obstructive sleep apnea

1. Diagnosis and
Investigations
By
Dr.Faizan Ali

3. Summary
 Polysomnography (PSG)
 Mallampati score
 Friedman tongue score
 Muller’s maneuver
 AHI
 RDI
 Epworth Scale

4. OSA
Diagnosis
Medical
history
Physical
Examination
Airway
analysis
PSG(Gold
standard)

5. Medical History
0-10 Normal
10-
12
Borderline
12-
24
Abnormal

7. David P. White, M.D., Professor of Sleep Medicine at Harvard

9. Medical conditions
 Chronic obstructive pulmonary
disease
 Restrictive lung diseases
 Muscular dystrophy
 Cardiac dysfunction
 Kyphoscoliosis
 Hypothyroidism
 Pituitary tumors
 achondroplasia or Marfan Syndrome

10. Physical Examination
 Oral Examination
 Others

11.  Body Mass Index = (Weight in Kilograms) / (Height in meters)2
 Neck circumference measured at a point
2 cm below the Adam's apple
 The presence of retrognathia or
micrognathia should be noted.

12. Oral Examination
Focus on the
 Length of the soft palate (long palate is one that
descends below the base of the tongue and cannot be directly seen).
 The size of the palatine
 Tonsils
 Width of the palatal vault and dental
arches.

15. Modified Mallampati score
 Assessed by asking the patient (in a sitting posture) to open his/her
mouth and protrude the tongue as much as possible.
 The anatomy of the oral cavity is visualized; specifically, whether the base
of the uvula, faucial pillars (the arches in front of and behind the tonsils)
and soft palate are visible.
 Scoring may be done with or without phonation. Depending on whether
the tongue is maximally protruded and/or the patient asked to phonate,
the scoring may vary.

16. Original Mallampati Scoring:
Class 1: Facial pillars, soft palate and
uvula could be visualized.
Class 2: Facial pillars and soft palate
could be visualized, but uvula was
masked by the base of the tongue.
Class 3: Only soft palate visualized.

17. Friedman tongue score
Friedman Palate Position I allows
visualization of the
entire uvula and tonsils/pillars.
Friedman Palate Position II allows
visualization of the
uvula but not the tonsils.
Grading is based on
the tongue in a
neutral, natural
position inside the
mouth

18. Friedman Palate Position III
allows visualization of
the soft palate but not the uvula.
Friedman Palate Position IV
allows visualization of
the hard palate only.
Friedman tongue
score

19. Friedman Tonsils score
Tonsils, size 1, are hidden
within the pillars.
Tonsils, size 2, extend to the pillar

20. Friedman Tonsils score
Tonsils, size 3, extend
beyond the pillars
but not to the midline.
Tonsils, size 4, extend to the midline.

21. Clinical Staging For OSA pt
MICHAEL FRIEDMAN, MD, HANI IBRAHIM, MD, and LEE BASS, BS, Chicago, IllinoisOtolaryngology–
Head and Neck Surgery July 2002

23. Mueller’s maneuver
Diagnostic technique
 to detect airway narrowing.
 It is performed by attempting to inhale against
pinched-off nose and closed mouth with a
fiberoptic nasopharyngoscope in place.
 The resulting negative inspiratory pressure will
cause the walls of the upper airway to collapse in
the narrowed airway.
 A positive test is suggestive of OSAS.
 AHI is correlated positively with the Mueller’s
maneuver
Evaluation of Obstructive Sleep ApneaSyndrome by Computational Fluid Dynamics
Somsak Sittitavornwong, Peter D. Waite, Alan M. Shih, Roy Koomullil, Yasushi Ito, Gary C. Cheng, and Deli Wang
(Seminar 2009)

27. Flexible fiber optic scope

28. NASAL SPRAY TEST
 Using topical nasal decongestant on
alternate nights andcomparing
severity of snoring and aponea

29. Airway Analysis
Apnea-Hypopnea Index
 calculates sleep apnea severity based on the
total number of complete cessations (apnea)
and partial obstructions (hypopneas) of
breathing per hour of sleep.

