Exercise-induced laryngeal obstruction (EILO) in athletes: a narrative review by a subgroup of the IOC Consensus on 'acute respiratory illness in the athlete'

Exercise-induced laryngeal obstruction (EILO) is caused by paradoxical inspiratory adduction of laryngeal structures during exercise. EILO is an important cause of upper airway dysfunction in young individuals and athletes, can impair exercise performance and mimic lower airway dysfunction, such as asthma and/or exercise-induced bronchoconstriction. Over the past two decades, there has been considerable progress in the recognition and assessment of EILO in sports medicine. EILO is a highly prevalent cause of unexplained dyspnoea and wheeze in athletes. The preferred diagnostic approach is continuous visualisation of the larynx (via laryngoscopy) during high-intensity exercise. Recent data suggest that EILO consists of different subtypes, possibly caused via different mechanisms. Several therapeutic interventions for EILO are now in widespread use, but to date, no randomised clinical trials have been performed to assess their efficacy or inform robust management strategies. The aim of this review is to provide a state-of-the-art overview of EILO and guidance for clinicians evaluating and treating suspected cases of EILO in athletes. Specifically, this review examines the pathophysiology of EILO, outlines a diagnostic approach and presents current therapeutic algorithms. The key unmet needs and future priorities for research in this area are also covered.

Resumption of Sport at the United States Olympic and Paralympic Training Facilities During the COVID-19 Pandemic

In this brief report, we describe the safety of reopening US Olympic and Paralympic Training facilities (USOPTFs) during the coronavirus disease 2019 (COVID-19) pandemic from July 2020 through October 2020. We evaluated the prevalence of COVID-19 infection at the time of reentry and cardiopulmonary sequelae of COVID-19 in elite athletes. All athletes returning to a USOPTF were required to go through a reentry protocol consisting of an electronic health history, a 6-day quarantine including twice-daily symptom surveys, COVID-19 polymerase chain reaction and antibody testing, physical examination, 12-lead electrocardiogram, high-sensitivity cardiac troponin I, and pulmonary function testing. Athletes with current or prior COVID-19 infection also underwent an echocardiogram, cardiology consultation, and additional testing as indicated. All athletes followed rigorous infection prevention measures and minimized contact with the outside community following reentry. At the time of this report, 301 athletes completed the reentry protocol among which 14 (4.7%) tested positive for active (positive polymerase chain reaction test, n = 3) or prior (positive antibody test, n = 11) COVID-19 infection. During the study period, this cohort accrued 14,916 days living and training at USOPTFs. Only one (0.3%) athlete was subsequently diagnosed with a new COVID-19 infection. No cardiopulmonary pathology attributable to COVID-19 was detected. Our findings suggest that residential elite athlete training facilities can successfully resume activity during the COVID-19 pandemic when strict reentry and infection prevention measures are followed. Dissemination of our reentry quarantine and screening protocols with COVID-19 mitigation measures may assist the global sports and medical community develop best practices for reopening of similar training centers.

Step-Up Therapy in Black Children and Adults with Poorly Controlled Asthma

BACKGROUND

Morbidity from asthma is disproportionately higher among black patients than among white patients, and black patients constitute the minority of participants in trials informing treatment. Data indicate that patients with inadequately controlled asthma benefit more from addition of a long-acting beta-agonist (LABA) than from increased glucocorticoids; however, these data may not be informative for treatment in black patients.

METHODS

We conducted two prospective, randomized, double-blind trials: one involving children and the other involving adolescents and adults. In both trials, the patients had at least one grandparent who identified as black and had asthma that was inadequately controlled with low-dose inhaled glucocorticoids. We compared combinations of therapy, which included the addition of a LABA (salmeterol) to an inhaled glucocorticoid (fluticasone propionate), a step-up to double to quintuple the dose of fluticasone, or both. The treatments were compared with the use of a composite measure that evaluated asthma exacerbations, asthma-control days, and lung function; data were stratified according to genotypic African ancestry.

RESULTS

When quintupling the dose of fluticasone (to 250 μg twice a day) was compared with adding salmeterol (50 μg twice a day) and doubling the fluticasone (to 100 μg twice a day), a superior response occurred in 46% of the children with quintupling the fluticasone and in 46% of the children with doubling the fluticasone and adding salmeterol (P = 0.99). In contrast, more adolescents and adults had a superior response to added salmeterol than to an increase in fluticasone (salmeterol-low-dose fluticasone vs. medium-dose fluticasone, 49% vs. 28% [P = 0.003]; salmeterol-medium-dose fluticasone vs. high-dose fluticasone, 49% vs. 31% [P = 0.02]). Neither the degree of African ancestry nor baseline biomarkers predicted a superior response to specific treatments. The increased dose of inhaled glucocorticoids was associated with a decrease in the ratio of urinary cortisol to creatinine in children younger than 8 years of age.

CONCLUSIONS

In contrast to black adolescents and adults, almost half the black children with poorly controlled asthma had a superior response to an increase in the dose of an inhaled glucocorticoid and almost half had a superior response to the addition of a LABA. (Funded by the National Heart, Lung, and Blood Institute; BARD ClinicalTrials.gov number, NCT01967173.).

Exercise-Induced Laryngeal Obstruction: When Pediatric Exertional Dyspnea Does not Respond to Bronchodilators

Exertional dyspnea is a common complaint in general pediatric practice. While a high proportion of the general pediatric population has asthma, other diagnoses, including exercise-induced laryngeal obstruction should be considered, especially when asthma therapy is not sufficient to control symptoms. This review describes some of the key clinical features of exercised-induced laryngeal obstruction as well as preferred diagnostic and therapeutic approaches. Importantly, current diagnostic technology has considerably improved in the last decade at specialty centers. At the same time, infrastructure for clinical trials is emerging and there is not strong evidence to support specific therapies at the current time.

