Techniques, success, and adverse events of emergency department adult intubations.

STUDY OBJECTIVE: We describe the operators, techniques, success, and adverse event rates of adult emergency department (ED) intubation through multicenter prospective surveillance. METHODS: Eighteen EDs in the United States, Canada, and Australia recorded intubation data onto a Web-based data collection tool, with a greater than or equal to 90% reporting compliance requirement. We report proportions with binomial 95% confidence intervals (CIs) and regression, with year as the dependent variable, to model change over time. RESULTS: Of 18 participating centers, 5 were excluded for failing to meet compliance standards. From the remaining 13 centers, we report data on 17,583 emergency intubations of patients aged 15 years or older from 2002 to 2012. Indications were medical in 65% of patients and trauma in 31%. Rapid sequence intubation was the first method attempted in 85% of encounters. Emergency physicians managed 95% of intubations and most (79%) were physician trainees. Direct laryngoscopy was used in 84% of first attempts. Video laryngoscopy use increased from less than 1% in the first 3 years to 27% in the last 3 years (risk difference 27%; 95% CI 25% to 28%; mean odds ratio increase per year [ie, slope] 1.7; 95% CI 1.6 to 1.8). Etomidate was used in 91% and succinylcholine in 75% of rapid sequence intubations. Among rapid sequence intubations, rocuronium use increased from 8.2% in the first 3 years to 42% in the last 3 years (mean odds ratio increase per year 1.3; 95% CI 1.3 to 1.3). The first-attempt intubation success rate was 83% (95% CI 83% to 84%) and was higher in the last 3 years than in the first 3 (86% versus 80%; risk difference 6.2%; 95% CI 4.2% to 7.8%). The airway was successfully secured in 99.4% of encounters (95% CI 99.3% to 99.6%). CONCLUSION: In the EDs we studied, emergency intubation has a high and increasing success rate. Both drug and device selection evolved significantly during the study period.

Fracture of a GlideScope® Cobalt GVL® Stat disposable blade during an emergency intubation.

BACKGROUND: Emergency airway management is a diverse discipline, often utilizing advanced equipment with video technology to enable the intubator to visualize a patient's vocal cords that would be difficult or impossible to see with routine direct laryngoscopy. The GlideScope® Cobalt (Saturn Biomedical Systems, Inc., Burnaby, BC, Canada) is one type of video laryngoscope with disposable plastic GVL® Stat blades (Saturn Biomedical Systems) that can improve glottic view over direct laryngoscopy. It also benefits from rapid turnaround time and few infection control issues due to its disposable blade. OBJECTIVE: To report what we believe to be the first GlideScope® blade failure to be reported in the medical literature. The circumstances surrounding the blade failure may raise awareness of GVL® Stat usage in obese patients with limited mouth opening. CASE REPORT: During a standard emergency intubation, insertion of the GVL® Stat into the patient's mouth resulted in breakage of the distal segment of the blade. The patient was severely obese and had limited mouth opening, which required the blade to be inserted obliquely, rather than in the midline, into the patient's mouth. As the handle was repositioned back to midline, the distal segment of the blade broke off. No excessive force was used during blade repositioning when breakage occurred. CONCLUSION: Twisting forces on the distal flat segment of the GVL® Stat may have caused its failure. Because this was only a single occurrence of breakage, it is not clear if design issues or atypical insertion of the blade was responsible for breakage. Care must be exercised when midline insertion is not possible, which can occur in obese patients with limited mouth opening.

Emergency airway management: a multi-center report of 8937 emergency department intubations.

OBJECTIVE: Emergency department (ED) intubation personnel and practices have changed dramatically in recent decades, but have been described only in single-center studies. We sought to better describe ED intubations by using a multi-center registry. METHODS: We established a multi-center registry and initiated surveillance of a longitudinal, prospective convenience sample of intubations at 31 EDs. Clinicians filled out a data form after each intubation. Our main outcome measures were descriptive. We characterized indications, methods, medications, success rates, intubator characteristics, and associated event rates. We report proportions with 95% confidence intervals and chi-squared testing; p-values < 0.05 were considered significant. RESULTS: There were 8937 encounters recorded from September 1997 to June 2002. The intubation was performed for medical emergencies in 5951 encounters (67%) and for trauma in 2337 (26%); 649 (7%) did not have a recorded mechanism or indication. Rapid sequence intubation was the initial method chosen in 6138 of 8937 intubations (69%) and in 84% of encounters that involved any intubation medication. The first method chosen was successful in 95%, and intubation was ultimately successful in 99%. Emergency physicians performed 87% of intubations and anesthesiologists 3%. Several other specialties comprised the remaining 10%. One or more associated events were reported in 779 (9%) encounters, with an average of 12 per 100 encounters. No medication errors were reported in 6138 rapid sequence intubations. Surgical airways were performed in 0.84% of all cases and 1.7% of trauma cases. CONCLUSION: Emergency physicians perform the vast majority of ED intubations. ED intubation is performed more commonly for medical than traumatic indications. Rapid sequence intubation is the most common method of ED intubation.