30. Respiratory disturbance
index (RDI) used in reporting polysomnography (sleep study) findings.
 Unlike the AHI, it also includes respiratory-effort related
arousals (RERAs).
 RERAs are arousals from sleep that do not technically meet
the definitions of apneas or hypopneas, but do disrupt sleep.
They are abrupt transitions from a deeper stage of sleep to a
shallower.
 The gold standard for measuring RERAs is esophageal
manometry, as recommended by the American Academy of
Sleep Medicine (AASM). However, esophageal manometry is
uncomfortable for patients and impractical to use in
most sleep centers.
 High RDI was significantly correlated with excessive daytime
sleepiness, and that this correlation was stronger than that for
the frequency of oxygen saturation decreases below 85%, but
other studies have found only a weak correlation

31. RDI
 RDI = (RERAs + Hypopneas +
apneas) X 60 / TST (in minutes).

33. Sleep
Study

34. Multiple sleep latency test
(MSLT)
 is performed to determine the level of
daytime sleepiness in the patient.
 The time it takes for the patient to fall
asleep during daytime naps is
measured in the MSLT.
 Patients with excessive daytime
sleepiness will have an abnormal
MSLT and will have an average sleep
latency during the MSLT of less than 5
to 8 minutes.

35. Maintenance of wakefulness test
(MWT)
measures a person’s ability to stay awake.
 It consists of four nap periods each lasting 40
minutes in which the patient is asked to try to
stay awake.
 Most normal persons without excessive
sleepiness can remain awake during these
naps.
 MWT is sensitive to sleep deprivation and
the effects of circadian sleep-wake rhythms
 Performance vigilance testing Tests that
involve repetitive tasks, such as driving
simulators, which measure performance,
attention, and alertness, can be used to
assess excessive sleepiness.

36. OSLER TEST (Journal of sleep research 1997 A
behavioral test to identify OSA L.S.BENNET,J.R.STRADLING
R.J.O.DAVIES)

37. Pupillography
 Several studies have shown that the diameter of the
pupil is inversely and its variability over time positively
related to subjective complaints of sleepiness.
 The method has been used mainly in a clinical
environment to assess EDS because it requires little co-
operation and is hence very objective.
 It has been shown to be sensitive to sleep restriction in
healthy subjects .The method provides reliable results
when comparing sequential tests in the same individual,
but seems less suitable when comparing one subject
with another or between different studies.

38. Polysomonography

40. PSG
 reference method for the diagnosis of patients with suspicion for
SAHS and other non-respiratory sleep disorders (consistent
recommendation, high quality of evidence).
 Typically, during an overnight sleep study electrodes are placed to
record brain activity, eye movements, and muscle activity as you
sleep. The sleep technician may place other sensors on your chest
or near the nose to record your breathing patterns.
 Testing is usually performed in a private room beginning at your
normal bedtime and you will be allowed to leave early the next
morning. After your sleep data is analyzed, a detailed sleep report
is sent to your family physician

43. TheAmerican Academy of Sleep
Medicine (AASM) has
classified sleep studies into 4
types.
 Type 1 is conventional PSG
overseen by a technician in a
sleep laboratory (with a
minimum of 7 channels)
 Type 2 is PSG done with
portable equipment and no
technician present
 Type 3 is so-called RP, where
breathing, thoracoabdominal
effort and pulse-oximetry are
recorded (with a total of 4-7
channels)
 Type 4 are super-simplified
studies with a 1-2 channel
apparatus (oximetry and/or
breathing).

44.  PSG should be done either at night or
during the subject's usual sleep schedule,
with a register of no less than 6.5 hours,
including at least 3 hours of sleep.
 PSG is a relatively expensive, laborious and
technically complex technique that is not
available at all centers, and due to the large
demand of examinations it cannot be used
in all patients.

47. Actigraphy
A small, portable
 movement detector typically using a piezoelectric
accelerometer that generates voltages when motion is
detected across three planes.
 The data are stored in a self-contained memory chip which
can collect data for up to 8 weeks and is then downloaded
via wireless technology for analysis.
Does not measure
 sleep, but sleep is inferred by relative quiescence and
wakefulness is inferred by comparatively increased
movement.

48. WatchPAT,
(an at-home sleep apnea test)
-approved portable diagnostic device that uses
the most innovative technology to ensure the
accurate screening, detection, and follow-up of
sleep apnea

49. Sleep diaries
 Sleep and activity patterns over
several days or weeks can be
charted in a sleep diary, which may
help uncover sleep disorders
unsuspected from the patient’s
history such as circadian sleep
disorders and insufficient sleep
syndrome.
 Entries can include bedtime; sleep
latency; nighttime awakenings
(frequency and duration);arising
time; number, if any, of naps during
the day; mealtimes; exercise times;
and the use of medications, alcohol,
and caffeine.

52. CEPHALOMETRI
C METHODS
 The size of the posterior airway
space,
 The length of the soft palate
 The distance from the mandible to the
hyoid bone.
These measurements are especially
beneficial for decisions concerning
surgical management.