Quintupling Inhaled Glucocorticoids to Prevent Childhood Asthma Exacerbations

BACKGROUND

Asthma exacerbations occur frequently despite the regular use of asthma-controller therapies, such as inhaled glucocorticoids. Clinicians commonly increase the doses of inhaled glucocorticoids at early signs of loss of asthma control. However, data on the safety and efficacy of this strategy in children are limited.

METHODS

We studied 254 children, 5 to 11 years of age, who had mild-to-moderate persistent asthma and had had at least one asthma exacerbation treated with systemic glucocorticoids in the previous year. Children were treated for 48 weeks with maintenance low-dose inhaled glucocorticoids (fluticasone propionate at a dose of 44 μg per inhalation, two inhalations twice daily) and were randomly assigned to either continue the same dose (low-dose group) or use a quintupled dose (high-dose group; fluticasone at a dose of 220 μg per inhalation, two inhalations twice daily) for 7 days at the early signs of loss of asthma control ("yellow zone"). Treatment was provided in a double-blind fashion. The primary outcome was the rate of severe asthma exacerbations treated with systemic glucocorticoids.

RESULTS

The rate of severe asthma exacerbations treated with systemic glucocorticoids did not differ significantly between groups (0.48 exacerbations per year in the high-dose group and 0.37 exacerbations per year in the low-dose group; relative rate, 1.3; 95% confidence interval, 0.8 to 2.1; P=0.30). The time to the first exacerbation, the rate of treatment failure, symptom scores, and albuterol use during yellow-zone episodes did not differ significantly between groups. The total glucocorticoid exposure was 16% higher in the high-dose group than in the low-dose group. The difference in linear growth between the high-dose group and the low-dose group was -0.23 cm per year (P=0.06).

CONCLUSIONS

In children with mild-to-moderate persistent asthma treated with daily inhaled glucocorticoids, quintupling the dose at the early signs of loss of asthma control did not reduce the rate of severe asthma exacerbations or improve other asthma outcomes and may be associated with diminished linear growth. (Funded by the National Heart, Lung, and Blood Institute; STICS ClinicalTrials.gov number, NCT02066129 .).

Working Towards a Common Transatlantic Approach for Evaluation of Exercise-Induced Laryngeal Obstruction

Exertional dyspnea can be a manifestation of dysfunction in a variety of organ systems. Exercise-induced laryngeal obstruction (EILO), a condition previously known as vocal cord dysfunction and paradoxic vocal fold motion, is defined as inappropriate, reversible narrowing of the larynx during vigorous exercise. EILO is usually characterized by typical symptoms, which nevertheless frequently are confused with those of other conditions, including asthma. Laryngoscopy performed as symptoms evolve from rest to peak exercise is pivotal in patient work-up. Moving forward, laryngoscopy findings that definitively characterize EILO need to be defined as do objective measures that can quantitate absolute laryngeal measurements during exercise.

The Fortuitous Discovery of the Olin EILOBI Breathing Techniques: A Case Study

Exercise-induced laryngeal obstruction (EILO) is the term for the condition previously named vocal cord dysfunction and paradoxical vocal fold motion. It is defined by glottic or supraglottic obstruction during periods of intense exercise. Not all patients respond to conventional therapy with speech-language pathology, behavioral health interventions, and treatment of contributing conditions. In this edition of Journal of Voice, the authors describe a novel series of respiratory retraining techniques, now called Olin EILOBI (EILO biphasic inspiratory) breathing techniques, specifically designed for athletes with EILO. This case presentation describes the discovery of one of these techniques during a session of therapeutic laryngoscopy during exercise. The patient was an adolescent with EILO who demonstrated a positive response to therapy with a variant of these techniques over a few days, having previously struggled with symptoms despite multiple sessions of conventional respiratory retraining over the course of months.

The Olin EILOBI Breathing Techniques: Description and Initial Case Series of Novel Respiratory Retraining Strategies for Athletes with Exercise-Induced Laryngeal Obstruction

INTRODUCTION

Exercise-induced laryngeal obstruction (EILO), the condition previously known as paradoxical vocal fold motion and vocal cord dysfunction, is characterized by inappropriate glottic or supraglottic obstruction during high-intensity exercise, causing exertional dyspnea, frequently with stridor. EILO is definitively diagnosed through upper-airway visualization during a characteristic episode. Although respiratory retraining is a primary therapy for EILO, many patients report symptom persistence despite adequate performance of traditional techniques. This report describes three novel breathing techniques for EILO, the Olin EILOBI (EILO biphasic inspiratory) breathing techniques. We include a teaching process and case series with patient-reported assessments.

MATERIALS AND METHODS

Following descriptions of the techniques and teaching process, we present data from a questionnaire offered to all patients who learned at least one of the techniques between September 2015 and March 2017. Subjects evaluated (1) expectation setting, (2) teaching processes, (3) their ability to implement the techniques during high-intensity exercise, and (4) perceived clinical effectiveness.

RESULTS

Ninety-five percent of eligible patients participated, a primarily young, female, and Caucasian sample. Over 50% of subjects competed at the high school varsity level. Sixty-two percent of subjects perceived reasonable expectations, and 82% positively evaluated the teaching process. Seventy-nine percent were able to employ their technique in the high-intensity activity of choice, and 66% perceived clinical effectiveness with the techniques.