Improved glottic exposure with the Video Macintosh Laryngoscope in adult emergency department tracheal intubations.

STUDY OBJECTIVE: Glottic visualization with video is superior to direct laryngoscopy in controlled operating room studies. However, glottic exposure with video laryngoscopy has not been evaluated in the emergency department (ED) setting, where blood, secretions, poor patient positioning, and physiologic derangement can complicate laryngoscopy. We measure the difference in glottic visualization with video versus direct laryngoscopy. METHODS: We prospectively studied a convenience sample of tracheal intubations at 2 academic EDs. We performed laryngoscopy with the Karl Storz Video Macintosh Laryngoscope, which can be used for conventional direct laryngoscopy, as well as video laryngoscopy. We rated glottic visualization with the Cormack-Lehane (C-L) Scale, defining "good" visualization as C-L I or II and "poor" visualization as C-L III or IV. We compared glottic exposure between direct and video laryngoscopy, determining the proportion of poor direct visualizations improved to good visualization with video laryngoscopy. We also determined the proportion of good direct visualizations worsened to poor visualization by video laryngoscopy. RESULTS: We report data on 198 patients, including 146 (74%) medical, 51 (26%) trauma, and 1 (0.51%) unknown indications. All were tracheally intubated by emergency physicians. Postgraduate year 3 or 4 residents performed 102 (52.3%) of the laryngoscopies, postgraduate year 2 residents performed 60 (30.8%), interns performed 20 (10.3%), attending physicians performed 9 (4.6%), and operator experience and specialty were not reported in 4. Overall, good visualization (C-L grade I or II) was attained in 158 direct (80%) versus 185 video laryngoscopies (93%; McNemar's P<.0001). Of the 40 patients with poor glottic exposure on direct laryngoscopy, video laryngoscopy improved the view in 31 (78%; 95% confidence interval 62% to 89%). Of the 158 patients with good glottic view on direct laryngoscopy, video laryngoscopy worsened the view in 4 (3%; 95% confidence interval 0.7% to 6%). CONCLUSION: Video laryngoscopy affords more grade I and II views than direct laryngoscopy and improves glottic exposure in most patients with poor direct glottic visualization. In a small proportion of cases, glottic exposure is worse with video than direct laryngoscopy.

Feasibility of the preoperative Mallampati airway assessment in emergency department patients.

BACKGROUND: Multiple predictors have been proposed to assist in identifying patient features that would predict difficult airway management. The Mallampati score (MS) has been shown to be useful in the preoperative assessment of patients being intubated in the operating room. OBJECTIVE: We sought to define the feasibility of this assessment in the Emergency Department. METHODS: A prospective, observational study was performed on all patients being intubated at a university Level I trauma center over a period of 6 months. We recorded and calculated the proportion of patients who were successfully assessed using the MS. Reasons given by individual intubators for failure to assess were recorded. We also tracked patient characteristics between groups and complication rates. RESULTS: Of 328 patients, 32 (10%) were excluded due to incomplete data. Among the remaining 296, 58% were intubated for non-trauma indications, 70% were male, and the mean age was 45.9 years. Only 76 of 296 (26%) (95% confidence interval 21-31%) were able to have the MS performed. Lack of patient cooperation and clinical instability were listed as factors that precluded evaluation in patients whose assessment was unsuccessful. The frequency of procedure-related minor events did not differ significantly between the assessed and non-assessed groups. Major events included two cricothyrotomies in the non-assessed group. CONCLUSIONS: We were unable to perform a Mallampati assessment in three-quarters of our patients requiring emergency intubation. These findings call into question the feasibility of the standard Mallampati assessment in the practice of Emergency Medicine.

Longitudinal exploration of in situ mock code events and the performance of cardiac arrest skills.

