Forearm Fracture Fixation with Locking Plates: Does Size Matter?

Purpose: Forearm shaft fractures of the radius and/or ulna are typically repaired with plates and screws, with 3.5 mm nonlocking screws being generally recommended. However, smaller plates and screws, either nonlocking or locking, can also be applied. The purpose of this study was to retrospectively review whether fracture healing rates and related complications are affected by plate size and type. Methods: Patient demographic and descriptive data were retrospectively collected for all patients with a forearm shaft fracture treated with repair of the radial shaft and/or ulna shaft between 2017 and 2021 at a multiprovider and multilocation single institution. Inclusion criteria involved use of a locking plate with a minimum radiographic follow-up of 60 days and/or until fracture union was confirmed. Results: A total of 110 patients met inclusion criteria. There were 45 (40.9%) females and 65 (59.1%) males included with the mean age at time of injury being 47 years (± 22). There were 34 (30.1%) isolated radius fractures, 50 (45.5%) isolated ulna fractures, and 26 (23.6%) both bone forearm fractures. Screw sizes consisted of 3.5 mm (small fragment) screws in 57 (52%) cases, whereas 2.7 mm/2.5 mm/2.4 mm (mini fragment) screws were used in 53 (48%) cases. Fracture union was confirmed in 108 (98%) cases. Among the two nonunion cases, one case (50%) involved a small fragment, and one case (50%) involved a mini fragment plate. Conclusions: This study confirms that fracture union is high following any size plate fixation of radius and/or ulna fractures. Moreover, smaller screw sizes did not affect fracture union rates. Choice of plate type and screw diameter should be based on patient characteristics and surgeon preference and need not be limited to only 3.5 mm plate and screws. Type of Study/Level of Evidence: Prognosis IIb.

The Effect of Nonsteroidal Anti-inflammatory Drugs on Union Rates Following Joint Arthrodesis: A Meta-Analysis.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most widely used and prescribed medications because of their important role in reducing inflammation and pain, in addition to their non-addictive properties and safety profiles. However, some studies have documented an association between NSAIDs and delayed union or nonunion of joint arthrodesis procedures due to a potential inhibition of the bone's inflammatory healing response. As a result, some orthopedic surgeons hesitate to prescribe NSAIDs after an arthrodesis procedure. The purpose of this meta-analysis is to review all relevant literature regarding the effect of NSAIDs on union rates after arthrodesis and determine if NSAID therapy increases the risk of non-union in the setting of arthrodesis procedures. The study hypothesis was that NSAIDs would not have a significant effect on the risk of nonunion after arthrodesis. A thorough systematic review of Medline, Embase, the Cochrane Database of Systematic Reviews, and the Web of Science identified 3,050 articles to be screened. The variables of interest encompassed demographic factors, procedural details, type and administration of NSAIDs, the number of patients exposed to NSAIDs with and without successful union (case group), as well as the number of patients who did not receive NSAIDs with and without successful union (control group). All the data were analyzed using a maximum likelihood random-effects model. The number of non-union events versus routine healing from each study was used to calculate the odds ratio (OR) of successful healing after arthrodesis procedures with versus without NSAID therapy. Thirteen articles met the inclusion criteria for the meta-analysis. NSAID exposure showed an increased risk of nonunion, delayed union, or both following arthrodesis procedures; however, this did not meet statistical significance (OR, 1.48; confidence interval [CI], 0.96 to 2.30). A sub-analysis of pediatric and adult studies showed a significant increase in non-union risk in adults (OR, 1.717; CI, 1.012 to 2.914) when removing the pediatric cohort (p = 0.045). This meta-analysis provides evidence that NSAIDs can increase the risk of nonunion, delayed union, or both following arthrodesis procedures in adults. However, the study did not identify a risk of nonunion, delayed union, or both following arthrodesis procedures in the pediatric population.

Phenylephrine Alters Phase Synchronization between Cerebral Blood Velocity and Blood Pressure in Chronic Fatigue Syndrome with Orthostatic Intolerance.

