Peri-intubation cardiac arrest in the Emergency Department: A National Emergency Airway Registry (NEAR) study.

AIM: To determine the incidence of peri-intubation cardiac arrest through analysis of a multi-center Emergency Department (ED) airway registry and to report associated clinical characteristics. METHODS: This is a secondary analysis of prospectively collected data (National Emergency Airway Registry) comprising ED endotracheal intubations (ETIs) of subjects >14 years old from 2016 to 2018. We excluded those with cardiac arrest prior to intubation. The primary outcome was peri-intubation cardiac arrest. Multivariable logistic regression generated adjusted odds ratios (aOR) of variables associated with this outcome, controlling for clinical features, difficult airway characteristics, and ETI modality. RESULTS: Of 15,776 subjects who met selection criteria, 157 (1.0%, 95% CI 0.9-1.2%) experienced peri-intubation cardiac arrest. Pre-intubation systolic blood pressure <100 mm Hg (aOR 6.2, 95% CI 2.5-8.5), pre-intubation oxygen saturation <90% (aOR 3.1, 95% CI 2.0-4.8), and clinician-reported need for immediate intubation without time for full preparation (aOR 1.8, 95% CI, 1.2-2.7) were associated with higher likelihood of peri-intubation cardiac arrest. The association between pre-intubation shock and cardiac arrest persisted in additional modeling stratified by ETI indication, induction agent, and oxygenation status. CONCLUSIONS: Peri-intubation cardiac arrest for patients undergoing ETI in the ED is rare. Higher likelihood of arrest occurs in patients with pre-intubation shock or hypoxemia. Prospective trials are necessary to determine whether a protocol to optimize pre-intubation haemodynamics and oxygenation mitigates the risk of peri-intubation cardiac arrest.

Ketamine Versus Etomidate and Peri-intubation Hypotension: A National Emergency Airway Registry Study.

BACKGROUND: The hemodynamic impact of induction agents is a critically important consideration in emergency intubations. We assessed the relationship between peri-intubation hypotension and the use of ketamine versus etomidate as an induction agent for emergency department (ED) intubation. METHODS: We analyzed ED intubation data for patients aged >14 years from the National Emergency Airway Registry performed in 25 EDs during 2016 through 2018. We excluded patients with preintubation hypotension (systolic blood pressure <100 mm Hg) or cardiac arrest prior to intubation. The primary outcome was peri-intubation hypotension. Secondary outcomes included interventions for hypotension (e.g., intravenous fluids or vasopressors). We report adjusted odds ratios (aOR) from multivariable logistic regression models controlling for patient demographics, difficult airway characteristics, and intubation modality. RESULTS: There were 738 encounters with ketamine and 6,068 with etomidate. Patients receiving ketamine were more likely to have difficult airway characteristics (effect size difference = 8.8%, 95% confidence interval [CI] = 5.3% to 12.4%) and to undergo intubation with video laryngoscopy (8.1%, 95% CI = 4.4% to 12.0%). Peri-intubation hypotension incidence was 18.3% among patients receiving ketamine and 12.4% among patients receiving etomidate (effect size difference = 5.9%, 95% CI = 2.9% to 8.8%). Patients receiving ketamine were more likely to receive treatment for peri-intubation hypotension (effect size difference = 6.5%, 95% CI = 3.9% to 9.3%). In logistic regression analyses, patients receiving ketamine remained at higher risk for peri-intubation hypotension (aOR = 1.4, 95% CI = 1.2 to 1.7) and treatment for hypotension (aOR = 1.8, 95% CI = 1.4 to 2.0). There was no difference in the aOR of hypotension between patients receiving ketamine at doses ≤1.0 mg/kg versus >1.0 mg/kg or patients receiving etomidate at doses ≤0.3 mg/kg versus >0.3 mg/kg. CONCLUSIONS: Pending additional data, our results suggest that clinicians should not necessarily prioritize ketamine over etomidate based on concern for hemodynamic compromise among ED patients undergoing intubation.

