The Impact of Changing Step 1 to Pass/Fail Reporting on Anxiety, Learning Approaches, and Curiosity.

Purpose: Given the significance of the US Medical Licensing Exam (USMLE) Step 1 score moving from a 3-digit value to pass/fail, the authors investigated the impact of the change on students' anxiety, approach to learning, and curiosity. Method: Two cohorts of pre-clerkship medical students at three medical schools completed a composite of four instruments: the State-Trait Anxiety Inventory, the revised two-factor Study Process Questionnaire, the Interest/Deprivation Type Epistemic Curiosity Scale, and the Short Grit Scale prior to taking the last 3-digit scored Step 1 in 2021 or taking the first pass/fail scored Step 1 in 2022. Responses of 3-digit and pass/fail exam takers were compared (Mann-Whitney U) and multiple regression path analysis was performed to determine the factors that significantly impacted learning strategies. Results: There was no difference between 3-digit (n = 86) and pass/fail exam takers (n = 154) in anxiety (STA-I scores, 50 vs. 49, p = 0.85), shallow learning strategies (22 vs. 23, p = 0.84), or interest curiosity scores (median scores 15 vs. 15, p = 0.07). However, pass/fail exam takers had lower deprivation curiosity scores (median 12 vs. 11, p = 0.03) and showed a decline in deep learning strategies (30 vs. 27, p = 0.0012). Path analysis indicated the decline in deep learning strategies was due to the change in exam scoring (ß = - 2.0428, p < 0.05). Conclusions: Counter to the stated hypothesis and intentions, the initial impact of the change to pass/fail grading for USMLE Step 1 failed to reduce learner anxiety, and reduced curiosity and deep learning strategies. Supplementary Information: The online version contains supplementary material available at 10.1007/s40670-023-01878-w.

An integrated pre-clerkship curriculum to build cognitive medical schema: It's not just about the content.

Both physiology and pathophysiology are essential disciplines in health professional education however, clinicians do not use this knowledge in isolation. Instead, physicians use inter-disciplinary concepts embedded within integrated cognitive schema (illness scripts) established through experience/knowledge that manifest as expert-level thinking. Our goal was to develop a pre-clerkship curriculum devoid of disciplinary boundaries (akin to the physician's illness script) and enhance learners' clerkship and early clinical performance. As well as developing curricular content, the model considered non-content design elements such as learner characteristics and values, faculty and resources and the impact of curricular and pedagogical changes. The goals of the trans-disciplinary integration were to develop deep learning behaviors through, 1) developing of integrated, cognitive schema to support the transition to expert-level thinking, 2) authentic, contextualization to promote knowledge transfer to the clinical realm 3) allowing autonomous, independent learning, and 4) harnessing the benefits of social learning. The final curricular model was a case-based approach with independent learning of basic concepts, differential diagnosis and illness scripting writing, and concept mapping. Small-group classroom sessions were team-taught with basic scientists and physicians facilitating learners' self-reflection and development of clinical reasoning. Specifications grading was used to assess the products (written illness scripts and concept maps) as well as process (group dynamics) while allowing a greater degree of learner autonomy. Although the model we adopted could be transferred to other program settings, we suggest it is critical to consider both content and non-content elements that are specific to the environment and learner.

A Simple and Sustainable Exercise to Enhance Student Self-Reflection on Error-Making, Focus Support, and Guide Curricular Design.

