A Review of Natural Language Processing in Medical Education.

Natural language processing (NLP) aims to program machines to interpret human language as humans do. It could quantify aspects of medical education that were previously amenable only to qualitative methods. The application of NLP to medical education has been accelerating over the past several years. This article has three aims. First, we introduce the reader to NLP. Second, we discuss the potential of NLP to help integrate FOAM (Free Open Access Medical Education) resources with more traditional curricular elements. Finally, we present the results of a systematic review. We identified 30 articles indexed by PubMed as relating to medical education and NLP, 14 of which were of sufficient quality to include in this review. We close by discussing potential future work using NLP to advance the field of medical education in emergency medicine.

Severe Delayed Postpartum Hemorrhage after Cesarean Section.

BACKGROUND: Severe secondary or delayed postpartum hemorrhage (PPH) is rare and affects 0.23-3% of all pregnancies. It happens between 24 hours to 12 weeks postdelivery. These PPHs occur more often during normal vaginal delivery; only a small subset of these PPHs occur after cesarean section. The top differential diagnoses of both primary and secondary PPH are different, and as a result, the management may be different. Although uterine atony causes 80% of primary PPHs, extensive literature review exposed the rarity of it in the setting of secondary PPH. CASE REPORT: A 27-year-old woman presented to the emergency department 1 week after a cesarean section for severe vaginal bleeding that started an hour earlier. The patient required rigorous uterine massage for approximately 30 min along with oxytocin, carboprost, methergine, and misopristol before bleeding subsided. She required 1 unit of O- blood transfusion during resuscitation and still had a hemoglobin drop of 2.7 g/dL from arrival to after bleeding subsided. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: PPH is a life-threatening condition that emergency physicians rarely encounter and may be uncomfortable managing. It is important to be familiar with the differential diagnosis of both primary and secondary PPH and the management of each of the causes.

Emergency care and health systems: consensus-based recommendations and future research priorities.

The theme of the 14th annual Academic Emergency Medicine consensus conference was "Global Health and Emergency Care: A Research Agenda." The goal of the conference was to create a robust and measurable research agenda for evaluating emergency health care delivery systems. The concept of health systems includes the organizations, institutions, and resources whose primary purpose is to promote, restore, and/or maintain health. This article further conceptualizes the vertical and horizontal delivery of acute and emergency care in low-resource settings by defining specific terminology for emergency care platforms and discussing how they fit into broader health systems models. This was accomplished through discussion surrounding four principal questions touching upon the interplay between health systems and acute and emergency care. This research agenda is intended to assist countries that are in the early stages of integrating emergency services into their health systems and are looking for guidance to maximize their development and health systems planning efforts.

Hyperlactatemia affects the association of hyperglycemia with mortality in nondiabetic adults with sepsis.

BACKGROUND: Admission hyperglycemia has been reported as a mortality risk factor for septic nondiabetic patients; however, hyperglycemia's known association with hyperlactatemia was not addressed in these analyses. OBJECTIVES: The objective was to determine whether the association of hyperglycemia with mortality remains significant when adjusted for concurrent hyperlactatemia. METHODS: This was a post hoc, nested analysis of a retrospective cohort study performed at a single center. Providers had identified study subjects during their emergency department (ED) encounters; all data were collected from the electronic medical record (EMR). Nondiabetic adult ED patients hospitalized for suspected infection, two or more systemic inflammatory response syndrome (SIRS) criteria, and simultaneous lactate and glucose testing in the ED were enrolled. The setting was the ED of an urban teaching hospital from 2007 to 2009. To evaluate the association of hyperglycemia (glucose > 200 mg/dL) with hyperlactatemia (lactate ≥ 4.0 mmol/L), a logistic regression model was created. The outcome was a diagnosis of hyperlactatemia, and the primary variable of interest was hyperglycemia. A second model was created to determine if coexisting hyperlactatemia affects hyperglycemia's association with mortality; the main outcome was 28-day mortality, and the primary risk variable was hyperglycemia with an interaction term for simultaneous hyperlactatemia. Both models were adjusted for demographics; comorbidities; presenting infectious source; and objective evidence of renal, respiratory, hematologic, or cardiovascular dysfunction. RESULTS: A total of 1,236 ED patients were included, and the median age was 77 years (interquartile range [IQR] = 60 to 87 years). A total of 115 (9.3%) subjects were hyperglycemic, 162 (13%) were hyperlactatemic, and 214 (17%) died within 28 days of their initial ED visits. After adjustment, hyperglycemia was significantly associated with simultaneous hyperlactatemia (odds ratio [OR] = 4.14, 95% confidence interval [CI] = 2.65 to 6.45). Hyperglycemia and concurrent hyperlactatemia were associated with increased mortality risk (OR = 3.96, 95% CI = 2.01 to 7.79), but hyperglycemia in the absence of simultaneous hyperlactatemia was not (OR = 0.78, 95% CI = 0.39 to 1.57). CONCLUSIONS: In this cohort of septic adult nondiabetic patients, mortality risk did not increase with hyperglycemia unless associated with simultaneous hyperlactatemia. The previously reported association of hyperglycemia with mortality in nondiabetic sepsis may be due to the association of hyperglycemia with hyperlactatemia.

