 % CI, 86.5­96.6) and a negative predictive value of 100 % (95 % CI,81.6­100) for ciTBI. The use of Infrascanner would have led to avoid ten CT scan, reducing the CT scan rate by 58.8 %. CONCLUSIONS: Infrascanner seems an easy-to-use tool for children presenting to the ED following a MHI, given the high completion rate and short time to completion. Our preliminary results suggest that Infrascanner is worthy of further investigation as a potential tool to decrease the CT scan rate in children with MHI.

Emergency department diagnosis and treatment of traumatic hip dislocations in children under the age of 7 years: a 10-year review.

BACKGROUND AND AIMS: Traumatic hip dislocations (THD) are uncommon in children. They constitute true emergencies because unrecognised THD leads to avascular necrosis (AVN) of the femoral head. This review presents the evidence for best practice for the diagnosis and treatment of THD in the emergency department (ED) of children under the age of 7 years. METHODS: Searches for the period 2002-2012 were performed in PubMED, Cochrane database, EMBASE, Google Scholar and hand search. RESULTS: Twenty-five case reports and case series articles were identified, 53 described children with acute and 23 with neglected THD. Overall, 42 (55%) were male and 73 (96%) sustained a posterior dislocation. Forty-eight (63%) had THD following a low-energy trauma. Eight (11%) reported associated injuries. Twenty-one (39.6%) acute dislocations were reduced in the ED without complications. AVN was identified in 3 (5.7%) children, who underwent reduction ≥10 h after dislocation. Redislocation occurred in 3 (5.7%) children and coxa magna developed in 5 (9.4%). Long-term functional outcome of 42 patients resulted in full recovery, and it was fair to good in 3 (including 2 children with AVN). All neglected cases (≥4 weeks from trauma) needed open reduction in the operating room (OR). AVN was identified in 11 children (47.8%). Hip function was completely recovered in 16 (70%) patients. CONCLUSIONS: THD in this age group mainly occurs with low-energy trauma and leads to posterior dislocations. Urgent closed reduction of acute cases are done in the OR, or the ED. ED reduction appears to be safe. Neglected THDs need open reduction.

Sedation for children with intraoral injuries in the emergency department: a case-control study.

OBJECTIVE: Intraoral procedures (IOPs) are performed within the oral cavity of a spontaneously breathing, deeply sedated child. The objective of this study was to retrospectively evaluate the safety of sedation for IOP in a pediatric emergency department. METHODS: An unmatched, case-control study was conducted. The records of patients who had an IOP between January 1, 2012, and December 31, 2012, were analyzed. We evaluated the rate of serious adverse events during sedation (SAEDS) in patients who had an IOP (case subjects) and in patients who had a closed reduction of a forearm fracture (controls) and compared the 2 cohorts. RESULTS: Forty-one study subjects and 38 controls had complete records. Demographic characteristics were similar for both groups. Cases and controls were treated with the combination of propofol-ketamine for most of the cases (30/41 [73.2%] and 32/38 [84.2%]), and doses were similar between the groups. Study subjects had 5 hypoxic events and 2 apneic events; controls had 4 hypoxic events and 2 apneic events. No aspiration events were recorded. There were no statistically significant differences in the rate of SAEDS between the 2 groups (P = 0.55 and P = 0.54, respectively). All SAEDS were successfully managed in the emergency department, and no patient required hospitalization due to an adverse reaction. CONCLUSIONS: Findings of this study suggest that when performed by a skilled provider, sedation for an IOP is as safe as sedation for a fracture reduction.

The use of handheld near-infrared device (Infrascanner) for detecting intracranial haemorrhages in children with minor head injury.

OBJECTIVE: A handheld device using near-infrared technology (Infrascanner) has shown good accuracy for detection of traumatic intracranial haemorrhages in adults. This study aims to determine the feasibility of use of Infrascanner in children with minor head injury (MHI) in the Emergency Department (ED). Secondary aim was to assess its potential usefulness to reduce CT scan rate. METHODS: Prospective pilot study conducted in two paediatric EDs, including children at high or intermediate risk for clinically important traumatic brain injury (ciTBI) according to the adapted PECARN rule in use. Completion of Infrascanner measurements and time to completion were recorded. Decision on CT scan and CT scan reporting were performed independently and blinded to Infrascanner results. RESULTS: Completion of the Infrascanner measurement was successfully achieved in 103 (94 %) of 110 patients enrolled, after a mean of 4.4 ± 2.9 min. A CT scan was performed in 18 (17.5 %) children. Only one had an intracranial haemorrhage that was correctly identified by the Infrascanner. The exploratory analysis showed a specificity of 93 % (95 % CI, 86.5-96.6) and a negative predictive value of 100 % (95 % CI, 81.6-100) for ciTBI. The use of Infrascanner would have led to avoid ten CT scan, reducing the CT scan rate by 58.8 %. CONCLUSIONS: Infrascanner seems an easy-to-use tool for children presenting to the ED following a MHI, given the high completion rate and short time to completion. Our preliminary results suggest that Infrascanner is worthy of further investigation as a potential tool to decrease the CT scan rate in children with MHI.