Problem: Self-reflection is a critical component of professional development and clinical practice, but medical students' ability to self-reflect is typically limited. While inadequate self-reflection impacts future clinical decision-making, it may also adversely impact current learning through an inability to identify learning-behavior deficits. This may be exacerbated by common use of multiple-choice questions (MCQ) where incorrect responses provide less insight than other measures for students, faculty, or academic support. To address this, an Error Reflection Method (ERM) was developed to help students focus on 'why' they got an MCQ wrong rather than 'what' they got wrong, thereby promoting self-reflection and a learning-focus on assessment. Understanding students' learning-behavior deficits could also enrich engagement with academic support services and guide curricular design. Intervention: The ERM is a list of 10 common types of exam errors that were either 'test-taking' (unwitting) errors or 'learning-behavior' errors that reflected learning deficits. The ERM is simple, transferable, and sustainable, allowing longitudinal and regular monitoring of individual and collective error-making to focus support and guide curricular development. Context: Undergraduate medical students at the Virginia Tech Carilion School of Medicine, USA, used the ERM in formative assessment review sessions in pre-clinical years to select an error type that best described the cause of each incorrect response. Impact: Initial findings suggest the ERM is robust and associated with improved student performance and curricular development. Analysis of 3,775 student-identified errors showed the error types in the ERM described 96% of errors students made. Learning-behavior errors were more common (76%), but surprisingly, 19% were test-taking errors, allowing academic support to focus on test-taking skills in a population previously thought of as consummate test-takers. The most common error type reported was 'the content looked familiar but I couldn't answer the question' (32%); which we suggest is consistent with shallow learning. This finding has helped steer recent curricular development toward active and applied learning techniques. Lessons Learned: By formally and regularly identifying learning deficits, students may be more capable of addressing them and improve summative exam performance. As well as focusing academic support, understanding common student errors has been useful in guiding curricular design and content delivery. Further potential of the ERM may be realized in faculty development and directing assessment culture toward a learning focus.

Dyspnea.

The clinical term dyspnea (a.k.a. breathlessness or shortness of breath) encompasses at least three qualitatively distinct sensations that warn of threats to breathing: air hunger, effort to breathe, and chest tightness. Air hunger is a primal homeostatic warning signal of insufficient alveolar ventilation that can produce fear and anxiety and severely impacts the lives of patients with cardiopulmonary, neuromuscular, psychological, and end-stage disease. The sense of effort to breathe informs of increased respiratory muscle activity and warns of potential impediments to breathing. Most frequently associated with bronchoconstriction, chest tightness may warn of airway inflammation and constriction through activation of airway sensory nerves. This chapter reviews human and functional brain imaging studies with comparison to pertinent neurorespiratory studies in animals to propose the interoceptive networks underlying each sensation. The neural origins of their distinct sensory and affective dimensions are discussed, and areas for future research are proposed. Despite dyspnea's clinical prevalence and impact, management of dyspnea languishes decades behind the treatment of pain. The neurophysiological bases of current therapeutic approaches are reviewed; however, a better understanding of the neural mechanisms of dyspnea may lead to development of novel therapies and improved patient care.

Changing Medical Education, Overnight: The Curricular Response to COVID-19 of Nine Medical Schools.

Issue: Calls to change medical education have been frequent, persistent, and generally limited to alterations in content or structural re-organization. Self-imposed barriers have prevented adoption of more radical pedagogical approaches, so recent predictions of the 'inevitability' of medical education transitioning to online delivery seemed unlikely. Then in March 2020 the COVID-19 pandemic forced medical schools to overcome established barriers overnight and make the most rapid curricular shift in medical education's history. We share the collated reports of nine medical schools and postulate how recent responses may influence future medical education. Evidence: While extraneous pandemic-related factors make it impossible to scientifically distinguish the impact of the curricular changes, some themes emerged. The rapid transition to online delivery was made possible by all schools having learning management systems and key electronic resources already blended into their curricula; we were closer to online delivery than anticipated. Student engagement with online delivery varied with different pedagogies used and the importance of social learning and interaction along with autonomy in learning were apparent. These are factors known to enhance online learning, and the student-centered modalities (e.g. problem-based learning) that included them appeared to be more engaging. Assumptions that the new online environment would be easily adopted and embraced by 'technophilic' students did not always hold true. Achieving true distance medical education will take longer than this 'overnight' response, but adhering to best practices for online education may open a new realm of possibilities. Implications: While this experience did not confirm that online medical education is really 'inevitable,' it revealed that it is possible. Thoughtfully blending more online components into a medical curriculum will allow us to take advantage of this environment's strengths such as efficiency and the ability to support asynchronous and autonomous learning that engage and foster intrinsic learning in our students. While maintaining aspects of social interaction, online learning could enhance pre-clinical medical education by allowing integration and collaboration among classes of medical students, other health professionals, and even between medical schools. What remains to be seen is whether COVID-19 provided the experience, vision and courage for medical education to change, or whether the old barriers will rise again when the pandemic is over.

Air Hunger: A Primal Sensation and a Primary Element of Dyspnea.

