Relationship Between the Anion Gap and Serum Lactate in Hypovolemic Shock.

Background and objectives: Previous studies evaluating patients in the Intensive Care Unit with established lactic acidosis determined that the anion gap is an insensitive screening tool for elevated blood lactate. No prior study has examined the relationship between anion gap and serum lactate within the first hours of the development of lactic acidosis. Design, setting, participants, & measurements: Data were obtained prospectively from a convenience sample of adult trauma patients at a single level 1 trauma center. Venous samples were drawn prior to initiation of intravenous fluid resuscitation. A linear regression model was constructed to assess the relationship between serum lactate and anion gap, and 95% prediction intervals were computed. Logistic regression models were constructed to determine the sensitivity and specificity for several different anion gap and lactate cutpoints. Results: 128 patients with elevated serum lactate levels (>2.1 mmol/L) and 63 patients with normal serum lactate levels (< 2.1 mmol/L) were included. The sensitivity of an elevated anion gap (> 10) to reveal hyperlactatemia was only 43% whereas specificity was 84%. Sensitivity improved if the upper limit of normal anion gap was lowered and with increasing levels of serum lactate. The coefficient of determination between serum lactate level and AG yielded an R2 of 0.30 (p < 0.001) and the slope of this relationship was 2.185 with a 95% confidence interval of 2.011-2.359. The mean 95% prediction interval was + 8.9. Conclusions: Within the first hour of the development of lactic acidosis due to hypovolemic shock, the anion gap was not a sensitive indicator of an elevated serum lactate level, but it was fairly specific. The anion gap increased to a greater extent than the serum lactate, the 95% mean prediction interval was wide and approximately 70% of the change in anion gap could not be explained by increases in serum lactate, suggesting that other anions contribute to the anion gap in lactic acidosis.

Assessing Acid-Base Status in Circulatory Failure: Relationship Between Arterial and Peripheral Venous Blood Gas Measurements in Hypovolemic Shock.

BACKGROUND AND OBJECTIVES: In severe circulatory failure agreement between arterial and mixed venous or central venous values is poor; venous values are more reflective of tissue acid-base imbalance. No prior study has examined the relationship between peripheral venous blood gas (VBG) values and arterial blood gas (ABG) values in hemodynamic compromise. The objective of this study was to examine the correlation between hemodynamic parameters, specifically systolic blood pressure (SBP) and the arterial-peripheral venous (A-PV) difference for all commonly used acid-base parameters (pH, Pco 2, and bicarbonate). DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS: Data were obtained prospectively from adult patients with trauma. When an ABG was obtained for clinical purposes, a VBG was drawn as soon as possible. Patients were excluded if the ABG and VBG were drawn >10 minutes apart. RESULTS: The correlations between A-PV pH, A-PV Pco 2, and A-PV bicarbonate and SBP were not statistically significant (P = .55, .17, and .09, respectively). Although patients with hypotension had a lower mean arterial and peripheral venous pH and bicarbonate compared to hemodynamically stable patients, mean A-PV differences for pH and Pco 2 were not statistically different (P = .24 and .16, respectively) between hypotensive and normotensive groups. CONCLUSIONS: In hypovolemic shock, the peripheral VBG does not demonstrate a higher CO2 concentration and lower pH compared to arterial blood. Therefore, the peripheral VBG is not a surrogate for the tissue acid-base status in hypovolemic shock, likely due to peripheral vasoconstriction and central shunting of blood to essential organs. This contrasts with the selective venous respiratory acidosis previously demonstrated in central venous and mixed venous measurements in circulatory failure, which is more reflective of acid-base imbalance at the tissue level than arterial blood. Further work needs to be done to better define the relationship between ABG and both central and peripheral VBG values in various types of shock.

Imaging of acute ischemic stroke.

