Automated HEART score determination via ChatGPT: Honing a framework for iterative prompt development

Objectives

This study presents a design framework to enhance the accuracy by which large language models (LLMs), like ChatGPT can extract insights from clinical notes. We highlight this framework via prompt refinement for the automated determination of HEART (History, ECG, Age, Risk factors, Troponin risk algorithm) scores in chest pain evaluation.

Methods

We developed a pipeline for LLM prompt testing, employing stochastic repeat testing and quantifying response errors relative to physician assessment. We evaluated the pipeline for automated HEART score determination across a limited set of 24 synthetic clinical notes representing four simulated patients. To assess whether iterative prompt design could improve the LLMs' ability to extract complex clinical concepts and apply rule-based logic to translate them to HEART subscores, we monitored diagnostic performance during prompt iteration.

Results

Validation included three iterative rounds of prompt improvement for three HEART subscores with 25 repeat trials totaling 1200 queries each for GPT-3.5 and GPT-4. For both LLM models, from initial to final prompt design, there was a decrease in the rate of responses with erroneous, non-numerical subscore answers. Accuracy of numerical responses for HEART subscores (discrete 0-2 point scale) improved for GPT-4 from the initial to final prompt iteration, decreasing from a mean error of 0.16-0.10 (95% confidence interval: 0.07-0.14) points.

Conclusion

We established a framework for iterative prompt design in the clinical space. Although the results indicate potential for integrating LLMs in structured clinical note analysis, translation to real, large-scale clinical data with appropriate data privacy safeguards is needed.

Inequities among patient placement in emergency department hallway treatment spaces

BACKGROUND

Limited capacity in the emergency department (ED) secondary to boarding and crowding has resulted in patients receiving care in hallways to provide access to timely evaluation and treatment. However, there are concerns raised by physicians and patients regarding a decrease in patient centered care and quality resulting from hallway care. We sought to explore social risk factors associated with hallway placement and operational outcomes.

STUDY DESIGN/METHODS

Observational study between July 2017 and February 2020. Primary outcome was the adjusted odds ratio (aOR) of patient placement in a hallway treatment space adjusting for patient demographics and ED operational factors. Secondary outcomes included left without being seen (LWBS), discharge against medical advice (AMA), elopement, 72-h ED revisit, 10-day ED revisit and escalation of care during boarding.

RESULTS

Among 361,377 ED visits, 100,079 (27.7%) visits were assigned to hallway beds. Patient insurance coverage (Medicaid (aOR 1.04, 95% CI 1.01,1.06) and Self-pay/Other (1.08, (1.03, 1.13))) with comparison to private insurance, and patient sex (Male (1.08, (1.06, 1.10))) with comparison to female sex are associated with higher odds of hallway placement but patient age, race, and language were not. These associations are adjusted for ED census, triage assigned severity, ED staffing, boarding level, and time effect, with social factors mutually adjusted. Additionally adjusting for patients' social factors, patients placed in hallways had higher odds of elopement (1.23 (1.07,1.41)), 72-h ED revisit (1.33 (1.08, 1.64)) and 10-day ED revisit (1.23 (1.11, 1.36)) comparing with patients placed in regular ED rooms. We did not find statistically significant associations between hallway placement and LWBS, discharge AMA, or escalation of care.

CONCLUSION

While hallway usage is ad hoc, we find consistent differences in care delivery with those insured by Medicaid and self-pay or male sex being placed in hallway beds. Further work should examine how new front-end processes such as provider in triage or split flow may be associated with inequities in patient access to emergency and hospital care.

Rapid serum tubes reduce transport hemolysis and false positive rates for high-sensitivity troponin T

INTRODUCTION

Hemolysis in the emergency department (ED) can significantly delay results and appropriate action. We evaluated the main sources of hemolysis during sample collection, and to evaluate the use of rapid serum tubes (RST) as a transport hemolysis-mitigating measure for high-sensitivity troponin T (hs-cTnT) testing.

METHODS

We examined the effect of tube type, tube fill, types of sample draw and collection methods on hemolysis and hs-cTnT in samples (n = 158) from ED patients. We also compared hs-cTnT values in paired RST and plasma separate tube (PST) samples that were hemolysis-free.

RESULTS

The primary source of hemolysis in samples collected in the ED was underfilling tubes. In both tube types, PST and RST, filled tubes showed a median reduction in hemolysis of 69.1 % (p < 0.0001). Blood collected in RST also experienced less hemolysis compared to PST. In hemolysis-free samples, false positive results in PST were noted in patients with hs-cTnT values < 50 ng/l.

CONCLUSION

We suggest that proper tube filling during sample collection and use of RST tubes can significantly reduce the effects of hemolysis. In addition, laboratories should be aware that PST tubes have a non-trivial rate of false positives when hs-cTnT < 50 ng/l.

Correlations among common emergency medicine physician performance measures: Mixed messages or balancing forces?

The increasing complexity of ED physician performance measures has resulted in significant challenges, including duplicative and conflicting measures that fail to account for different ED settings. We performed a cross sectional analysis of correlations between measures to characterize their relationships and determine if differences exist between academic versus non-academic ED settings. Pearson correlations were calculated for 12 measures among 220 ED physicians at 11 EDs. Higher admission rate was strongly correlated with higher CT utilization rate (R = 0.7, p < 0.01) and longer room to discharge time (R = 0.7, p < 0.01). Higher patients per hour was strongly correlated with shorter room to doctor time (R = -0.7, p < 0.01). Stronger measure correlations were found in the academic setting compared to the non-academic setting. Strong correlations between ED measures imply opportunities to reduce competing performance demands on clinicians. Differences in correlations at academic versus non-academic settings suggest that it may be inappropriate to apply the same performance standards across settings.

Sociodemographic Disparities in Queue Jumping for Emergency Department Care

Importance

Emergency department (ED) triage models are intended to queue patients for treatment. In the absence of higher acuity, patients of the same acuity should room in order of arrival.

Objective

To characterize disparities in ED care access as unexplained queue jumps (UQJ), or instances in which acuity and first come, first served principles are violated.

Design, Setting, and Participants

Retrospective, cross-sectional study between July 2017 and February 2020. Participants were all ED patient arrivals at 2 EDs within a large Northeast health system. Data were analyzed from July to September 2022.

Exposure

UQJ was defined as a patient being placed in a treatment space ahead of a patient of higher acuity or of a same acuity patient who arrived earlier.

Main Outcomes and Measures

Primary outcomes were odds of a UQJ and association with ED outcomes of hallway placement, leaving before treatment complete, escalation to higher level of care while awaiting inpatient bed placement, and 72-hour ED revisitation. Secondary analysis examined UQJs among high acuity ED arrivals. Regression models (zero-inflated Poisson and logistic regression) adjusted for patient demographics and ED operational variables at time of triage.

