Breathe | June 2016 | Volume 12 | No 2
Common causes of dyspnoea in athletes: a practical approach for diagnosis and management
James M. Smoliga , Zahra S. Mohseni, Jeffrey D. Berwager, Eric J. Hegedus
Dyspnoea during exercise is a common chief complaint in athletes and active individuals. It is not uncommon for dyspneic athletes to be diagnosed with asthma, “exercise-induced asthma” or exercise-induced bronchoconstriction based on their symptoms, but this strategy regularly leads to misdiagnosis and improper patient management. Dyspnoea during exercise can ultimately be caused by numerous respiratory and nonrespiratory conditions, ranging from nonpathological to potentially fatal in severity. As, such it is important for healthcare providers to be familiar with the many factors that can cause dyspnoea during exercise in seemingly otherwise-healthy individuals and have a general understanding of the clinical approach to this patient population. This article reviews common conditions that ultimately cause athletes to report dyspnoea and associated symptoms, and provides insight for developing an efficient diagnostic plan.
Common causes of dyspnoea in athletes: a practical approach for diagnosis and management
James M. Smoliga , Zahra S. Mohseni, Jeffrey D. Berwager, Eric J. Hegedus
Dyspnoea during exercise is a common chief complaint in athletes and active individuals. It is not uncommon for dyspneic athletes to be diagnosed with asthma, “exercise-induced asthma” or exercise-induced bronchoconstriction based on their symptoms, but this strategy regularly leads to misdiagnosis and improper patient management. Dyspnoea during exercise can ultimately be caused by numerous respiratory and nonrespiratory conditions, ranging from nonpathological to potentially fatal in severity. As, such it is important for healthcare providers to be familiar with the many factors that can cause dyspnoea during exercise in seemingly otherwise-healthy individuals and have a general understanding of the clinical approach to this patient population. This article reviews common conditions that ultimately cause athletes to report dyspnoea and associated symptoms, and provides insight for developing an efficient diagnostic plan.
Epidemiology and misdiagnosis EIB is commonly diagnosed in active individuals who report symptoms of dyspnoea, fatigue or inferior performance during exercise. EIB occurs across ages and fitness levels. The prevalence is reported prevalence ranges from ∼10 to >50% or greater in competitive athletes. Guidelines for diagnosis and management of asthma and EIB are well established. However, asthma and EIB are frequently misdiagnosed in clinical practice, in part because diagnosis is typically made based on symptoms alone
(as in the previous examples), rather than strictly adhering to proper diagnostic algorithms. The signs and symptoms of EIB are very nonspecific and therefore have poor clinical diagnostic value. Inappropriate diagnosis and management of EIB can lead to continuation or progression of symptoms, which may lead to impaired performance, discontinuation of sport or in extreme cases, sudden death. Case reports abound in which a serious condition was initially missed due to a misdiagnosis of EIB. A recent multicenter study found that adherence to asthma guidelines was quite poor for children and adults in primary care centers throughout the USA
A couple examples of history questions and their purpose are:
Do you ever feel lightheaded or dizzy while experiencing these symptoms?
These symptoms suggests the individual may be developing hypoxaemia (e.g. inadequate alveolar gas exchange) or inadequate blood flow to the brain during exercise (e.g. inadequate blood pressure or vertebrobasilar artery insufficiency)
Aside from your respiratory symptoms, have you been feeling unusually tired or exhausted when you are not exercising?
Overtraining syndrome and infectious disease (e.g. Lyme disease, mononucleosis or influenza) are common and may contribute to general fatigue, malaise and unusual soreness Emotional illness (e.g. clinical depression) may also be considered Less common conditions that influence metabolic dysfunction (e.g. mitochondrial myopathy) may also be considered
Do you have unusual muscle or joint pain, beyond what you would normally expect from exercise? Exercise-specific symptoms How long have you been doing the type of exercise in which you experience these symptoms?
It is important to understand the individual’s reference point for the dyspnoeic symptoms reported; for instance, an individual with a long history of recreational running is likely to be familiar with their ventilatory response during running, whereas they may feel unusually out of breath in unaccustomed forms exercise with different neuromuscular demands (e.g. swimming) or intensity (e.g. sprint-interval sports like soccer
EUROPEAN CLINICAL RESPIRATORY JOURNAL
REVIEW ARTICLE Exercise and asthma: an overview
Stefano R. Del Giacco, Davide Firinu, Leif Bjerme, Kai-Ha ˚kon, M. Aresu
The terms ‘exercise-induced asthma’ (EIA) and ‘exercise-induced bronchoconstriction’ (EIB) are often used interchangeably to describe symptoms of asthma such as cough, wheeze, or dyspnoea provoked by vigorous physical activity. In this review, we refer to EIB as the broncho constrictive response and to EIA when bronchoconstriction is associated with asthma symptoms. EIB is a common occurrence for most of the asthmatic patients, but it also affects more than 10% of otherwise healthy individuals as shown by epidemiological studies. EIA and EIB have a high prevalence also in elite athletes, especially within endurance type of sports, and an athlete’s asthma phenotype has been described. However, the occurrence in elite athletes shows that EIA/EIB, if correctly managed, may not impair physical activity and tops ports performance. The pathogenic mechanisms of EIA/EIB classically involve both osmolar and vascular changes in the airways in addition to cooling of the airways with parasympathetic stimulation. Airways inflammation plays a fundamental role in EIA/EIB. Diagnosis and pharmacological management must be carefully performed, with particular consideration of current anti-doping regulations, when caring for athletes. Based on the demonstration that the inhaled asthma drugs do not improve performance in healthy athletes, the doping regulations are presently much less strictthanpreviously. Somesportsareatahigherasthmari skthanothers, probablyduetoahighenvironmenta l exposure while performing the sport, with swimming and chlorine exposure during swimming as one example. It is considered very important for the asthmatic child and adolescent to master EIA/EIB to be able to participate in physical activity on an equal level with their peers, and a precise early diagnosis with optimal treatment follow-up is vital in this aspect. In addition, surprising recent preliminary evidences offer new perspectives for moderate exercise as a potential therapeutic tool for asthmatics.
