Obstructive Sleep Apnea Syndrome

Transcription

1 SMGr up Obstructive Sleep Apnea Syndrome Alper Dilci, Handan Koyuncu and Vural Fidan* Otorhinolaryngology Department, Yunus Emre Government Hospital, Turkey *Corresponding author: Vural Fidan, Otorhinolaryngology Department, Yunus Emre Government Hospital, Eskisehir, Turkey, Published Date: May 30, 2017 OBSTRUCTIVE SLEEP APNEA SYNDROME 2% of women and 4% of men over age 50 have symptomatic obstructive sleep apnoea syndrome (OSAS) due to the population based studies. Our population has become older and more overweight so incidence of this disease may be considerably higher today. Snoring is the low-pitched noise arising mainly by vibration of the pharynx. The noise is typically worse when the patient is asleep because the pharyngeal muscles relax and become atonic. Partial obstruction can cause greatly reduced airflow resulting sleep disturbances. Therefore; OSAS is characterized by episodes of obstructive airflow during sleep so that the patient stops breathing despite continuing respiratory efforts. OSAS is characterized by repetitive episodes of complete or partial upper airway obstruction during sleep [1]. These events can occur multiple times per hour of sleep and result with reductions in oxygen saturation [2]. OSAS, snoring, sleep-related breathing disorder (SRBD) are different degrees of a broadly identified disorder. They have a major impact on a patient s life. The medical implications of these disorders such as increased risk of stroke, hypertension and other cardiovascular conditions such as arrhythmias and myocardial is chaemia. Daytime somnolence poses a risk to road traffic accidents. Lastly, marital and relationship disharmony can occur as a consequence of simple snoring; significant improvement in the quality of life is achieved with successful surgery [3]. 1

2 Main Types of Sleep Related Disorders Snoring Upper airway resistance syndrome Obesity-hypoventilation syndrome Obstructive sleep apnoea syndrome (OSAS) Snoring It is very common; does not have to be associated with arousals or sleep fragmentation, but increased upper airway resistance. Simple snoring is categorized by disruptive low frequency sound produced during partial obstruction and vibration of the pharynx without apnoeic episodes. This usually arises from soft palate, but the tonsils, epiglottis and the base of the tongue may also contribute in up to 30% of cases. It affects at least 40% of men and 20% of women and often accompanies sleep-disordered breathing. Upper Airway Resistance Syndrome Upper airway resistance syndrome (UARS) involves respiratory events that do not include apnoeas or hypopnoeas, but lead to arousals, sleep fragmentation, and excessive daytime sleepiness. UARS is categorized by increased sleep disruption and excessive daytime sleepiness without evidence of obstructive apneas or desaturations. Obesity-Hypoventilation Syndrome It is a condition which overweight people fail to breath deep enough. It results in low blood oxygen levels and high carbon dioxide levels in blood stream. It is defined as a combination of obesity, hypoxemia, hypercapnia resulting from hypoventilation. Obstructive Sleep Apnea Syndrome Obstructive sleep apnoea involves repetitive episodes of upper airway obstruction during sleep. These episodes may be hypopnoeas (partial obstructions) or apnoeas (complete obstructions). The apnoeic and hypopnoeic events last a minimum of 10 seconds and are associated with oxygen desaturations and arousals from sleep. Severity of OSAS is determined by frequency of the apnoeas and hypopnoea called the apnoea/hypopnoea index (AHI). Severity of OSAS AHI (apnoea/hypopnoea events per hour) Mild 5-14 Moderate Severe greater than 30 2