Results

Of 314 763 included study visits, 170 391 (54.1%) were female, the mean (SD) age was 50.46 (20.5) years, 132 813 (42.2%) patients were non-Hispanic White, 106 401 (33.8%) were non-Hispanic Black, and 66 465 (21.1%) were Hispanic or Latino. Overall, 90 698 (28.8%) patients experienced a queue jump, and 78 127 (24.8%) and 44 551 (14.2%) patients were passed over by a patient of the same acuity or lower acuity, respectively. A total of 52 959 (16.8%) and 23 897 (7.6%) patients received care ahead of a patient of the same acuity or higher acuity, respectively. Patient demographics including Medicaid insurance (incident rate ratio [IRR], 1.11; 95% CI, 1.07-1.14), Black non-Hispanic race (IRR, 1.05; 95% CI, 1.03-1.07), Hispanic or Latino ethnicity (IRR, 1.05; 95% CI, 1.02-1.08), and Spanish as primary language (IRR, 1.06; 95% CI, 1.02-1.10) were independent social factors associated with being passed over. The odds of a patient receiving care ahead of others were lower for ED visits by Medicare insured (odds ratio [OR], 0.92; 95% CI, 0.88-0.96), Medicaid insured (OR, 0.81; 95% CI, 0.77-0.85), Black non-Hispanic (OR, 0.94; 95% CI, 0.91-0.97), and Hispanic or Latino ethnicity (OR, 0.87; 95% CI, 0.83-0.91). Patients who were passed over by someone of the same triage severity level had higher odds of hallway bed placement (OR, 1.01; 95% CI, 1.00-1.02) and leaving before disposition (OR, 1.02; 95% CI, 1.01-1.04).

Conclusions and Relevance

In this cross-sectional study of ED patients in triage, there were consistent disparities among marginalized populations being more likely to experience a UQJ, hallway placement, and leaving without receiving treatment despite being assigned the same triage acuity as others. EDs should seek to standardize triage processes to mitigate conscious and unconscious biases that may be associated with timely access to emergency care.

Exploratory Descriptive Analysis of Smart Speaker Utilization in the Emergency Department During the COVID-19 Pandemic

BACKGROUND

In March 2020, the U.S. Department of Health and Human Services Office for Civil Rights stated that they would use discretion when enforcing the Health Insurance Portability and Accountability Act regarding remote communication technologies that promoted telehealth delivery during the COVID-19 pandemic. This was in an effort to protect patients, clinicians, and staff. More recently, smart speakers-voice-activated, hands-free devices-are being proposed as productivity tools within hospitals.

OBJECTIVE

We aimed to characterize the novel use of smart speakers in the emergency department (ED).

METHODS

A retrospective observational study of Amazon Echo Show® utilization from May 2020 to October 2020 in a large academic Northeast health system ED. Voice commands and queries were classified as either patient care-related or non-patient care-related, and then further subcategorized to explore the content of given commands.

RESULTS

Of 1232 commands analyzed, 200 (16.23%) were determined to be patient care-related. Of these commands, 155 (77.5%) were clinical in nature (i.e., "drop in on triage") and 23 (11.5%) were environment-enhancing commands (i.e., "play calming sounds"). Among non-patient care-related commands, 644 (62.4%) were for entertainment. Among all commands, 804 (65.3%) were during night-shift hours, which was statistically significant (p < 0.001).

CONCLUSIONS

Smart speakers showed notable engagement, primarily being used for patient communication and entertainment. Future studies should examine content of patient care conversations using these devices, effects on frontline staff wellbeing, productivity, patient satisfaction, and even explore opportunities for "smart" hospital rooms.

Emergency department visits in Connecticut for survivors of sexual assault before and during the COVID-19 pandemic

STUDY OBJECTIVE

We evaluate the impact of the COVID-19 pandemic on care for survivors of sexual assault in three urban Emergency Departments (ED) in the United States.

METHODS

A retrospective chart review was conducted on patients who presented after sexual assault to three EDs during 6-month intervals before and during the COVID-19 pandemic. We excluded individuals <18 years old. We performed a structured chart review to ascertain demographics, ED treatments, and adherence to guidelines for care of sexual assault survivors.

RESULTS

Of 105 patients who received care after a sexual assault, 57 presented during the COVID-19 pandemic. The majority were female, White/Caucasian, and presented within 120 h of sexual assault. There was an increase in ED presentations for sexual assault during the pandemic. While there was no difference in medical care, there were fewer sexual assault advocates called during the pandemic. In addition, there was an increase in non-White survivors in the first 3 months of the pandemic that did not remain at 6 months.

CONCLUSION

The care of survivors in the ED was disrupted by the COVID-19 pandemic. While medical care remained similar, fewer calls to sexual assault advocates, a key component of ED and long-term care of survivors, demonstrate a disruption in their care.

Choice Architecture to Assist Clinicians with Appropriate COVID-19 Test Ordering

BACKGROUND

Despite improving supplies, SARS-CoV-2 nucleic acid amplification tests remain limited during surges and more so given concerns around COVID-19/influenza co-occurrence. Matching clinical guidelines to available supplies ensures resources remain available to meet clinical needs. We report a change in clinician practice after an electronic health record (EHR) order redesign to impact emergency department (ED) testing patterns.

METHODS

We included all ED visits between December 1, 2021 and January 18, 2022 across a hospital system to assess the impact of EHR order changes on provider behavior 3 weeks before and after the change. The EHR order redesign included embedded symptom-based order guidance. Primary outcomes were the proportion of COVID-19 + flu/respiratory syncytial virus (RSV) testing performed on symptomatic, admitted, and discharged patients, and the proportion of COVID-19 + flu testing on symptomatic, discharged patients.

RESULTS

A total of 52 215 ED visits were included. For symptomatic, discharged patients, COVID-19 + flu/RSV testing decreased from 11.4 to 5.8 tests per 100 symptomatic visits, and the rate of COVID-19 + flu testing increased from 7.4 to 19.1 before and after the intervention, respectively. The rate of COVID-19 + flu/RSV testing increased from 5.7 to 13.1 tests per 100 symptomatic visits for symptomatic patients admitted to the hospital. All changes were significant (P < 0.0001).

CONCLUSIONS

A simple EHR order redesign was associated with increased adherence to institutional guidelines for SARS-CoV-2 and influenza testing amidst supply chain limitations necessitating optimal allocation of scarce testing resources. With continually shifting resource availability, clinician education is not sufficient. Rather, system-based interventions embedded within exiting workflows can better align resources and serve testing needs of the community.

Prehospital emergency department care activations during the initial COVID-19 pandemic surge

OBJECTIVE

To describe trends in prehospital presentations of critical medical and trauma conditions during the COVID-19 pandemic using prehospital and emergency department (ED) care activations.

METHODS

Observational analysis of ED care activations in a tertiary, urban ED between March 10, 2020 and September 1, 2020 was compared to the same time periods in 2018 and 2019. ED care activations for critical medical conditions were classified based on clinical indication: undifferentiated medical, trauma, or stroke.

MAIN OUTCOME

The primary outcomes were the number of patients presenting from the prehospital setting with specified ED activation criteria, total ED volume, ambulance arrival volume, and volume of COVID-19 hospital admissions. Locally weighted scatterplot smoothing curves were used to visually display our results.

