Studies show that some asthma patients suffer from worsening symptoms at night, a condition called nocturnal asthma, which can worsen both quality of sleep and quality of life.
By Lisa Spear
Sleep may not be the first thing physicians ask their asthma patients about during a consultation but asthma symptoms can become active at night just as they do during the day. In fact, there are several variables that can cause symptoms to flare only after a person goes to sleep. Dust mites can hide inside bedding and may cause nighttime coughing and wheezing. Pet dander may drift through the air, unnoticed during the day when people may spend less time inside their homes, but may be inhaled at night and lead to irritated airways.
Not to mention, obstructive sleep apnea (OSA) is far more common in people who experience asthma than in the general population. If a patient’s OSA is treated, but not the sudden spasms in their bronchioles from their asthma, then their quality of life may suffer as well as their overall health.
While the first symptoms of asthma and other lung diseases regularly show up during sleep, according to research published in the journal Internist, patients may not always connect their asthma symptoms to their fragmented shuteye.1 So it is often up to the clinicians to ask the right questions to determine whether or not a patient experiences nocturnal asthma and how to formulate the best individual treatment plan.
“Often times the patients don’t volunteer the right information. They need to be asked and prompted,” said Nadia Krupp, MD, asthma program director at Riley Hospital for Children in Indianapolis, Indiana.
Krupp treats some of the most severe pediatric asthma cases in the state of Indiana. She stressed that it is essential to evaluate potential co-occurring conditions that may lead to nighttime respiratory distress in asthma patients.
All asthma patients, she said, should be asked about their nighttime symptoms since nocturnal manifestations of the condition are common. At Stanford Healthcare in California, physicians also make sure to ask all their asthma patients about nighttime symptoms, said Sharon Chinthrajah, MD, a pulmonologist at Stanford Healthcare.
Nocturnal asthma is defined as a nighttime exacerbation of the underlying asthma condition associated with increases in symptoms, need for more medication, increased airway responsiveness and possible worsening of lung function.
Nocturnal Asthma by the Numbers
Of the 20 million Americans who live with asthma, many experience nighttime sleep disturbances, leading to chronic insomnia, sleep fragmentation and excessive daytime sleepiness and fatigue. Nighttime blood oxygen levels may fall during asthma attacks, according to information provided by the National Sleep Foundation (NSF).
Since asthma most often appears during childhood, when the brain and body are developing, it is all the more crucial for clinicians to accurately assess the condition and initiate treatment according to the National Heart, Lung, and Blood Institute (NHLBI) at the National Institutes of Health. A poll conducted for the Asthma and Allergy Foundation of America found that 48% of pediatric asthma patients experienced disturbed sleep as a because of asthma, the NSF reported. This can cause psychological issues and impaired school performance in children, according to a study from the University of Oxford, published in Archives of Diseases in Children.2 The researchers also found that children improved their mental function when the nocturnal symptoms were treated and their sleep disturbances reduced.
Krupp suggested that clinicians who treat asthma patients ask parents of children or bed partners of adults if they hear the individual coughing or wheezing at night. The patient may also experience tightness in their chest and shortness of breath.
“You can often tell it is nocturnal asthma if the parent hears them coughing at night,” she said. “Typically, they wake up coughing. They take their albuterol, and that alleviates their symptoms.”
In cases where typical asthma medications don’t resolve the sleep issues, emergency treatment may be necessary. According to information provided by the Mayo Clinic, patients should be advised to seek emergency treatment if they experience no relief after using a quick-relief inhaler, such as albuterol.
Remedies for nighttime asthma symptoms typically include avoidance of precipitants, inhaled corticosteroids, short- and long-acting bronchodilators, and leukotriene inhibitors.
Do Your Asthma Patients Have Sleep Apnea?
“Also, do they have co-existing sleep apnea that may have not have been diagnosed?” said Chinthrajah, a clinical associate professor of pediatrics, immunology and allergy, at Stanford Medical School.
When typical asthma treatments are not effective in addressing nighttime symptoms, it may be worth ordering a sleep study to evaluate why someone may have disturbed sleep from their respiratory symptoms.
Some research has demonstrated that treating the OSA with continuous positive pressure (CPAP), can lead to positive outcomes, said Krupp, an assistant professor of clinical pediatrics and pediatric pulmonology at Indiana University School of Medicine.
Teofilo Lee-Chiong, MD, chief medical liaison at Philips, added: “The prevalence of obstructive sleep apnea is increased in persons with asthma, being highest in those with moderate-to-severe asthma. Conversely, untreated obstructive sleep apnea can contribute to worsening asthma symptoms.”
According to one meta-analysis published in Scientific Reports, the prevalence of OSA in adult asthma patients is 49.50%.3
In these patients continuous positive airway pressure (CPAP) may help improve clinical outcomes in asthma patients, according to a study published in the journal Respiratory Medicine.4
“It has been studied in both children and adults. Not everyone responds to CPAP, but if you have sleep apnea, what we do see sometimes is that if you do treat the sleep apnea with the CPAP, then a lot of time their asthma symptoms may also improve,” said Krupp. “It not clear that across the board treating with CPAP will help asthma patients with their nocturnal symptoms. That is still an area that needs more research to see which patients will benefit the most from CPAP.”