Prehospital injury severity of children evacuated by helicopters from combat zones: a retrospective report.

BACKGROUND: In Israel, the Airborne Rescue and Evacuation Unit (AREU) provides prehospital trauma care in times of peace and during times of armed conflict. In peacetime, the AREU transports children who were involved in motor vehicle collisions (MVC) and those who fall off cliffs (FOC). During armed conflict, the AREU evacuates children who sustain firearm injuries (FI) from the fighting zones. OBJECTIVE: To report on prehospital injury severity of children who were evacuated by the AREU from combat zones. METHODS: A retrospective comparative analysis was conducted on indicators of prehospital injury severity for patients who had MVC, FOC, and FI. It included the National Advisory Committee for Aeronautics (NACA) score, the Glasgow Coma Scale (GCS) score on scene, and the number of procedures performed by emergency medical personnel and by the AREU air-crew. RESULTS: From January 2003 to December 2009, 36 MVC, 25 FOC, and 17 FI children were transported from the scene by the AREU. Five patients were dead at the scene: 1 (2.8%) MVC, 1 (4%) FOC, and 3 (17.6%) FI. Two (11.7%) FI patients were dead on arrival at the hospital. MVC, FOC, and FI patients had mean (±SD) NACA scores of 4.4 ± 1.2, 3.6 ± 1.2, and 5 ± 0.7, respectively. Mean (±SD) GCS scores were 8.9 ± 5.6, 13.6 ± 4, and 6.9 ± 5.3, respectively. Life support interventions were required by 29 (80.6%) MVC, 3 (12%) FOC, and 15 (88.2%) FI patients. CONCLUSIONS: In the prehospital setting, children evacuated from combat zones were more severely injured than children who were transported from the scene during peacetime.

Competency-based achievement system: using formative feedback to teach and assess family medicine residents' skills.

PROBLEM ADDRESSED: Family medicine residency programs require innovative means to assess residents' competence in "soft" skills (eg, patient-centred care, communication, and professionalism) and to identify residents who are having difficulty early enough in their residency to provide remedial training. OBJECTIVE OF PROGRAM: To develop a method to assess residents' competence in various skills and to identify residents who are having difficulty. PROGRAM DESCRIPTION: The Competency-Based Achievement System (CBAS) was designed to measure competence using 3 main principles: formative feedback, guided self-assessment, and regular face-to-face meetings. The CBAS is resident driven and provides a framework for meaningful interactions between residents and advisors. Residents use the CBAS to organize and review their feedback, to guide their own assessment of their progress, and to discern their future learning needs. Advisors use the CBAS to monitor, guide, and verify residents' knowledge of and competence in important skills. CONCLUSION: By focusing on specific skills and behaviour, the CBAS enables residents and advisors to make formative assessments and to communicate their findings. Feedback indicates that the CBAS is a user-friendly and helpful system to assess competence.

Internal jugular venous thrombosis after in vitro fertilization.

Internal jugular vein thrombosis is an uncommon entity with high morbidity and an increased risk of mortality. Spontaneous clotting of the internal jugular vein without any known risk factors is virtually unheard of, and intravenous drug use is the most common cause for thrombosis. Assisted reproductive techniques alone or in conjunction with ovarian hyperstimulation syndrome seem to predispose patients for thrombosis of the internal jugular vein. We present the case of a patient who, after in vitro fertilization, developed ovarian hyperstimulation syndrome and clotted the internal jugular vein. In the setting of the Emergency Department, the norm should be to "rule out internal jugular venous thrombosis" in pregnant patients who have undergone in vitro fertilization and present with neck pain, with or without swelling or distended collaterals.

Comparison of adverse events during procedural sedation between specially trained pediatric residents and pediatric emergency physicians in Israel.