RESULTS

There were 1,461 undifferentiated medical activations, 905 stroke activations, and 1,478 trauma activations recorded, representing absolute decreases of 11.3, 28.1, and 20.3 percent, respectively, relative to the same period in 2019, coinciding with the declaration of a public health emergency in Connecticut. For all three types of presentation, post-peak spikes in activations were observed in early May, approximately two weeks after our health system in Connecticut reached its peak number of COVID-19 hospitalizations-eg, undifferentiated medical activations: increase in 280 percent, n = 140 from 2019, p < 0.0001-and declined thereafter, reaching a nadir in early June 2020.

CONCLUSIONS

After the announcement of public health measures to mitigate COVID-19, ED care activations declined in a large Northeast academic ED, followed by post-peak surges in activations as COVID- 19 cases decreased.

Implementation of an Electronic Health Record Integrated Clinical Pathway Improves Adherence to COVID-19 Hospital Care Guidelines

BACKGROUND

During the COVID-19 pandemic, frequently changing guidelines presented challenges to emergency department (ED) clinicians. The authors implemented an electronic health record (EHR)-integrated clinical pathway that could be accessed by clinicians within existing workflows when caring for patients under investigation (PUI) for COVID-19. The objective was to examine the association between clinical pathway utilization and adherence to institutional best practice treatment recommendations for COVID-19.

METHODS

The authors conducted an observational analysis of all ED patients seen in a health system inclusive of seven EDs between March 18, 2020, and April 20, 2021. They implemented the pathway as an interactive flow chart that allowed clinicians to place orders while viewing the most up-to-date institutional guidance. Primary outcomes were proportion of admitted PUIs receiving dexamethasone and aspirin in the ED, and secondary outcome was time to delivering treatment.

RESULTS

A total of 13 269 patients were admitted PUIs. The pathway was used by 40.6% of ED clinicians. When clinicians used the pathway, patients were more likely to be prescribed aspirin (OR, 7.15; 95% CI, 6.2-8.26) and dexamethasone (10.4; 8.85-12.2). For secondary outcomes, clinicians using the pathway had statistically significant ( P < 0.0001) improvement in timeliness of ordering medications and admission to the hospital. Aspirin, dexamethasone, and admission order time were improved by 103.89, 94.34, and 121.94 minutes, respectively.

CONCLUSIONS

The use of an EHR-integrated clinical pathway improved clinician adherence to changing COVID-19 treatment guidelines and timeliness to associated medication administration. As pathways continue to be implemented, their effects on improving patient outcomes and decreasing disparities in patient care should be further examined.

Universal SARS-CoV-2 Testing of Emergency Department Admissions Increases Emergency Department Length of Stay

Study objective

Our institution experienced a change in SARS-CoV-2 testing policy as well as substantial changes in local COVID-19 prevalence, allowing for a unique examination of the relationship between SARS-CoV-2 testing and emergency department (ED) length of stay.

Methods

This was an observational interrupted time series of all patients admitted to an academic health system between March 15, 2020, and September 30, 2020. Given testing limitations from March 15 to April 24, all patients receiving SARS-CoV-2 tests were symptomatic. On April 24, testing was expanded to all ED admissions. The primary and secondary outcomes were ED length of stay and number needed to test to obtain a positive, respectively.

Results

A total of 70,856 patients were cared for in the EDs during the 7-month period. The testing change increased admission length of stay by 1.89 hours (95% confidence interval 1.39 to 2.38). The number needed to test was 2.5 patients and was highest yield on April 1, 2020, when the state positivity rate was 39.7%; however, the number needed to test exceeded 170 patients by Sept 1, 2020, at which point the state positivity rate was 0.5%.

Conclusion

Although universal SARS-CoV-2 testing of ED admissions may meaningfully support mitigation and containment efforts, the clinical cost of testing all admissions amid low community positivity is notable. In our system, universal ED SARS-CoV-2 testing was associated with a 24% increase in admission length of stay alongside the detection of only 1 positive case every other day. Given the known harms and risks of ED boarding and crowding, solutions must be developed to support regular operational flow while balancing infection prevention needs.

Simulating approaches to emergency department pandemic physician staffing during COVID-19

OBJECTIVE

During pandemics, emergency departments (EDs) are challenged by the need to replace quarantined ED staff and avoid staffing EDs with nonemergency medicine (EM) trained physicians. We sought to design and examine three feasible ED staffing models intended to safely schedule EM physicians to staff three EDs within a health system during a prolonged infectious disease outbreak.

METHODS

We conducted simulation analyses examining the strengths and limitations of three ED clinician staffing models: two-team and three-team fixed cohort, and three-team unfixed cohort. Each model was assessed with and without immunity, and by varying infection rates. We assumed a 12-week pandemic disaster requiring a 2-week quarantine.

MAIN OUTCOME

The outcome, time to staffing shortage, was defined as depletion of available physicians in both 8- and 12-hour shift duration scenarios.

RESULTS

All staffing models initially showed linear physician attrition with higher infection rates resulting in faster staffing shortages. The three-team fixed cohort model without immunity was not viable beyond 11 weeks. The three-team unfixed cohort model without immunity avoided staffing shortage for the duration of the pandemic up to an infection rate of 50 percent. The two-team model without immunity also avoided staffing shortage up to 30 percent infection rate. When accounting for immunity, all models behaved similarly initially but returned to adequate staffing during week 5 of the pandemic.

CONCLUSIONS

Simulation analyses reveal fundamental tradeoffs that are critical to designing feasible pandemic disaster staffing models. Emergency physicians should test similar models based on local assumptions and capacity to ensure adequate staffing preparedness for prolonged pandemics.

Leadership communication, stress, and burnout among frontline emergency department staff amid the COVID-19 pandemic: A mixed methods approach

Background

Organizations have a key role to play in supporting healthcare workers (HCWs) and mitigating stress during COVID-19. We aimed to understand whether perceptions of support and communication by local leadership were associated with reduced reports of stress and burnout among frontline HCWs.

Methods

We conducted cross-sectional surveys embedded within emergency department (ED) workflow during the first wave of COVID-19 from April 9, 2020 to June 15th, 2020 within three EDs of a multisite health system in the Northeast United States. All ED HCWs were administered electronic surveys during shift via text message. We simultaneously conducted 64 qualitative interviews to better characterize and validate survey responses. Primary survey outcomes were levels of work stress and burnout.

Results

Over 10 week study, 327 of 431 (76%) frontline HCWs responded to at least one round of the survey. More useful communication mediated through higher perception of support was significantly associated with lower work stress (B = −0.33, p < 0.001) and burnout (B = −7.84, p < 0.001). A one-point increase on the communication Likert scale was associated with a 9% reduction in stress and a 19% reduction in burnout. Three themes related to effective crisis communication during COVID-19 emerged in interviews: (1) information consolidation prior to dissemination, (2) consistency of communication, and (3) bi-directional communication.

Conclusion

This work suggests that effective local leadership communication, characterized by information consolidation, consistency, and bi-directionality, leads to higher perceptions of support and lower stress and burnout among ED frontline workers. As the pandemic continues, these results present an evidence-based framework for leaders to support frontline HCWs through effective crisis communication.