For decades, imaging has been a critical component of the diagnostic evaluation and management of patients suspected of acute ischemic stroke (AIS). With each new advance in the treatment of AIS, the role of imaging has expanded in scope, sophistication, and importance in selecting patients who stand to benefit from potential therapies. Although the field of stroke imaging has been evolving for many years, there have been several major recent changes. Most notably, in late 2017, the window for treatment expanded to 24 h from onset of stroke symptoms in selected patients. Furthermore, for those patients in expanded time windows, guidelines issued in early 2018 now recommend the use of "advanced" imaging techniques in the acute setting, including CT perfusion and MRI, to guide therapeutic decision-making. With these and other changes, the emergency radiologist must be prepared to handle a growing volume and complexity of AIS imaging. This article reviews the various imaging modalities and techniques employed in the imaging of AIS patients, with an emphasis on recommendations from recent randomized controlled trials and national consensus guidelines.

Special Issue on Informatics Education: Developing and Implementing a Clinical Informatics Fellowship Curriculum.

We developed and implemented a novel internal clinical informatics curriculum for the UCI Fellowship Program. We sought to innovate the program's educational approach by transitioning from an external to an internal curriculum in response to feedback and the evolving needs of the field. This case study outlines the rationale, design process, challenges, and outcomes of this curriculum development effort.

Prospective correlation of arterial vs venous blood gas measurements in trauma patients.

OBJECTIVE: The objective of this study is to assess if venous blood gas (VBG) results (pH and base excess [BE]) are numerically similar to arterial blood gas (ABG) in acutely ill trauma patients. METHODS: We prospectively correlated paired ABG and VBG results (pH and BE) in adult trauma patients when ABG was clinically indicated. A priori consensus threshold of clinical equivalence was set at ± less than 0.05 pH units and ± less than 2 BE units. We hypothesized that ABG results could be predicted by VBG results using a regression equation, derived from 173 patients, and validated on 173 separate patients. RESULTS: We analyzed 346 patients and found mean arterial pH of 7.39 and mean venous pH of 7.35 in the derivation set. Seventy-two percent of the paired sample pH values fell within the predefined consensus equivalence threshold of ± less than 0.05 pH units, whereas the 95% limits of agreement (LOAs) were twice as wide, at -0.10 to 0.11 pH units. Mean arterial BE was -2.2 and venous BE was -1.9. Eighty percent of the paired BE values fell within the predefined ± less than 2 BE units, whereas the 95% LOA were again more than twice as wide, at -4.4 to 3.9 BE units. Correlations between ABG and VBG were strong, at r(2) = 0.70 for pH and 0.75 for BE. CONCLUSION: Although VBG results do correlate well with ABG results, only 72% to 80% of paired samples are clinically equivalent, and the 95% LOAs are unacceptably wide. Therefore, ABG samples should be obtained in acutely ill trauma patients if accurate acid-base status is required.

Implementation and impact on length of stay of a post-discharge remote patient monitoring program for acutely hospitalized COVID-19 pneumonia patients.

Objective: In order to manage COVID-19 patient population and bed capacity issues, remote patient monitoring (RPM) is a strategy used to transition patients from inpatients to home. We describe our RPM implementation process for post-acute care COVID-19 pneumonia patients. We also evaluate the impact of RPM on patient outcomes, including hospital length of stay (LOS), post-discharge Emergency Department (ED) visits, and hospital readmission. Materials and Methods: We utilized a cloud-based RPM platform (Vivify Health) and a nurse-monitoring service (Global Medical Response) to enroll COVID-19 patients who required oxygen supplementation after hospital discharge. We evaluated patient participation, biometric alerts, and provider communication. We also assessed the program's impact by comparing RPM patient outcomes with a retrospective cohort of Control patients who similarly required oxygen supplementation after discharge but were not referred to the RPM program. Statistical analyses were performed to evaluate the 2 groups' demographic characteristics, hospital LOS, and readmission rates. Results: The RPM program enrolled 75 patients with respondents of a post-participation survey reporting high satisfaction with the program. Compared to the Control group (n = 150), which had similar demographics and baseline characteristics, the RPM group was associated with shorter hospital LOS (median 4.8 vs 6.1 days; P=.03) without adversely impacting return to the ED or readmission. Conclusion: We implemented a RPM program for post-acute discharged COVID-19 patients requiring oxygen supplementation. Our RPM program resulted in a shorter hospital LOS without adversely impacting quality outcomes for readmission rates and improved healthcare utilization by reducing the average LOS.