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) with orthostatic intolerance (OI) is characterized by neuro-cognitive deficits perhaps related to upright hypocapnia and loss of cerebral autoregulation (CA). We performed N-back neurocognition testing and calculated the phase synchronization index (PhSI) between Arterial Pressure (AP) and cerebral blood velocity (CBV) as a time-dependent measurement of cerebral autoregulation in 11 control (mean age=24.1 years) and 15 ME/CFS patients (mean age=21.8 years). All ME/CFS patients had postural tachycardia syndrome (POTS). A 10-minute 60° head-up tilt (HUT) significantly increased heart rate (109.4 ± 3.9 vs. 77.2 ± 1.6 beats/min, P <0.05) and respiratory rate (20.9 ± 1.7 vs. 14.2 ± 1.2 breaths/min, P < 0.05) and decreased end-tidal CO2 (ETCO2; 33.9 ± 1.1 vs. 42.8 ± 1.2 Torr, P < 0.05) in ME/CFS vs. control. In ME/CFS, HUT significantly decreased CBV compared to control (-22.5% vs -8.7%, p<0.005). To mitigate the orthostatic CBV reduction, we administered supplemental CO2, phenylephrine and acetazolamide and performed N-back testing supine and during HUT. Only phenylephrine corrected the orthostatic decrease in neurocognition by reverting % correct n=4 N-back during HUT in ME/CFS similar to control (ME/CFS=38.5±5.5 vs. ME/CFS+PE= 65.6±5.7 vs. Control 56.9±7.5). HUT in ME/CFS resulted in increased PhSI values indicating decreased CA. While CO2 and Acetazolamide had no effect on PhSI in ME/CFS, PE caused a significant reduction in PhSI (ME/CFS=0.80±0.03 vs ME/CFS+PE= 0.69±0.04, p< 0.05) and improved cerebral autoregulation. Thus, PE improved neurocognitive function in ME/CFS patients, perhaps related to improved neurovascular coupling, cerebral autoregulation and maintenance of CBV.

Assessment of comorbid symptoms in pediatric autonomic dysfunction.

PURPOSE: Pediatric patients with autonomic dysfunction and orthostatic intolerance (OI) often present with co-existing symptoms and signs that might or might not directly relate to the autonomic nervous system. Our objective was to identify validated screening instruments to characterize these comorbidities and their impact on youth functioning. METHODS: The Pediatric Assembly of the American Autonomic Society reviewed the current state of practice for identifying symptom comorbidities in youth with OI. The assembly includes physicians, physician-scientists, scientists, advanced practice providers, psychologists, and a statistician with expertise in pediatric disorders of OI. A total of 26 representatives from the various specialties engaged in iterative meetings to: (1) identify and then develop consensus on the symptoms to be assessed, (2) establish committees to review the literature for screening measures by member expertise, and (3) delineate the specific criteria for systematically evaluating the measures and for making measure recommendations by symptom domains. RESULTS: We review the measures evaluated and recommend one measure per system/concern so that assessment results from unrelated clinical centers are comparable. We have created a repository to apprise investigators of validated, vetted assessment tools to enhance comparisons across cohorts of youth with autonomic dysfunction and OI. CONCLUSION: This effort can facilitate collaboration among clinical settings to advance the science and clinical treatment of these youth. This effort is essential to improving management of these vulnerable patients as well as to comparing research findings from different centers.

A framework to simplify paediatric syncope diagnosis.

This paper aims to improve the diagnosis of syncope and transient loss of consciousness (TLOC) in children. Diagnostic problems stem, first, from some causes spanning various disciplines, e.g. cardiology, neurology and psychiatry, while the most common cause, vasovagal syncope, is not embraced by any specialty. Second, clinical variability is huge with overlapping signs and symptoms. Third, the approach to TLOC/syncope of the European Society of Cardiology (ESC) is underused in childcare. We explain the ESC guidelines using an additional paediatric literature review. Classification of TLOC and syncope is hierarchic and based on history taking. Loss of consciousness (LOC) is defined using three features: abnormal motor control including falling, reduced responsiveness and amnesia. Adding a < 5 min duration and spontaneous recovery defines TLOC. TLOC simplifies diagnosis by excluding long LOC (e.g. some trauma, intoxications and hypoglycaemia) and focussing on syncope, tonic-clonic seizures and functional TLOC. Syncope, i.e. TLOC due to cerebral hypoperfusion, is divided into reflex syncope (mostly vasovagal), orthostatic hypotension (mostly initial orthostatic hypotension in adolescents) and cardiac syncope (arrhythmias and structural cardiac disorders). The initial investigation comprises history taking, physical examination and ECG; the value of orthostatic blood pressure measurement is unproven in children but probably low. When this fails to yield a diagnosis, cardiac risk factors are assessed; important clues are supine syncope, syncope during exercise, early death in relatives and ECG abnormalities.  Conclusions: In adults, the application of the ESC guidelines reduced the number of absent diagnoses and costs; we hope this also holds for children. What is Known: • Syncope and its mimics are very common in childhood, as they are at other ages. • Syncope and its mimics provide considerable diagnostic challenges. What is New: • Application of the hierarchic framework of transient loss of consciousness (TLOC) simplifies diagnosis. • The framework stresses history-taking to diagnose common conditions while keeping an eye on cardiac danger signs.