The Development of an Emergency Medicine Resident Research Program in the United States Military.

INTRODUCTION: The Accreditation Council for Graduate Medical Education stipulates that residents should participate in scholarly activity. As of 2019 that verbiage will be changed to, "Residents must participate in scholarship." However, scholarly activity is not clearly defined. We set out to define our graduation research requirement in a measurable way and structure a research curriculum that better prepared residents to conduct scholarly activity. MATERIALS AND METHODS: This study compares resident scholarly output in several categories before and after the initiation of a revised research curriculum and graduation requirement. Scholarly activity was measured by comparing the production of Pubmed Indexed (PMID) publications, online publications, and conference presentations of two Emergency Medicine Residency classes. The intervention class was represented by the class of 2018 which exposed 16 residents to the new curriculum and graduation requirement for the full three years of their residency. The comparison class was represented by the class of 2015 which exposed 16 residents to the old curriculum and old graduation requirement. The old graduation requirement and curriculum were undefined. The new requirement involved two options, participate in original research starting from the process of question formulation and carried through manuscript drafting or publishing at first author PMID of any kind. The new curriculum involved monthly journal clubs, two annual deep dives, and an 8-day Intern Research Course modeled after the Emergency Medicine Basic Research Skills workshop sponsored by the American College of Emergency Physicians. In addition to the new curriculum, several new leadership positions were created at both the staff and resident level that solely focused on the promotion of scholarly activity. In addition to creating a culture within the department that encouraged scholarship, these overlapping leadership positions also helped create continuity in a program that could easily be hampered by frequent staff turnover due to new military assignments and military deployments. RESULTS: Resident scholarly activity in the form of PMIDs increased from 4 to 22. The production of online publications was 0 and 12, respectively. There were 2 and 11 conference presentations, respectively. CONCLUSION: Resident scholarly activity increased following the institution of a new research curriculum and graduation requirement.

The Prevalence of Faculty Physician Burnout in Military Graduate Medical Education Training Programs: A Cross-Sectional Study of Academic Physicians in the United States Department of Defense.

INTRODUCTION: In military populations, physician burnout has potential to adversely affect medical readiness to deploy in support of joint operations. Burnout among Graduate Medical Education (GME) faculty may further threaten the welfare of the medical force given the central role these officers have in training and developing junior physicians. The primary aim of this investigation was to estimate the prevalence of burnout among faculty physicians in United States (US) Army, Navy, and Air Force GME programs. MATERIALS AND METHODS: We conducted a cross-sectional study of faculty physicians at US military GME training programs between January 2018 and July 2018. Through direct coordination with Designated Institutional Officials, we administered the Maslach Burnout Inventory Health Services Survey (MBI-HSS) via online web link to faculty physicians listed in Accreditation Data System at each sponsoring institution. In addition to the MBI-HSS, we collected demographic data and queried physicians about common occupational stressors in order to assist institutional leaders with identifying at-risk physicians and developing future interventions to address burnout. RESULTS: Sixteen of 21 institutions that currently sponsor military GME programs agreed to distribute the MBI-HSS survey to core faculty. We received completed assessments from 622 of the 1,769 (35.1%) reported physician core faculty at these institutions. Of the 622 physician respondents, 162 demonstrated high levels of emotional exhaustion and depersonalization for an estimated 26% prevalence of burnout. We identified only one independent risk factor for burnout: increasing numbers of deployments (OR 1.38, 95% CI 1.07-1.77). Physicians in our cohort who reported a desire to stay beyond their initial active duty service obligation were less likely to be classified with burnout (OR 0.45, 95% CI 0.26-0.77). The most common drivers of occupational distress were cumbersome bureaucratic tasks, insufficient administrative support, and overemphasis on productivity metrics. CONCLUSIONS: We estimate that 26% of physician faculty in military GME programs are experiencing burnout. No specialty, branch of service, or specific demographic was immune to burnout in our sample. Institutional leaders in the MHS should take action to address physician burnout and consider using our prevalence estimate to assess effectiveness of future interventions.