Impact of metformin use on the prognostic value of lactate in sepsis.

OBJECTIVE: The objective of this study is to determine if metformin use affects the prevalence and prognostic value of hyperlactatemia to predict mortality in septic adult emergency department (ED) patients. METHODS: This is a single-center retrospective cohort study. Emergency department providers identified study subjects; data were collected from the medical record. PATIENTS: Adult ED patients with suspected infection and 2 or more systemic inflammatory response syndrome criteria were included. The outcome was 28-day mortality. The primary risk variable was serum lactate (<2.0, 2.0-3.9, ≥ 4.0 mmol/L) categorized by metformin use; covariates: demographics, Predisposition, Infection, Response, Organ Dysfunction score and metformin use contraindications. SETTING: The study was conducted at an urban teaching hospital; February 1, 2007 to October 31, 2008. RESULTS: A total of 1947 ED patients were enrolled; 192 (10%) were taking metformin; 305 (16%) died within 28 days. Metformin users had higher median lactate levels than nonusers (2.2 mmol/L [interquartile range, 1.6-3.2] vs 1.9 mmol/L [interquartile range, 1.3-2.8]) and a higher, although nonsignificant, prevalence of hyperlactatemia (lactate ≥ 4.0 mmol/L) (17% vs 13%) (P = .17). In multivariate analysis (reference group nonmetformin users, lactate <2.0 mmol/L), hyperlactatemia was associated with an increased adjusted 28-day mortality risk among nonmetformin users (odds ratio [OR], 3.18; P < .01) but not among metformin users (OR, 0.54; P = .33). In addition, nonmetformin users had a higher adjusted mortality risk than metformin users (OR, 2.49; P < .01). These differences remained significant when only diabetic patients were analyzed. CONCLUSIONS: In this study of adult ED patients with suspected sepsis, metformin users had slightly higher median lactate levels and prevalence of hyperlactatemia. However, hyperlactatemia did not predict an increased mortality risk in patients taking metformin.

Inter-rater reliability of sonographic measurements of the inferior vena cava.

BACKGROUND: Bedside ultrasound is emerging as a useful tool in the assessment of intravascular volume status by examining measurements of the inferior vena cava (IVC). Many previous studies do not fully describe their scanning protocol. OBJECTIVES: The objective of this study was to evaluate which of three commonly reported IVC scanning methods demonstrates the best inter-rater reliability. METHODS: Three physicians visualized the IVC in three common views and utilized M-mode to measure the maximal and minimal diameter during quiet respiration. Pairwise correlation coefficients were determined using Pearson product-moment correlation. RESULTS: The most reliable pair of measurements (inspiratory and expiratory) was found to be using the anterior midaxillary line longitudinal view with a Kappa value for both at 0.692. CONCLUSION: Imaging with the anterior midaxillary longitudinal approach using the liver as an acoustic window provides the best inter-rater reliability when measuring the IVC. Our findings demonstrate that IVC measurements differ based on anatomic location.

Real-time lung ultrasound for the diagnosis of alveolar consolidation and interstitial syndrome in the emergency department.

During the last few years, a growing number of studies have shown the accuracy of lung ultrasound in the diagnosis of pulmonary diseases. The latest developments in lung ultrasound are not because of technological advance, but are based on new applications and discovering the meanings of sonographic artifacts. Real-time sonography of the lung in the emergency department saves time and cost, providing immediate information to the clinician, relying on very easy-to-acquire data. The bedside sonographic recognition of pulmonary diseases practically guides management and reduces the amount of negative radiologic image testings. This review describes some innovative practical applications of B-mode lung ultrasound in the diagnosis of alveolar consolidations and interstitial syndrome in the emergency department.

Validation of self-reported chronic obstructive pulmonary disease among patients in the ED.