Eclampsia

Audience

Emergency medicine residents.

Introduction

Eclampsia is the development of a generalized seizure in pregnant patients with hypertension of pregnancy.1 Eclampsia exists on the spectrum of hypertension-related disorders in pregnancy, occurs in 1 out of 1,000-10,000 deliveries,1-3and is associated with significant maternal and fetal morbidity and mortality.4 Given the emergent nature of eclampsia and the benefit of rapid treatment, emergency medicine (EM) physicians need to quickly recognize and treat this rare pathology. Although residents have three to four years before becoming an attending, not all emergent pathologies may present clinically during their training. It is important to simulate rare, treatable conditions such as eclampsia to give learners exposure confidence in managing this disease.

Educational Objectives

By the end of this simulation session, learners will be able to:Demonstrate care of a gravid patient with altered mental statusDemonstrate care of a gravid patient with seizuresRecognize care involved in assessment of fetal statusExecute appropriate subspecialty consultationRecognize the clinical signs and symptoms of eclampsiaDistinguish different treatment options for eclampsiaIdentify magnesium toxicity and reversal agentDifferentiate the spectrum of preeclampsia.

Educational Methods

As an educational strategy, simulation allows learners to partake in experiential learning. By creating a safe and supportive learning environment, simulation allows learners to facilitate deliberate practice and transfer learning in debriefing sessions. High-fidelity sessions involve software and technology to mimic realistic patient environments, which also activate learners' affective states to aid in decision-making abilities in complex medical cases.This session was conducted using a high-fidelity mannequin, SimMom (Laerdal), and a controlling Laerdal LLEAP Software. Faculty-led debriefing followed the simulation case and included discussion regarding presentation, spectrum, and management of the obstetrical emergency.5.

Research Methods

Resident participants completed an evaluation form consisting of questions on a 5-point Likert scale assessing the realism and usefulness of the simulation.

Results

All 18 residents who participated in the simulation completed an evaluation form, and all agreed or strongly agreed the case was realistic and useful.

Discussion

Incorporating high-stakes, low-frequency presentations through simulation can be readily applied in residency education and well-received by residents. Increasing the difficulty through adjusting the clinical history and exam may challenge learners further.

Topics

Medical simulation, eclampsia, pregnancy, obstetrics, emergency medicine.

Delays in antibiotic redosing: Association with inpatient mortality and risk factors for delay

OBJECTIVE

Although timely administration of antibiotics has an established benefit in serious bacterial infection, the majority of studies evaluating antibiotic delay focus only on the first dose. Recent evidence suggests that delays in redosing may also be associated with worse clinical outcome. In light of the increasing burden of boarding in Emergency Departments (ED) and subsequent need to redose antibiotic in the ED, we examined the association between delayed second antibiotic dose administration and mortality among patients admitted from the ED with a broad array of infections and characterized risk factors associated with delayed second dose administration.

METHODS

We performed a retrospective cohort study of patients admitted through five EDs in a single healthcare system from 1/2018 through 12/2018. Our study included all patients, aged 18 years or older, who received two intravenous antibiotic doses within a 30-h period, with the first dose administered in the ED. Patients with end stage renal disease, cirrhosis and extremes of weight were excluded due to a lack of consensus on antibiotic dosing intervals for these populations. Delay was defined as administration of the second dose at a time-point greater than 125% of the recommended interval. The primary outcome was in-hospital mortality.

RESULTS

A total of 5605 second antibiotic doses, occurring during 4904 visits, met study criteria. Delayed administration of the second dose occurred during 21.1% of visits. After adjustment for patient characteristics, delayed second dose administration was associated with increased odds of in-hospital mortality (OR 1.50, 95%CI 1.05-2.13). Regarding risk factors for delay, every one-hour increase in allowable compliance time was associated with a 18% decrease in odds of delay (OR 0.82 95%CI 0.75-0.88). Other risk factors for delay included ED boarding more than 4 h (OR 1.47, 95%CI 1.27-1.71) or a high acuity presentation as defined by emergency severity index (ESI) (OR 1.54, 95%CI 1.30-1.81 for ESI 1-2 versus 3-5).

CONCLUSIONS

Delays in second antibiotic dose administration were frequent in the ED and early hospital course, and were associated with increased odds of in-hospital mortality. Several risk factors associated with delays in second dose administration, including ED boarding, were identified.

Work team identification associated with less stress and burnout among front-line emergency department staff amid the COVID-19 pandemic

Background

The COVID-19 pandemic has exposed front-line healthcare workers to unprecedented risks and stressors threatening both physical and mental health. Prior work in the military has found that team identification, or the sense that one was a part of a team, can help reduce stress and prevent burnout during prolonged stress.

Methods

We conducted repeated cross-sectional surveys embedded within emergency department workflow to understand whether team identification was associated with reduced reports of stress and burnout among front-line workers.

Results

During the 10-week study which spanned the first wave of COVID-19, 327 of 431 (76%) front-line healthcare workers responded to at least one round of the survey. Higher team identification was associated with significantly less work stress (B=−0.60, 95% CI −0.84 to to -0.40, p<0.001) and burnout (B=−12.87, 95% CI −17.73 to -8.02, p<0.001) in cross-sectional analyses. Further evidence of the protective effect of team identification for work stress (B=−0.36, 95% CI −0.76 to 0.05, p=0.09) and burnout (B=−13.25, 95% CI −17.77 to -8.73, p<0.001) was also found in prospective longitudinal evidence.

Conclusion

This work suggests work team identification is a key buffering factor against feelings of stress and burnout. Efforts to promote team identification may offer a promising way for leaders to support front-line healthcare workers’ well-being during the COVID-19 pandemic. These results can inform ongoing COVID-19 operational and quality improvement initiatives.

Identification of Patients with Nontraumatic Intracranial Hemorrhage Using Administrative Claims Data

INTRODUCTION

Nontraumatic intracranial hemorrhage (ICH) is a neurological emergency of research interest; however, unlike ischemic stroke, has not been well studied in large datasets due to the lack of an established administrative claims-based definition. We aimed to evaluate both explicit diagnosis codes and machine learning methods to create a claims-based definition for this clinical phenotype.

METHODS

We examined all patients admitted to our tertiary medical center with a primary or secondary International Classification of Disease version 9 (ICD-9) or 10 (ICD-10) code for ICH in claims from any portion of the hospitalization in 2014-2015. As a gold standard, we defined the nontraumatic ICH phenotype based on manual chart review. We tested explicit definitions based on ICD-9 and ICD-10 that had been previously published in the literature as well as four machine learning classifiers including support vector machine (SVM), logistic regression with LASSO, random forest and xgboost. We report five standard measures of model performance for each approach.