Return-to-learn after concussion in Washington state public high schools during the COVID-19 pandemic.

Aim: To understand academic support structures for Washington state public high school students with concussion during the COVID-19 pandemic. Materials & methods: Prospective, repeated cross-sectional study of 21 schools in 2020 and 2021. Results: About 28% of schools reported not providing any return-to-learn (RTL) accommodations for students with concussion throughout the COVID-19 pandemic. RTL accommodation provision was associated with larger student body size (ß = 0.002) and higher graduation rate (ß = 0.261) but was not associated with presence of RTL school policy. About 38.1% of schools received no guidance on how to provide RTL accommodations during the COVID-19 pandemic, and many reported that students with concussion struggled more. Conclusion: Schools struggled to provide RTL accommodations for students with concussion during the COVID-19 pandemic, highlighting the need for evidence-based guidance and resource allocation to vulnerable schools.

Anticipatory central command on standing decreases cerebral blood velocity causing hypocapnia in hyperpneic postural tachycardia syndrome.

Fifty percent of patients with postural tachycardia syndrome (POTS) are hypocapnic during orthostasis related to initial orthostatic hypotension (iOH). We determined whether iOH drives hypocapnia in POTS by low BP or decreased cerebral blood velocity (CBv). We studied three groups; healthy volunteers (n = 32, 18 ± 3 yr) were compared with POTS, grouped by presence [POTS-low end-tidal CO2 (↓ETCO2), n = 26, 19 ± 2 yr] or absence [POTS-normal upright end-tidal carbon dioxide (nlCO2), n = 28, 19 ± 3 yr] of standing hypocapnia defined by end-tidal CO2 (ETCO2) ≤ 30 mmHg at steady-state, measuring middle cerebral artery CBv, heart rate (HR), and beat-to-beat blood pressure (BP). After 30 min supine, subjects stood for 5 min. Quantities were measured prestanding, at minimum CBv, minimum BP, peak HR, CBv recovery, BP recovery, minimum HR, steady-state, and 5 min. Baroreflex gain was estimated by α index. iOH occurred with similar frequency and minimum BP in POTS-↓ETCO2 and POTS-nlCO2. Minimum CBv was reduced significantly (P < 0.05) in POTS-↓ETCO2 (48 ± 3 cm/s) preceding hypocapnia compared with POTS-nlCO2 (61 ± 3 cm/s) or Control (60 ± 2 cm/s). The anticipatory increased BP was significantly larger (P < 0.05) in POTS (8 ± 1 mmHg vs. 2 ± 1) and began ∼8 s prestanding. HR increased in all subjects, CBv increased significantly (P < 0.05) in both POTS-nlCO2 (76 ± 2 to 85 ± 2 cm/s) and Control (75 ± 2 to 80 ± 2 cm/s) consistent with central command. CBv decreased in POTS-↓ETCO2 (76 ± 3 to 64 ± 3 cm/s) correlating with decreased baroreflex gain. Cerebral conductance [meanCBv/mean arterial blood pressure (MAP)] was reduced in POTS-↓ETCO2 throughout. Data support the hypothesis that excessively reduced CBv during iOH may intermittently reduce carotid body blood flow, sensitizing that organ and producing postural hyperventilation in POTS-↓ETCO2. Excessive fall in CBv occurs in part during prestanding central command and is a facet of defective parasympathetic regulation in POTS.NEW & NOTEWORTHY Dyspnea is frequent in postural tachycardia syndrome (POTS) and is associated with upright hyperpnea and hypocapnia that drives sinus tachycardia. It is initiated by an exaggerated reduction in cerebral conductance and decreased cerebral blood flow (CBF) that precedes the act of standing. This is a form of autonomically mediated "central command." Cerebral blood flow is further reduced by initial orthostatic hypotension common in POTS. Hypocapnia is maintained during the standing response and might account for persistent postural tachycardia.