Implementation of an Electronic Health Record-Based Messaging System in the Emergency Department: Effects on Physician Workflow and Resident Burnout.

INTRODUCTION: The traditional methods of communication between nurses and physicians through paging or phone calls have been known to cause patient care interruptions, increase stress and workload, and cause burnout. Our study assessed the impact of using an electronic health record-based messaging system (Epic Secure Chat) for nonemergent communication between nurses and physicians in the emergency department (ED). METHOD: This study was performed at a large urban academic ED. Surveys were distributed through e-mail using Google forms. Preimplementation and postimplementation surveys were performed from May 2019 (presurvey) to August 2019 (postsurvey). RESULT: The number of nonurgent phone calls from registered nurse staff decreased after intervention (P < 0.001). The frequency of nonurgent calls disrupting workflow decreased after the intervention (P = 0.029). The number of calls that were appropriately alerted to increased but was not significant (P = 0.120), whereas the degree of burnout from nonurgent calls remained relatively the same (P = 0.841). CONCLUSIONS: The findings provide insight into the implementation of an EMR messaging system in an ED setting. These findings suggest the messaging system can decrease unnecessary nonurgent calls from registered nurses and medical doctors, allowing for more efficient workflow in the ED. These findings suggest further research especially regarding burnout implemented on a larger scale and yield redesign suggestions in the ED.

The Δ Anion Gap/Δ Bicarbonate Ratio in Early Lactic Acidosis: Time for Another Delta?

Background: The ratio of Δ anion gap and Δ bicarbonate (ΔAG/ΔHCO3) is used to detect coexisting acid-base disorders in patients with high anion gap metabolic acidosis. Classic teaching holds that, in lactic acidosis, the ΔAG/ΔHCO3 is 1:1 within the first few hours of onset and subsequently rises to 1.8:1. However, this classic 1:1 stoichiometry in early lactic acidosis was derived primarily from animal models and only limited human data. The objective of this study was to examine the ΔAG/ΔHCO3 within the first hours of the development of lactic acidosis. Methods: Data were obtained prospectively from a convenience sample of adult (age >18 years) trauma-designated patients at a single level-1 trauma center. Venous samples, including a chemistry panel and serum lactate, were drawn before initiation of intravenous fluid resuscitation. Results: A total of 108 patients were included. Of these, 63 patients had normal serum lactate levels (≤2.1 mmol/L) with a mean AG of 7.1 mEq/L, the value used to calculate subsequent ΔAG values. ΔAG/ΔHCO3 was calculated for 45 patients who had elevated serum lactate levels (>2.1 mmol/L). The mean ΔAG/ΔHCO3 for all patients with elevated serum lactate levels was 1.86 (SD, 1.40). Conclusions: The mean ΔAG/ΔHCO3 was 1.86 within the first hours of the development of lactic acidosis due to hypovolemic shock, confirming a small prior human study. This contradicts the traditional belief that, in lactic acidosis, the ΔAG/ΔHCO3 is 1:1 within the first several hours. The classic 1:1 stoichiometry was determined on the basis of animal models in which lactic acid is infused into the extracellular space, facilitating extracellular buffering of protons by bicarbonate. In contrast, our results demonstrate a higher initial ΔAG/ΔHCO3 ratio in early endogenous lactic acidosis in humans. Our analysis indicates this is likely due to unmeasured anions contributing to an elevation in AG.

Improving service quality by understanding emergency department flow: a White Paper and position statement prepared for the American Academy of Emergency Medicine.