INTRODUCTION: In hospital cardiac arrest (IHCA) affects 200,000 adults in the United States each year, and resuscitative efforts are often suboptimal. The objective of this study was to determine whether a program of "mock codes" improves group-level performance of IHCA skills. Our primary outcome of interest was change in CPR fraction, and the secondary outcomes of interest were time to first dose of epinephrine and time to first defibrillation. We hypothesized that a sustained program of mock codes would translate to greater than 10% improvement in each of these core metrics over the first three years of the program. METHODS: We conducted mock codes in an urban teaching hospital between August, 2012 and October, 2015. Mock codes occurred on telemetry and medical/surgical units on day and night shifts. Codes were managed by unit staff and members of the hospital's "Code Blue" team, and data were recorded by trained observers. Data were summarized using descriptive statistics, and repeated measures outcomes were calculated using a mixed effects model. RESULTS: Fifty-seven mock codes were included in the analysis: 42 on Medical/Surgical units and 15 on Telemetry units. CPR fraction increased by 2.9% per six-month time interval on Telemetry units, and 1.3% per time interval on Medical/Surgical units. Neither time to first epinephrine dosing nor time to defibrillation changed significantly. CONCLUSIONS: While we observed a significant improvement in CPR fraction over the course of this program of mock codes, similar improvements were not observed for other key measures of cardiac arrest performance.

Intubation confirmation techniques associated with unrecognized non-tracheal intubations by pre-hospital providers.

This study examined pre-hospital intubations performed by paramedics, which were later determined to be non-tracheal upon arrival at an urban, academic emergency department (ED). The aim was to characterize the various confirmation techniques used among these unrecognized non-tracheal intubations. A retrospective review of the emergency medical services (EMS) quality assurance database was conducted over a period of 65 months. Paramedic patient care reports and hospital medical records were reviewed with regard to techniques used for airway evaluation. Simple descriptive statistics are used to summarize the data. During this study period, paramedics intubated 1643 patients. There were 35 (2%) intubations that were ultimately determined to be non-tracheal by receiving physicians. Among these, 20 (57%) were intubations for trauma indications. Seven patients (20%) were children (< 10 years). Fifteen patients (43%) did not have a pulse before intubation attempts. Overall, 21 (60%) had multiple confirmatory techniques employed by paramedics. The most commonly documented was 'equal lung sounds' (91%), followed by 'visualized cords' (52%). Per protocol, colorimetric end tidal CO2 was used selectively among patients with pulses, 9/20 (45%). Aspiration techniques were not used among this study population. Based on paramedic documentation, 17 (49%) of the non-tracheal intubations were potentially recognizable. An unrecognized, non-tracheal intubation is a potentially devastating consequence of failed airway management. We report a small, but important experience with failed pre-hospital airway management. In this EMS system, more frequent use of multiple confirmatory techniques (including end tidal CO2 detection) may help to reduce the incidence of this potentially life-threatening scenario.

The fast is positive, now what? Derivation of a clinical decision rule to determine the need for therapeutic laparotomy in adults with blunt torso trauma and a positive trauma ultrasound.

INTRODUCTION: The object of this study was to derive a clinical decision rule for therapeutic laparotomy among adult blunt trauma patients with a positive abdominal ultrasound for trauma (FAST) examination. METHODS: We retrospectively reviewed the trauma registry and medical records of all critical trauma patients who underwent a FAST examination in the emergency department (ED) in a university Level I trauma center over a 3-year period. Blunt trauma patients aged >16 years who had a positive FAST examination (defined as the presence of intraperitoneal fluid) were eligible. We selected seven clinical and ultrasound variables available during ED resuscitation for analysis: age, presence of an episode of hypotension (systolic blood pressure <90 torr in the ED), presence of abdominal tenderness, chest injury, pelvic fracture, femur fracture, and FAST fluid location (right upper quadrant [RUQ] only; RUQ plus other location; other location only). The primary outcome variable was whether a laparotomy was performed and whether this laparotomy was needed to provide the definitive surgical intervention ("therapeutic laparotomy"). We analyzed the variables using binary recursive partitioning analysis to create a decision rule. RESULTS: There were 2336 FAST examinations performed during the study period, resulting in 230 (9.8%) positive examinations in patients meeting inclusion criteria. There were 135 patients who had therapeutic laparotomies and 95 who did not need laparotomy. The groups were similar in baseline characteristics. In the recursive partitioning analysis, the first node in the decision tree was the presence of fluid in the RUQ. Of the 144 patients with RUQ fluid, 105 (73%, 95% confidence interval [CI] 64%-80%) required therapeutic laparotomy. Of the 86 patients without RUQ fluid, 30 (35%, 95% CI 25%-46%) nevertheless required therapeutic laparotomies, and the variables blood pressure, femur fracture, abdominal tenderness, and age further divided these patient into high- and low-risk groups. Of the 12 patients without RUQ fluid who had normal blood pressures, no femur fractures, no abdominal tenderness, and were aged 60 years and younger, none (95% CI 0%-22%) required therapeutic laparotomy. In conclusion, given a positive FAST examination, the presence of fluid in the RUQ is an important predictor of the need for therapeutic laparotomy. CONCLUSION: In the absence of fluid in the RUQ, there are other clinical variables that may allow for the development of a clinical decision rule regarding the need for therapeutic laparotomy.