BACKGROUND: To determine whether the self-reported diagnosis of adults who present to the emergency department (ED) with an acute exacerbation of either asthma or chronic obstructive pulmonary disease (COPD) is validated by medical record review. METHODS: This is cross-sectional study of 78 consecutive adults, 55 years and older, presenting to 3 EDs with symptoms suggestive of an exacerbation of asthma or COPD. We used current spirometric guidelines for a "spirometrically validated" diagnosis of COPD (eg, postbronchodilator forced expiratory volume in 1 second/forced ventilatory capacity <70%). Patients without office spirometry result were classified with COPD using clinical validation based on at least one of the following: primary care physician diagnosis of COPD, chronic bronchitis, or emphysema in the medical record or chest radiography, chest computed tomography, or arterial blood gas (ABG) diagnostic of COPD. RESULTS: Among 60 patients who self-reported diagnosis of COPD, 98% (95% confidence interval, 89-100) had clinically validated or spirometrically validated COPD. In addition, 83% (95% confidence interval, 59-96) of patients who reported either asthma only or no respiratory disease had clinically validated or spirometrically validated COPD. In no case was the chest radiograph or the ABG useful as a stand-alone test in establishing the diagnosis of COPD. CONCLUSIONS: Patients 55 years and older presenting to the ED with acute asthma or COPD, even those with clinical symptoms but no diagnosis of COPD, are likely to have COPD. Clinicians should maintain a high index of suspicion for COPD when older asthma patients deny COPD.

The utility of bedside ultrasound in the detection of a ruptured globe in a porcine model.

BACKGROUND: Recent case reports have shown that ultrasonography can be used to diagnose ocular pathology in an emergency setting. Ultrasound may be especially useful when periorbital edema and pain interfere with the examination of the post-traumatic eye. OBJECTIVE: This study evaluated the ability of emergency physicians to detect a ruptured globe in an ex-vivo porcine model. METHODS: Following a brief training lecture, 15 emergency medicine residents and 4 emergency medicine attending physicians used ultrasonography to evaluate 18 porcine eyes, randomized as normal, ruptured, or completely devoid of vitreous humor. The consequences of ultrasound applanation with this method were evaluated by measuring intraocular pressure changes with and without a 1mm clear plastic shield. RESULTS: Our study participants were able to identify abnormal eyes with a sensitivity of 79% (95% CI 73% to 84%) and a specificity of 51% (95% CI 41% to 61%). Intraocular pressure increased 5% with ultrasound applanation, though with a 1mm thick plastic shield there was no measurable change. CONCLUSIONS: Ultrasound imaging may be a future modality to be used by trained emergency physicians to expedite the identification of a rupture globe, but it is unlikely to replace more definitive imaging techniques. The use of a clear plastic barrier in this porcine model prevents an increase in intra-ocular pressure without affecting image quality, and should be used in any future studies on this method.

Spirometric correlates of dyspnea improvement among emergency department patients with chronic obstructive pulmonary disease exacerbation.

OBJECTIVE: To examine whether change in slow vital capacity (SVC) correlates to dyspnea improvement during emergency department (ED) treatment of chronic obstructive pulmonary disease (COPD) exacerbation. METHODS: We performed a prospective cohort study and enrolled consecutive patients during a 3-week period. ED patients > or = 55 years old with COPD exacerbation were asked to perform bedside spirometry shortly after ED arrival and again at discharge. SVC was measured first, then forced expiratory volume in the first second (FEV1), peak expiratory flow (PEF), and forced vital capacity (FVC). Concurrent with spirometry, patients rated their dyspnea on a 10-cm visual analogue scale. RESULTS: Thirty-six patients were enrolled. The median ED stay was 271 min (interquartile range 219-370 min). Seventy-one percent of the patients reported dyspnea improvement during their ED stay. Change in SVC was significantly higher among the patients whose dyspnea improved than among those whose did not (median increase of 0.15 L vs median decrease of 0.25 L, respectively, p < 0.01). By contrast, the change in spirometry values were similar for FEV1, PEF, and FVC (all p > 0.30). Spearman correlation supported these findings: SVC r = 0.45 (p = 0.02) versus nonsignificant correlation with FEV(1) (r = 0.33), PEF (r = -0.22), and FVC (r = 0.35). CONCLUSIONS: Increase in SVC significantly correlated with dyspnea improvement among ED patients with moderate-to-severe COPD exacerbation. Change in SVC merits consideration when evaluating therapeutic response during COPD exacerbation.

Does parental report of insurance status agree with hospital administrative data for children presenting to the ED?

We screened nearly 10,000 consecutive parents presenting to EDs throughout the United States and examined whether parent/guardian self-report of insurance status agrees with hospital administrative data. We also examined the relationship of patient characteristics with any observed discordance.

