swallowing, deglutition, dysphagia. physiology, investigations, manometry, fluroscopy, HRM, FEES, FEESST,

1. Physiology of Swallowing
By- Vikas
1

2. Introduction
2
 Swallowing involves co-ordinated activity of
muscles of oral cavity, pharynx, larynx and
esophagus
 The whole process is partly under voluntary
control & partly reflexive in nature
 Swallowing by definition involves passage of
bolus of food (solid / liquid) from the oral cavity
to stomach via the pharynx and esophagus,
passing over the entrance to laryngeal
vestibule.
 Voluntary control of Swallowing involves control
of jaw, tongue, degree of constriction and
length of pharynx and closure of laryngeal inlet.

3. 3

4. Components of deglutition
4
 Deglution has 3 components
 Passage of bolus from oral cavity to stomach
 Protection of airway
 Inhibition of air entry into the stomach

5. Deglutition - phases
5
Three stages have been traditionally described for
the sake of convenience. They help in the better
understanding of the physiological process
involved.
 Oral
 Pharyngeal
 Esophageal

6. Oral phase
 In this phase food is
prepared for swallowing
 Tongue plays a vital role in
this processThis phase is
divided into
6
 oral preparatory phase
and
 oral phase proper
 This phase is vital in all
land animals which don’t
swallow their food as a
whole
 This phase is under

7. Oral preparatory phase
 This phase involves breaking
down of food in the oral cavity
 During this phase the food is
chewed and mixed with saliva
making it into a bolus which
can be swallowed
 The elevators of lower jaw play
an important role in bolus
preparation
7

8. oral preparatory phase (contd..)
8
 Tongue plays a vital role in bolus formation by the
action of its intrinsic muscles which alters its
shape.
 extrinsic muscles changes its position within the
oral cavity thereby helping in chewing the food by
dental occlusion
 Occlusal action of the lips help in creating an
effective seal preventing the bolus from dribbling
out of the oral cavity.
 The action of buccinator muscle helps in pushing
the bolus out of the vestibule into the oral cavity
proper

9. oral preparatory phase (contd..)
9
Salivary Glands produce saliva which contains
mucin.
 Mucin binds the food togather and helps in bolus
formation

10. Bolus formation
10
 This is the most
important function of
preparatory phase
 This involves repeated
transfer of food from
oral cavity to
oropharyngeal surface
of tongue
 Bolus accumulates on
the oropharyngeal
surface of tongue due to
repeated cycles of
upward & downward
movement of the tongue

11. Oral phase proper
 During this phase the bolus
is moved towards the back
of the tongue
 The contraction of soft
palate prevents nasal
regurgitation, also prevents
premature movement of
bolus into the oropharynx
 Once the bolus is of suitable
consistency the transit from
mouth to oropharynx just
takes a couple of seconds
11

12.  Tongue plays a vital role during this phase.
 Its intrinsic muscles contracts and reduces its
size,
 while genioglossus muscle elevates the tongue
towards the palate
 The elevation of the mandible plays a vital role
here When the mandible is elevated the
suprahyoid muscles raises the hyoid bone

13. Pharyngeal phase (Pumping action of
tongue & hypopharyngeal suction)
 This phase of deglutition is
reflexive in nature
 during this phase
Ventilatory and alimentary
streams cross each other.
Dynamic separation of
these streams is possible
due to the co-ordination of
reflex phase that occurs
 It just takes a second for
the bolus to traverse the
13
pharynx and reach the
cricopharyngeal area

14. 14
 Contraction of diaphragm is inhibited making
simultaneous breathing & swallowing impossible
 Soft palate is elevated in order to seal off the
nasopharynx (T. palatini & L. palatini)
 Vocal cords adduct protecting the airway
 As the bolus passes the palatoglossal &
palatopharyngeal folds the act of swallowing
becomes reflexive

15. Functions of trigger points
in oropharynx
 Stimulation of trigger points
present in the oropharynx
starts off the pharyngeal
reflexive stage of
swallowing
 present at the faucial
arches & mucosa of the
posterior pharyngeal wall
 innervated by
glossopharyngeal nerve
15

16. 16
 Stimulation of these trigger points causes
dilatation of pharynx due to relaxation of the
constrictors, and elevation of pharynx & larynx
due to contraction of longitudinal muscles
 The pharynx constricts behind the bolus thereby
propelling it
 Contraction of the inferior constrictor moves the
bolus towards the oesophagus