Effect of RISE Bundle implementation on school adoption of a student-centered return-to-learn program in Washington state.

BACKGROUND: Appropriate concussion care in school is vital for full recovery, but school return-to-learn (RTL) programs are lacking and vary in quality. Establishing student-centered RTL programs may reduce disparities in RTL care. OBJECTIVE: To examine the effect of RISE Bundle (Return to Learn Implementation Bundle for Schools) implementation on high school adoption of a student-centered RTL program. METHODS: A convenience sample of fourteen (4 rural and 10 urban) small and large Washington (WA) State public high schools were enrolled in a stepped-wedge study with baseline, end of study, and monthly measures over the 2021-2022 academic year. Schools identified an RTL champion who led RISE Bundle implementation in 6-week steps. Concussion knowledge and impact of RTL program on concussion care were examined. RESULTS: Ten schools (71.4%) successfully completed RISE Bundle implementation and established a functional RTL program. Self-reported concussion knowledge from RTL Champions increased post intervention. Establishing RTL programs facilitated provision of tailored accommodations, and perceived variation and inequities in RTL care were reduced. CONCLUSION: RISE Bundle implementation proved feasible, supported the establishment of a functional RTL program, and perceived to reduce disparities in concussion care in rural and urban WA State public high schools of varying sizes.

Characterizing Female Firearm Suicide Circumstances: A Natural Language Processing and Machine Learning Approach.

INTRODUCTION: Since 2005, female firearm suicide rates increased by 34%, outpacing the rise in male firearm suicide rates over the same period. The objective of this study was to develop and evaluate a natural language processing pipeline to identify a select set of common and important circumstances preceding female firearm suicide from coroner/medical examiner and law enforcement narratives. METHODS: Unstructured information from coroner/medical examiner and law enforcement narratives were manually coded for 1,462 randomly selected cases from the National Violent Death Reporting System. Decedents were included from 40 states and Puerto Rico from 2014 to 2018. Naive Bayes, Random Forest, Support Vector Machine, and Gradient Boosting classifier models were tuned using 5-fold cross-validation. Model performance was assessed using sensitivity, specificity, positive predictive value, F1, and other metrics. Analyses were conducted from February to November 2022. RESULTS: The natural language processing pipeline performed well in identifying recent interpersonal disputes, problems with intimate partners, acute/chronic pain, and intimate partners and immediate family at the scene. For example, the Support Vector Machine model had a mean of 98.1% specificity and 90.5% positive predictive value in classifying a recent interpersonal dispute before suicide. The Gradient Boosting model had a mean of 98.7% specificity and 93.2% positive predictive value in classifying a recent interpersonal dispute before suicide. CONCLUSIONS: This study developed a natural language processing pipeline to classify 5 female firearm suicide antecedents using narrative reports from the National Violent Death Reporting System, which may improve the examination of these circumstances. Practitioners and researchers should weigh the efficiency of natural language processing pipeline development against conventional text mining and manual review.

Creating a data dictionary for pediatric autonomic disorders.

PURPOSE: Whether evaluating patients clinically, documenting care in the electronic health record, performing research, or communicating with administrative agencies, the use of a common set of terms and definitions is vital to ensure appropriate use of language. At a 2017 meeting of the Pediatric Section of the American Autonomic Society, it was determined that an autonomic data dictionary comprising aspects of evaluation and management of pediatric patients with autonomic disorders would be an important resource for multiple stakeholders. METHODS: Our group created the list of terms for the dictionary. Definitions were prioritized to be obtained from established sources with which to harmonize. Some definitions needed mild modification from original sources. The next tier of sources included published consensus statements, followed by Internet sources. In the absence of appropriate sources, we created a definition. RESULTS: A total of 589 terms were listed and defined in the dictionary. Terms were organized by Signs/Symptoms, Triggers, Co-morbid Disorders, Family History, Medications, Medical Devices, Physical Examination Findings, Testing, and Diagnoses. CONCLUSION: Creation of this data dictionary becomes the foundation of future clinical care and investigative research in pediatric autonomic disorders, and can be used as a building block for a subsequent adult autonomic data dictionary.