The THINK (Treatment of Headache with Intranasal Ketamine) Trial: A Randomized Controlled Trial Comparing Intranasal Ketamine with Intravenous Metoclopramide.

BACKGROUND: Headache is a common chief complaint in the emergency department (ED) setting. OBJECTIVES: To compare analgesia with metoclopramide and diphenhydramine vs. intranasal ketamine among ED patients with primary headache. METHODS: We enrolled a convenience sample of adults with a primary headache in a randomized, single-blind, placebo-controlled trial. We randomized patients to either a control arm (intravenous metoclopramide and diphenhydramine) or intranasal ketamine. The primary outcome was change in pain 0-100 mm visual analog scale (VAS) score measured at study start and 30 min post completion of initial medication administration. Secondary outcomes included side effects, hospital admission, and return to care within 48-72 h. RESULTS: All 53 enrolled subjects completed the study, 26 of whom were allocated to the control arm and 27 to intranasal ketamine. The mean change in pain VAS score at 30 min post intervention was 22.2 mm in the control arm vs. 29.0 in the intranasal ketamine arm (effect size difference 6.8 mm, 95% confidence interval -5.8-19.4). The incidence of reported side effects was 65.4% in the control arm vs. 66.7% in the ketamine arm. Three patients (11.5%) allocated to the control arm required admission for headache pain control vs. 1 patient (3.7%) in the intranasal ketamine arm. Three (11.5%) additional patients in the control arm returned to the ED within 48-72 h for headache pain vs. none in the ketamine arm. CONCLUSIONS: In this small randomized study, intranasal ketamine was not superior to standard therapy among ED patients with primary headache syndromes.

Emergency Department Intubation Success With Succinylcholine Versus Rocuronium: A National Emergency Airway Registry Study.

STUDY OBJECTIVE: Although both succinylcholine and rocuronium are used to facilitate emergency department (ED) rapid sequence intubation, the difference in intubation success rate between them is unknown. We compare first-pass intubation success between ED rapid sequence intubation facilitated by succinylcholine versus rocuronium. METHODS: We analyzed prospectively collected data from the National Emergency Airway Registry, a multicenter registry collecting data on all intubations performed in 22 EDs. We included intubations of patients older than 14 years who received succinylcholine or rocuronium during 2016. We compared the first-pass intubation success between patients receiving succinylcholine and those receiving rocuronium. We also compared the incidence of adverse events (cardiac arrest, dental trauma, direct airway injury, dysrhythmias, epistaxis, esophageal intubation, hypotension, hypoxia, iatrogenic bleeding, laryngoscope failure, laryngospasm, lip laceration, main-stem bronchus intubation, malignant hyperthermia, medication error, pharyngeal laceration, pneumothorax, endotracheal tube cuff failure, and vomiting). We conducted subgroup analyses stratified by paralytic weight-based dose. RESULTS: There were 2,275 rapid sequence intubations facilitated by succinylcholine and 1,800 by rocuronium. Patients receiving succinylcholine were younger and more likely to undergo intubation with video laryngoscopy and by more experienced providers. First-pass intubation success rate was 87.0% with succinylcholine versus 87.5% with rocuronium (adjusted odds ratio 0.9; 95% confidence interval 0.6 to 1.3). The incidence of any adverse event was also comparable between these agents: 14.7% for succinylcholine versus 14.8% for rocuronium (adjusted odds ratio 1.1; 95% confidence interval 0.9 to 1.3). We observed similar results when they were stratified by paralytic weight-based dose. CONCLUSION: In this large observational series, we did not detect an association between paralytic choice and first-pass rapid sequence intubation success or peri-intubation adverse events.

High sensitivity troponin: The Sisyphean pursuit of zero percent miss rate for acute coronary syndrome in the ED.