RESULTS

A total of 1830 patients with 2145 unique ICD-10 codes were included in the initial dataset, of which 437 (24%) were true positive based on manual review. The explicit ICD-10 definition performed best (Sensitivity = 0.89 (95% CI 0.85-0.92), Specificity = 0.83 (0.81-0.85), F-score = 0.73 (0.69-0.77)) and improves on an explicit ICD-9 definition (Sensitivity = 0.87 (0.83-0.90), Specificity = 0.77 (0.74-0.79), F-score = 0.67 (0.63-0.71). Among machine learning classifiers, SVM performed best (Sensitivity = 0.78 (0.75-0.82), Specificity = 0.84 (0.81-0.87), AUC = 0.89 (0.87-0.92), F-score = 0.66 (0.62-0.69)).

CONCLUSIONS

An explicit ICD-10 definition can be used to accurately identify patients with a nontraumatic ICH phenotype with substantially better performance than ICD-9. An explicit ICD-10 based definition is easier to implement and quantitatively not appreciably improved with the additional application of machine learning classifiers. Future research utilizing large datasets should utilize this definition to address important research gaps.

Less social emergency departments: implementation of workplace contact reduction during COVID-19

The COVID-19 pandemic has led to rapid changes in community and healthcare delivery policies creating new and unique challenges to managing ED pandemic response efforts. One example is the practice of social distancing in the workplace as an internationally recommended non-pharmaceutical intervention to reduce transmission. While attention has been focused on public health measures, healthcare workers cannot overlook the transmission risk they present to their colleagues and patients. Our network of three EDs are all high traffic areas for both patients and staff, which makes the limitation of close person-to-person contact particularly difficult to achieve. To design, implement and communicate contact reduction changes in the ED workplace, our COVID-19 task force formalised a set of multidisciplinary recommendations that enumerated concrete ways to reduce healthcare worker transmission to coworkers and to patients from ED patient arrival to discharge. We also addressed staff-to-staff contact reduction strategies when not performing direct patient care. We describe our conceptual approach and successful implementation of workplace distancing.

Improving Emergency Department Patient Experience Through Implementation of an Informational Pamphlet

Objective:

Patient satisfaction is emerging as a new health-care metric. We hypothesized that an emergency department (ED) informational pamphlet would significantly improve patient understanding of ED operations and ultimately improve patient satisfaction.

Methods:

We performed a prospective study of patients presenting to a single tertiary care center ED from April to July 2017. All patients were given a pamphlet on alternating weeks with regular care on opposite weeks and were surveyed upon ED discharge. The primary outcome was patient satisfaction with ED care. Secondary outcomes included patient understanding of various wait times (test results, consultants), discharge process, who was on the care team and what to expect during the ED visit.

Results:

Four hundred ninety-four patients were included in this study and 266 (54%) were in the control group. Of 228 (46%) patients who were given the pamphlet, 116 (51%) were unaware they received it. Of the remaining 112 (49%) patients who remembered receiving the pamphlet, 43 (38%) stated they read it. Among those reading the pamphlet, only two statements were significant: knowing what to expect during the ED visit (88% vs 71%; P = 0.012) and waiting time for test results (95% vs 75%; P = 0.003) when compared to those who did not receive or read the pamphlet.

Conclusion:

An ED informational pamphlet, when utilized by patients, does improve patient understanding of some aspects of the ED visit but does not appear to be the best tool to convey all information. Ultimately, sustained improvement in patient satisfaction is a complex and dynamic issue necessitating a multifactorial approach and other methods should be explored.

Rodenticide Causing Lower Gastrointestinal Bleeding: Resident Simulation

Introduction

Gastrointestinal (GI) bleeding is becoming more common with an aging population. Lower GI bleeding is less common than its upper GI bleed counterpart. Incidence of bleeding is increasing because more patients are on anticoagulation medication. Abnormal coagulation can lead to this life-threatening condition requiring rapid diagnosis and treatment by a skilled medical provider. Simulation can be used to practice recognition of this disease process and work through treatment algorithms.

Methods

This simulation case used a high-fidelity simulator to teach emergency medicine providers how to manage lower GI bleeding in a patient with abnormal coagulation secondary to intentional ingestion of rodenticide. The case simulated a 58-year-old female with history of bipolar disorder presenting with brisk rectal bleeding. Residents were expected to identify the type of GI bleed, leading to recognition that the patient was in hemorrhagic shock; they then had to appropriately reverse the anticoagulation and resuscitate with blood products. Afterward, learners were given a short survey to evaluate the case and debriefing process.

Results

The case was performed at the University of Pennsylvania Simulation Center as part of the Emergency Medicine Resident Simulation Curriculum. Twenty-eight learners took part; of these, 20 (71%) found the simulation realistic, and 24 (86%) agreed or strongly agreed that the simulation was useful.

Discussion

Main learning points include management of lower GI bleeding and reversal of abnormal anticoagulation. This simulation case is straightforward to run, requires minimal resources, and has been well received by learners at our institution.

Preoperative High-Resolution Ultrasound for the Assessment of Malignant Central Compartment Lymph Nodes in Papillary Thyroid Cancer

BACKGROUND

The identification and removal of malignant central compartment lymph nodes (MCLN) is important to minimize the risk of persistent or recurrent local disease in patients with papillary thyroid cancer (PTC). While the diagnostic accuracy of preoperative ultrasound for the assessment of lateral compartment node metastases is well recognized, its role in the identification of central compartment node metastases in patients with PTC is less established. This study delineates the utility of high-resolution ultrasound (HUS) for the assessment of MCLN in patients with PTC.

METHODS

A retrospective chart review was performed of 227 consecutive patients who underwent total thyroidectomy for biopsy-proven PTC by a single endocrine surgeon in an academic tertiary care center between 2004 and 2014. Preoperative sonographic results were compared to postoperative pathology reports to determine the accuracy of HUS for the assessment of MCLN. Statistical analysis also included sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).

RESULTS

HUS identified abnormal central compartment nodes in 51 (22.5%) patients. All 227 patients underwent a careful central compartment node exploration. One hundred and four (45.8%) patients had MCLN identified by surgery, of whom 65 (62.5%) had a negative preoperative central compartment HUS. The sensitivity and specificity of preoperative HUS for the assessment of MCLN were 0.38 and 0.90, respectively. The PPV and NPV were 0.76 and 0.63, with an accuracy of 0.66.

CONCLUSION

Preoperative HUS is quite specific for the identification of MCLN in patients with PTC. The present findings emphasize, however, that a negative HUS does not obviate the need for careful exploration of the central compartment to minimize the risk of persistent or recurrent local disease.

Use of a Pneumatic Limb Positioner for Invasive Skeletal Traction in Posterior Hindfoot Arthroscopy

Posterior hindfoot arthroscopy is a useful tool to treat a variety of foot and ankle pathologies. Skeletal distraction of the hindfoot to increase visualization in posterior ankle arthroscopy has been described in previous studies, but the described distractor is not readily available in most operating rooms. We describe a case of posterior hindfoot distraction in the prone position using a pneumatic limb positioner and other readily available Food and Drug Administration-approved equipment to apply tension to a transcalcaneal wire. The distraction technique we describe does not require any custom equipment, can fit on most standard operating tables, and is readily available in standard operating rooms. This method achieves adequate distraction, resulting in better visualization and more space for arthroscopic instrumentation.