Using a Community-Informed Translational Model to Prioritize Translational Benefits in Youth Concussion Return-to-Learn Programs.

BACKGROUND: The Translational Science Benefit Model (TSBM) was developed to broadly capture systematic measures of health and societal benefits from scientific research, beyond traditional outcome measures. We aimed to develop a systematic process for the application of the TSBM and to then provide an example of a novel application of the TSBM to an ongoing Return-to-Learn (RTL) after youth concussion project involving partnerships with community stakeholders. METHODS: We invited investigators, project advisory board, and participants of the RTL project to participate in a modified Delphi process. We first generated a list of potential translational benefits using the indicators of the TSBM as guideposts. We then prioritized the benefits on an adapted Eisenhower matrix. RESULTS: We invited 35 concussion care or research experts to participate, yielding 20 ranked translational benefits. Six of these recommendations were ranked high priority, six were regarded as investments, and eight were ranked as either low yield or low priority. DISCUSSION: This study found that activities such as education and training of stakeholders, development of policy and consensus statements, and innovation in dissemination, were perceived as higher priority than other activities. Our approach using a modified Delphi process and incorporating the TSBM can be replicated to generate and prioritize potential benefits to society from research studies.

Hospice Transitions From the Perspective of the Caregiver: A Qualitative Study and Development of a Preliminary Hospice Transition Checklist.

Background: Relative to curative and traditional care delivery, hospice care has been associated with superior end of life (EOL) outcomes for both patient and caregiver. Still, comprehensive orientation and caregiver preparation for the transition to hospice is variable and often inadequate. From the perspective of the caregiver, it is unclear what information would better prepare them to support the transition of their loved one to hospice. Objectives: Our two sequential objectives were: 1) Explore caregivers' experiences and perceptions on the transition of their loved one to hospice; and 2) Develop a preliminary checklist of considerations for a successful transition. Design: We conducted semi-structured interviews and used a descriptive inductive/deductive thematic analysis to identify themes. Subjects: 19 adult caregivers of patients across the United States who had enrolled in hospice and died in the year prior (January - December 2019). Measurements: An interview guide was iteratively developed based on prior literature and expanded through collaborative coding and group discussion. Results: Four key themes for inclusion in our framework emerged: hospice intake, preparedness, burden of care and hospice resources. Conclusions: Focusing on elements of our preliminary checklist, such as educating families on goals of hospice or offering opportunities for respite care, into the orientation procedures may be opportunities to improve satisfaction with the transition and the entirety of the hospice experience. Future directions include testing the effectiveness of the checklist and adapting for expanded poputlations.

Sinus Tachycardia: a Multidisciplinary Expert Focused Review.

Sinus tachycardia (ST) is ubiquitous, but its presence outside of normal physiological triggers in otherwise healthy individuals remains a commonly encountered phenomenon in medical practice. In many cases, ST can be readily explained by a current medical condition that precipitates an increase in the sinus rate, but ST at rest without physiological triggers may also represent a spectrum of normal. In other cases, ST may not have an easily explainable cause but may represent serious underlying pathology and can be associated with intolerable symptoms. The classification of ST, consideration of possible etiologies, as well as the decisions of when and how to intervene can be difficult. ST can be classified as secondary to a specific, usually treatable, medical condition (eg, pulmonary embolism, anemia, infection, or hyperthyroidism) or be related to several incompletely defined conditions (eg, inappropriate ST, postural tachycardia syndrome, mast cell disorder, or post-COVID syndrome). While cardiologists and cardiac electrophysiologists often evaluate patients with symptoms associated with persistent or paroxysmal ST, an optimal approach remains uncertain. Due to the many possible conditions associated with ST, and an overlap in medical specialists who see these patients, the inclusion of experts in different fields is essential for a more comprehensive understanding. This article is unique in that it was composed by international experts in Neurology, Psychology, Autonomic Medicine, Allergy and Immunology, Exercise Physiology, Pulmonology and Critical Care Medicine, Endocrinology, Cardiology, and Cardiac Electrophysiology in the hope that it will facilitate a more complete understanding and thereby result in the better care of patients with ST.