3 Apnoeas and hypopnoeas can occur in any stage of sleep, but they are more common in stages 1, 2, and REM than they are in stage 3. Respiratory events that occur in REM sleep are usually of a longer duration and associated with more severe oxygen desaturations. SLEEP STAGES Normal Adult Sleep % of Total Sleep Time Stage 1 2%-5% Stage 2 45%-55% Stage 3 5%-20% REM 20%-25% THE PREDISPOSING FACTORS obesity nasal or pharyngeal obstruction increasing age alcohol smoking male gender neck circumference larger than 17 inches hypertension alcohol/sedative drugs craniofacial abnormality positive family history SYMPTOMS OF OSAS Snoring. Witnessed episodes of apnoea. Frequent movements that disrupt sleep. Restless sleep. Early morning headaches. Fatigue. Waking feeling tired and unrefreshed. 3

4 Excessive daytime sleepiness. Forgetfulness. Depression. Irritability. Sexual dysfunction. Motor vehicle accidents. Job-related accidents. DIAGNOSIS History When evaluating patients for OSAS, obtaining a careful medical history is important. Patients should be asked about snoring, restless sleeping, gasping or choking, reasons for waking up during the night, early morning fatigue, daytime sleepiness, waking up with headaches, and the average time they go to bed, how long it takes them to fall asleep, and the average time they get out of bed in the morning. This will help to rule out other sleep disorders. A thorough medication history should be obtained to rule out medications that may affect sleep. Patients should also be asked about any hypertension, cardiac disease, strokes, diabetes, depression, thyroid disorders, motor vehicle or job-related accidents. Obtaining a history from the bed partner can also be very helpful with regard to snoring and any respiratory events. The Epworth Sleepiness Scale is a widely used tool that assesses daytime sleepiness OSAS may be suspected in patients with an Epworth Sleepiness Scale score greater than 10 [4]. 4

5 Epworth Sleepiness Scale Physical examination The physical examination of patients should include a general examination with evaluation of height, weight, body mass index (BMI), and neck circumference in addition to a detailed examination of the upper airway. The nose, nasopharynx, oral cavity, oropharynx, hypopharynx, and larynx should all be examined to assess their patency and rule out any obstructions anatomical or pathologic. 5

6 Nose Congestion Infections Septal deviations and spurs Turbinate hypertropies Polyps or masses Nasal valve collapse Nasopharynx Residual or hypertrophied adenoidal tissue Masses Polyps Oral Cavity Dental occlusion problems Size or position of tongue Retrognathia or prognathia Hypoplastic mandible Problems of mandibular or palatal arches Oropharynx Tonsils Soft palate or uvula Webbing of tonsillar pillars Hypertrophied or prominent lateral pharyngeal walls Hypopharynx Size and position of the base of tongue Lingual tonsillar hypertrophy Masses 6

7 Larynx Mobility of vocal cords Masses Polyps The nasal cavity should be assessed with a nasal speculum before and after topical decongestant. Fiberoptic endoscopy may also be used to assess the nasal cavity and nasopharynx. Nasal obstruction and mouth breathing contribute to upper airway collapse and OSAS by several mechanisms. Nasal obstruction causes the mouth to open for the patient to breathe. This leads to a backward rotation of the mandible displacing the base of tongue posteriorly, and a lowering of the hyoid which leads to increased airway collapse. When examining the oral cavity the development and position of the mandible and the dental occlusion should be noted. A retrognathic mandible will lead to a backward rotation of the tongue and a narrowing of the pharyngeal airway. The relaxation of pharyngeal arches and lengthening of uvula also contribute to the disturbing of the airway. The size and position of the soft palate and uvula should be noted, including the relationship between the soft palate and the positioning of the tongue. This is often graded with the Mallampati classification or the Friedman classification. The size of the tonsils should be noted also. Tonsillar size is graded 1 to 4. Tonsillar Grade Grade 0-no tonsils present Grade 1-tonsils are small and remain hidden within the tonsillar fossa Grade 2-tonsils extend up to the edge of the tonsillar pillars Grade 3-tonsils are hypertrophic and extend beyond the pillars but do not touch in the midline Grade 4-tonsils are hypertrophic and touch in the midline A fiberoptic nasopharyngoscope should be used to examine the nasopharynx, oropharynx, and hypopharynx. The retropalatal area of the oropharynx and the retrolingual area of the hypopharynx are the two common areas for collapse. Mueller maneuver can be applied for detecting the degree of obstruction while examining with nasophrayngoscope [5]. During this maneuver the patient s nose is pinched close and with their mouth closed the patient is asked to inhale against a closed airway while the retropalatal and retrolingual areas are examined for collapse with the fiberoptic scope. The fiberoptic examination will also allow for examination of the base of the tongue and its 7