Research opportunities in the management of acute exacerbations of chronic obstructive pulmonary disease.

Acute exacerbations of chronic obstructive pulmonary disease are a common problem in the emergency department. Despite considerable research involving the management of this disease over the past decade, much remains unclear from an emergency medicine perspective. Increased research would better guide the management of these complex patients from the perspectives of the patient, the caregiver, and society. The major areas of research can be divided into diagnosis, therapy, and education. The reliability and validity of different definitions of acute exacerbations of chronic obstructive pulmonary disease need to be assessed. The utility and performance characteristics of diagnostic testing need to be determined for this difficult patient population. Specific diagnostic tests include measures of dyspnea, spirometry and exercise tolerance, measures of gas exchange, airway inflammation, and chest imaging. It remains unclear which patient-specific therapies (oxygen, bronchodilators, corticosteroids, antibiotics, noninvasive positive pressure ventilation, and methylxanthines) should be used and monitored. Finally, the utility of education of both health care providers and patients and how it may be applied to the acute setting need to be addressed.

A multicenter study of complementary and alternative medicine usage among ED patients.

OBJECTIVES: To estimate the prevalence of complementary and alternative medicine (CAM) usage among emergency department (ED) patients. METHODS: This study was a cross-sectional study in four Boston-area EDs. For two 24-hour periods, the authors interviewed consecutive patients age 18 and older about whether they had ever used or had recently (within the past year) used CAM "remedies" (e.g., herbal treatments) or "therapies" (e.g., chiropractic). The authors also asked about the patient's disclosure of CAM usage to allopathic health care providers. RESULTS: Of 978 patients, 752 patients were eligible. Among these, 539 (72%) were interviewed. Of these patients, ever having used CAM was reported by 57% (95% CI = 52% to 61%), and 37% (95% CI = 33% to 41%) reported use in the past year. In a multivariate model of recent CAM usage, independent predictors were younger age, higher education level, and chronic pain. Patients who spoke Spanish as their primary language were less likely to report CAM usage. Disclosure of CAM usage to allopathic providers was low, yet >80% reported that they would be comfortable discussing their CAM usage with allopathic providers. CONCLUSIONS: CAM usage was common among ED patients enrolled in our study, despite underreporting to ED staff. Given the growing evidence of benefits and hazards from popular CAM remedies and therapies, ED staff should consider raising this health issue with their patients.

Predicted peak expiratory flow: differences across formulae in the literature.

The study objectives were to examine the differences between Peak Expiratory Flow (PEF) formulae in the literature and to assess the potential impact of those differences on the interpretation of clinical guidelines for asthma management. We calculated 100% PEF values for hypothetical patients at the 50(th) percentile for height and weight and classified the percent predicted PEF into severity groups according to national asthma guidelines. Choosing different formulae could give an 18 year old man a 100% predicted PEF as low as 501 L/min and as high as 730 L/min (delta = 229 L/min); and a 35 year old woman a classification of severe (46%) using one, but moderate (57%) using another. Predicted PEF varied widely across formulae and choice of formula may alter guideline-based care. We propose recently published population-based equations as the reference standard for future asthma guidelines.

Parental perception of waiting time and its influence on parental satisfaction in an urban pediatric emergency department: are parents accurate in determining waiting time?

OBJECTIVE: The objective of this study was to determine whether parental perception of waiting time in an urban pediatric emergency department (ED) is accurate and whether the actual waiting times or their perception of waiting times impact on parental satisfaction. METHODS: A prospective convenience sample study in which the on-duty emergency physicians randomly administered a questionnaire at the time of the ED visit was used. During a 3-week period from December 15, 1999, through January 7, 2000, 500 parents or legal guardians of children who visited our ED were questioned about their perceived waiting time, and the responses were compared with the actual waiting time. The parents or guardians were also asked if they were satisfied with the waiting time. RESULTS: The majority (84%) of parents overestimated waiting time in the ED (median difference, 26 min; interquartile range, 9-50 min). Parents with perceived or actual waiting times that exceeded 2 hours were significantly more likely to be dissatisfied than parents with actual or perceived waiting times that were 1 hour or less (P < 0.001). Satisfaction was not related to the age (P = 0.35), sex (P = 0.30), race/ethnicity (P = 0.90), or mode of arrival (P = 0.28). CONCLUSION: Parents tend to overestimate waiting time. Both perceived and actual waiting times that exceed 2 hours were associated with parental dissatisfaction. ED administrators may need to keep this in mind when arranging ED staffing patterns to match peak patient hours to achieve optimal parental satisfaction.