The sensation that develops as a long breath hold continues is what this article is about. We term this sensation of an urge to breathe "air hunger." Air hunger, a primal sensation, alerts us to a failure to meet an urgent homeostatic need maintaining gas exchange. Anxiety, frustration, and fear evoked by air hunger motivate behavioral actions to address the failure. The unpleasantness and emotional consequences of air hunger make it the most debilitating component of clinical dyspnea, a symptom associated with respiratory, cardiovascular, and metabolic diseases. In most clinical populations studied, air hunger is the predominant form of dyspnea (colloquially, shortness of breath). Most experimental subjects can reliably quantify air hunger using rating scales, that is, there is a consistent relationship between stimulus and rating. Stimuli that increase air hunger include hypercapnia, hypoxia, exercise, and acidosis; tidal expansion of the lungs reduces air hunger. Thus, the defining experimental paradigm to evoke air hunger is to elevate the drive to breathe while mechanically restricting ventilation. Functional brain imaging studies have shown that air hunger activates the insular cortex (an integration center for perceptions related to homeostasis, including pain, food hunger, and thirst), as well as limbic structures involved with anxiety and fear. Although much has been learned about air hunger in the past few decades, much remains to be discovered, such as an accepted method to quantify air hunger in nonhuman animals, fundamental questions about neural mechanisms, and adequate and safe methods to mitigate air hunger in clinical situations. © 2021 American Physiological Society. Compr Physiol 11:1449-1483, 2021.

Using Near-Peer Teaching to Address Concepts of Cystic Fibrosis in Undergraduate Medical Learners.

Introduction: Cystic fibrosis (CF) is a high-yield undergraduate medical education topic that lends itself to adaptability of content. We used a CF case paired with activities to deliver content in a near-peer teaching session. First-year (M1) and second-year (M2) medical students contributed acquired knowledge of protein structure and obstructive lung disease, respectively, to generate a concept map and address discussion questions. Methods: Combined groups of M1 and M2 students reviewed a CF case and a concept map prompt. For 30 minutes, they created a concept map describing connections between molecular biology and clinical manifestations. We summarized by reviewing concept maps and discussion questions. The efficacy of the session was determined by comparing exam performance of class attenders and nonattenders (M2) and performance on questions related and unrelated to the exercise (M1). We also determined students' perception of the session and incorporation of additional core competencies. Results: M2 students' performance was 3.8% higher (p = .296) and M1 students' performance was 1.8% higher (p = .286) than their respective controls. Students commented positively on the exercise and perceived more than one core competency as part of the session. Discussion: Although there was no significant improvement in exam performance, this curriculum used near-peer teaching to reinforce previously learned material and apply recently acquired material in an engaging format without detriment to either group. This method can be adapted to different learner groups and provides an opportunity to deliver and assess other core medical competencies.

Integrating Acid-Base and Metabolic Lab Panels Across Systems in an M1 Classroom Activity.

Introduction: It is important to deliver acid-base balance concepts in the context of multiple physiological systems and metabolic processes that influence acid-base homeostasis. This activity combines the interactions of the respiratory, gastrointestinal, and renal systems in conjunction with basic metabolism to generate an integrated activity for first-year medical students. Methods: We developed four concise case scenarios around various presentations of acid-base disturbance along with five sets of arterial blood gases (ABGs) and five different metabolic lab panels. M1 students were given class time to match the three different types of data in order to address how the underlying biochemistry and physiology of a scenario translated into ABG and metabolic laboratory values. Results: Although not statistically significant, the students' performance on acid-base questions was marginally higher than on standardized National Board of Medical Examiners questions on other topics covered in the same exam, and the improvement over national average scores on the same questions increased. Student evaluation of the activity was positive, with general appreciation of its application and integration of concepts. Discussion: The incorporation of this activity into the M1 year was positively received and enhanced integration of content related to acid-base balance. The activity is flexible and can be adapted to most any curricular structure, with the potential to include additional content depending on the level of the learner.

Electromagnetic Navigational Bronchoscopy Reduces the Time Required for Localization and Resection of Lung Nodules.