Femoroacetabular impingement: a review of current concepts

Femoroacetabular impingement is becoming an increasingly more common diagnosis in the orthopaedic community for hip pain in the younger population. Variations in the femoral head and acetabulum can lead to a sequelae of changes to the cartilage that can lead to osteoarthritis. Diagnosis is made through a combination of patient history, physical examination, and diagnostic imaging. Plain radiographs are a very useful tool for evaluating the bony anatomy, while CT scan and MRI have roles for surgical planning and more definitive diagnosis. Most patients should trial physical therapy prior to consideration for any arthroscopic or open procedures. Long-term outcome studies are being performed to determine if surgical intervention has any impact on quality of life and development of osteoarthritis.

Bilateral consequences of chronic unilateral deafferentation in the auditory system of the cricket Gryllus bimaculatus

The auditory system of the cricket has the unusual ability to respond to deafferentation by compensatory growth and synapse formation. Auditory interneurons such as ascending neuron 2 (AN-2) in the cricket Gryllus bimaculatus possess a dendritic arbor that normally grows up to, but not over, the midline of the prothoracic ganglion. After chronic deafferentation throughout larval development, however, the AN-2 dendritic arbor changes dramatically, and medial dendrites sprout across the midline where they form compensatory synapses with the auditory afferents from the contralateral ear. We quantified the extent of the effects of chronic, unilateral deafferentation by measuring several cellular parameters of 3 different neuronal components of the auditory system: the deafferented AN-2, the contralateral (or nondeafferented) AN-2 and the contralateral auditory afferents. Neuronal tracers and confocal microscopy were used to visualize neurons, and double-label experiments were performed to examine the cellular relationship between pairs of cells. Dendritic complexity was quantified using a modified Sholl analysis, and the length and volume of processes and presynaptic varicosities were assessed under control and deafferented conditions. Chronic deafferentation significantly influenced the morphology of all 3 neuronal components examined. The overall dendritic complexity of the deafferented AN-2 dendritic arbor was reduced, while both the contralateral AN-2 dendritic arbor and the remaining, intact, auditory afferents grew longer. We found no significant changes in the volume or density of varicosities after deafferentation. These complex cellular changes after deafferentation are interpreted in the light of the reported differential regulation of vesicle-associated membrane protein and semaphorin 2a.

Increased central adiposity in morbidly obese patients with obstructive sleep apnoea

BACKGROUND

With the growing epidemic of obesity, few data are available regarding adipose distribution and the severity of sleep apnoea. Our aim was to measure precisely adipose distribution with dual-energy X-ray absorptiometry (DXA) in a morbidly obese population with and without obstructive sleep apnoea (OSA).

METHODS

Morbidly obese female subjects without a history of OSA underwent overnight polysomnography and DXA analysis. Subject demographics, DXA variables, serum laboratory markers and physical exam characteristics were compared between individuals with and without OSA.

RESULTS

For the study population (n= 26), mean body mass index (BMI) was 45.9 ± 7.8 kg/m(2); mean age was 47.5 ± 10.2 years and all were female. The central adiposity ratio (CAR) was higher in individuals with OSA (apnoea-hypopnoea index > 5) than those without OSA (1.1 ± 0.05 vs 1.0 ± 0.04; P = 0.004). No difference was observed in Epworth Sleepiness Scale scores, body mass index (BMI) or neck circumference between groups.

CONCLUSIONS

OSA is associated with increased central adipose deposition in patients with a BMI of >40 kg/m(2). These data may be helpful in designing future studies regarding the pathophysiology of OSA, and potential treatment options.

Subjective sleepiness ratings (Epworth sleepiness scale) do not reflect the same parameter of sleepiness as objective sleepiness (maintenance of wakefulness test) in patients with narcolepsy

OBJECTIVE

To evaluate whether subjective (Epworth Sleepiness Scale or ESS) and objective (Maintenance of Wakefulness Test or MWT) tests of sleepiness are equally useful in patients with narcolepsy.

METHODS

Correlational study evaluating the relationship between ESS and MWT as measures of sleepiness.

SETTING

Multi-center.

PATIENTS

522 patients (17-68 year old men and women) with a current diagnosis of narcolepsy.

INTERVENTIONS

None.

RESULTS

Correlations were: MSLT and MWT, r = 0.52 (P<0.001); MWT and ESS, r = -0.29 (P<0.001); MSLT and ESS, r = -0.27 (P<0.001). Regression curve estimation using linear and curvilinear models revealed no difference among linear and curvilinear models between MWT and MSLT, and between MSLT and ESS. However, curvilinear models were better at explaining the relationship between MWT and ESS, with the cubic model being the best. As the level of severe sleepiness (as measured by the MWT) changed, the ESS remained stable.

CONCLUSIONS

In a large narcolepsy sample, the MWT and ESS are not equally useful, and do not measure the same parameter of sleepiness.

Visual P300 latency predicts treatment response to modafinil in patients with narcolepsy

OBJECTIVE

To evaluate the hypothesis that visual P300 latency (VL) predicts treatment response to modafinil (a new wake-promoting agent) in patients with narcolepsy.

METHODS

DESIGN

Comparison of responders and non-responders in a double-blind randomized placebo-controlled trial.

SETTING

Private practice referral sleep disorders center.

PATIENTS

Twenty one patients with narcolepsy (ages 17-65 years).

INTERVENTIONS

Auditory and visual P300 testing using 31 evenly spaced scalp electrodes, and baseline polysomnograms and objective and subjective tests of daytime sleepiness, followed by modafinil treatment for 9 weeks. Polysomnograms and tests of sleepiness were then repeated.

MAIN OUTCOME MEASURE

The Maintenance of Wakefulness Test (MWT). Response defined as a final MWT > 7.3min (normative sample mean - 3 SD), plus an increase > 1SD based on normative sample (3.6 min) over baseline MWT.

RESULTS

Non-responders had longer age-adjusted 31-electrode mean VL (448.4 ms vs. 410.8 ms, P = 0.024), and larger auditory P300 amplitude, with no topographical P300 differences. Non-responders and responders did not differ on any other baseline clinical variable. Using a cut-off of 0.5 SE from normal regression constant, shorter age-adjusted VL predicted modafinil response, with specificity of 0.71 and sensitivity of 0.86.

CONCLUSIONS

VL predicts treatment response to modafinil in patients with narcolepsy.

Subjective and objective indices of sleepiness (ESS and MWT) are not equally useful in patients with sleep apnea

To understand the relationship between subjective and objective indices of sleepiness, we studied the relationship of the Epworth Sleepiness Scale (ESS) and the Maintenance of Wakefulness Test (MWT) in 41 consecutive patients complaining of snoring and excessive day-time sleepiness. The correlation between ESS and MWT was significant but small (rho = -0.39). There was considerable discordance between the two tests. The Lowess fit line between the ESS and the MWT indicates that the ESS falls as the MWT rises to about 4 min. It then stays at a plateau until the MWT rises to about 12 min. Thereafter, it resumes its downward slope as the MWT rises further. Thus, in patients who are severely sleepy on the MWT, the ESS may not be sensitive to different levels of sleepiness. We conclude that the ESS and the MWT are not equally useful in assessing sleepiness in patients with sleep apnea.