In addition, a recent report raised attention on a potential loss of bronchoprotection for athletes using LABAs, independent from the Arg16Gly polymorphisms that may affect the efficacy of these medications.
Non-pharmacological measures are also of importance: nasal breathing and pre-exercise warm-ups (15-30 sec exertions alternate with 60-90 sec rest) followed by a warm-down segment are suggested, together with anti-cold masks for cold environments.
Perception of Exercise-Induced Bronchoconstriction in College Athletes
David M Burnett PhD RRT AE-C, John P Vardiman PhD ATC, Jake A Deckert MSc, Jaimie L Ward and Matthew R Sharpe MD
BACKGROUND: Exercise-induced bronchoconstriction (EIB) can lead to long-term respiratory illness and even death. EIB prevalence rates are both high and variable in college athletes. Also, prevalence rates may be underestimated due to ineffective screening.
CONFERENCE PROCEEDINGS Section 2.
Exercise-Induced Bronchospasm: Albuterol versus Montelukast Highlights of the Asthma Summit 2009: Beyond the Guidelines
Gene Colice, MD, FCCP, and William J. Calhoun, MD, FACP, FCCP, FAAAAI, FACAAI2
A peculiar feature of EIB is the so-called refractory period. If exercise is repeated within 1 to 3 hours, there will be less of an EIB response. This has led some to advocate a warm-up for asthma patients before full intensity exercise. Whether late bronchoconstriction, defined as that occurring 4 to 6 hours after exercise, is a part of EIB remains in debate. Although there are numerous theories about why EIB occurs, the underlying mechanisms of EIB are not clear. Several drugs and some nonpharmacological approaches seem to be effective in protecting against, or relieving symptoms of, EIB. The National Asthma Education and Prevention Program Third Expert Panel Report (EPR-3) recommends use of either short-acting or long acting inhaled 2-agonists as the preferred preventive treatment for EIB.4 Using these agents before exercise will effectively prevent EIB in more than 80% of patients. The EPR-3 guidelines do note that leukotriene receptor antagonists (LTRA) can attenuate EIB in up to 50% of patients, but the onset of the protective effect of LTRAs occurs only hours after administration of these agents.4 There are clear advantages of albuterol, or other short acting inhaled 2-agonists, over montelukast in managing EIB. The protective effect of albuterol against EIB is apparent quickly, unlike LTRAs that must be given hours before exercise to prevent EIB. Albuterol can be administered 15 to 30 minutes before exercise in both children and adults to prevent exercise-related symptoms.5–9 In addition, albuterol seems to more effectively prevent EIB than montelukast. In a
direct comparative study patients with proven EIB were treated with either montelukast for 3–7 days or albuterol 15 minutes preexercise. Albuterol virtually eliminated the postexercise fall in FEV1 in these patients, whereas montelukast provided only a mild attenuating effect8 (Fig. 2). A preexercise warm up has also been shown to not be as effective as albuterol pretreatment for preventing EIB.5 Albuterol can also be used as a rescue medication if symptoms of EIB occur despite use of preventive measures.9 This is another differentiating factor between albuterol and LTRAs. Of 3 studies that evaluated the effect of single-dose montelukast in preventing EIB, 2 specified that albuterol was to be used for rescue therapy if patients became symptomatic during exercise,10,11 and one included use of short-acting -agonists as rescue therapy as a prespecified secondary end point.12 A total of 31% of the patients in one study who used montelukast as prophylaxis experienced postexercise falls in FEV1 exceeding 15%.10 This degree of bronchospasm would usually be treated with a rescue medication, specifically albuterol. Similarly, in the other study 17% of patients experienced declines of more than 20%.11 In the third study, 6% of patients were given albuterol for rescue despite being pretreated with montelukast to prevent EIB.12 From the practical, patient care perspective, asthma patients using montelukast to prevent EIB should still have albuterol on hand to treat unanticipated episodes of EIB that might still occur. There are concerns about the use of albuterol in EIB. Tachyphylaxis is a concern with the regular use of albuterol, and the question remains whether using albuterol pretreatment for exercise daily results in tachyphylaxis that might make therapy less effective. In one study in which patients took albuterol or placebo for 6 to 10 days and exercised without pretreatment, the exercise-induced fall in FEV1 was greater among the group using albuterol than it was among the placebo group.13 In this study, though, treatment with albuterol after EIB developed effectively improved lung function. Similar results were seen in another study where patients took albuterol 4 times a day for 7 days.9 However, in this study albuterol administered immediately before exercise was still effective in preventing EIB.9 It should be emphasized, though, the guidelines on the management of asthma make it clear that regular use of albuterol is not recommended.4 Tachyphylaxis to the effects of albuterol might also occur if patients were regularly using an inhaled long acting 2-agonist. Regular use of salmeterol has been reported to reduce the effect of albuterol treatment to protect against methacholine-induced bronchoconstriction. Nelson et al, though, showed that the acute bronchodilator response to albuterol was maintained in asthma patients who were either inhaled corticosteroid (ICS)naive or receiving ICS, regardless of regular salmeterol use. However, another study found that the effect of albuterol against EIB was reduced in asthmatic patients who regularly used a combination of ICS and long-acting -agonists.16 Overall, it is unclear whether the regular use of an inhaled long-acting 2-agonist will reduce either the protective or treatment effect of albuterol in EIB. Any possible decreased protection by albuterol for EIB should be carefully weighed against the overall clinical benefits achieved from using combination therapy with an ICS and an inhaled long-acting
2-agonist.