8 positioning, lingual tonsils, patency of the glottis, and mobility of the vocal cords, while ruling out any obstructive masses or polyps [6]. Drug-Induced Sleep Endoscopy Determining the actual level of obstruction and anatomy involved with the obstruction for an individual patient can be difficult because of the patient s awakening at the examination. Drug induced sleep endoscopy may be used to examine the patient while sleeping. A flexible nasopharyngoscope is used to examine the nasopharynx, oropharynx, and hypopharynx with the patient asleep, snoring, and obstructing. Cephalometry Cephalometry involves the measurement of various landmarks and their angles seen on a standardized lateral facial x-ray. The film is taken in a standard head position with gaze parallel to the horizon, the teeth lightly opposed at end expiration. Cephalometry provides evaluation of soft tissue and skeletal relationships, posterior airway space, length of soft palate, and hyoid position. Radiologic Studies Computed tomography (CT) provides good anatomic detail of the bone and soft tissue. Magnetic resonance imaging (MRI) provides excellent soft tissue differentiation and does not require radiation exposure. However, it can be hard to tolerate, is expensive, has limited availability, and is noisy, which may preclude asleep evaluations. Polysomnography The gold standard for diagnosis of OSAS. This is the study involving overnight assessment of parameters including- EEG, electromyogram, electro-oculogram, respiratory airflow, thoracoabdominal movement, ECG, oximetry, body position, snoring sound and video. It is a relatively intrusive and costly study whose interpretation can be complex. Polysomnography (PSG) is the simultaneous recording of multiple physiologic parameters during sleep, and is essential in the diagnosis of sleep disorders. This is usually performed overnight in a sleep laboratory with a trained technologist; however, home sleep studies are now gaining more acceptance today. Parameters typically measured include: Electroencephalogram (EEG) Electrocardiogram (ECG) Electro-oculogram (EOG) Electromyogram (EMG) Nasal and oral airflow 8

9 Blood oxygen concentration ( oximetry ) Thoracic and abdominal movements Body position Snoring TREATMENT The goals of treatment are to reduce the morbidity and mortality associated with obstructive sleep apnoea, and improving the patient s quality of life by eliminating their daytime somnolence. Behavioral Modifications Patients with OSAS should be warned against the use of alcohol or sedatives at bedtime. Alcohol and sedatives will promote a very deep sleep, thus making the apnea much more easily and deep, and blunt the patient s effort to arouse themselves. Patients should also be directed to weight reduction which has a direct impact on sleep disturbance. Weight reduction is very effective and even curative in many cases; however, it is difficult to achieve. Sleeping in a supine position allows the tongue to fall posteriorly which enhances the airway obstruction. In many patients their apnoea is worst or only occurs in the supine position, therefore positional therapy can be helpful. This involves training the patient to not sleep on their back by tying a ball to the back, or using a fanny pack with tennis balls in it strapped to the back. There are commercially available pillows to aid in positional therapy as well [7]. Continuous Positive Airway Pressure This is the most effective treatment for OSAS. It eliminates apnoea/hypopnoea, improves daytime alertness, neurocognitive functions, mood and neurocardiovascular sequelae. CPAP is the gold standard treatment for OSAS. CPAP functions as a pneumatic splint preventing the airway from collapsing. If a patient is able to tolerate CPAP and use it during sleep, their OSAS is effectively treated. CPAP reduces excessive daytime sleepiness and the morbidity and mortality associated with OSAS successfully. Oral Appliances Oral appliances may be used to help keep the upper airway intact during sleep. They work by bringing the mandible and base of tongue forward and stabilize the mandible to prevent it from falling during sleep. Mandibular repositioning device is the most common, can be custom made or there are many different types of appliances that are commercially available. Side effects associated with appliance use include temporomandibular joint discomfort, dental separation, excessive salivation, and dry mouth [8]. 9