There are many different theories about why people may or may not have nighttime asthma symptoms, said Chinthrajah.
Why Does Nocturnal Asthma Develop?
The exact cause of nocturnal asthma is inconclusive, but in some cases the symptoms can be remedied by eliminating environmental triggers. Bedding, mattresses and stuffed animals may harbor allergens that could irritate the respiratory system and lead to asthma symptoms during sleep, said Bill Pruitt, MBA, RRT, CPFT, AE-C, FAARC, a senior instructor and director of clinical education in the department of Cardiorespiratory Sciences, College of Allied Health Sciences, at the University of South Alabama in Mobile. [See Pruitt’s latest article on pulmonary fibrosis on page 08.]
“You are usually going into an environment in the bedroom that would maybe have a lot of dust mites,” said Pruitt. “…Some people sleep with a pet, a dog or a cat, maybe during the day they may not have that same exposure, but when they get into the bedroom, particularly if they have a pet sleeping with them, that can cause trouble.”
Reflux may also aggravate the airways at night. If someone experiences reflux during the night, there may be some aspiration, which can irritate the airways. “It could be micro aspirations, it could be very minor, but it could be enough to increase the problem with asthma flare symptoms at night.”
Another factor may be sleeping position. Chinthrajah said that when people lay down flat in bed, there is more compression of the airways, and potentially decreased lung volume. Post-nasal drip can also lead to coughing and airway irritation, which can work in concert with asthma to keep patients awake.
Cold, dry air from running an air conditioner in the bedroom may also play a role in nighttime exasperations. This can lead to a lack of moisture in the airways and bronchospasms. “Lack of moisture can lead to twitchy airways,” said Chinthrajah.
Some research suggests that mechanisms of nocturnal asthma are connected to circadian rhythms, which impact inflammatory cells and mediators, hormone levels and cholinergic tone.5 But studies designed to uncover the exact influence of sleep or circadian rhythms on asthma have been largly inconclusive, according to the NSF.
“Different hormones have a circadian rhythm,” Chinthrajah explained.
According to a review article in the Mount Sinai Journal of Medicine, nighttime worsening of asthma has been recognized since the 5th century AD and is thought to be common, affecting a majority of people who live with asthma. Patients with nocturnal asthma symptoms may have more nighttime activation of inflammatory cells and mediators, lower levels of epinephrine and increased vagal tone.6
Treatment Options Continue To Grow
No matter what the cause, there are several options for treating nocturnal asthma and many emerging biologics that may serve as alternative therapies for those who might not be able to tolerate long-term steroid use. “We have a lot more tools to help improve nocturnal asthma symptoms for our patients,” said Krupp.
Inhaled steroids and long-acting beta-agonists have been around for a long time, but over the last 15 years more asthma treatments have become available. Now, long-acting muscarinic antagonists are available to help with reactivity of the airways. There are also biologic agents to help with the inflammatory pathways. Krupp said all of these have made a tremendous impact on the lives of her patients.
“We have a lot of different tools that we didn’t have several years ago. There is something that we can do for patients to help these symptoms for these patients who are struggling with them, which makes it all the more important to ask,” said Krupp.
“We can make their quality of life better, which makes their daytime functioning better, which means they can sleep better at night and are more functional during the day,” said Krupp. “It’s pretty amazing when you finally find the right regiment to fix somebody’s nocturnal symptoms, get their daytime symptoms under decent control, sometimes it seems like personalities even change when they come back to see you because they are so much happier and so much more engaged because they couldn’t sleep before.
“They hadn’t slept through the night in years and once you finally get them better so that they are feeling well, all of a sudden their eyes are brighter.”
RT
Lisa Spear is associate editor of RT. For more information, contact [email protected].
References
- Becker, H. (2004). Relevance of sleep for patients with lung diseases. Internist. (https://www.ncbi.nlm.nih.gov/pubmed/15340696?dopt=Abstract)
- Stores, G., Ellis, A.J., Wiggs, L., et al Sleep and psychological disturbance in nocturnal asthma. Archives of Disease in Childhood.(1998);78: p.413-419.
- Kong, D., Qin, Z., et al (2017). Association of obstructive sleep apnea with asthma: A meta-analysis. Scientific Reports.
- Davies, S., Bishopp, A., et al (2018). Does Continuous Positive Airway Pressure (CPAP) treatment of obstructive sleep apnoea (OSA) improve asthma-related clinical outcomes in patients with co-existing conditions?- A systematic review, Respiratory Medicine. 143: p.18-30.
- Skloot, G.S., (2002) Nocturnal asthma: mechanisms and management. Mount Sinai Journal of Medicine. 69(3): p.140-147.
- Skloot, G.S., (2002) Nocturnal asthma: mechanisms and management. Mount Sinai Journal of Medicine. 69(3): p.140-147.