CONCLUSIONS

The Olin EILOBI breathing techniques are novel respiratory retraining techniques for use in high-intensity exercise. Case series subjects reported reasonable expectations, a helpful teaching process, the ability to use these techniques during high-intensity exercise, and perceived clinical effectiveness.

Therapeutic laryngoscopy during exercise: A novel non-surgical therapy for refractory EILO

BACKGROUND

Exercise-induced laryngeal obstruction (EILO) may affect as many as 6% of the adolescent population, with some patients experiencing symptoms refractory to conservative interventions.

OBJECTIVES

This report describes therapeutic laryngoscopy during exercise, a novel, non-surgical intervention that harnesses real-time laryngoscopy video as biofeedback to control laryngeal aperture during high-intensity exercise. Additionally, we quantitate patient-reported perceptions of procedure safety, tolerability, learning value, and effectiveness.

METHODS

Clinical EILO patients with symptoms refractory to conventional respiratory retraining and other therapies were referred for the procedure which features laryngoscopy video as biofeedback during serial physician-guided 1-min exercise sprints. We quantify perceptions of procedure safety, tolerability, learning value, and effectiveness through questionnaires offered to all patients as well as observers of the procedure.

RESULTS

Forty-one patients and 37 parent observers were approached for feedback; 88% of patients and 95% of observers consented to participation. Patients and observers reported perceptions of safety and tolerability (81% and 86%, respectively), learning value (78% and 91%, respectively), and effectiveness (58% and 80%, respectively) with patient age predicting some responses. Seventy-five percent of patients noted that "Since the procedure, my breathing during exercise has improved," and 85% of this group noted that therapeutic laryngoscopy during exercise was "the most important therapy leading to my breathing improvement." The procedure also provided insight into the psychological experience of patients, a domain not clinically apparent prior to the procedure.

CONCLUSIONS

Our data support further study of therapeutic laryngoscopy during exercise as a possible intervention for patients with refractory EILO. Pediatr Pulmonol. 2017;52:813-819. © 2016 Wiley Periodicals, Inc.

Acetaminophen versus Ibuprofen in Young Children with Mild Persistent Asthma

BACKGROUND

Studies have suggested an association between frequent acetaminophen use and asthma-related complications among children, leading some physicians to recommend that acetaminophen be avoided in children with asthma; however, appropriately designed trials evaluating this association in children are lacking.

METHODS

In a multicenter, prospective, randomized, double-blind, parallel-group trial, we enrolled 300 children (age range, 12 to 59 months) with mild persistent asthma and assigned them to receive either acetaminophen or ibuprofen when needed for the alleviation of fever or pain over the course of 48 weeks. The primary outcome was the number of asthma exacerbations that led to treatment with systemic glucocorticoids. Children in both groups received standardized asthma-controller therapies that were used in a simultaneous, factorially linked trial.

RESULTS

Participants received a median of 5.5 doses (interquartile range, 1.0 to 15.0) of trial medication; there was no significant between-group difference in the median number of doses received (P=0.47). The number of asthma exacerbations did not differ significantly between the two groups, with a mean of 0.81 per participant with acetaminophen and 0.87 per participant with ibuprofen over 46 weeks of follow-up (relative rate of asthma exacerbations in the acetaminophen group vs. the ibuprofen group, 0.94; 95% confidence interval, 0.69 to 1.28; P=0.67). In the acetaminophen group, 49% of participants had at least one asthma exacerbation and 21% had at least two, as compared with 47% and 24%, respectively, in the ibuprofen group. Similarly, no significant differences were detected between acetaminophen and ibuprofen with respect to the percentage of asthma-control days (85.8% and 86.8%, respectively; P=0.50), use of an albuterol rescue inhaler (2.8 and 3.0 inhalations per week, respectively; P=0.69), unscheduled health care utilization for asthma (0.75 and 0.76 episodes per participant, respectively; P=0.94), or adverse events.

CONCLUSIONS

Among young children with mild persistent asthma, as-needed use of acetaminophen was not shown to be associated with a higher incidence of asthma exacerbations or worse asthma control than was as-needed use of ibuprofen. (Funded by the National Institutes of Health; AVICA ClinicalTrials.gov number, NCT01606319.).

Continuous laryngoscopy quantitates laryngeal behaviour in exercise and recovery

Exercise-induced laryngeal obstruction (E-ILO) causes exertional dyspnoea. There is no standardised methodology which characterises laryngeal obstruction in relation to exercise or links laryngeal obstruction and dyspnoea severity. Continuous laryngoscopy during exercise (CLE) may improve diagnostic sensitivity by enabling laryngeal visualisation at peak work capacity in patients with rapidly resolving obstruction. The time course of laryngeal obstruction across exercise and recovery has not been quantitated until this report.

Adolescents and young adults referred for CLE were laryngoscopically monitored across rest, maximal cycle ergometry exercise, and recovery. Three reviewers, blinded to time sequencing, rated inspiratory glottic and supraglottic obstruction during 10 windows of 15-s corresponding to rest, 25%, 50%, 75%, 90% and 100% of individual symptom-limited peak work capacity (expressed in Watts), and four consecutive recovery windows.

85 patients were screened and 71 included. Over 96% of time windows were interpretable. Laryngeal obstruction severity reached observed maximal levels at peak work capacity, and rapidly resolved. A spectrum of observed maximal obstruction was measured.

CLE provides interpretable data demonstrating laryngeal obstruction in patients with suspected E-ILO that is more severe at peak work capacity than during rest, submaximal exercise, or recovery. Observed maximal obstruction was infrequently severe and rapidly resolved.