OBJECTIVE: The aims of the study were to evaluate electromagnetic navigational bronchoscopy (ENB) and computed tomography-guided placement as localization techniques for minimally invasive resection of small pulmonary nodules and determine whether electromagnetic navigational bronchoscopy is a safer and more effective method than computed tomography-guided localization. METHODS: We performed a retrospective review of our thoracic surgery database to identify patients who underwent minimally invasive resection for a pulmonary mass and used either electromagnetic navigational bronchoscopy or computed tomography-guided localization techniques between July 2011 and May 2015. RESULTS: Three hundred eighty-three patients had a minimally invasive resection during our study period, 117 of whom underwent electromagnetic navigational bronchoscopy or computed tomography localization (electromagnetic navigational bronchoscopy = 81; computed tomography = 36). There was no significant difference between computed tomography and electromagnetic navigational bronchoscopy patient groups with regard to age, sex, race, pathology, nodule size, or location. Both computed tomography and electromagnetic navigational bronchoscopy were 100% successful at localizing the mass, and there was no difference in the type of definitive surgical resection (wedge, segmentectomy, or lobectomy) (P = 0.320). Postoperative complications occurred in 36% of all patients, but there were no complications related to the localization procedures. In terms of localization time and surgical time, there was no difference between groups. However, the down/wait time between localization and resection was significant (computed tomography = 189 minutes; electromagnetic navigational bronchoscopy = 27 minutes); this explains why the difference in total time (sum of localization, down, and surgery) was significant (P < 0.001). CONCLUSIONS: We found electromagnetic navigational bronchoscopy to be as safe and effective as computed tomography-guided wire placement and to provide a significantly decreased down time between localization and surgical resection.

Cthrc1 lowers pulmonary collagen associated with bleomycin-induced fibrosis and protects lung function.

Idiopathic pulmonary fibrosis (IPF) involves collagen deposition that results in a progressive decline in lung function. This process involves activation of Smad2/3 by transforming growth factor (TGF)-ß and Wnt signaling pathways. Collagen Triple Helix Repeat-Containing-1 (Cthrc1) protein inhibits Smad2/3 activation. To test the hypothesis that Cthrc1 limits collagen deposition and the decline of lung function, Cthrc1 knockout (Cthrc1-/-) and wild-type mice (WT) received intratracheal injections of 2.5 U/kg bleomycin or saline. Lungs were harvested after 14 days and Bronchoalveolar lavage (BAL) TGF-ß, IL1-ß, hydroxyproline and lung compliance were assessed. TGF-ß was significantly higher in Cthrc1-/- compared to WT (53.45 ± 6.15 ng/mL vs. 34.48 ± 11.05) after saline injection. Bleomycin injection increased TGF-ß in both Cthrc1-/- (66.37 ± 8.54 ng/mL) and WT (63.64 ± 8.09 ng/mL). Hydroxyproline was significantly higher in Cthrc1-/- compared to WT after bleomycin-injection (2.676 ± 0.527 µg/mg vs. 1.889 ± 0.520, P = 0.028). Immunohistochemistry of Cthrc1-/- lung sections showed intracellular localization and activation of ß-catenin Y654 in areas of tissue remodeling that was not evident in WT Lung compliance was significantly reduced by bleomycin in Cthrc1-/- but there was no effect in WT animals. These data suggest Cthrc1 reduces fibrotic tissue formation in bleomycin-induced lung fibrosis and the effect is potent enough to limit the decline in lung function. We conclude that Cthrc1 plays a protective role, limiting collagen deposition and could form the basis of a novel therapy for pulmonary fibrosis.

ICU Clinicians Underestimate Breathing Discomfort in Ventilated Subjects.

BACKGROUND: Breathing discomfort (dyspnea) during mechanical ventilation in the ICU may contribute to patient distress and complicate care. Assessment of nonverbal cues may allow caregivers to estimate patient breathing discomfort. This study assesses the accuracy of those caregiver estimates. METHODS: Thirty subjects were identified from ventilated, hemodynamically stable patients in the special care unit of Maine Medical Center. Those with impaired neurological function or too unstable to waken were excluded. Subjects provided a subjective score of breathing discomfort (0-10 using a modified Borg scale) during daily wake-up from sedation (sedation-agitation score of 3 or 4). Clinicians (physicians, respiratory therapists, and nurses) then provided a blinded estimate of subject breathing discomfort (0-10) through observation of the subject and inspection of ventilator parameters alone. Subject scores and caregiver estimates were compared. RESULTS: All subjects reported breathing discomfort with median score (interquartile range) of 4 (3-4). Caregiver estimates of breathing discomfort were significantly lower than subject scores (2 [0-3]), and the discrepancy was seen in all professions (physicians 1 point lower [0-2], P = .02; respiratory therapists 1 point lower [0-2], P = .01; nurses 2 points lower [1-3], P < .001). There was a positive correlation between subject breathing discomfort and degree of underestimation (ie, the degree of underestimation increased as the subject scores rose). The 3 most commonly used cues were subjects' facial expression, use of accessory muscles, and nasal flaring. CONCLUSIONS: Significant breathing discomfort is prevalent in mechanically ventilated ICU patients and is underestimated by caregivers, regardless of profession. The increasing disparity in caregiver estimate as breathing discomfort rises may expose patients to levels of dyspnea that promote anxiety and fear. This study demonstrates the need for further development and standardization of methods to assess dyspnea in nonverbal patients.