10 Surgery Surgery for sleep disturbance is usually reserved for patients with primary snoring, patients with obstructive sleep apnoea syndrome who have failed or cannot use CPAP, or to improve CPAP compliance in patients. There are many available procedures addressing the different levels of obstruction. Surgical plan should be planned for each individual patient based on their physical examination, fiberoptic examination, sleep endoscopy, or cephalometric studies. Multilevel surgery is often required in patients with OSAS and may improve outcomes Nasal Surgery Nasal valve surgery Septoplasty Turbinate reduction Polypectomy Adenoidectomy (children) Oropharyngeal Surgery Enlarged tonsils will narrow the oropharyngeal airway, and a tonsillectomy will help to alleviate this obstruction. It is unusual in an adult to be the primary site of obstruction, but more of a contributing factor. In adults, tonsillectomy is usually performed as part of a palatal procedure. In children, enlarged tonsils and adenoids are oftentimes the primary cause of obstruction and an adenotonsillectomy may be curative [9]. Palatopharyngeal Procedures The most important part of the upper airway for OSAS is the soft palate and the lateral pharyngeal tissues. The retropalatal region is one of the main areas of collapse in sleep disturbances. There are many procedures available to shorten and stiffen these tissues to prevent collapse and snoring. These procedures include: Uvulopalatopharyngoplasty (UPPP) Transpalatal advancement pharyngoplasty Expansion sphincterplasty Uvulopalatal flap Laser-assisted uvulopalatoplasty (LAUP) Cautery-assisted palatal stiffening (CAPSO) Radiofrequency ablation of soft palate Palatal implants Injection snoreplasty 10

11 Hypopharyngeal Procedures The hypopharyngeal airway is another area of obstruction and usually reason for surgical failure in patients undergoing only palatal procedures. This region can be assessed preoperatively by Mueller maneuver, cephalometrics, or sleep endoscopy. Procedures to help achieve this include: Radiofrequency ablation of tongue base Genioglossus advancement Hyoid suspension Tongue suspension Transoral midline glossectomy Mandibular advancement Maxillomandibular advancement Tracheotomy A tracheotomy bypasses the site of upper airway obstruction and therefore is the most successful ways of treating OSAS. However, it should be conisidered in patients who have failed all other OSAS treatments, in those who have life-threatening OSAS and are unable to tolerate CPAP, or in patients who are neurodevelopmentally impaired. References 1. Fairbanks DNF, Mickelson SA, Woodson BT, eds. Snoring and Obstructive Sleep Apnea. Philadelphia, PA: Lippincott Williams & Wilkins, Kryger MH, Roth T, Dement WC, eds. Principles and Practices of Sleep Medicine. Philadelphia, PA: Elsevier Saunders, Shahar E, Whitney CW, Redline S, Lee ET, Newman AB, et al. Sleep disordered breathing and cardiovascular disease. Am J Respir Crit Care Med. 2001; 163: The International Classification of Sleep Disorders. Diagnostic & Coding Manual. Westchester, Il: American Academy of Sleep Medicine. 2005: Chan J, Edman J, Koltai PJ. Obstructive sleep apnea in children. Am Fam Physician 2004; 69: Lim J, McKean M. Adenotonsillectomy for obstructive sleep apnea in children. Cochrane Database Syst Rev. 2009; 4: CD Management of Obstructive Sleep Apnoea/Hypopnoea Syndrome in Adults. A National Clinical Guideline. Scottish Intercollegiate Guideline network, June Ulualp SO. Snoring and obstructive sleep apnea. Med Clin North Am. 2010; 94: Hörmann K, Verse T. Surgery for Sleep Disordered Breathing. 2nd Ed