BACKGROUND: The United States Food and Drug Administration recently approved a high sensitivity troponin (hsTn) assay for use. Recent literature has investigated the diagnostic accuracy of hsTn for acute coronary syndrome (ACS) in the emergency department (ED) and its use in accelerated diagnostic protocols. OBJECTIVE: This article evaluates the existing literature and discusses incorporation of hsTn testing into ED clinical practice based on best available evidence. DISCUSSION: Interpretation of this literature for clinical application is challenging due to heterogeneity across studies with regards to the hsTn assays examined, time intervals for delta troponin tests, and study populations. The high sensitivity of these assays is predicated upon the ability of the physician to clinically determine a patient to have a low pre-test probability of disease. Physicians may further ensure maximal sensitivity by defining the cut-off for a positive value as the limit of detection and utilizing delta troponin testing. These assays do not obviate the need to consider follow-up for risk stratification for discharged patients. Higher sensitivity compared to standard troponin tests comes at the expense of lower specificity. Indiscriminate testing may translate to greater numbers of abnormal troponin results in patients with non-ACS syndromes, potentially leading to increased healthcare costs, hospital admissions, increased ED lengths of stay, and unnecessary interventions. CONCLUSION: As hsTn becomes more widespread, it is imperative emergency physicians understand its potential and limitations. Knowledge of test characteristics is vital to ensure appropriate use. Further study of hsTn is required to optimize use.

A 12-month descriptive analysis of emergency intubations at Brooke Army Medical Center: a National Emergency Airway Registry study.

Emergency airway management is a critical skill for military healthcare providers. Our goal was to describe the Emergency Department (ED) intubations at Brooke Army Medical Center (BAMC) over a 12-month period. MATERIAL AND METHODS: Physicians performing endotracheal intubations in the BAMC ED complete data collection forms for each intubation event as part of the National Emergency Airway Registry, including patient demographics, intubation techniques, success and failure rates, adverse events, and patient disposition. We cross-referenced these forms against the numbers of intubation events reported in the ED nursing daily reports to ensure capture of all intubations. Providers completed forms for every intubation within 6 weeks of the procedure. We analyzed data from March 28, 2016, to March 27, 2017. RESULTS: During the study period, providers performed 259 intubations in the BAMC ED. Reasons for intubation were related to trauma for 184 patients (71.0%) and medical conditions for 75 patients (29.0%). Overall, first-attempt success was 83.0%. Emergency medicine residents performed a majority of first attempts (95.0%). Most common devices chosen on first attempt were a video laryngoscope for 143 patients (55.2%) and a direct laryngoscope for 115 patients (44.4%). One patient underwent cricothyrotomy. The 2 most common induction agents were ketamine (59.8%; 95% CI, 55.2%-67.4%) and etomidate (19.3%; 95% CI, 14.7%-24.7%). The most common neuromuscular blocking agents were rocuronium (62.9%; 95% CI, 56.7%-68.8%) and succinylcholine (18.9%; 95% CI, 14.3%-24.2%). CONCLUSION: In the BAMC ED, emergency intubation most commonly occurred for trauma indications using video laryngoscopy with a high first-pass success.

Diagnostic Accuracy of Emergency Bedside Ultrasonography to Detect Cutaneous Wooden Foreign Bodies: Does Size Matter?

BACKGROUND: Soft-tissue occult foreign bodies are a concerning cause of morbidity in the emergency department. The identification of wooden foreign bodies is a unique challenge because they are often not detectable by plain radiography. The purpose of this study was to determine the diagnostic accuracy of emergency physician-performed ultrasonography to detect wooden foreign bodies of varying sizes. We hypothesized that sonographic sensitivity would improve with increasing foreign body size. METHODS: We conducted a blinded, prospective evaluation using a previously validated, chicken, soft-tissue model to simulate human tissue. We inserted wooden toothpicks of varying lengths (1mm, 2.5mm, 5mm, 7.5mm, 10mm) to a depth of 1cm in five tissue models. Five additional models were left without a foreign body to serve as controls. Fifty emergency physicians with prior ultrasonography training performed sonographic examinations of all 10 models and reported on the presence or absence of wooden foreign bodies. RESULTS: Subjects performed 10 ultrasonography examinations each for a total of 500 examinations. For the detection of wooden foreign bodies, overall test characteristics for sonography included sensitivity 48.4% (95% confidence interval [CI], 42.1%-54.8%) and specificity 67.6% (95% CI, 61.3%- 73.2%). Sensitivity did not change as object size increased (ρ = s.709). CONCLUSION: Emergency physician bedside ultrasonography demonstrated poor diagnostic accuracy for the detection of wooden foreign bodies. Accuracy did not improve with increasing object size up to 10mm. Providers should consider alternative diagnostic modalities if there is persistent clinical concern for a retained, radiolucent, soft-tissue foreign body.