Longer auditory and visual P300 latencies in patients with narcolepsy

To compare auditory and visual P300 amplitude and latency magnitudes and topographies in patients with narcolepsy and normal subjects, 20 patients with polysomnographically-confirmed narcolepsy and 40 normal subjects were administered auditory and visual P300 testing using 31 evenly spaced scalp electrodes. Patients with narcolepsy were then administered baseline polysomnograms and objective (MSLT, Maintenance of Wakefulness Test or MWT) and subjective tests (Epworth Sleepiness Scale, Clinical Global Impression) of daytime sleepiness. Patients had longer 31-electrode mean age-adjusted auditory P300 latencies (406.0 +/- 27.8 vs. 385.7 +/- 28.9 ms, p = 0.012) and visual P300 latencies (427.3 +/- 29.0 vs. 411.4 +/- 27.7 ms., p = 0.044) than 40 normal subjects in the same age range. Age-adjusted auditory P300 latency was correlated with MWT (r = -0.49, p = 0.028), but not with any other clinical variable or measure of sleepiness. Age-adjusted visual P300 latency was not correlated with any clinical variable or measure of sleepiness. Patients with narcolepsy had longer auditory and visual P300 latencies than normal subjects.

Sleep latency on the maintenance of wakefulness test (MWT) for 530 patients with narcolepsy while free of psychoactive drugs

OBJECTIVES

To compare maintenance of wakefulness test (MWT) data gathered at baseline in the course of two, multicenter studies on the therapeutic efficacy of modafinil with published MWT norms.

METHODS

The MWT is a procedure that uses electrophysiological measures to determine the ability to remain awake while sitting in a quiet, darkened room. The test consists of 4 20 min trials conducted 4 times at 2 h intervals commencing 2 h after awakening from a night of sleep. MWT data were gathered at baseline in the course of two, multicenter studies on the therapeutic efficacy of modafinil. Subjects were 17-68 year old men (n = 239) and women (n = 291) diagnosed with narcolepsy according to the International Classification of Sleep Disorders (ICSD). All patients were free of psychoactive medication for a minimum of 14 days.

RESULTS

Mean MWT sleep latency was 6.0 +/- 4.8 min. However, the mean for the first MWT trial was 7.0 min which was longer that the means for the following 3 trials (5.8, 5.6 and 5.7 min, respectively). The 4 distributions of the individual MWT trials were similar and adequately summarized by the distribution of the average MWT sleep latency. As a group, patients with narcolepsy were less able to remain awake than normals; only 8 of 530 (1.5%) patients were able to remain awake on 4 20 min MWT trials compared with 35 of 64 (54.7%) normals in another study. However, using a mean MWT sleep latency of 12 min (the 5th percentile for normals) as the lowest cut-point for normalcy, 15% of patients with narcolepsy appeared to have an unimpaired ability to remain awake.

CONCLUSIONS

The diagnosis of narcolepsy did not always predict inability to remain awake on the MWT. Age, gender and the duration of illness did not predict ability to remain awake. Patients with severe cataplexy and other ancillary symptoms were least able to remain awake on MWT trials. Patients who used tobacco and caffeine moderately had the lowest MWT sleep latencies relative to patients with heavy and light use.

P300 latency and age: a quadratic regression explains their relationship from age 5 to 85

The use of P300 latency to demonstrate cognitive dysfunction is important. P300 latency decreases with age in children and then increases with age in adults. It has been debated whether the relationship between age and P300 latency is linear or quadratic. If the relationship is linear, then at least two regression equations in opposite directions are required for children and for adults, and perhaps a third for the elderly. This is a report of data from an age-stratified sample of 97 normal individuals ages 5 through 85. The best regression equation is quadratic, using log transformed age, with accurate projection of 95% confidence limits for P300 latency by age. This quadratic regression simplifies the application of P300 latency across the life-span in the management of disorders affecting cognition, such as Traumatic Brain Injury, Attention Deficit-Hyperactivity Disorder, and Obstructive Sleep Apnea.

A normative study of the maintenance of wakefulness test (MWT)

The maintenance of wakefulness test (MWT) is a daytime polysomnographic procedure which quantifies wake tendency by measuring the ability to remain awake during soporific circumstances. We present normative data based on 64 healthy subjects (27 males and 37 females) who adhered to uniform MWT procedural conditions including polysomnographic montage, illuminance level, seating position, room temperature, meal timing, and subject instructions. When allowed a maximum trial duration of 40 min, subjects' mean sleep latency to the first epoch of sustained sleep was 35.2 +/- 7.9 min. The lower normal limit, defined as two standard deviations below the mean, was 19.4 min. Calculation of data on the basis of a maximum trial duration of 20 min and sleep latency to the first appearance of brief sleep (a microsleep episode or one epoch of any stage of sleep) yielded a mean sleep latency of 18.1 +/- 3.6 min and a lower normal limit of 10.9 min. Sleep latency scores were significantly higher than those previously reported in patients with disorders of excessive somnolence. Therefore, the MWT appears to be a useful procedure in differentiating groups with normal daytime wake tendency from those with impaired wake tendency and in identifying individuals with pathologic inability to remain awake under soporific circumstances.

Abnormal visual P300 latency in obstructive sleep apnea does not change acutely upon treatment with CPAP

This study evaluated the effects of 2-4 months of continuous positive airway pressure (CPAP) treatment on previously demonstrated P300 latency prolongations in obstructive sleep apnea (OSA). Subjects with severe OSA (respiratory disturbance index > 40/hour sleep) were administered polysomnograms, auditory and visual P300 testing using 31 scalp electrodes, and multiple sleep latency testing before and after treatment with CPAP for 2-4 months. Despite significant improvements in sleep and respiratory variables and the mean sleep latency, there were no significant P300 changes. Obstructive sleep apnea patients had prolonged visual P300 latency compared to normals, both before and after treatment. Prolongations in P300 latency that are resistant to the acute effects of CPAP may suggest that OSA causes physiological cortical changes that are unrelated to sleepiness and may be resistant to treatment.

Measurement of P300 and sleep characteristics in patients with hypersomnia: do P300 latencies, P300 amplitudes, and multiple sleep latency and maintenance of wakefulness tests measure different factors?

To explore further the relationship between ease of falling asleep, ability to maintain wakefulness, attention and information processing in sleep apnea and other sleep disorders, we conducted a thorough analysis of the similarities, differences and correlations between auditory and visual P300 amplitudes and latencies, and tests of sleepiness. The 283 consecutive patients presenting with hypersomnia were administered nocturnal polysomnography. Next day they underwent auditory and visual P300 recordings, Multiple Sleep Latency Test (MSLT) and Maintenance of Wakefulness Test (MWT). Correlation coefficients were calculated between auditory and visual P300 amplitudes and latencies, respiratory disturbance index (RDI), sleep efficiency, % stage 1, and the tests for sleepiness. Factor analysis was performed with data from P300 testing, MSLT and MWT. Auditory P300 amplitude was correlated with sleep efficiency. Auditory P300 latency was correlated with % stage 1, RDI, MSLT and MWT. Visual P300 latency was correlated with % stage 1, sleep efficiency and MWT. MSLT but not MWT was negatively correlated with sleep efficiency. Factor analysis suggests three factors: attention, information processing, and sleepiness. We conclude that P300 latencies and tests of sleepiness (MSLT and MWT) measure different abilities in patients with diagnosable disorders of daytime sleepiness.