17. Importance of laryngeal elevation
during pharyngeal stage
 It narrows the laryngeal inlet
 It ensures better sealing of
the laryngeal inlet by the
downturned epiglottis
 Laryngeal elevation also
contributes to dilatation of
pharynx
 The laryngeal inlet is closed
due to the actions of
interarytenoid, aryepiglottic
17
and thyroepiglottic muscles

18. Role of epiglottis in the pharyngeal
phase
 The movement of
epiglottis occurs in two
stages
 The epiglottis moves from
vertical – horizontal
position
 The upper third of
epiglottis moves below the
horizontal to a slightly
lower level to cover the
narrowed laryngeal inlet
18

19. Esophageal stage
 This is purely reflexive
 In this phase
cricopharyngeus
relexses and the
anterior superior
movement of the
laryngohyoid complex
acts to open the upper
oesophageal sphincter.
 The bolus passes
through the sphincter
and moves along the
19
esophagus by
peristalsis.

20. 20
 The levator and tensor veli palatini relax lowering
the soft palate.
 The laryngeal vestibule opens, the hyoid drops
and the vocal cords open
 This opening of the glottis at the very end of
oropharyngeal swallow sequence is part of the
airway protection mechanism.

21. Neural control of swallowing
21
 Two areas of brain are involved
Cerebral cortex
Brain stem

22. Neural control (initiation)
22
 Initiation of swallow is voluntary
 Bilateral prefrontal, frontal and parietal cortices
are involved
 Swallowing is initiated when food comes into
contact with certain trigger areas like fauces /
mucosa of posterior pharyngeal wall

23. Neural control (initiation)
23
 Afferent nerve is the glossopharyngeal nerve
 Nucleus tractus solitarius & spinal nucleus of
trigeminal nerve play a vital role
 Efferents involve several cranial nerve nuclei
which include nucleus ambiguus (muscles of
palate, pharynx and larynx), hypoglossal
nucleus supplying the muscles of the tongue,
motor nuclei of trigeminal and facial nerves
supplying the muscles of face, jaws and lips.

24. Role of medulla
24
 There are two groups of neurons in the medulla
while lie between the afferent and efferent system
 First group lie in the dorsal medulla above the
nucleus of the solitary tract
 The second group lie in the ventral medulla
around nucleus ambiguus
 These groups of neurons are named as lateral &
medial medullary swallowing centers

25. Role of central pattern generator
25
 Central pattern generator are a set of neurons
capable of initiating sequential swallow
 These neurons act like a cardiac pacemaker
 Since the process of swallowing and breathing
are interlinked there is a certain degree of central
co ordination taking place

26. Phase of respiration &
swallowing
26
 Swallowing occurs during expiratory phase of
respiration
 This helps in clearing food material left in the
vestibule. Thus it should be considered to be a
protective phenomenon
 The rhythm of respiration is reset after a
successful swallow

27. 27
Functional investigations of the
upper gastrointestinal
tract

28. Common principles
28
 A detailed history of onset and progression,
specific symptoms and relief strategies.
 Awareness of adverse situations during
assessment.
 Recording clinical observations, instructions,
bolus volumes and consistencies given.
 Accurate recording of penetration (material
entering the larynx but remaining above the vocal
folds) or aspiration (below the level of the vocal
folds).
 Assessing patients in their usual feeding position.
 Awareness of multifactoral risks for developing
pneumonia.

29. 29
 Challenging the swallow during assessment by
increasing the speed and bolus volume if
necessary up to the safe limit.
 Both single mouthful and continuous swallowing
should be recorded.
 Sterilizing equipment from contamination of nasal
mucus and blood, due to the semi-invasive nature
of nasendoscopy and manometry.
 A team approach, including speech and language
therapists, radiologists, otolaryngologists,
gastroenterologists, neurologists and psychiatrists,
etc., as required.

30. Investigations
30
 Videofluroscopy
 Barium swallow
 Fibreoptic endoscopic evaluation of swallowing
(FEES)
 Manometry
 Oesophageal manometry
 Pharyngeal manometry
 High-resolution manometry
 Manofluoroscopy
 Other investigations

31. RADIOLOGY
31
 There are two distinctly different barium swallows
available
 the traditional barium swallow,
 video fluoroscopy (aka modified barium swallow
or dynamic swallowing study).

32. Barium swallow
32
 Includes both static and dynamic components to
identify intrinsic disease (tumours, diverticula,
webs and dysmotility) and extrinsic disease
(cervical osteophytes, enlarged thyroid gland).
 The oesophageal lumen is distended with liquid
barium, or coated in thick barium and distended
by gas to show intrinsic irregularities and extrinsic
impressions.
 Static imaging with plain radiographs provides
information on structural abnormalities (e.g.
Zenker's diverticulum, cervical osteophytes), but
little contribute to the investigation of dysphagia.