MONTELUKAST AND EXERCISE-INDUCED ASTHMA: COMMENTARY BY WILLIAM J. CALHOUN, MD, FACP, FCCP, FAAAAI, FACAAI
Taken on a regular once-daily basis, the LTRA montelukast has been shown to improve the exercise-induced deficit in lung function: blunting the early fall in FEV1, reducing the area under the curve (AUC), and decreasing the time to recovery of normal lung function. Similarly, montelukast has been demonstrated to reduce the fall in FEV1 after eucapnic voluntary hyperventilation, an experimental model of EIB that focuses on the cooling and drying of the airway. The benefit of montelukast against exercise challenge can be seen as early as 3 days on regular treatment. Specific challenge studies have reported improvements in lung function as soon as 2 hours after a single dose. The positive effects of montelukast therapy can persist for up to 8 weeks after discontinuation, suggesting that treatment induces physiological changes in the airway. No tachyphylaxis or loss of protection have been observed. For the most part, montelukast provides comparable (and sometimes even superior) protection to other approaches used to address EIB. For example, in children with mild asthma both montelukast and fitness training reduced BHR and also decreased the incidence of EIB by 50%. Another randomized study in atopic children reported a 54% reduction in the maximum postexercise fall in FEV1 with montelukast (5 or 10 mg once daily) compared with reductions of 52, 32, and 24% for montelukast budesonide (100
g bid), budesonide alone, and budesonide formoterol (100
g/4.5
g bid), respectively; patients treated with placebo showed an increase of 9%. In a study in adults with EIA single doses of montelukast (10 mg) and salmeterol (42
g) provided comparable prophylaxis against EIB more than 12 hours, reducing the fall in FEV1 by [1]70% (P
0.001 for salmeterol, and P
0.001 for montelukast).28 The difference between the 2 agents was an onset of action within 10 minutes after challenge for salmeterol compared with an onset within 1 hour for montelukast. A comparison of the effects of regular use of salmeterol (50
g bid) and montelukast (10 mg qd) on EIB more than 8 weeks in 197 patients with mild asthma reported few differences between the 2 treatments, but overall, montelukast provided slightly better control with no tolerance evident and fewer adverse events.29 The benefit of montelukast compared with albuterol, however, is not as clear cut. In a crossover study of 11 children (7–17 years), EIB was better controlled by pretreatment with 2 puffs of albuterol than with 3–7 days of daily treatment with montelukast (5 or 10 mg). Albuterol significantly reduced EIB in 100% of the patients, compared with 55% for montelukast. Thus, a dose of albuterol given immediately before exercise might be superior to daily dosing with montelukast. However, other data suggest that montelukast preserves the bronchodilator responsiveness to albuterol. Some patients may benefit from using both, and additional study is warranted to address this.
DISCUSSION Dr. Calhoun: Obviously, it is scientifically untenable for either of us to take a position that the only appropriate treatment for EIB is either montelukast or albuterol. However, I would like to emphasize three things. First, I think the question of tachyphylaxis is important. Dr. Colice presented data showing that people who had regular albuterol for a week had a larger decrement in FEV1 postexercise than those who were on placebo. Four times a day albuterol is not a lot, it does not saturate the beta receptors continuously; so, to the extent that patients needed more and more and more albuterol, the issue of tachyphylaxis is significant. Second, there are things that are unmeasured. For example, activation of the counter-regulatory phospholipase C pathway with chronic stimulation of the beta receptors is probably not good.
Dr. Colice: Yes, the data show that if a patient uses albuterol regularly, the fall in FEV1 with EIB might actually be enhanced. However, when these patients then took a dose of albuterol preexercise, it still completely eliminated the fall in FEV1 during exercise.
For more information, read attached article below.
| exercise_induced_asthma.pdf |
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