Emergency Department (ED) crowding is a common problem in the United States and around the world. Process reengineering methods can be used to understand factors that contribute to crowding and provide tools to help alleviate crowding by improving service quality and patient flow. In this article, we describe the ED as a service business and then discuss specific methods to improve the ED quality and flow. Methods discussed include demand management, critical pathways, process-mapping, Emergency Severity Index triage, bedside registration, Lean and Six Sigma management methods, statistical forecasting, queuing systems, discrete event simulation modeling and balanced scorecards. The purpose of this review is to serve as a background for emergency physicians and managers interested in applying process reengineering methods to improving ED flow, reducing waiting times, and maximizing patient satisfaction. Finally, we present a position statement on behalf of the American Academy of Emergency Medicine addressing these issues.

Public Performance Metrics: Driving Physician Motivation and Performance.

INTRODUCTION: As providers transition from "fee-for-service" to "pay-for-performance" models, focus has shifted to improving performance. This trend extends to the emergency department (ED) where visits continue to increase across the United States. Our objective was to determine whether displaying public performance metrics of physician triage data could drive intangible motivators and improve triage performance in the ED. METHODS: This is a single institution, time-series performance study on a physician-in-triage system. Individual physician baseline metrics-number of patients triaged and dispositioned per shift-were obtained and prominently displayed with identifiable labels during each quarterly physician group meeting. Physicians were informed that metrics would be collected and displayed quarterly and that there would be no bonuses, punishments, or required training; physicians were essentially free to do as they wished. It was made explicit that the goal was to increase the number triaged, and while the number dispositioned would also be displayed, it would not be a focus, thereby acting as this study's control. At the end of one year, we analyzed metrics. RESULTS: The group's average number of patients triaged per shift were as follows: Q1-29.2; Q2-31.9; Q3-34.4; Q4-36.5 (Q1 vs Q4, p < 0.00001). The average numbers of patients dispositioned per shift were Q1-16.4; Q2-17.8; Q3-16.9; Q4-15.3 (Q1 vs Q4, p = 0.14). The top 25% of Q1 performers increased their average numbers triaged from Q1-36.5 to Q4-40.3 (ie, a statistically insignificant increase of 3.8 patients per shift [p = 0.07]). The bottom 25% of Q1 performers, on the other hand, increased their averages from Q1-22.4 to Q4-34.5 (ie, a statistically significant increase of 12.2 patients per shift [p = 0.0013]). CONCLUSION: Public performance metrics can drive intangible motivators (eg, purpose, mastery, and peer pressure), which can be an effective, low-cost strategy to improve individual performance, achieve institutional goals, and thrive in the pay-for-performance era.

Impact of a Central-Line Insertion Site Assessment (CLISA) score on localized insertion site infection to prevent central-line-associated bloodstream infection (CLABSI).

OBJECTIVE: To assess the impact of a newly developed Central-Line Insertion Site Assessment (CLISA) score on the incidence of local inflammation or infection for CLABSI prevention. DESIGN: A pre- and postintervention, quasi-experimental quality improvement study. SETTING AND PARTICIPANTS: Adult inpatients with central venous catheters (CVCs) hospitalized in an intensive care unit or oncology ward at a large academic medical center. METHODS: We evaluated CLISA score impact on insertion site inflammation and infection (CLISA score of 2 or 3) incidence in the baseline period (June 2014-January 2015) and the intervention period (April 2015-October 2017) using interrupted times series and generalized linear mixed-effects multivariable analyses. These were run separately for days-to-line removal from identification of a CLISA score of 2 or 3. CLISA score interrater reliability and photo quiz results were evaluated. RESULTS: Among 6,957 CVCs assessed 40,846 times, percentage of lines with CLISA score of 2 or 3 in the baseline and intervention periods decreased by 78.2% (from 22.0% to 4.7%), with a significant immediate decrease in the time-series analysis (P < .001). According to the multivariable regression, the intervention was associated with lower percentage of lines with a CLISA score of 2 or 3, after adjusting for age, gender, CVC body location, and hospital unit (odds ratio, 0.15; 95% confidence interval, 0.06-0.34; P < .001). According to the multivariate regression, days to removal of lines with CLISA score of 2 or 3 was 3.19 days faster after the intervention (P < .001). Also, line dwell time decreased 37.1% from a mean of 14 days (standard deviation [SD], 10.6) to 8.8 days (SD, 9.0) (P < .001). Device utilization ratios decreased 9% from 0.64 (SD, 0.08) to 0.58 (SD, 0.06) (P = .039). CONCLUSIONS: The CLISA score creates a common language for assessing line infection risk and successfully promotes high compliance with best practices in timely line removal.