Asthma: pathogenesis and novel drugs for treatment

Asthma affects almost 20 million people in the United States and more than 300 million people worldwide. Of these, 10-15% have severe asthma, which is refractory to commonly available drugs. New drugs are needed because those that are currently available cannot control symptoms and exacerbations in all patients and can cause adverse reactions. In the past 10 years, there have been substantial advances in the understanding of asthma genetics, airway biology, and immune cell signaling. These advances have led to the development of small molecule therapeutics and biologic agents that may improve asthma care in the future. Several new classes of asthma drugs--including ultra long acting β agonists and modulators of the interleukin 4 (IL-4), IL-5, IL-13, and IL-17 pathways--have been evaluated in randomized controlled trials. Other new drug classes--including dissociated corticosteroids, CXC chemokine receptor 2 antagonists, toll-like receptor 9 agonists, and tyrosine kinase inhibitors--remain in earlier phases of development. Despite some preliminary efficacy data, there is insufficient evidence to make strong recommendations about the use of these newer agents. Future research on the clinical efficacy of these biologic agents, the effect of newer agents on severe asthma in pediatric patients, and the biology of non-eosinophilic and corticosteroid resistant asthma is needed to reduce the morbidity of asthma worldwide.

The clinical translation gap in child health exercise research: a call for disruptive innovation

In children, levels of play, physical activity, and fitness are key indicators of health and disease and closely tied to optimal growth and development. Cardiopulmonary exercise testing (CPET) provides clinicians with biomarkers of disease and effectiveness of therapy, and researchers with novel insights into fundamental biological mechanisms reflecting an integrated physiological response that is hidden when the child is at rest. Yet the growth of clinical trials utilizing CPET in pediatrics remains stunted despite the current emphasis on preventative medicine and the growing recognition that therapies used in children should be clinically tested in children. There exists a translational gap between basic discovery and clinical application in this essential component of child health. To address this gap, the NIH provided funding through the Clinical and Translational Science Award (CTSA) program to convene a panel of experts. This report summarizes our major findings and outlines next steps necessary to enhance child health exercise medicine translational research. We present specific plans to bolster data interoperability, improve child health CPET reference values, stimulate formal training in exercise medicine for child health care professionals, and outline innovative approaches through which exercise medicine can become more accessible and advance therapeutics across the broad spectrum of child health.

Glottic configuration in patients with exercise-induced stridor: a new paradigm

OBJECTIVES/HYPOTHESIS

Paradoxical vocal fold motion and exercise-induced paradoxical vocal fold motion (EIPVFM) are two related conditions that do not have definitive diagnostic criteria. Much of the EIPVFM literature describes patients with characteristic physiologic findings of severe upper airway obstruction or obvious airflow limitation in the clinical context of exertional dyspnea with audible stridor. The objective of this study was to highlight a group of patients who demonstrate important clinical findings of EIPVFM (exertional dyspnea with audible stridor) without simultaneously definitive physiologic findings (mild glottic adduction and normal flow volume loops).

STUDY DESIGN

Retrospective medical record review.

METHODS

We reviewed the records of 150 patients who performed continuous laryngoscopy during exercise for inclusion in a case series. We excluded patients for technical (incomplete records) and physiologic (extremes of disease severity) reasons. Three blinded physicians (practicing in laryngology, pulmonology, and allergy/immunology) independently evaluated isolated audio tracks, video tracks, and flow volume loops of the remaining patients for the presence or absence of stridor, the glottic configuration, and the presence or absence of inspiratory limitation on exercise flow volume loops at peak work capacity.

RESULTS

Exercise laryngoscopy and flow volume loops were fully evaluated for 23 patients. Five patients with exertional dyspnea were unanimously described as having audible stridor, open glottic configuration, and normal flow volume loops.

CONCLUSIONS

EIPVFM can occur in the absence of widely recognized confirmatory physiologic measures. Improved quantitative metrics are needed to better characterize patients with EIPVFM.

LEVEL OF EVIDENCE

4.

A simple method to clamp end-tidal carbon dioxide during rest and exercise

Carbon dioxide regulates ventilation and cerebral blood flow during exercise. There are significant limitations in breathing systems designed to control end-tidal gas concentrations when used during high-intensity exercise. We designed a simple, inexpensive breathing system which controls end-tidal carbon dioxide (PET CO2) during exercise from rest to peak work capacity (W(max)). The system is operated by an investigator who, in response to breath-by-breath PET CO2, titrates flow of a 10 % CO(2), 21 % O(2) mixture into an open-ended 5-L inspiratory reservoir. To demonstrate system efficacy, nine fit male subjects performed two maximal, incremental exercise tests (25 W min(-1) ramp) on a cycle ergometer: a poikilocapnic control trial in which PET CO2 varied with work intensity, and an experimental trial, in which we planned to clamp PET CO2 at 50 mmHg. With our breathing system, we maintained PET CO2 at 51 ± 2 mmHg throughout exercise (rest, 50 ± 2; W(max), 52 ± 5 mmHg; mean ± SD) despite large changes in ventilation (range 27-65 at rest, 134-185 L min(-1) BTPS at W (max)) and carbon dioxide production (range 0.3-0.7 at rest, 4.5-5.5 L min(-1) at W (max)). This simple, inexpensive system achieves PET CO2 control at rest and throughout exercise.

Does cerebral oxygen delivery limit incremental exercise performance?