The inaccuracy of using landmark techniques for cricothyroid membrane identification: a comparison of three techniques.

OBJECTIVES: Successful cricothyrotomy is predicated on accurate identification of the cricothyroid membrane (CTM) by palpation of superficial anatomy. However, recent research has indicated that accuracy of the identification of the CTM can be as low as 30%, even in the hands of skilled providers. To date, there are very little data to suggest how to best identify this critical landmark. The objective was to compare three different methods of identifying the CTM. METHODS: A convenience sample of patients and physician volunteers who met inclusion criteria was consented. The patients were assessed by physician volunteers who were randomized to one of three methods for identifying the CTM (general palpation of landmarks vs. an approximation based on four finger widths vs. an estimation based on overlying skin creases of the neck). Volunteers would then mark the skin with an invisible but florescent pen. A single expert evaluator used ultrasound to identify the superior and inferior borders of the CTM. The variably colored florescent marks were then visualized with ultraviolet light and the accuracy of the various methods was recorded as the primary outcome. Additionally, the time it took to perform each technique was measured. Descriptive statistics and report 95% confidence intervals (CIs) are reported. RESULTS: Fifty adult patients were enrolled, 52% were female, and mean body mass index was 28 kg/m(2) (95% CI = 26 to 29 kg/m(2) ). The general palpation method was successful 62% of the time (95% CI = 48% to 76%) and took an average of 14 seconds to perform (range = 5 to 45 seconds). In contrast, the four-finger technique was successful 46% of the time (95% CI = 32% to 60%) and took an average of 12 seconds to perform (range = 6 to 40 seconds). Finally, the neck crease method was successful 50% of the time (95% CI = 36% to 64%) and took an average of 11 seconds to perform (range = 5 to 15 seconds). CONCLUSIONS: All three methods performed poorly overall. All three techniques might potentially be even less accurate in instances where the superficial anatomy is not palpable due to body habitus. These findings should alert clinicians to the significant risk of a misplaced cricothyrotomy and highlight the critical need for future research.

Discrete event simulation of emergency department activity: a platform for system-level operations research.

OBJECTIVES: This article explores the potential of discrete event simulation (DES) methods to advance system-level investigation of emergency department (ED) operations. To this end, the authors describe the development and operation of Emergency Department SIMulation (EDSIM), a new platform for computer simulation of ED activity at a Level 1 trauma center. The authors also demonstrate one potential application of EDSIM by using simulated ED activity to compare two patient triage methods. METHODS: The Extend DES modeling package was used to develop a model of ED activity for a five-day period in July 2003. Model input includes staffing levels, facility characteristics, and patient data drawn from electronic patient tracking databases, billing records, and a detailed review of 674 ED charts. The accuracy of model output was tested by comparing predicted and known patient service times. The EDSIM model was then used to compare the fast-track triage approach with an alternative acuity ratio triage (ART) approach whereby patients were assigned to staff on an acuity ratio basis. RESULTS: The EDSIM model predicts average patient service times within 10% of actual values. The accuracy of individual patient paths, however, was variable. In the authors' model, 28% of individual patient treatment times had an absolute error of less than one hour, and 59% less than three hours. A preliminary comparison of two triage methods showed that the ART approach reduced imaging bottlenecks and average treatment times for high-acuity patients, but resulted in an overall increase in average service time for low-acuity patients. CONCLUSIONS: The EDSIM model provides a flexible platform for studying ED operations as they relate to average treatment times for ED patients, but the model will require further refinement to predict individual patient times. A comparative study of triage methods suggests that ART provides a mix of benefits and drawbacks, but further investigation will be required to substantiate these preliminary findings.

An evaluation of a blind rotational technique for selective mainstem intubation.