Association of concussion with high school academic standing: sex, school grade and race as stratifiers.

INTRODUCTION: The purpose was to examine the association between concussion history and academic standing among high school students, and whether the association varies by sex, school grade and race/ethnicity. METHODS: Data from the 2019 Youth Risk Behaviour Survey were used for our cross-sectional study. Exposure was self-reported history of concussions in the past 12 months. Outcome was self-reported academic standing in the past 12 months. Poisson regression was used to analyse the exposure-outcome association, and whether there were differences by our stratifying variables. RESULTS: Having a history of concussion in the past 12 months was significantly associated with a higher risk of poor academic standing during the same period, and the association varied by race/ethnicity. DISCUSSION: Youth with a history of concussion may be at risk for poorer academic standing, indicating to the importance of prevention. Future studies are needed to examine the interaction of race/ethnicity on the presented association.

Microscale pedestrian environment surrounding pedestrian injury sites in Washington state, 2015-2020.

OBJECTIVE: While microscale pedestrian environment features such as sidewalks and crosswalks can affect pedestrian safety, it is challenging to assess microscale environment associated risk across locations or at scale. Addressing these challenges requires an efficient auditing protocol that can be used to assess frequencies of microscale environment features. For this reason, we developed an eight-item pedestrian environment virtual audit protocol and conducted a descriptive epidemiologic study of pedestrian injury in Washington State, USA. METHODS: We used data from police reports at pedestrian-automotive collision sites where the pedestrian was seriously injured or died. At each collision site, high school students participating in an online summer internship program virtually audited Google Street View imagery to assess the presence of microscale pedestrian environment features such as crosswalks and streetlighting. We assessed inter-rater reliability using Cohen's kappa and explored prevalence of eight microscale environment features in relation to injury severity and municipal boundaries. RESULTS: There were 2248 motor vehicle crashes eliciting police response and resulting in death or serious injury of a pedestrian in Washington State between January 1, 2015 and May 8, 2020. Of the crashes resulting in serious injury or death, 498 (22%) resulted in fatalities and 1840 (82%) occurred within municipal boundaries. Cohen's kappa scores for the eight pedestrian features that were audited ranged from 0.52 to 0.86. Audit results confirmed that features such as sidewalks and crosswalks were more common at collision sites within city limits. CONCLUSIONS: High school student volunteers with minimal training can reliably audit microscale pedestrian environments using limited resources.

Physician recommended school accommodations and student outcomes following a mild traumatic brain injury among youth with persistent post-concussive symptoms.

BACKGROUND: Post-concussion return-to-learn (RTL) guidelines include implementation of school accommodations. Yet, little is known about physician recommendations for school accommodations and their impact, particularly among youth experiencing persistent post-concussive symptoms (PPCS). OBJECTIVE: We examined the association between physician recommended school accommodations and student outcomes among youth experiencing PPCS. METHODS: Data from a randomized comparative effectiveness trial was used. Physician recommended school accommodations (≤90 days post-injury) were collected via chart abstraction. Grade point average was extracted from school records. Reports of problems at school, concussion symptoms, health-related quality of life (HRQOL), anxiety symptoms, and depressive symptoms were collected by survey (at baseline, three months, and 12 months post study entry). RESULTS: Of 200 participants (Mage = 14.7, 62% female), 86% were recommended school accommodations. Number of recommended school accommodations was positively associated with number of school problems at three months (aRR 1.18, 95% CI:1.12-1.24) and 12 months (aRR 1.11, 95% CI:1.05-1.18). No significant associations were found between recommended school accommodations and GPA, HRQOL, anxiety symptoms, or depressive symptoms. CONCLUSIONS: Physicians recommend more school accommodations for students experiencing more school problems post-concussion. Appropriate implementation of RTL recommendations made by physicians by fostering partnerships among physicians, students, and schools may be needed to achieve student-centered RTL.

Postural orthostatic tachycardia syndrome: A respiratory disorder?