OBJECTIVES: The aim was to compare the rate of procedural sedation-related adverse events of pediatric residents with specific training in "patient safety during sedation" and pediatric emergency physicians (PEPs) who completed the same course or were teaching faculty for it. METHODS: This prospective single-blinded, nonrandomized study was conducted in two university-affiliated pediatric emergency departments (PEDs) in Israel. Pediatric residents who were authorized to perform unsupervised sedations had previously completed a course in patient safety during sedation. Unsupervised sedations by residents were defined as sedations where the entire procedure was performed independently. Study subjects had autonomy in choosing medications for sedation. Adverse events were defined as transient hypoxia (oxygen saturation < or = 90%) or apnea. Adverse outcomes were situations where intubation or hospitalization directly related to sedation complications would occur. Sedations over 12 consecutive months were recorded, and rates of adverse events in each group were compared. RESULTS: A total of 984 eligible sedations were recorded, 635 by unsupervised residents and 349 by PEPs. A total of 512 (80.6%) sedations were performed by residents when attending physicians were not in the ED. The total adverse event rate was 24/984 (2.44%). When the two groups used a similar type drugs, residents had 8/635 (1.26%) events, compared to 11/328 (3.35%) by PEPs. There was no statistically significant difference in the rates of hypoxia or apnea between the two groups (p = 0.29 and p = 0.18, respectively). Adverse outcomes did not occur. CONCLUSIONS: Unsupervised pediatric residents with training in patient safety during sedation performed procedural sedations with a rate of adverse events similar to that of PEPs.

Introducing a nurse practitioner into an urban Canadian emergency department.

OBJECTIVE: Our objective was to compare the emergency care provided by a nurse practitioner (NP) with that provided by emergency physicians (EPs), to identify emergency department (ED) patients appropriate for autonomous NP practice and to acquire data to facilitate the development of the clinical scope of practice recommendations for ED practice for NPs. METHODS: Using a comprehensive 3-part process, we selected and hired the best NP from 12 applicants. The NP was oriented to the operations of our free-standing community ED and incorporated in the care team, working in real time with EP preceptors during a 6-month, prospective clinical assessment comparing NP care with EP care. ED preceptors reviewed every case in real time with the NP and completed an explicit evaluation form to determine whether NP assessment, investigation, treatment and disposition were "all equivalent to emergency physician care" (AEEPC) or whether they differed. The proportion of AEEPC interactions was determined for 23 patient presentation categories. Our a priori assumption was that a patient presentation category might be suitable for autonomous NP practice if 50% of NP encounters in that category were rated as AEEPC. Descriptive data were presented for patient case mix, teaching domains and time criteria. RESULTS: Eighty-three NP shifts and 711 patient encounters were evaluated by 21 EP preceptors. The NP saw a median of 8 patients per shift. In 43% of encounters, NP care was AEEPC. Highest AEEPC rates were found in the patient follow-up categories general follow-up (55.4%), diagnostic imaging (91.7%) and microbiology laboratory results (87.6%). NP scores over 50% were also seen for lacerations (63.6%) and isolated sore throats (53%). With teaching, NP performance improved over time. CONCLUSION: With the exception of follow up-related complaints, simple lacerations and isolated sore throats, NP care differed substantially from EP care. Although NPs with extensive emergency experience and training might ultimately be able to function as autonomous ED care providers, Canadian EDs currently developing job descriptions for emergency NPs should focus on a model of collaborative practice with EPs.

Enhancing patient safety during pediatric sedation: the impact of simulation-based training of nonanesthesiologists.

OBJECTIVE: To evaluate the impact of simulation-based education on patient safety during pediatric procedural sedation. DESIGN: A prospective, observational, single-blind, controlled study of pediatric procedural sedation outside the operating room. SETTING: Two university teaching hospitals in Israel. PARTICIPANTS: Nonanesthesiologists, with or without training in simulation-based education on patient safety, who routinely perform procedural sedation outside the operating room. These comprise full-time pediatricians practicing emergency medicine and a cohort of pediatric gastroenterologists. INTERVENTION: The study investigators used the internally developed, 9-criteria Sedation Safety Tool to observe and evaluate nonanesthesiologists who were trained in sedation safety and compared their performance with that of colleagues who did not receive similar training. OUTCOME MEASURE: For each of the 9 criteria on the evaluation form, odds ratios and 95% confidence intervals were calculated to compare the actions of the individuals in the 2 study groups. RESULTS: Thirty-two clinicians were evaluated. Half of the physicians were graduates of the simulation-based sedation safety course. Significant differences in performance pertaining to patient safety were found between those physicians who did and those who did not complete simulation-based training. CONCLUSIONS: Pediatric procedural sedations conducted by simulator-trained nonanesthesiologists were safer. The simulation-based sedation safety course enhanced physician performance during pediatric procedural sedation.

A controlled trial to increase detection and treatment of osteoporosis in older patients with a wrist fracture.