Heated Ultrasound Gel and Patient Satisfaction with Bedside Ultrasound Studies: The HUGS Trial.

INTRODUCTION: Our goal was to determine if heated gel for emergency department (ED) bedside ultrasonography improves patient satisfaction compared to room-temperature gel. METHODS: We randomized a convenience sample of ED patients determined by their treating physician to require a bedside ultrasound (US) study to either heated gel (102.0° F) or room-temperature gel (82.3° F). Investigators performed all US examinations. We informed all subjects that the study entailed investigation into various measures to improve patient satisfaction with ED US examinations but did not inform them of our specific focus on gel temperature. Investigators wore heat-resistant gloves while performing the examinations to blind themselves to the gel temperature. After completion of the US, subjects completed a survey including the primary outcome measure of patient satisfaction as measured on a 100-mm visual analogue scale (VAS). A secondary outcome was patient perceptions of sonographer professionalism measured by an ordinal scale (1-5). RESULTS: We enrolled 124 subjects; 120 completed all outcome measures. Of these, 59 underwent randomization to US studies with room-temperature gel and 61 underwent randomization to heated US gel. Patient 100-mm VAS satisfaction scores were 83.9 among patients undergoing studies with room-temperature gel versus 87.6 among subjects undergoing studies with heated gel (effect size 3.7, 95% confidence interval -1.3-8.6). There were similarly no differences between the two arms with regard to patient perceptions of sonographer professionalism. CONCLUSION: The use of heated ultrasound gel appears to have no material impact on the satisfaction of ED patients undergoing bedside ultrasound studies.

Vascular Access Complications: An Emergency Medicine Approach.

Millions of central venous and arterial catheters are placed across the United States annually as mechanisms of obtaining advanced hemodynamic monitoring and facilitating acute resuscitation. Although presumably life saving or sustaining in many circumstances, current literature identifies the preprocedural and postprocedural complications of infection, thrombosis, embolism, and iatrogenic injury as resulting in patient morbidity and mortality. Today, through the application of aseptic technique, performance of operator training, and the utilization of ultrasound, emergency physicians may limit vascular access complications and improve patient outcomes.

Diagnostic accuracy of a novel software technology for detecting pneumothorax in a porcine model.

INTRODUCTION: Our objective was to measure the diagnostic accuracy of a novel software technology to detect pneumothorax on Brightness (B) mode and Motion (M) mode ultrasonography. METHODS: Ultrasonography fellowship-trained emergency physicians performed thoracic ultrasonography at baseline and after surgically creating a pneumothorax in eight intubated, spontaneously breathing porcine subjects. Prior to pneumothorax induction, we captured sagittal M-mode still images and B-mode videos of each intercostal space with a linear array transducer at 4cm of depth. After collection of baseline images, we placed a chest tube, injected air into the pleural space in 250mL increments, and repeated the ultrasonography for pneumothorax volumes of 250mL, 500mL, 750mL, and 1000mL. We confirmed pneumothorax with intrapleural digital manometry and ultrasound by expert sonographers. We exported collected images for interpretation by the software. We treated each individual scan as a single test for interpretation by the software. RESULTS: Excluding indeterminate results, we collected 338M-mode images for which the software demonstrated a sensitivity of 98% (95% confidence interval [CI] 92-99%), specificity of 95% (95% CI 86-99), positive likelihood ratio (LR+) of 21.6 (95% CI 7.1-65), and negative likelihood ratio (LR-) of 0.02 (95% CI 0.008-0.046). Among 364 B-mode videos, the software demonstrated a sensitivity of 86% (95% CI 81-90%), specificity of 85% (81-91%), LR+ of 5.7 (95% CI 3.2-10.2), and LR- of 0.17 (95% CI 0.12-0.22). CONCLUSIONS: This novel technology has potential as a useful adjunct to diagnose pneumothorax on thoracic ultrasonography.