33. 33
 Both the oral and pharyngeal stages should be
assessed even if the complaint is only
oesophageal as 35 percent of patients have
simultaneous disorders of the pharynx and
oesophagus and the level of the lesion does not
necessarily correspond to the site of the patient's
symptoms.

34. Videofluoroscopy
34
 Video fluoroscopy is a
dynamic fluoroscopic
imaging procedure
 Advantageous for
observing all stages of
swallowing, estimating
the amount of
aspiration, and
identifying structural
or anatomical
abnormalities as well
as the physiological
abnormalities causing
dysphagia.

35. PROCEDURE
35
 Patients are assessed in a sitting position
 Boluses are given in increasing volume to
minimize the risk of aspiration of large amounts
of barium, often starting with 1 mL to coat oral
structures.
 All consistencies are given (liquid, semi-solid
and solid) using video fluoroscopic specific
contrast material.
 These are designed to optimize bolus
visualization using standard viscosities and to
minimize adherence and coating on mucosa.

36. 36
 Simultaneous viewing of the oral, pharyngeal and
laryngeal areas should be included.
 Images are recorded on videotape or digitally, in
the lateral and anterior-posterior views for later
analysis and interpretation.
 If dynamic measurements of distance and area
are to be calculated, then a metal ring of known
diameter (e.g. coin) is taped in the midline to the
underside of the chin for calibration.

37. ANALYSIS
37
 Subjective interpretation of video fluoroscopy by
experienced clinicians provides descriptions
about the bolus flow, reactions to a misdirected
bolus and variations from the normal anatomy
and physiology.
 Rating scales attempt to standardize
observations over time or between clinicians, for
parameters of oral transit, pharyngeal transit and
laryngeal valving and for penetration and
aspiration.

38. 38
 Objective analyses of videofluoroscopy are called
dynamic swallow study measurements or
kinematics of swallowing.
 These involve capturing and manipulating digital
images with computer technology to make exact
timing measures of bolus flow and movement of
structures, as well as spatial measurements of
distance and area against reference points.

39. Fluroscopic imaging of swallowing
39

40. 40

41. 41

42. 42

43. 43

44. 44

45. 45

46. 46

47. Video-abc VF
47

48. vf
48

49. ADVANTAGES
49
 All stages of the swallowing mechanism are seen.
 Estimates of volume, depth and clearance of
aspiration can be made.
 A full range of consistencies can be tested.
 Anatomical abnormalities can be detected
(pouches, diverticulae, fistulae).
 Biofeedback to patients

50. LIMITATIONS
50
 Radiation exposure to the patient, especially for
repeated or lengthy studies..
 High cost of equipment and involvement of
several staff.
 Patient intolerance of procedure.
 Difficulties with seating some patients within the
confined space.

51. 51
 Properties of barium are designed to coat
structures, so liquid and food containing barium
does not behave in the same way as normal
liquids or food.
 Limited information is gained about mucosa and
secretions, sensation, inter-bolus pressure, and
details of glottic closure.
 Greater standardization of the procedure, with
higher interjudge reliability between experienced
clinicians,is required before it is truly a 'gold
standard' technique.

52. CONTRAINDICATIONS
52
 Patients without a pharyngeal swallow, as
aspiration of barium will almost certainly occur.
 Unsuitable patients (e.g. those who are unable to
maintain a stable position, drowsy, uncooperative,
nil by mouth for reasons other than dysphagia,
have adverse reactions to contrast media, should
avoid unnecessary exposure to radiation).
 Caution needs to be taken when
 patients are suspected of large volume aspiration,
or
 have a history of respiratory distress/arrest due to
aspiration.

53. 53
 If large volume aspiration is suspected, there
should be a small volume « 5 mL) initial test
swallow using water soluble contrast materials
such as nonionic isotonic agents (e.g.
Omnipaque or Gastromiro).
 Aspiration of barium can be assessed with a
chest radiograph to document the pattern and
extent of aspiration, before suction and
physiotherapy.
 Repeated or prolonged radiation exposure.

54. 54
 Oesophageal motility is assessed with multiple
single swallows in different positions,
 including recumbent (unlike in a videofluoroscopy
assessment of oropharyngeal dysphagia) , to assess
peristalsis without the effect of gravity.
 Continuous and single swallows are observed
separately as a second swallow obliterates
peristalsis of the first. The oesophageal stage lasts
for 8-20 seconds.