The indications for polysomnography and related procedures

This paper is a review of the literature on the use of polysomnography in the diagnosis of sleep disorders in the adult. It is based on a search of MEDLINE from January 1966 through April 1996. It has been reviewed and approved by the Board of Directors of the American Sleep Disorders Association and provides the background for the accompanying ASDA Standards of Practice Committee's Parameters for the Practice of Sleep Medicine in North America. The diagnostic categories reviewed are: sleep-related breathing disorders; other respiratory disorders; narcolepsy; parasomnias and sleep-related epilepsy; restless legs syndrome and periodic limb movement disorders: insomnia; and circadian rhythm sleep disorders. Where appropriate, previously published practice parameters papers are cited and discussed. The relevant published peer-reviewed literature used as the basis for critical decisions was compiled into accompanying evidence tables and is analyzed in the text. In the section on the assessment of sleep apnea syndrome, options for estimating pretest probability to select high risk patients are also reviewed. Sleep-testing procedures other than standard polysomnography are also addressed (daytime polysomnography, split-night studies, oximetry, limited full respiratory recordings, and less-than-full respiratory recording) and treatment-related follow-up studies are discussed.

Computerized scoring of abnormal human sleep: a validation

A computerized assessment of sleep staging, arousals, premature ventricular contractions (PVCs), and respiratory events in sleep, was developed. Performance of the computerized system was assessed using epoch-by-epoch comparison and two human scorers across 30 consecutive patients. Percentages of agreement and Cohen's kappa coefficients were used for comparison. All agreements between all scorers for sleep staging, arousals, PVCs and respiratory events in sleep were significant (p < 0.001). The ratios of computer-human agreement descriptors to human-human agreement descriptors indicate that computerized analysis of abnormal human sleep offers reasonable results with savings in technologist time and work, but not in physician time and work.

Obstructive sleep apnea and abnormal P300 latency topography

This study was conducted to evaluate cognitive abnormalities in obstructive sleep apnea (OSA) using cognitive evoked potentials (P300), and to clarify if such cognitive dysfunction is related to the OSA itself or to the hypersomnolence in OSA. Subjects were administered a polysomnogram, auditory and visual P300 testing using 31 scalp electrodes, and the multiple sleep latency test. There were 40 normal subjects ages 26 to 75. Of 143 consecutive OSA patients ages 26 to 75, 56 had severe OSA (Respiratory Disturbance Index or RDI 40-80/h sleep) with objective somnolence (Mean Sleep Latency < 5 min). Thirty-three had severe OSA without objective somnolence. Fifty-four had profound OSA (RDI > 80/h sleep) with or without objective somnolence. The normals and the three OSA groups did not differ in age. Patients with profound OSA or with severe OSA without somnolence had longer visual P300 latency than normals. The groups also differed in visual P300 latency topography. OSA patients had significantly longer latencies frontally than normals. Thus, OSA, even in the absence of hypersomnolence, is associated with abnormalities in cognitive evoked potentials. Visual P300 latency at frontal electrodes seems to be a neurophysiological index of dysfunction in OSA that is independent of tests of sleepiness.

Prolonged P300 latency in attention deficit hyperactivity disorder predicts poor response to imipramine

P300 is a cognitive evoked potential that evaluates attention and information processing. This study uses auditory and visual P300 topography to develop a classification of attention deficit hyperactivity disorder (ADHD), and find predictors of treatment response. Of 45 ADHD children ages 6 to 15 treated with pemoline in a previous study, 25 were poor responders. Of these 25, 17 participated in an imipramine treatment protocol. Auditory and visual P300 testing was performed before and after treatment using 31 scalp electrodes. Good and poor responders to imipramine were clinically identical. Poor imipramine responders had longer auditory and visual P300 latencies than good responders. Treatment with imipramine decreased auditory P300 latencies and increased auditory P300 amplitudes. We have previously reported that ADHD patients with small right frontocentral auditory P300 amplitudes respond poorly to pemoline. Thus, P300 topography and latency classifies ADHD into three groups: group 1 with normal P300 topography, and good response to pemoline; group 2 with small right frontocentral auditory P300 amplitudes, poor response to pemoline, and good response to imipramine; and group 3 with long auditory and visual P300 latencies and small right frontocentral auditory P300 amplitudes, and poor response to pemoline and imipramine.

Topography of auditory and visual P300 in normal children

Auditory and visual P300 recordings were performed on 39 normal, right-handed individuals from age 6 through 15, using 31 evenly spaced scalp electrodes. Amplitude at the P300 peak and latency to this peak at each electrode site were measured. Age was significantly correlated with the 31-electrode mean for auditory and visual P300 latencies, but not for amplitudes. The younger age group (6-10) had longer auditory and visual P300 latencies than the older age group. Visual P300 amplitudes were of an overall larger magnitude than auditory amplitudes. There were no other differences including significant topographical differences in P300 amplitudes or latencies by gender, age group, modality, or side of scalp. Radial current density maps on group-averaged auditory and visual P300 waveforms at the group mean P300 latency at Cz, showed a right centroparietal sink surrounded by sources. This suggests a major right centroparietal P300 generator. Description of the normal topography of the P300, and demonstration of the lack of topographic differences by gender, age group, modality, or side of scalp, may facilitate the meaningful examination of P300 topography in cognitive disorders. Such an examination might lead to better diagnostic tools and more appropriate treatment of cognitive disorders in children.

Abnormal auditory P300 topography in attention deficit disorder predicts poor response to pemoline

P300 is a cognitive evoked potential that evaluates attention and information processing. This study uses auditory and visual P300 topography to develop a classification of attention deficit disorder (ADD), and to find predictors of treatment response to the stimulant pemoline. Forty-five ADD children ages 6 to 15 were administered auditory and visual P300 using 31 scalp electrodes. They were compared with 39 normals. Patients were treated with pemoline, and good and poor responders compared. There were no P300 differences between normals and ADD patients. Good and poor responders to pemoline were clinically identical. Poor pemoline responders had smaller right fronto-central auditory P300 amplitudes than good responders. The ratio of right fronto-central to parietal auditory P300 amplitude, had a sensitivity of 0.70 and specificity of 0.76, as a test for good pemoline response. A ratio greater than 0.5 predicted good response to pemoline, while a ratio less than 0.5 predicted poor response. Treatment with pemoline produced no P300 changes. We conclude that P300 topography classifies ADD into group 1 with normal P300 topography and good response to pemoline, and group 2 with small right fronto-central auditory P300 amplitudes and poor response to pemoline.