OBJECTIVES: Although rare, massive hemoptysis and major bronchial disruptions are associated with high mortality. Selective ventilation of the uninvolved lung can increase the likelihood of survival. Specialized devices used for single lung ventilation are often not readily available and can be difficult to place in the emergency department. The authors evaluated a blind rotational technique for selective mainstem intubation using either a standard endotracheal tube (ET) or a directional-tip endotracheal tube (DTET). METHODS: This was a prospective, randomized trial on 25 human cadavers. The desired side of mainstem intubation was determined by randomization. Each cadaver was used for four ET, four DTET, and four control intubations. In the ET group, the trachea was intubated. The tube was then rotated 90 degrees in the direction of the desired placement and advanced until resistance was met. In the DTET group, the technique was identical, except the trigger was activated to flex the tip during advancement. In the control group, an ET was advanced in neutral alignment until resistance was met. A bronchoscopist blinded to the desired placement determined tube position. Comparison testing was performed using Pearson's chi-square test. RESULTS: When attempting to intubate the left mainstem, use of the ET with the rotational technique was successful 72.3% of the time (95% confidence interval [95% CI] = 57% to 84%). Intubation of the left mainstem using the DTET was successful 68.5% of the time (95% CI = 54% to 81%; p = 0.67). Attempts to selectively intubate the right mainstem using the rotational technique were highly successful in both groups: 94% for the ET (95% CI = 84% to 99%) versus 97.8% for the DTET (95% CI = 89% to 100%). Among controls, the right mainstem was intubated 93% of the time (95% CI = 86% to 97%). CONCLUSIONS: In a cadaveric model, the left mainstem bronchus can be selectively intubated with moderate reliability using this rotational technique. Use of a DTET confers no significant advantage. The ability to generalize these findings to living subjects is unknown.

The failed intubation attempt in the emergency department: analysis of prevalence, rescue techniques, and personnel.

The aims of this study were: To describe the prevalence of Emergency Department (ED) airway management failures requiring rescue maneuvers, to describe successful rescue methods used when the primary method chosen is unsuccessful, and to characterize the roles of emergency physicians and other specialists in rescue airway management. A prospective observational study was conducted of ED airway management in 30 hospitals in the USA, Canada, and Singapore participating in the National Emergency Airway Registry (NEAR) database project. Patients were entered in the study if they underwent ED airway management, the first method chosen was not successful in achieving intubation, and a rescue technique was required. Data were collected on a structured data form for entry into a relational database with subsequent search for subjects fulfilling inclusion and exclusion criteria. Descriptive statistics were used for analysis of these data. There were 7,712 patients identified who underwent emergency intubation during the study period from January 1998 to February 2001. A total of 207 (2.7%) patient intubations met the inclusion criteria. Of these, 102 (49%) patients underwent rescue rapid sequence intubation (RSI). RSI was used after failure of oral intubation with sedation alone (n = 29), oral intubation without medications (n = 37), or blind nasotracheal intubation (n = 36). Forty-three (21%) patients underwent rescue cricothyrotomy after failure of RSI (n = 26) or other intubation methods (n = 17). Seventy-nine percent of rescue RSIs and 53% of rescue surgical airways were performed by emergency physicians. In conclusion, a total of 2.7% of emergency intubations required rescue. RSI is the most commonly used first line technique for ED airway management and is also the principal back-up technique when other oral or nasal intubation methods fail. Emergency physicians manage the majority of ED intubations, including those requiring rescue techniques.

Cricothyrotomy: a 5-year experience at one institution.

We describe the prevalence, primary indications and immediate complications of emergency cricothyrotomy (cric) techniques, in a single institution's Emergency Department (ED) and associated air-medical transport service. This is a retrospective review at an academic, level-one trauma center with an annual ED census of 65,000 and an associated air-medical transport service (AMTS). All patients undergoing cric in the field or in the ED between July 1995 and June 2000 were included. Expert reviewers from Emergency Medicine, Trauma Surgery and the AMTS prospectively defined the complication criteria. All charts with a possible complication underwent a blinded evaluation by reviewers representing each of the three clinical services. Descriptive statistics were used to summarize the data. Fifty crics were performed over 5 years. Seventy-six percent of crics were performed in trauma patients. The prevalence of cric in patients requiring airway management in the ED was 1.1% (95% CI, 0.7-1.6) and 10.9% (95% CI, 6.9-16.1) in the field by the AMTS. The prevalence of complications was 14% (95% CI, 4-32.6) in ED patients and 54.5% (95% CI, 32-75.6) for prehospital patients. The overall inter-rater agreement for complication rate was excellent (kappa =.87). Overall, 77% of crics were performed using the rapid four-step technique (RFST). There were no reports of complications associated with the RFST when performed in the ED. Non-RFST crics in the ED had an associated complication rate of 25% (95% CI, 2.8-60). Emergency cricothyrotomy was performed in approximately 1% of all emergency airway cases in the ED and at a higher rate by the AMTS. The most frequent indications were trauma related. Additionally, the RFST was the most commonly used technique for cric at this institution. The complication rate of cric was significantly higher in the prehospital environment than in the ED.