The time-course of cortico-limbic neural responses to air hunger.

Several studies have mapped brain regions associated with acute dyspnea perception. However, the time-course of brain activity during sustained dyspnea is unknown. Our objective was to determine the time-course of neural activity when dyspnea is sustained. Eight healthy subjects underwent brain blood oxygen level dependent functional magnetic imaging (BOLD-fMRI) during mechanical ventilation with constant mild hypercapnia (∼ 45 mm Hg). Subjects rated dyspnea (air hunger) via visual analog scale (VAS). Tidal volume (V(T)) was alternated every 90 s between high VT (0.96 ± 0.23 L) that provided respiratory comfort (12 ± 6% full scale) and low V(T) (0.48 ± 0.08 L) which evoked air hunger (56 ± 11% full scale). BOLD signal was extracted from a priori brain regions and combined with VAS data to determine air hunger related neural time-course. Air hunger onset was associated with BOLD signal increases that followed two distinct temporal profiles within sub-regions of the anterior insula, anterior cingulate and prefrontal cortices (cortico-limbic circuitry): (1) fast, BOLD signal peak <30s and (2) slow, BOLD signal peak >40s. BOLD signal during air hunger offset followed fast and slow temporal profiles symmetrical, but inverse (signal decreases) to the time-courses of air hunger onset. We conclude that differential cortico-limbic circuit elements have unique contributions to dyspnea sensation over time. We suggest that previously unidentified sub-regions are responsible for either the acute awareness or maintenance of dyspnea. These data enhance interpretation of previous studies and inform hypotheses for future dyspnea research.

Gray matter blood flow change is unevenly distributed during moderate isocapnic hypoxia in humans.

Hypoxia increases cerebral blood flow (CBF), but it is unknown whether this increase is uniform across all brain regions. We used H(2)(15)O positron emission tomography imaging to measure absolute blood flow in 50 regions of interest across the human brain (n = 5) during normoxia and moderate hypoxia. Pco(2) was kept constant ( approximately 44 Torr) throughout the study to avoid decreases in CBF associated with the hypocapnia that normally occurs with hypoxia. Breathing was controlled by mechanical ventilation. During hypoxia (inspired Po(2) = 70 Torr), mean end-tidal Po(2) fell to 45 +/- 6.3 Torr (means +/- SD). Mean global CBF increased from normoxic levels of 0.39 +/- 0.13 to 0.45 +/- 0.13 ml/g during hypoxia. Increases in regional CBF were not uniform and ranged from 9.9 +/- 8.6% in the occipital lobe to 28.9 +/- 10.3% in the nucleus accumbens. Regions of interest that were better perfused during normoxia generally showed a greater regional CBF response. Phylogenetically older regions of the brain tended to show larger vascular responses to hypoxia than evolutionary younger regions, e.g., the putamen, brain stem, thalamus, caudate nucleus, nucleus accumbens, and pallidum received greater than average increases in blood flow, while cortical regions generally received below average increases. The heterogeneous blood flow distribution during hypoxia may serve to protect regions of the brain with essential homeostatic roles. This may be relevant to conditions such as altitude, breath-hold diving, and obstructive sleep apnea, and may have implications for functional brain imaging studies that involve hypoxia.

The air hunger response of four elite breath-hold divers.

