Introduction
In the ever-expansive realm of sleep medicine, a multidisciplinary field has emerged, integrating physicians and researchers from various disciplines. Pulmonology is a noteworthy contributor to sleep medicine, which plays a substantial role in creating awareness and treating patients. Growing awareness of sleep disorders has led to growth in this field. Breathing intersects with sleep, which, as a whole, affects the well-being. This article explores the complex relationship between sleep and respiratory health, highlighting the pivotal contributions of pulmonary medicine and increasing awareness surrounding sleep disorders.
What Is Normal Sleep?
Sleep is a basic functional need for humans and is crucial for a good quality of life. It is not just a closing of eyes. There are a lot of things going on behind the stage. Waking up refreshed after a good night's sleep is a scientific miracle. Sleep is a decrease in the level of consciousness. Sleep occurs in stages of rapid eye movements (REM) and non-REM sleep.
Normal individuals fall asleep within 20 minutes after going to bed and entering the successive stages of sleep, with REM occurring at about 90 to 100 minutes. Initially, deeper NREM occurs in the first half of sleep, with more REM in the second half.
During sleep, there is :
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Decrease in thermal setpoint.
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Cortisol, thyroid stimulating hormone, and adrenocorticotropic hormone peak between 4 and 8 am.
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A progressive reduction in the central respiratory drive through stages 1 to 4 of NREM sleep exists.
Disorders in sleep alter the nature of sleep, which, in turn, alters breathing patterns.
What Is the Effect of Sleep on Breathing?
Sleeping, to a certain extent, impairs breathing in normal individuals. Impaired gas exchange is seen with an increase in CO2 level. Sleep also decreases oxygen stores in the body, and response to hypoxia (low oxygen content) and hypercapnia (high carbon dioxide content) decreases. Also, sleep exaggerates instability in breathing patterns.
What Are the Common Respiratory Conditions?
The most common sleep and breathing disorder is obstructive sleep apnoea. This results in arousal from sleep that improves airway patency but results in more daytime tiredness. Some of the respiratory diseases may cause breathing failure without any obvious obstruction. Apnea means cessation of airflow lasting ten seconds or more. Hypopnea means a decrease in airflow latency, a decrease in flow accompanied by oxygen desaturation.
Many medical conditions are associated with sleep problems. Obstructive pulmonary disease includes reversible airway disorders like asthma, COPD, and chronic upper airway obstruction due to vocal cord paralysis. These conditions may mimic obstructive sleep apnea. In asthmatics, shortness of breath usually starts in childhood, from around two to three years old up to 40 years of age. A pattern is noticed with the change of seasons. Most patients experience worsening symptoms during the night because of the decline in airway function.
In patients with chronic obstructive pulmonary disease, destruction of lungs and lung tissue is noticed. Most patients are chronic smokers. Hypoxemia (low oxygen content in the blood) occurs more during sleep than wakeful patterns.
Patients with lung cancer usually present with a cough that does not heal or is accompanied by blood, chest pain, and unexplained weight loss. All this will affect the individual's sleep pattern.
Hypoventilation syndromes happen due to mechanical restraint on ventilation and dead space, thereby increasing CO2 production in pulmonary diseases. Such patients experience excessive efforts in breathing.
How to Diagnose Sleep Disorders?
Diagnosis is an integral aspect of managing sleep disorders. There are various methods, as given below.
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Conventional Method of Examination: Sleep assessment is usually conducted by overnight polysomnography (8-hour recording). Thus, a person suspected of having sleep apnea is referred to a sleep clinic and spends the night there connected to electrophysiologic recordings that monitor electroencephalography, electrooculography, electromyography, respiratory effort, airflow, body position, and arterial oxygen saturation level, all of which provide the necessary information for a diagnosis.
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Split Night Examinations: These are also carried out where the patient spends a portion of their night's sleep in the clinic for assessment. Daytime sleep can be assessed using multiple sleep latency tests (MSLT).
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Portable Home Recording: This is not recommended for general population screening as they are inaccurate. Wrist-worn accelerometers have been tested, but they tend to overestimate sleep time. Additionally, questionnaires can be used to evaluate daytime sleepiness.
How to Treat Sleep Breathing Disorders?
There are diverse treatment strategies for sleep-breathing disorders. While physiotherapy remains a cornerstone, other modalities like continuous positive airway pressure (CPAP) therapy are commonly practiced. This is focused on its ability to maintain airway patency during sleep. Various oral appliances are also used for individuals with mild to moderate apnea.
Physiotherapy mainly focuses on removing blocked secretions. It is very beneficial, along with drug therapy. For individuals with respiratory conditions like asthma and COPD, optimal disease management and adherence to prescribed medications should be emphasized. Inhalation therapy, bronchodilators, and anti-inflammatory medications are crucial in maintaining respiratory health and improving sleep quality.
Behavioral interventions and lifestyle modifications are considered components of a holistic treatment approach. Weight management, positional therapy, and sleep hygiene practices are explored for their potential to mitigate sleep-related breathing issues. Patient education for self-management and adherence to treatment regimens should be practiced.
What Are the Challenges in the Management of Sleep Disorders?
While advancements have been made in diagnosing and treating, challenges persist. The biggest challenge is limited access to specialized sleep clinics. Also, every individual shows a different treatment response, so treatment is more individualized. This emphasizes the need for ongoing research and collaboration.
What Is the Role of Technology in Sleep Medicine?
Advancements in technology have significantly influenced the landscape of sleep issues. From diagnosing to monitoring, various artificial intelligence-based wearable devices have evolved and are currently being researched.
What Are the Future Directions in Sleep Medicine?
Personalized medicine approaches should be undertaken by tailoring treatments to individual sleep profiles. Research into sleep disorders' genetic and molecular basis should pave the way for better interventions. Continuous collaborations between sleep specialists, pulmonologists, and other healthcare professionals are emphasized to move this forward.
Conclusion
In conclusion, this article comprehensively explores the substantial interaction between sleep and respiratory diseases. It underscores the necessity for a collaborative effort among the medical disciplines. In the current era, where respiratory issues are on the rise due to an increase in passive smoking and air pollution, sleep medicine is also adversely affected. Fostering an improved understanding and management of sleep disorders can significantly enhance the overall quality of life.