The worsening of ED on-call coverage in California: 6-year trend.

To reassess problems with on-call physician coverage in California, we repeated our anonymous 2000 survey of the California chapter of the American College of Emergency Physicians. Physicians responded from 77.4% of California emergency departments (EDs), 51.0% of ED directors, and 34% of those surveyed. Of 21 specialties, on-call availability worsened since 2000 for 9, was unchanged for 11, and improved for 1. Of ED directors, 54% report medical staff rules require on-call duty, down from 72% in 2000. Hospitals have increased specialist on-call payments (from 21% to 35%, with 75% paying at least one specialty). Most emergency physicians (80.3%) report insurance status negatively affects on-call physician responsiveness, up from 42% in 2000. Emergency departments with predominantely minority or uninsured patients had fewer specialists and more trouble accessing them. Insurance status has a major negative effect on ED consultation and follow-up care. The on-call situation in California has worsened substantially in 6 years.

Positive cerebrospinal fluid cultures after normal cell counts are contaminants.

Previous literature on meningitis reports that cerebrospinal fluid (CSF) culture contaminants are threefold more common than true pathogens. Clinical follow-up of patients with CSF contaminants is costly, time-consuming, and potentially unnecessary. In this study, we hypothesized that, in immunocompetent Emergency Department (ED) patients with normal CSF cell counts and negative Gram stains, all positive bacterial cultures are contaminants and patient follow-up is unnecessary. We retrospectively reviewed 191 ED charts of patients with positive CSF cultures over 5 years. We abstracted lumbar puncture results, disposition, and follow-up activities, and determined monetary charges. There were 137 patients (72%) who met inclusion criteria with CSF white blood cells < or = 7 microL, negative Gram stain, and immunocompetence. Ninety-eight were discharged from the ED and 39 were admitted to the hospital for reasons other than meningitis. All 137 positive cultures were found to be contaminants, with coagulase-negative staphylococci found most commonly. Follow-up activities included telephone calls (49%), repeat ED visits (13%), repeat lumbar punctures (9%), unnecessary antibiotic treatment (6%), and hospitalizations (6%), generating $55,000 in charges. Follow-up may be unnecessary in ED patients with positive bacterial CSF cultures who were discharged from the ED, if their initial lumbar punctures were normal.

Management of Primary Osseous Spinal Tumors with PET.

Knowledge of the PET imaging findings of osseous spinal neoplasms is essential, because they are common incidental findings on PET scans done for staging of unrelated primary malignancies. Additionally, PET can help differentiate lesions that are not clearly defined by anatomic modalities alone. PET can also be used for follow-up of aggressive tumors to assess response to treatment, often proving superior to CT or MR imaging alone for this purpose. This review discusses the role of PET/CT and PET/MR imaging in the diagnosis and management of primary benign and malignant osseous tumors of the spine.

Migrating from One Comprehensive Commercial EHR to Another: Perceptions of Front-line Clinicians and Staff.

