How to determine the possible primary contribution of a sleep abnormality in a patient with fatigue?
Some illustrative examples will be useful. A female patient complains of fatigue and believes it must be caused by a thyroid problem; and a male patient has similar complaints and attributes his fatigue to low testosterone. The following is presented to allow the clinician to pick and choose an individualized approach to each specific patient.
1. Differentiate whether there is an element of sleepiness to what a patient means by “fatigue”—that is, seek to differentiate, if possible, fatigue and sleepiness. Fatigue and sleepiness may mean the same thing to some patients. However, fatigue is usually felt after prolonged exertion or hard physical work. Patients may have a sense of not feeling normal, decreased efficiency, loss of power, and even loss of responsiveness to stimulation. If the fatigue has an element of sleepiness, however, this may be historical evidence that the primary complaint is actually sleepiness. Such a patient usually has deficient sleep duration and/or disrupted sleep (insomnia, untreated OSA, or restless leg syndrome), may admit to sleepiness upon awakening despite > 7 hours of apparent sleep time and/or difficulty staying awake in the late morning, afternoon, or with family in evening.
2. Use a basic sleep history to implicate a problem with sleep habits that might provide a clue to sleep pathology. The average adult should be getting at least 7 hours of consolidated sleep with < 20 to 30 minutes to get to sleep and < 20 to 30 minutes of awake time after they initially achieve sleep. Are the time they go to bed, the time they are asleep, and their wake time usually consistent? Do they have the typical features of SDB; for example, do they wake up frequently during the night, often for reasons unknown, sometimes snoring themselves awake? Are there unprovoked sweating episodes, and are there awakenings consistent with hot flushing (which may also happen during the day)? Do they have increased heartburn at night? Is there increased movement or fitful sleeping, such as moving back and forth or finding the bed covers helter-skelter in the morning? Does their partner complain of loud snoring or breath holding? Is there difficulty with leg movement or features of a clinical diagnosis of restless leg syndrome (RLS)? The mnemonic for diagnosing RLS is “URGE,” U rge to move legs (can only be ill-defined leg discomfort), worse with R est, better if the patient G ets up and walks around, and finally worse in E vening – fascinatingly there is this circadian feature to RLS.
3. Use the screening tools for sleepiness and for risk of occult OSA. Remember, the tools are specific and not sensitive. Use the ESS (see question #29) for assessment of daytime sleepiness; a score in the 9 to 10 range warrants further review of the sleep history (though not necessarily a sleep study). Additionally, one can screen for the risk of sleep apnea using the pneumonic STOPBANG :
S noring loudly (louder than usual speech, or heard behind closed doors)
T ired during the day
O bserved apneas
P ressure—treated for hypertension
B MI > 35 kg/m 2
A ge > 50 years
N eck circumference > 16 inches (40 cm)
G ender male
Each parameter = 1 point. The total score is used to predict risk of OSA: low risk = 0 to 2; intermediate risk = 3 to 4; high risk = 5 to 8.
4. Use the physical examination to look for features that may worsen collapsibility of the already malleable adult posterior oropharynx (OP) during sleep. Recall that it is only the airway segment below the jaw angle and above the manubrium that does not have anatomic buttressing and is, therefore, vulnerable to nighttime narrowing. So, look for anything in the OP that can impact this dynamic. For example, examine the overall anterior perspective of the OP for these features: narrow jaw (high arched palate, teeth crowding); septal deviation; insufficiency of the mandible; so-called receding chin with attendant maxillary overjet. For example, is there ≥ 3 to 5 mm space between the posterior surface of the maxillary incisors and the anterior surface of the mandibular incisors? If so, this could indicate a narrowed OP. Another related tip is to check for mandibular insufficiency (i.e., protrusion of the maxillary incisors, also known as “buckteeth”). From the profile view of the face, maxillary insufficiency gives the patient a flat-to-concave facial profile; these patients can also have a smaller zygomatic arch. With the mouth open assess tonsil size. Tonsillar enlargement is graded as follows: grade 0 = tonsils are absent ; grade 1 = tonsils hidden behind tonsillar pillars; grade 2 = tonsils extend to pillars; grade 3 = tonsils visible beyond pillars; and grade 4 = tonsils enlarged to midline. With the mouth still open and the patient seated, inspect the OP directly. Ask the person to protrude the tongue. The following assessment is the Mallampati classification. Class I = all of the following are visible—the soft palate, uvula, tonsillar columns (anterior and posterior), and fauces (the passage from mouth to throat, anterior boundary behind and lateral to uvula); Class II = the uvula, soft palate, and fauces are visible but tonsillar pillars are not visible; Class III = the soft palate, fauces, and only the base of uvula are visible; Class IV = the soft palate is no longer visible, nor are the fauces, uvula, or tonsillar pillars.