Whole body CT versus selective radiological imaging strategy in trauma: an evidence-based clinical review.

BACKGROUND: Trauma patients often present with injuries requiring resuscitation and further evaluation. Many providers advocate for whole body computed tomography (WBCT) for rapid and comprehensive diagnosis of life-threatening injuries. OBJECTIVE: Evaluate the literature concerning mortality effect, emergency department (ED) length of stay, radiation, and incidental findings associated with WBCT. DISCUSSION: Physicians have historically relied upon history and physical examination to diagnose life-threatening injuries in trauma. Diagnostic imaging modalities including radiographs, ultrasound, and computed tomography have demonstrated utility in injury detection. Many centers routinely utilize WBCT based on the premise this test will improve mortality. However, WBCT may increase radiation and incidental findings when used without considering pre-test probability of actionable traumatic injuries. Studies supporting WBCT are predominantly retrospective and incorporate trauma scoring systems, which have significant design weaknesses. The recent REACT-2 trial randomized trauma patients with high index of suspicion for actionable injuries to WBCT versus selective imaging and found no mortality difference. Additional prospective trials evaluating WBCT in specific trauma subgroups (e.g. polytrauma) are needed to evaluate benefit. In the interim, the available data suggests clinicians should adopt a selective imaging strategy driven by history and physical examination. CONCLUSIONS: While observational data suggests an association between WBCT and a benefit in mortality and ED length of stay, randomized controlled data suggests no mortality benefit to this diagnostic tool. The literature would benefit from confirmatory studies of the use of WBCT in trauma sub-groups to clarify its impact on mortality for patients with specific injury patterns.

A Case of Brachiocephalic Fistula Steal and the Emergency Physician's Approach to Hemodialysis Arteriovenous Fistula Complications.

BACKGROUND: Chronic kidney disease is common in the United States, with many patients maintained on hemodialysis (HD). The process of HD requires vascular access through an arteriovenous (AV) fistula, AV graft, or central venous catheter. Today, as a result of the National Kidney Foundation's "Fistula First" initiative, nearly 55% of HD patients utilize an AV fistula. As there is significant morbidity and mortality associated with fistula placement and recurrent fistula cannulation, emergency physicians must be equipped to recognize and treat fistula complications. OBJECTIVE: To detail a case study of vascular insufficiency (vascular steal) presenting to an emergency department (ED) and provide an evidence-based approach to the emergency assessment and management of HD AV fistula complications. DISCUSSION: A 66-year-old man presented to the ED with left upper extremity pain, paresthesias, and loss of grip strength of 1-week duration 15 days after placement of left upper extremity brachiocephalic fistula. He was diagnosed with dialysis access-associated steal syndrome and taken to the operating room for revision. Patients with HD fistulas may experience several complications, including vascular insufficiency, hemorrhage, infection, stenosis, thrombosis, aneurysms, or pseudoaneurysms. Emergency physicians must be able to identify these complications and deliver timely treatment. CONCLUSIONS: A comprehensive understanding of the appropriate management of AV fistula complications is paramount for the emergency physician. Early recognition and treatment of vascular insufficiency resulting from fistula creation, fistula hemorrhage, fistula infection, stenosis, thrombosis, and aneurysms or pseudoaneurysms is vital to reducing the morbidity and mortality associated with HD.