As healthcare organizations continue to grow and evolve, migrations from one commercial electronic health record (EHR) system to another are likely to become more common. However, little is known about front-line clinicians' and staff's perceptions of such changes. Our study addresses this gap through an organization-wide survey of employees immediately prior to the transition to a new commercial EHR. We found that almost all front-line clinicians and staff were aware of the upcoming migration, and that most felt positive or neutral about the change, with only about 11% indicating that they were uncomfortable with the migration. Reasons for discomfort included the beliefs that the new EHR will be more time consuming to use and that moving to a new EHR is too costly, as well as concerns about the migration process. Attitudes differed by demographic characteristics and satisfaction with the current EHR. We discuss the implications of these results.

Epipericardial fat necrosis: Uncommon cause of acute pleuritic chest pain.

Epipericardial fat necrosis (EPFN) is a rare cause for acute chest. We describe the case of a previously healthy 25-year-old man who presented with sudden onset of left-sided chest pain. Laboratory values showed only mildly elevated d-dimer and electrocardiogram was normal. However, subsequent CT angiogram of the chest revealed fat necrosis in the epipericardial fat, characteristic for EPFN, for which the patient was treated with nonsteroidal anti-inflammatory drug. This case highlights the importance of radiologists to consider the prospect of EPFN in the differential diagnosis of acute chest pain as correct diagnosis allows for conservative management and avoidance of more aggressive techniques in symptomatic patients.

Diffuse peritoneal leiomyomatosis status post laparoscopic hysterectomy with power morcellation: A case report with review of literature.

•Leiomyomatosis following laparoscopic hysterectomy with morcellation is reported.•Parasitic myomas grow in a benign fashion but may be fatal depending on location.•Fibroids are a contraindication for laparoscopic hysterectomy with morcellation.•Containment bags may address intraperitoneal spillage of malignant tissue.

A Comparison of Urolithiasis in the Presence and Absence of Microscopic Hematuria in the Emergency Department.

INTRODUCTION: Urolithiasis is a common medical condition that accounts for a large number of emergency department (ED) visits each year and contributes significantly to annual healthcare costs. Urinalysis is an important screening test for patients presenting with symptoms suspicious for urolithiasis. At present there is a paucity of medical literature examining the characteristics of ureteral stones in patients who have microscopic hematuria on urinalysis versus those who do not. The purpose of this study was to examine mean ureteral stone size and its relationship to the incidence of clinically significant hydronephrosis in patients with and without microscopic hematuria. METHODS: This is a retrospective chart review of patient visits to a single, tertiary academic medical center ED between July 1, 2008, and August 1, 2013, of patients who underwent non-contrast computed tomography of the abdomen and pelvis and urinalysis. For patient visits meeting inclusion criteria, we compared mean stone size and the rate of moderate-to-severe hydronephrosis found on imaging in patients with and without microscopic hematuria on urinalysis. RESULTS: Out of a total of 2,370 patient visits 393 (16.6%) met inclusion criteria. Of those, 321 (82%) had microscopic hematuria present on urinalysis. Patient visits without microscopic hematuria had a higher rate of moderate-to-severe hydronephrosis (42%), when compared to patients with microscopic hematuria present (25%, p=.005). Mean ureteral stone size among patient visits without microscopic hematuria was 5.7 mm; it was 4.7 mm for those patients with microscopic hematuria (p=.09). For ureteral stones 5 mm or larger, the incidence of moderate-to-severe hydronephrosis was 49%, whereas for ureteral calculi less than 5 mm in size, the incidence of moderate-to-severe hydronephrosis was 14% (p < 0.0001). CONCLUSION: Patients visiting the ED with single-stone ureterolithiasis without microscopic hematuria on urinalysis could be at increased risk of having moderate-to-severe hydronephrosis compared to similar patients presenting with microscopic hematuria on urinalysis. Although the presence of hematuria on urinalysis is a moderately sensitive screening test for urolithiasis, these results suggest patients without hematuria tend to have more clinically significant ureteral calculi, making their detection more important. Clinicians should maintain a high index of suspicion for urolithiasis, even in the absence of hematuria, since ureteral stones in these patients were found to be associated with a higher incidence of obstructive uropathy.