Previous studies have suggested that a reduction in cerebral oxygen delivery may limit motor drive, particularly in hypoxic conditions, where oxygen transport is impaired. We hypothesized that raising end-tidal Pco(2) (Pet(CO(2))) during incremental exercise would increase cerebral blood flow (CBF) and oxygen delivery, thereby improving peak power output (W(peak)). Amateur cyclists performed two ramped exercise tests (25 W/min) in a counterbalanced order to compare the normal, poikilocapnic response against a clamped condition, in which Pet(CO(2)) was held at 50 Torr throughout exercise. Tests were performed in normoxia (barometric pressure = 630 mmHg, 1,650 m) and hypoxia (barometric pressure = 425 mmHg, 4,875 m) in a hypobaric chamber. An additional trial in hypoxia investigated effects of clamping at a lower Pet(CO(2)) (40 Torr) from ∼75 to 100% W(peak) to reduce potential influences of respiratory acidosis and muscle fatigue imposed by clamping Pet(CO(2)) at 50 Torr. Metabolic gases, ventilation, middle cerebral artery CBF velocity (transcranial Doppler), forehead pulse oximetry, and cerebral (prefrontal) and muscle (vastus lateralis) hemoglobin oxygenation (near infrared spectroscopy) were monitored across trials. Clamping Pet(CO(2)) at 50 Torr in both normoxia (n = 9) and hypoxia (n = 11) elevated CBF velocity (∼40%) and improved cerebral hemoglobin oxygenation (∼15%), but decreased W(peak) (6%) and peak oxygen consumption (11%). Clamping at 40 Torr near maximal effort in hypoxia (n = 6) also improved cerebral oxygenation (∼15%), but again limited W(peak) (5%). These findings demonstrate that increasing mass cerebral oxygen delivery via CO(2)-mediated vasodilation does not improve incremental exercise performance, at least when accompanied by respiratory acidosis.

Diagnostic yield of nasal scrape biopsies in primary ciliary dyskinesia: a multicenter experience

Examination of ciliary ultrastructure remains the cornerstone diagnostic test for primary ciliary dyskinesia (PCD), a disease of abnormal ciliary structure and/or function. Obtaining a biopsy with sufficient interpretable cilia and producing quality transmission electron micrographs (TEM) is challenging. Methods for processing tissues for optimal preservation of axonemal structures are not standardized. This study describes our experience using a standard operating procedure (SOP) for collecting nasal scrape biopsies and processing TEMs in a centralized laboratory. We enrolled patients with suspected PCD at research sites of the Genetic Disorders of Mucociliary Clearance Consortium. Biopsies were performed according to a SOP whereby curettes were used to scrape the inferior surface of the inferior turbinate, with samples placed in fixative. Specimens were shipped to a central laboratory where TEMs were prepared and blindly reviewed. Four hundred forty-eight specimens were obtained from 107 young children (0-5 years), 189 older children (5-18 years), and 152 adults (> 18 years), and 88% were adequate for formal interpretation. The proportion of adequate specimens was higher in adults than in children. Fifty percent of the adequate TEMs showed normal ciliary ultrastructure, 39% showed hallmark ultrastructural changes of PCD, and 11% had indeterminate findings. Among specimens without clearly normal ultrastructure, 72% had defects of the outer and/or inner dynein arms (IDA), while 7% had central apparatus defects with or without IDA defects. In summary, nasal scrape biopsies can be performed in the outpatient setting and yield interpretable samples, when performed by individuals with adequate training and experience according to an SOP.

Dose effects associated with rivastigmine transdermal patch in patients with mild-to-moderate Alzheimer's disease

AIM

The cholinesterase inhibitor rivastigmine is available in both oral and transdermal forms. The efficacy of oral rivastigmine appears to be dose-dependent. The current analysis investigates the effect of dose on the efficacy of the rivastigmine transdermal patch.

METHODS

This was a retrospective analysis of a large, international, 24-week, randomised, placebo- and active-controlled trial (IDEAL, CENA713D2320) of rivastigmine in patients with mild-to-moderate Alzheimer's disease (AD). Patients received the 9.5 mg/24 h rivastigmine patch, the 17.4 mg/24 h rivastigmine patch, 12 mg/day rivastigmine capsules or placebo. Changes from baseline at week 24 on the AD Assessment Scale-cognitive subscale (ADAS-cog), AD Cooperative Study-Clinical Global Impression of Change (ADCS-CGIC) and the AD Cooperative Study-Activities of Daily Living (ADCS-ADL) scale were calculated based on the patient's mode and last prescribed patch dose. The analysis included the 4.6 mg/24 h and 13.3 mg/24 h patch doses, for which efficacy data have not previously been reported.

RESULTS

Significant differences (p<0.05 vs. placebo) were seen on the ADAS-cog and ADCS-ADL for all mode rivastigmine patch doses (except 4.6 mg/24 h) and all last prescribed rivastigmine patch doses (except 4.6 mg/24 h and 13.3 mg/24 h). Patients with a last prescribed/mode patch dose of 9.5 mg/24 h and 13.3 mg/24 h showed significant improvements (p<0.05 vs. placebo) on the ADCS-CGIC.

CONCLUSION

Rivastigmine patch doses higher than 9.5 mg/24 h may offer additional benefits. The 13.3 mg/24 h patch is worthy of further investigation.

Quality improvement for asthma care within a hospital-based teaching clinic

OBJECTIVE

The aim of this study was to determine if a quality improvement intervention in a teaching clinic was associated with the following: 1) improved asthma action plan creation and distribution, 2)increased classification of asthma patients as intermittent or persistent, 3) increased prescriptions of asthma controller medications, 4) decreased emergency department visits and hospitalizations, and 5) sustainable changes in outcomes after the intervention year.

METHODS

A retrospective analysis was conducted of a quality improvement project involving children aged >2 years who were diagnosed with asthma, evaluated in a large hospital-based teaching clinic. Outcomes were assessed for 1 year before and 3 years after quality improvement intervention.