BACKGROUND: Despite the high risk for future fractures and the availability of effective treatments, fewer than 10% to 20% of patients who sustain a fragility fracture are tested or treated for osteoporosis. OBJECTIVES: To improve rates of testing and treatment for osteoporosis in patients with wrist fractures who are seen in the emergency department. DESIGN: Nonrandomized, controlled trial with blinded ascertainment of outcomes. SETTING: Emergency departments in Edmonton, Alberta, Canada. PATIENTS: Persons 50 years of age or older who were treated for a wrist fracture and their physicians. Patients admitted to the hospital or treated for osteoporosis were excluded. Overall, 572 consecutive patients with fractures were screened, and 102 patients (55 intervention, 47 control) and 101 physicians were studied. MEASUREMENTS: The primary end point was the prescription of osteoporosis treatment 6 months after fracture. Secondary end points included rates of testing for bone mineral density and patients' knowledge, satisfaction, and quality of life. INTERVENTION: Faxed physician reminders that contained osteoporosis treatment guidelines endorsed by local opinion leaders and patient education. Control patients received usual care and information about falls and home safety. RESULTS: The median patient age was 66 years. Most patients were female (78%) and white (79%); 70% of patients reported a previous fracture, and 22% had a fall with injury in the previous year. The intervention increased the rates of testing for bone mineral density to 62% (vs. 17% for controls; adjusted relative increase, 3.6 [P < 0.001]) and the rates of osteoporosis treatment to 40% (vs. 10% for controls; adjusted relative increase, 3.8 [P = 0.002]) within 6 months of fracture. Intervention patients were more likely to report a diagnosis of osteoporosis, but other patient-reported outcomes did not differ significantly between groups. LIMITATIONS: This was a small, nonrandomized, controlled study with process-based outcomes. CONCLUSIONS: In a multifaceted intervention directed at patients and their physicians, the rates of testing and treatment for osteoporosis after emergency department care for a fragility fracture were more than 3 times those of controls.

Brugada syndrome in a young patient with palpitations.

Brugada syndrome is a potentially lethal and eminently treatable entity that may present with palpitations or syncope. This article presents the case of a young patient with Brugada syndrome and reviews key features in the epidemiology, pathophysiology, diagnosis, treatment and prognosis of this condition.

Resident evaluation of clinical teachers based on teachers' certification.

OBJECTIVE: To examine the influence of emergency medicine (EM) certification of clinical teaching faculty on evaluations provided by residents. METHODS: A prospective cohort analysis was conducted of assessments between July 1994 and July 2000 on residents' evaluations of EM faculty at the University of Alberta, Edmonton, Canada. Resident- and faculty-related variables were entered anonymously using the validated evaluation tool (ER Scale). Credentialing and demographic information on EM faculty was supplemented by data obtained through a nine-question survey. Groups were compared using ANOVA. RESULTS: The 562 residents returned 705 (91%) valid evaluation sheets on 115 EM faculty members. The four domains of didactic teaching, clinical teaching, approachability, and helpfulness were assessed. The majority of ratings were in the very good or superb categories for each domain. Instructors with certification in EM had higher scores in didactic, clinical teaching compared with others, and teachers without national certification scored lower in the helpful and approachable categories (p < 0.05). The route of obtaining EM certifications either through training or practice eligibility did not affect scores. Instructors under the age of 40 years had higher scores than the older age groups in three of four categories (p < 0.05). Instructors working at the teaching sites on a half-time basis received higher scores than those working full-time, and scores varied based on site. Overall, teaching ratings improved over the study period (p < 0.05). CONCLUSIONS: Significant differences exist among instructors in the EM setting that affect their teaching rating scores. National certification in EM, academic track, rotation year, and site are all correlated with better teaching performance.

Analysis of factors influencing length of stay in the emergency department.

OBJECTIVES: Length of stay (LOS) is a key measure of emergency department (ED) throughput and a marker of overcrowding. Time studies that assess key ED processes will help clarify the causes of patient care delays and prolonged LOS. The objectives of this study were to identify and quantify the principal ED patient care time intervals, and to measure the impact of important service processes (laboratory testing, imaging and consultation) on LOS for patients in different triage levels. METHODS: In this retrospective review, conducted at a large urban tertiary care teaching hospital and trauma centre, investigators reviewed the records of 1047 consecutive patients treated during a continuous 7-day period in January 1999. Key data were recorded, including patient characteristics, ED process times, tests performed, consultations and overall ED LOS. Of the 1047 patient records, 153 (14.6%) were excluded from detailed analysis because of incomplete documentation. Process times were determined and stratified by triage level, using the Canadian Emergency Department Triage and Acuity Scale (CTAS). Multiple linear regression analysis was performed to determine which factors were most strongly associated with prolonged LOS. RESULTS: Patients in intermediate triage Levels III and IV generally had the longest waiting times to nurse and physician assessment, and the longest ED lengths of stay. CTAS triage levels predicted laboratory and imaging utilization as well as consultation rate. The use of diagnostic imaging and laboratory tests was associated with longer LOS, varying with the specific tests ordered. Specialty consultation was also associated with prolonged LOS, and this effect was highly variable depending on the service consulted. CONCLUSIONS: Triage level, investigations and consultations are important independent variables that influence ED LOS. Future research is necessary to determine how these and other factors can be incorporated into a model for predicting LOS. Improved information systems will facilitate similar ED time studies to assess key processes, lengths of stay and clinical efficiency.