Postural orthostatic tachycardia syndrome (POTS) is a disorder epitomized by the story of the blind men and the elephant. Patients may see primary care internists or pediatricians due to fatigue, be referred to neurologists for "spells", to cardiologists for evaluation of pre-syncope or chest pain, to gastroenterologists for nausea or dyspepsia, and even pulmonologists for dyspnea. Adoption of a more systematic approach to their evaluation and better characterization of patients has led to greater understanding of comorbidities, hypotheses prompting mechanistic investigations, and pharmacologic trials. Recent work has implicated disordered sympathetic nervous system activation in response to central (thoracic) hypovolemia. It is this pathway that leads one zero in on a putative focal point from which many of the clinical manifestations can be explained - specifically the carotid body. Despite heterogeneity in etiopathogenesis of a POTS phenotype, we propose that aberrant activation and response of the carotid body represents one potential common pathway in evolution. To understand this postulate, one must jettison isolationist or reductionist ideas of chemoreceptor and baroreceptor functions of the carotid body or sinus, respectively, and consider their interaction and interdependence both locally and centrally where some of its efferents merge. Doing so enables one to connect the dots and appreciate origins of diverse manifestations of POTS, including dyspnea for which the concept of neuro-mechanical uncoupling is wanting, thereby expanding our construct of this symptom. This perspective expounds our premise that POTS has a prominent respiratory component.

Postural orthostatic tachycardia syndrome (POTS): Priorities for POTS care and research from a 2019 National Institutes of Health Expert Consensus Meeting - Part 2.

The National Institutes of Health hosted a workshop in 2019 to build consensus around the current state of understanding of the pathophysiology of postural orthostatic tachycardia syndrome (POTS) and to identify knowledge gaps that must be addressed to enhance clinical care of POTS patients through research. This second (of two) articles summarizes current knowledge gaps, and outlines the clinical and research priorities for POTS. POTS is a complex, multi-system, chronic disorder of the autonomic nervous system characterized by orthostatic intolerance and orthostatic tachycardia without hypotension. Patients often experience a host of other related disabling symptoms. The functional and economic impacts of this disorder are significant. The pathophysiology remains incompletely understood. Beyond the significant gaps in understanding the disorder itself, there is a paucity of evidence to guide treatment which can contribute to suboptimal care for this patient population. The vast majority of physicians have minimal to no familiarity or training in the assessment and management of POTS. Funding for POTS research remains very low relative to the size of the patient population and impact of the syndrome. In addition to efforts to improve awareness and physician education, an investment in research infrastructure including the development of standardized disease-specific evaluation tools and outcome measures is needed to facilitate effective collaborative research. A national POTS research consortium could facilitate well-controlled multidisciplinary clinical research studies and therapeutic trials. These priorities will require a substantial increase in the number of research investigators and the amount of research funding in this area.

Postural orthostatic tachycardia syndrome (POTS): State of the science and clinical care from a 2019 National Institutes of Health Expert Consensus Meeting - Part 1.

Postural orthostatic tachycardia syndrome (POTS) is a chronic and often disabling disorder characterized by orthostatic intolerance with excessive heart rate increase without hypotension during upright posture. Patients often experience a constellation of other typical symptoms including fatigue, exercise intolerance and gastrointestinal distress. A typical patient with POTS is a female of child-bearing age, who often first displays symptoms in adolescence. The onset of POTS may be precipitated by immunological stressors such as a viral infection. A variety of pathophysiologies are involved in the abnormal postural tachycardia response; however, the pathophysiology of the syndrome is incompletely understood and undoubtedly multifaceted. Clinicians and researchers focused on POTS convened at the National Institutes of Health in July 2019 to discuss the current state of understanding of the pathophysiology of POTS and to identify priorities for POTS research. This article, the first of two articles summarizing the information discussed at this meeting, summarizes the current understanding of this disorder and best practices for clinical care. The evaluation of a patient with suspected POTS should seek to establish the diagnosis, identify co-morbid conditions, and exclude conditions that could cause or mimic the syndrome. Once diagnosed, management typically begins with patient education and non-pharmacologic treatment options. Various medications are often used to address specific symptoms, but there are currently no FDA-approved medications for the treatment of POTS, and evidence for many of the medications used to treat POTS is not robust.