55. Obstructive sleep apnoea: a cephalometric study. Part I. Cervico-
craniofacial skeletal morphology
Vivat Tangugsorn, Olav Skatvedt, Olaf Krogstad, Torstein LybergDOI: http://dx.doi.org/10.1093/ejo/17
.1.45 45-56 First published online: 1 February 1995
 A comprehensive cephalometric analysis of cervico-craniofacial
skeletal morphology in 100 male patients with obstructive sleep
apnoea (OSA) and 36 male controls was performed. The significant
aberrations in the OSA group feature:
 shorter dimension of cranial base with slight counter-clockwise
rotation and depression of clivus;
 shorter maxillary length with normal height;
 maxillo-mandibular retrognathia related to nasion perpendicular
plane (N⊥FH) despite normal angles of prognathism;
 47 per cent of the OSA group had mandibular retrognathia;
 increased anterior lower facial height and mandibular plane angle;
 reduced size of bony pharynx;
 inferiorly positioned hyoid bone at C4–C6 level;
 deviated head posture with larger cranio-cervical angle.
 Cephalometric analysis is highly recommended in OSA patients as
one of the most important tools in diagnosis and treatment planning.

56. Obstructive sleep apnoea: a cephalometric study. Part II. Uvulo-glossopharyngeal morphology
Vivat Tangugsorn, Olav Skatvedt, Olaf Krogstad, Torstein LybergDOI: http://dx.doi.org/10.1093/ejo/17.1.57 57-67 First
published online: 1 February 1995
 A comprehensive cephalometric analysis of uvulo-glossopharyngeal morphology
in 100 patients with obstructive sleep apnoea (OSA) and 36 controls was
performed. The aberrations in the OSA patients included:
 Increased length, thickness, and sagittal area of palate (PM-U; SPT;
SPA; P<0.001) with a more upright position (NL/PM-U; P<0.05) and 15
per cent more pharyngeal area occupation [SPA/(OPA-OA);P0.001].
 The contact length between the soft palate and the tongue was increased
approximately two-fold (CL:P<0.001).
 The sagittal area of the tongue was 10 per cent larger (TA: P<0.001)
despite similar length and height and 3 per cent more oral area
occupation (TA/OA: P<0.05).
 More upright tongue position (VT/FH: P<0.05) and caudally extended
tongue mass (V⊥FH: P<0.05).
 Decreased sagittal dimension of nasopharynx (pm-UPW: P<0.001),
velopharynx (U-MPW: P<0.001) and minimum distance between the
base of the tongue and the posterior pharyngeal wall (PSAmin:P<0.001).
 The residual oropharyngeal area (area not occupied by soft tissues) was
9 per cent less due to larger tongue and soft palate [(TA +
SPA)/OPA; P<0.001].
 Cephalometric analysis is highly recommended in OSA patients as one of
the most important tools in diagnosis and treatment planning.

57. Cephalometric predictors for orthopaedic mandibular advancement in obstructive
sleep apnoea
G. Mayer, K. Meier-EwertDOI: http://dx.doi.org/10.1093/ejo/17.1.35 35-43 First published
online: 1 February 1995
 The cephalometric analysis of two groups: 30 sleep apnoea patients, and
30 age- and sex-matched control patients, established predictors for the
orthopaedic mandibular advancement by means of the Esmarch device
(ED) in treating obstructive sleep apnoea (OSA). Polysomnographic sleep
and ventilation data gathered for each patient with and without
mandibular advancement by means of the ED were compared.
Cephalometric data and treatment efficacy for each patient were
submitted to a regression analysis. Maximal efficacy is predicted by:
 The combination of an orthognathic to prognathic maxilla (SNA larger than or
equal to 83 degrees) with an orthognathic to retrognathic mandible (SNB less
than or equal to 77 degrees)
 An anterior superior displacement of the mandible, with the supramentale
situated at a distance from the anterior part of second cervical vertebra (B-HWK
2 longer than or equal to 95.5 mm) and a narrow angle between the skull and
the mandibular ramus (SN/B-Go equal to or less than 1.5 degrees)
 Short oral height (TB-PNS equal to or less than 35.5 mm), with the uvula not
extending beyond the tongue base (UT-PNS, equal to or less than 30 mm).
 A narrow oropharynx (PAS equal to or less than 3.4 mm). The narrower the
SNB-angle, the wider the SNA-angle, and the shorter the uvula, the more
effective the device.