RESULTS

Data from children with asthma seen in the clinic over the 4 years of the study (N = 1797) were analyzed. Mixed effects model regressions showed that children after the intervention were over twofold more likely to receive an asthma action plan (using 2006 as referent, adjusted risk ratio [ARR] 2.29, 95% confidence interval [CI] 2.03-2.56 in 2007; ARR 2.40, 95% CI 2.15-2.66 in 2008; ARR 2.86, 95% CI 2.60-3.20 in 2009). Recorded assessment of asthma severity was 31% to 47% more likely post-intervention (ARR 1.31, 95% CI 1.26-1.36 in 2007, ARR 1.44 95% CI 1.38-1.50 in 2008, ARR 1.47 95% 1.41-1.54 in 2009). Controller medication prescribing increased postintervention ARR 1.08, 95% CI, 1.02-1.14 in 2007; ARR 1.11, 95% CI, 1.04-1.17 in 2008; ARR 1.11, 95% CI, 1.05-1.19 in 2009. Emergency department visits and hospitalizations trended lower postintervention (not significant).

CONCLUSIONS

A quality improvement intervention in a hospital-based teaching clinic was associated with increased use of asthma action plans, classification of asthma severity, and controller medications, and possibly a trend toward fewer emergency visits and hospitalizations.

Cerebral blood flow and oxygenation at maximal exercise: the effect of clamping carbon dioxide

During exercise, as end-tidal carbon dioxide (P(ET)(CO₂)) drops after the respiratory compensation point (RCP), so does cerebral blood flow velocity (CBFv) and cerebral oxygenation. This low-flow, low-oxygenation state may limit work capacity. We hypothesized that by preventing the fall in P(ET)(CO₂) at peak work capacity (W(max)) with a newly designed high-flow, low-resistance rebreathing circuit, we would improve CBFv, cerebral oxygenation, and W(max). Ten cyclists performed two incremental exercise tests, one as control and one with P(ET)(CO₂) constant (clamped) after the RCP. We analyzed , middle cerebral artery CBFv, cerebral oxygenation, and cardiopulmonary measures. At W(max), when we clamped P(ET)(CO₂) (39.7 ± 5.2 mmHg vs. 29.6 ± 4.7 mmHg, P < 0.001), CBFv increased (92.6 ± 15.9 cm/s vs. 73.6 ± 12.5 cm/s, P < 0.001). However, cerebral oxygenation was unchanged (ΔTSI -21.3 ± 13.1% vs. -24.3 ± 8.1%, P = 0.33), and W(max) decreased (380.9 ± 20.4W vs. 405.7 ± 26.8 W, P < 0.001). At W(max), clamping P(ET)(CO₂) increases CBFv, but this does not appear to improve W(max).

Safety and tolerability of rivastigmine transdermal patch compared with rivastigmine capsules in patients switched from donepezil: data from three clinical trials

OBJECTIVES

To compare the safety and tolerability of switching patients with mild-to-moderate Alzheimer's disease from donepezil to either rivastigmine capsule or transdermal patch.

METHODS

Three studies investigated the switch from donepezil to rivastigmine; study US13 was a 26-week, single-arm, immediate-switch study; US18 was a 26-week, sequential cohort study (both studies evaluated rivastigmine capsules 3-12 mg/day); study US38 was a 25-week, randomised, parallel-group, open-label study which investigated switch (immediate or after 7 days' withdrawal) from donepezil to rivastigmine transdermal patch (4.6 mg/24 hr). Safety outcomes included adverse events (AEs), discontinuations caused by AEs and serious AEs (SAEs).

RESULTS

Patient groups receiving rivastigmine patch (n = 261) or capsules (n = 331) had mean +/- SD ages of 77.3 +/- 8.0 and 78.1 +/- 7.8 years, dementia durations of 3.9 +/- 2.6 and 3.6 +/- 2.2 years and Mini-Mental State Examination scores of 18.3 +/- 4.00 and 17.9 +/- 4.4 respectively. Overall, 184 (70.5%) and 276 (83.4%) patients experienced at least one AE, and 23 (8.8%) and 55 (16.6%) patients experienced an SAE with the rivastigmine patch and capsules respectively. Of the patients who experienced an AE, 10 (3.8%) and 109 (32.9%) experienced nausea, and 11 (4.2%) and 80 (24.1%) experienced vomiting with the rivastigmine patch and capsules respectively. Discontinuations because of AEs occurred in 64 (19.3%) patients receiving capsules and 38 (14.6%) patients in the transdermal patch group. The most common reasons for discontinuation with the transdermal patch were application site reaction and disease progression, and nausea and vomiting with the capsules.

CONCLUSIONS

The rivastigmine transdermal patch appears to have better tolerability than rivastigmine capsules, with fewer gastrointestinal AEs and discontinuations because of these AEs. Simple daily rotation of patch location will likely reduce the frequency of skin reactions. This post hoc analysis was carried out by Novartis Pharmaceuticals Corporation. Data for the analysis were collected from the US13 study (CENA713B US13), the US18 study (CENA713B US18) and the US38 study (CENA713D US38).

National Institute of Mental Health Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE): Alzheimer disease trial methodology

The authors describe the development of the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) protocol for Alzheimer disease (AD), a trial developed in collaboration with the National Institute of Mental Health (NIMH), assessing the effectiveness of atypical antipsychotics for psychosis and agitation occurring in AD outpatients. They provide an overview of the methodology utilized in the trial as well as the clinical-outcomes and effectiveness measures that were implemented.