55. CT & MRI
55
 These techniques each show structural lesions, for
example the intracranial disease causing
neurogenic dysphagia ?
 More recently, high speed MRI has been used for
dynamic analysis of the pharyngeal phase of
swallowing, where the oral, pharyngeal and
laryngeal musculature can be evaluated during
movement.
 experimental and costly, and patients need to be
supine - which does not reflect the true physiology
of swallowing.

56. Fibreoptic endoscopic evaluation of
swallowing (FEES)
56
 Also known as video endoscopic
evaluation of swallowing (VEES).
Or 'milk nasendoscopy.
 Trans-nasal insertion of the
nasendoscope provides
assessment of pharyngeal and
laryngeal anatomy and
physiology at rest and in the pre-and
post -swallow stages of dry
(saliva) and bolus swallows,
using normal food and drink.

57. Fibreoptic endoscopic Evaluation of
swallowing with sensory testing
(FEESST)
57
 This is extended technique
 Quantitatively measures sensory loss in the
supraglottic larynx and pharynx by sending air
pulses of differing intensity, duration and
frequency through an additional port in the
endoscope.
 it is an important development as reduced or
absent laryngeal sensation found in endoscopy
correlates with silent aspiration and thus the risk
of aspiration pneumonia.

58. PROCEDURE
58
 The patient sits upright, the nostrils are examined
to detect any septal deviation.
 topical anaesthesia is applied to the nasal
passages (sparingly to avoid desensitizing the
pharynx and larynx).
 Dry and bolus swallows of coloured liquid and
food (using food colouring), are given in
measured volumes.

59. Four different views allow observation of anatomy and physiology during swallowing
as follows:
59
1. Nasal
passage for
elevation of
the dorsal
side of the
velum.
2. Nasopharynx
for nasal
reflux and
lateral and
posterior
pharyngeal
walls.
3. Oropharynx
for base of
tongue,
epiglottis and
Larynx.
4. Hypopharynx
for pyriform
fossae, vocal
folds and
upper

60. Equipment
60
 Includes a flexible
nasendoscope, with
camera for video or digital
(including auditory)
recording and slow motion
playback facilities, with an
additional colour monitor
for immediate biofeedback
with the patient.
 Developments include
reducing the scope
diameter, picture clarity
and size, light source
strength and portability.
 For FEESST, a specially
designed scope and pulse
generator are needed to
deliver quantifiable air
Pulses .

61. ADVANTAGES
61
 Good views of any alterations in the anatomy and of
muscular function in the nasopharynx, oropharynx
and hypopharynx.
 Quantitative objective assessment of pharyngeal
and laryngeal sensitivity with FEESST.
 Assessment of initiation and maintenance of airway
protection.
 Visualization of secretions and any pooling of
secretions, thus helping overall management.

62. 62
 Ability to assess swallow without giving food or drink
to those patients who are nil by mouth.
 Observation of swallowing with a range of normal
food and drink.
 Lengthy or repeated assessments without radiation
exposure. This enables assessment throughout a
meal (to evaluate swallow fatigue, effective of
cumulative bolus residue, delayed reaction to
aspiration and effectiveness of coughing).
 Real time and repeated biofeedback to the patient
for evaluating the effectiveness of therapeutic
manoeuvres.
 Portable and easy implementation at the bedside
and in the clinic.

63. LIMITATIONS
 No view for evaluation of bolus management in the
oral cavity.
 Loss of view ('whiteout') during the swallow due to
pharyngeal constriction around the endoscope lens.
 Quantitative measures of structure displacement are
not possible.
 Limited ability to estimate amount of aspirated
material.
63

64. CONTRAINDICATIONS
64
 Unsuitable patients (e.g. those who are unable to
maintain a stable position, drowsy, uncooperative) .
 Predisposition to risk factors (history of
bronchospasm or laryngospasm, severe heart
disease, recent respiratory distress, allergies) .
 Lack of appropriate medical and nursing support.
Physical obstruction to passing the scope (e.g.
extreme deviation of septum, oedematous mucosa,
hypersensitivity) .
 Obscured view (e.g. large epiglottis, thick secretions)
 Maxillary and other supraglottic resections.

65. Risks
65
 The potential complications listed below are
extremely rare, however, awareness of the risks is
important for those performing FEES.
 Aspiration – (suction equipment should be readily
available).
 Vasovagal responses of hypotension, bradycardia or
cardiac dysrhythmia.
These risks are minimized by local anaesthesia of the
nasal mucosa and care manipulating the scope in
the hypopharynx.