Normal subjects terminate breath-holds due to intolerable 'air hunger'. We hypothesize that competitive breath-hold divers might have increased tolerance of air hunger. We tested the air hunger (AH) response of four divers who could hold their breath for 6-9 min. Tidal volume and respiratory rate were controlled by mechanical ventilation (ventilation approximately 0.16 L min(-1) kg(-1)). AH was induced by raising PCO2 and rated using a visual analog scale whose maximum was defined as intolerable. SpO2 was maintained at >97%. Three divers reported the same uncomfortable urge to breathe as normal subjects; the slopes of their responses were within normal range. Both resting CO2 and AH threshold were shifted to higher CO2 in some divers. Diver 3 was unique amongst neurologically intact subjects we have studied: he denied feeling an urge to breathe, and denied discomfort. We conclude that elite divers' strategies to tolerate intense air hunger are a minor factor in their ability to tolerate long breath-holds.

An inexpensive, MRI compatible device to measure tidal volume from chest-wall circumference.

Mouthpieces and masks change breathing, and distract the subject. Accepted non-invasive methods avoid this problem, inductive plethysmographs and respiratory magnetometers, but are expensive and unusable in magnetic resonance imaging (MRI) scanners. Because changes in ventilation affect arterial gases, and thus cerebral blood flow, measurement of breathing is desirable during many functional MRI studies. Using an old principle, we constructed an inexpensive, non-invasive device unaffected by magnetic fields. We adapted a simple calibration method to reduce error and make the method accessible to more users. 'Pneumobelts' consist of flexible corrugated silicon tubes worn around the rib cage (RC) and the abdomen (AB). Changes in RC and AB are determined from pressure changes within the 'pneumobelts'. Estimates of tidal volume are generated from the sum of the RC and AB changes. We empirically determined the appropriate RC weighting as 1.3:1 (RC:AB). Volume estimation was tested (n = 9) in different body positions and during different breathing maneuvers. The weighted sum of the two signals gave an accurate estimate of tidal volume with tidal volumes less than 1200 ml (mean error = 6-7%). Breaths over 1900 ml produced larger errors (mean error = 11-16%). Our results are generalizable to any linear circumference measuring device.

Effect of inhaled furosemide on air hunger induced in healthy humans.

Recent evidence suggests that inhaled furosemide relieves dyspnoea in patients and in normal subjects made dyspnoeic by external resistive loads combined with added dead-space. Furosemide sensitizes lung inflation receptors in rats, and lung inflation reduces air hunger in humans. We therefore hypothesised that inhaled furosemide acts on the air hunger component of dyspnoea. Ten subjects inhaled aerosolized furosemide (40 mg) or placebo in randomised, double blind, crossover experiments. Air hunger was induced by hypercapnia (50+/-2 mmHg) during constrained ventilation (8+/-0.9 L/min) before and after treatment, and rated by subjects using a 100 mm visual analogue scale. Subjects described a sensation of air hunger with little or no work/effort of breathing. Hypercapnia generated less air hunger in the first trial at 23+/-3 min after start of furosemide treatment (58+/-11% to 39+/-14% full scale); the effect varied substantially among subjects. The mean treatment effect, accounting for placebo, was 13% of full scale (P=0.052). We conclude that 40 mg of inhaled furosemide partially relieves air hunger within 1h and is accompanied by substantial diuresis.

"Tightness" sensation of asthma does not arise from the work of breathing.

Asthma evokes several uncomfortable sensations including increased "effort to breathe" and chest "tightness." We have tested the hypotheses that "effort" and "tightness" are due to perception of increased work performed by the respiratory muscles. Bronchoconstriction was induced by inhaled methacholine in 15 subjects with mild asthma (FEV(1)/FVC baseline = 81.9% +/- 5.8; bronchoconstriction = 64.0% +/- 8.6). To relieve the work of breathing, and thereby minimize activation of respiratory muscle afferents and motor command, subjects were mechanically ventilated. Subjects separately rated effort to breathe and tightness during mechanical ventilation and during spontaneous breathing. Bronchoconstriction produced elevated end-expiratory lung volume (279 +/- 62 ml); in a control study, end-expiratory lung volume was increased equally in the absence of bronchoconstriction by increasing end-expiratory pressure. During bronchoconstriction, ratings of effort were greater during spontaneous breathing than during mechanical ventilation (p < 0.05). Ratings of tightness were unchanged by the absence of respiratory muscle activity (p = 0.12). Hyperinflation alone did not produce tightness or effort. We conclude that tightness is not related to the increase in respiratory work during bronchoconstriction.