A pilot randomized trial of carbamazepine for behavioral symptoms in treatment-resistant outpatients with Alzheimer disease

The authors performed a 6-week, randomized, double-blind, placebo-controlled, parallel-group trial of carbamazepine (400 mg/day) with 21 agitated subjects (16 completers) who had been treated unsuccessfully with antipsychotics. There was greater improvement for the carbamazepine group on the Clinical Global Impression of Change (P=0.055) and the Brief Psychiatric Rating Scale (BPRS) Hostility item (P=0.009), with a trend toward worsening on the BPRS Hallucination item (P=0.067). Overall, carbamazepine showed modest clinical benefit in these subjects, who had not responded to antipsychotics, and particular benefit for hostility. The effect on global ratings was similar to those found in an earlier report in nursing home residents.

Can caregivers independently rate cognitive and behavioral symptoms in Alzheimer's disease patients?: A longitudinal analysis

To examine whether informant-based assessments of patients with Alzheimer's disease (AD) can be used longitudinally to track patient functioning, the authors followed AD patients (N=153) and their caregivers over 1 year with the Relative's Assessment of Global Symptomatology-Elderly (RAGS-E) and the Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADASc). Factor analysis of the RAGS-E yielded two subscales, Cognitive Functioning and Mood Disturbance. The cognitive subscale and ADASc correlated at all visits, whereas the mood subscale did not. After 12 months (n=62), the cognitive scale worsened at a rate similar to the ADASc, suggesting concurrent validity. Therefore, informant-based measures appear to be reliable and valid methods of identifying cognitive change in AD patients.

Severity of cognitive impairment in Alzheimer's disease affects list learning using the California Verbal Learning Test (CVLT)

Impairment in list learning is considered a primary symptom of Alzheimer's disease (AD), yet there are no published reports examining the relationship between list learning and severity of cognitive impairment. We gave nine-item and 16-item versions of the California Verbal Learning Test (CVLT; Delis et al., 1987), a standardized shopping list assessment of memory, to 24 AD patients (mean age = 76.2 +/- 8.1; mean years of education = 13.8 +/- 2.4), who were stratified into four groups based on MMSE scores (mean = 16.0 +/- 5.6). ANOVAs revealed severity effects for total list learning (p < 0.001), the first trial (p < 0.001), the last trial (p < 0.001) and short- and long-delay recall measures. Most of these differences seemed due to floor effects. For example, the modal number of words recalled after a delay was 0 by subjects with MMSE scores below 21. Severity of cognitive impairment was associated with the proportion of intrusions such that the most severely demented subjects gave almost entirely intrusion responses. Surprisingly, list length did not significantly affect any of the free recall measures. Our results suggest that list learning and recall seem to be lost relatively early in AD. Measures of list recall like the CVLT may not be useful in tracking severity of cognitive impairment over time.

Eligibility of Alzheimer's disease clinic patients for clinical trials

OBJECTIVES

To identify the percentage of patients with Alzheimer's disease (AD) in a general clinic population who would be provisionally eligible for randomized clinical trials and the extent to which these patients represent the overall clinic-based population.

BACKGROUND

Many randomized clinical trials have restricted enrollment criteria that may limit generalizability, i.e., AD patients who fulfill selection criteria for phase III clinical trials may not be representative of other AD patients in clinical settings.

DESIGN AND SETTING

Patients diagnosed as probable or possible AD from the nine clinical sites of the State of California's Alzheimer's Disease Diagnostic and Treatment Centers (ADDTC) were selected on the basis of their provisionally fulfilling the inclusion and exclusion criteria of two typical AD clinical trials at the time of their first visit (ECG and brain imaging criteria were not available).

RESULTS

From a sample of 3470 subjects with possible or probable AD, overall, only 4.4% or 7.9% would have been provisionally eligible for each of two trials. Patients provisionally eligible were younger, relatively underrepresented by women, better educated, wealthier, and more likely to be white than ineligible patients. The major independent demographic predictors for eligibility were (1) income greater than $15,000 per year, (2) male gender, and (3) college education. More than 60% of probable AD patients were excluded because of significant behavioral problems; approximately one-quarter each were excluded because of significant medical or neurological problems. Allowing patients with probable or possible AD to enroll would have resulted in 10.6% being eligible.

CONCLUSION

Selection criteria for AD clinical trials result in a demographically and clinically constrained subgroup that is not representative of the overall clinic population.

Validity and reliability of the Alzheimer's Disease Cooperative Study-Clinical Global Impression of Change. The Alzheimer's Disease Cooperative Study

This article reports the development and psychometric properties of the Alzheimer's Disease Cooperative Study-Clinical Global Impression of Change (ADCS-CGIC). At present, a number of unvalidated CGIC scales are used in clinical trials, with various methods for making ratings. The ADCS-CGIC was designed on the basis of a survey of ADCS clinicians and by adapting existing instruments. It includes an organized but unstructured format, with which a clinician can address clinically relevant change. The instrument's reliability and validity were assessed in a prospective trial of Alzheimer's disease (AD) and healthy subjects over a 12-month period. It showed good short-term reliability at 1 and 2 months, with 90 and 94% of AD subjects, respectively, rated as having changed not at all or only minimally. The ADCS-CGIC's face validity was demonstrated by untreated. AD subjects rated as having worsened over time at both 6 months (56% rated as having worsened) and 12 months (81% rated as having worsened), whereas only 2% of control subjects showed minimal worsening. As a measure of predictive validity, ADCS-CGIC ratings at 12 months were significantly associated with change on four severity scales. As with other measures, change ratings were sensitive to dementia severity. Moderately impaired subjects showed greater worsening than other subjects. ADCS-CGIC ratings of greater worsening were made after the informant interview, regardless of whether informants or subjects were interviewed first. The ADCS-CGIC is a valid and reliable instrument for use in clinical trials.