Emergency medicine resident crisis resource management ability: a simulation-based longitudinal study.

BACKGROUND: Simulation has been identified as a means of assessing resident physicians' mastery of technical skills, but there is a lack of evidence for its utility in longitudinal assessments of residents' non-technical clinical abilities. We evaluated the growth of crisis resource management (CRM) skills in the simulation setting using a validated tool, the Ottawa Crisis Resource Management Global Rating Scale (Ottawa GRS). We hypothesized that the Ottawa GRS would reflect progressive growth of CRM ability throughout residency. METHODS: Forty-five emergency medicine residents were tracked with annual simulation assessments between 2006 and 2011. We used mixed-methods repeated-measures regression analyses to evaluate elements of the Ottawa GRS by level of training to predict performance growth throughout a 3-year residency. RESULTS: Ottawa GRS scores increased over time, and the domains of leadership, problem solving, and resource utilization, in particular, were predictive of overall performance. There was a significant gain in all Ottawa GRS components between postgraduate years 1 and 2, but no significant difference in GRS performance between years 2 and 3. CONCLUSIONS: In summary, CRM skills are progressive abilities, and simulation is a useful modality for tracking their development. Modification of this tool may be needed to assess advanced learners' gains in performance.

GlideScope Videolaryngoscopy in the Simulated Difficult Airway: Bougie vs Standard Stylet.

OBJECTIVE: GlideScope(®) videolaryngoscopy (GVL) has been shown to improve visualization of the glottis compared to direct laryngoscopy (DL). However, due to the angle of approach to the glottis, intubation can still be challenging. We hypothesized that novice GVL users would be able to intubate faster and easier using an airway introducer (frequently known as a bougie) than with a standard intubating stylet. METHODS: Intubations were performed on a human airway simulator with settings for easy and difficult airways. Participants were emergency medicine (EM) residents or faculty (n=21) who were novice GVL users. Participants were intubated a total of eight times (four GVL, four DL) using either a bougie or an intubating stylet. We recorded time to intubate (TTI) and difficulty rating using a visual analog scale (VAS) and non-parametric statistical methods for analysis. We reported medians with interquartile range (IQR). RESULTS: The median TTI with difficult airway settings and the bougie-GVL was 76 seconds (IQR 50, 102) versus 64 seconds (IQR 50.5, 125), p=0.76 for the stylet-GVL combination. The median VAS difficulty score, on difficult airway settings, for the bougie-GVL was 5 cm (IQR 3.3, 8.0) versus 6.2 cm (IQR 5.0, 7.5) with the stylet-GVL, p=0.53. CONCLUSION: Among novices using GVL for simulated difficult airway management, there was no benefit, in terms of speed or ease of intubation, by using the bougie over the standard stylet.

Improving the efficiency of physical examination services.

The objective of our project was to improve the efficiency of the physical examination screening service of a large hospital system. We began with a detailed simulation model to explore the relationships between four performance measures and three decision factors. We then attempted to identify the optimal physician inquiry starting time by solving a goal-programming problem, where the objective function includes multiple goals. One of our simulation results shows that the proposed optimal physician inquiry starting time decreased patient wait times by 50% without increasing overall physician utilization.

The impact of inpatient boarding on ED efficiency: a discrete-event simulation study.

In this study, a discrete-event simulation approach was used to model Emergency Department's (ED) patient flow to investigate the effect of inpatient boarding on the ED efficiency in terms of the National Emergency Department Crowding Scale (NEDOCS) score and the rate of patients who leave without being seen (LWBS). The decision variable in this model was the boarder-released-ratio defined as the ratio of admitted patients whose boarding time is zero to all admitted patients. Our analysis shows that the Overcrowded(+) (a NEDOCS score over 100) ratio decreased from 88.4% to 50.4%, and the rate of LWBS patients decreased from 10.8% to 8.4% when the boarder-released-ratio changed from 0% to 100%. These results show that inpatient boarding significantly impacts both the NEDOCS score and the rate of LWBS patient and this analysis provides a quantification of the impact of boarding on emergency department patient crowding.