Computerized Diagnostic Assistant for the Automatic Detection of Pneumothorax on Ultrasound: A Pilot Study.

INTRODUCTION: Bedside thoracic ultrasound (US) can rapidly diagnose pneumothorax (PTX) with improved accuracy over the physical examination and without the need for chest radiography (CXR); however, US is highly operator dependent. A computerized diagnostic assistant was developed by the United States Army Institute of Surgical Research to detect PTX on standard thoracic US images. This computer algorithm is designed to automatically detect sonographic signs of PTX by systematically analyzing B-mode US video clips for pleural sliding and M-mode still images for the seashore sign. This was a pilot study to estimate the diagnostic accuracy of the PTX detection computer algorithm when compared to an expert panel of US trained physicians. METHODS: This was a retrospective study using archived thoracic US obtained on adult patients presenting to the emergency department (ED) between 5/23/2011 and 8/6/2014. Emergency medicine residents, fellows, attending physicians, physician assistants, and medical students performed the US examinations and stored the images in the picture archive and communications system (PACS). The PACS was queried for all ED bedside US examinations with reported positive PTX during the study period along with a random sample of negatives. The computer algorithm then interpreted the images, and we compared the results to an independent, blinded expert panel of three physicians, each with experience reviewing over 10,000 US examinations. RESULTS: Query of the PACS system revealed 146 bedside thoracic US examinations for analysis. Thirteen examinations were indeterminate and were excluded. There were 79 true negatives, 33 true positives, 9 false negatives, and 12 false positives. The test characteristics of the algorithm when compared to the expert panel were sensitivity 79% (95 % CI [63-89]) and specificity 87% (95% CI [77-93]). For the 20 images scored as highest quality by the expert panel, the algorithm demonstrated 100% sensitivity (95% CI [56-100]) and 92% specificity (95% CI [62-100]). CONCLUSION: This novel computer algorithm has potential to aid clinicians with the identification of the sonographic signs of PTX in the absence of expert physician sonographers. Further refinement and training of the algorithm is still needed, along with prospective validation, before it can be utilized in clinical practice.

The Absence of Gallstones on Point-of-Care Ultrasound Rules Out Acute Cholecystitis.

BACKGROUND: Cholelithiasis affects an estimated 20 million people in the United States yearly; 20% of symptomatic patients will develop acute cholecystitis (AC). A recent single-center study estimating test characteristics of point-of-care ultrasonography (POCUS) for the detection of AC, as defined by gallstones plus sonographic Murphy's or pericholecystic fluid or gallbladder wall-thickening, resulted in a sensitivity and specificity of 87% (95% confidence interval [CI] 66-97) and 82% (95% CI 74-88), respectively. No prior studies have been conducted to estimate the test characteristics of POCUS for the purpose of excluding acute calculous cholecystitis. OBJECTIVE: To determine whether the finding of gallstones alone on POCUS has high sensitivity, high negative predictive value, and low negative likelihood ratio for the exclusion of AC. METHODS: We conducted an analysis using data from a prospective cross-sectional single-center study of POCUS test to estimate the test characteristics using a simplified definition of a positive test - the presence of gallstones alone. Clinical follow-up and pathology reports were used as the reference standard. Test characteristics were calculated and compared to the standard definition, gallstones plus one secondary finding. RESULTS: The overall prevalence of AC was 14% (23 pathology-confirmed cases of 164 included patients). The sensitivity of the simplified definition was 100% (95% CI 85.7-100), negative predictive value 100% (95% CI 92.2-100), and negative likelihood ratio was < 0.1, compared to a sensitivity of 87% (95% CI 66-97%), negative predictive value 97% (95% CI 93-99%), and negative likelihood ratio of 0.16 (95% CI 0.06-0.5). CONCLUSION: Simplifying the definition of the test findings on POCUS to gallstones alone has excellent sensitivity and negative predictive value for the exclusion of AC. This finding, if broadly validated prospectively, confirms the practice of excluding acute calculous cholecystitis using POCUS in emergency department patients.