Clinical evaluation of global change in Alzheimer's disease: identifying consensus

It is important that clinicians who rate global change as part of Alzheimer's disease (AD) clinical drug trials agree on a relevant set of behaviors and information to be considered in formulating their rating. Yet, consensus among raters has been difficult to establish, and inter-rater reliability of clinical global impression of change (CGIC) ratings has been low. In preparation for the development of a new CGIC scale to be used in AD clinical trials, the Alzheimer's Disease Cooperative Study-Clinical Global Impression of Change (ADCS-CGIC), we surveyed clinicians at sites comprising the National Institute on Aging-sponsored ADCS participating centers to identify whether or not consensus regarding CGICs exists. Overall, respondents reported that a CGIC should include an assessment of the patient's function and mental status, a care giver interview, and a standardized set of questions, and it should take approximately 20 minutes per interview. Depending on a patient's level of impairment, raters consider different areas of behavior in formulating a CGIC rating. These findings demonstrate the considerable consensus regarding the CGIC rating process, and were integrated into the design of the ADCS-CGIC, currently in use.

Clinical global impressions in Alzheimer's clinical trials

This article reviews the history of Clinical Global Impressions of Change (CGIC) instruments, their use and limitations in clinical trials of Alzheimer's disease, and the development of the National Institute on Aging's Alzheimer's Disease Cooperative Study-Clinical Global Impression of Change Scale (ADCS-CGIC). Originally, CGICs were simple and unstructured instruments that asked a clinician to rate change over the duration of a clinical trial. The method, however, failed to consistently detect treatment effects, leading to the development of more structured and subsequently validated approaches, such as the Clinician Interview-Based Impression Scale (CIBI) and the ADCS-CGIC. Both are currently used in clinical trials. The implications and importance of choosing an appropriate global rating are discussed.

Efficacy of acute treatment for geriatric depression

The antidepressant literature for depression in late life tends to be interpreted as saying that certain antidepressant medications--e.g, nortriptyline, doxepin, fluoxetine--have fewer and milder side effects than others, whereas overall efficacy is equivalent (Plotkin et al., 1987; Rush, 1993; Salzman et al., 1995; Schneider, 1994). Further examination of this literature, however, suggests that both efficacy and side effect rates for any particular medication vary among trials, and often depend on the medications being compared, the use of placebo, the dose, and the design of the trial. In this report we review selected clinical trials, and summarize and discuss a previously published meta-analysis. Treatment recommendations from the 1991 NIH Consensus Development Conference on the Diagnosis and Treatment of Depression in Late Life and from the Agency for Health Care Policy Research are discussed. Directions for future research are suggested. Both antidepressant medications and brief structured psychotherapies have efficacy in the acute treatment of elderly depressed outpatients with major unipolar, nondelusional depression. Effective treatment for depression involves consideration of the type and severity of illness, adequate prescribing, patient education, and regular patient monitoring for compliance, symptom change, side effects, and intercurrent medical disorders, which may complicate antidepressant therapy.

Overview of clinical trials of hydergine in dementia

OBJECTIVE

To assess the overall effect of Hydergine (a combination drug called ergoloid mesylates) on patients with possible dementia and to investigate potential moderators of an effect.

DATA SOURCES

MEDLINE, EMBASE, and two proprietary databases were searched for reports of clinical trials.

STUDY SELECTION

Included were randomized, placebo-controlled, double-blind, parallel-group trials in subjects with symptoms consistent with dementia performed with specified outcome instruments and sufficient statistical information to calculate effect sizes. Forty-seven (31%) of 151 trials reviewed met selection criteria.

DATA EXTRACTION

Potential moderating variables were extracted from each trial: sample size, inpatient-outpatient status, trial duration, age, gender, medication dose, publication year, and diagnostic grouping. Outcome measures were extracted with their associated statistics.

DATA SYNTHESIS

The overall combined treatment effects ("adjusted d") for three types of outcome measures were calculated. Overall, Hydergine was more effective than placebo as assessed by comprehensive ratings (d = 0.47; 95% confidence interval [CI], 0.38 to 0.56; P = .0001), clinical global ratings (d = 0.56; 95% CI, 0.44 to 0.68; P = .0001), and combined neuropsychological measures (d = 0.27; 95% CI, 0.22 to 0.32; P = .0001). Inpatient status, daily doses of 4 mg or more, and vascular dementia were generally associated with larger effects. The effect in patients with possible Alzheimer's dementia was significant only for combined neuropsychological measures in five trials (d = 0.30; 95% CI, 0.16 to 0.44; P = .0001; and with a dose-response, P = .001).

CONCLUSIONS

Overall, ergoloid mesylates were more effective than placebo. However, the effect in patients with possible Alzheimer's dementia was very modest at best. The dose-response relation suggests that potentially effective doses may be higher than the currently approved. The circumstances of the efficacy of Hydergine remain inadequately defined.

A double-blind crossover pilot study of l-deprenyl (selegiline) combined with cholinesterase inhibitor in Alzheimer's disease

The potential efficacy of oral l-deprenyl (5 mg b.i.d.) added to the regimen of 10 patients with Alzheimer's disease receiving either tacrine or physostigmine was assessed in a double-blind, placebo-controlled, 4-week, two-period crossover pilot study. l-Deprenyl was associated with significant improvement in scores on the cognitive subscale of the Alzheimer's Disease Assessment Scale, suggesting possible additive effects of l-deprenyl to the effects of cholinesterase inhibitors.