66. 66
 Laryngospasm is less likely to occur in patients with
pooling and aspiration of secretions who also have
poor tactile sensitivity of the larynx, and who
therefore usually need sensation testing. Probing of
the hypopharynx and larynx should be cautious in
those who swallow normally, are asymptomatic of
aspiration, with an adequate cough reflex.
 Nose bleeds can be avoided by the use of topical
decongestant and lubrication of the scope.
 Adverse reactions to the topical anaesthetic are rare,
but take an adequate case history, adhere to
recommended doses and have resuscitation
measures available.

67. Video- FEES
67

68. MANOMETRY
68
 Directly measures:-
 amplitude and
duration of contraction
and relaxation
pressures in the
pharynx, UOS,
oesophagus and lower
oesophageal sphincter
(LOS).
 Measurements are
taken at rest and
during swallowing.

69. Oesophageal Manometry
69
 The oesophageal peristaltic wave pressure rises
slowly to approximately 50 mmHg, and falls rapidly.
 Secondary peristaltic waves arise locally in response
to distension, needed for more solid bolus
transportation.
 Tertiary oesophageal contractions are irregular,
nonpropulsive contractions involving long segments
of the oesophagus.
 The 3 cm long LOS behaves like the UOS, but with a
lower tonic (resting) contraction pressure of 10-30
mmHg relative to intragastric pressure.
 It remains closed except for relaxation when the
bolus and peristaltic wave arrive, as swallowing
induces inhibition of lower oesophageal sphincter
tone activity.

70. Pharyngeal Manometry
Pressure changes in the oropharynx and UOS are
required for effective bolus transit and UOS opening
during swallowing.
UOS opening involves:
 Cricopharyngeal muscle relaxation, preceding
opening by 0.1 second;
 Hyoid and laryngeal elevation, pulling the UOS
open;
 Pharyngeal and tongue base pressure (up to 90
mmHg) on the bolus further pushing open the UOS;
 Cricopharyngeal elasticity allowing the UOS to
stretch open for larger boluses;
70

71. 71
 Closure of the UOS with increased pressure (90
mmHg) ;
 Return to an UOS tonic (resting) pressure of
approximately 45 mmHg.
 The UOS remains closed with increased tonic
pressure with each inspiration to avoid aerophagy.

72. LIMITATIONS
72
 Conventional pharyngeal manometry involves using a
catheter with a limited number (three or four) of pressure
sensors spanning the oropharynx and hypopharynx
(including the UOS), in a unidirectional or multidirectional
orientation.
 Susceptible to technical difficulties with accurate sensor
placement, and inter- and intra subject variation.
 Radial asymmetry of the UOS, as anterior-posterior
pressures are two or three times greater than those
recorded laterally because contraction of the
cricopharyngeus muscle compresses the UOS against
the trachea into an oval slit-like aperture.
 Longitudinal (axial) asymmetry of the UOS, with larger
anterior pressures closer to the pharynx and larger
posterior pressures closer to the oesophagus, especially
in men;

73.  Upward movement of the UOS during swallowing due
to laryngeal movement. Consequently the sensor
may be left in the open oesophageal lumen without
recording UOS relaxation.
 Sensitivity of UOS to diameter size requires the
smallest diameter catheter possible (e.g. 3 mm or
less) to avoid inaccurate and increased UOS tonic
pressure readings;
 UOS tonic pressure increases with stress and
decreases during sleep;
 Over 60 years of age, tonic pressures decline and
pharyngeal pressures during swallowing increase as
a result of reduced compliance of the UOS, thus
requiring greater force to push large boluses through
a less stretchable sphincter
73

74. 74
 The barrier formed by LOS tonic pressure is lower
after meals and tighter at night.
 Similar to the UOS, measurement of the LOS tonic
pressure is complicated by radial asymmetry and a
respiratory pressure fluctuation.
 Because of the differences in anatomy and
physiology and the frequency of recordings,
catheters with miniature strain gauge pressure
transducer sensors are required.

75. High-resolution manometry
75
 Recent advance over conventional manometry for
taking measurements of the oesophagus and upper
and lower oesophageal sphincters.
 It has been made possible by the development of
micro-manometric water-perfused assemblies and
miniaturized solid-state pressure sensors.
 The presence of closely spaced recording sensors
in HRM (up to one pressure sensor per cm)
provides several procedural advantages over
conventional manometry.

76. 76
 It removes the need for the time-consuming station
pull through procedure and facilitates the accurate
positioning of the catheter.
 For pharyngeal and UOS measurements, a solid
state high-resolution manometry catheter can have
a total of 36 pressure sensing elements.
 Sensors are spaced at 1 cm intervals; with each
sensor detecting pressure changes over a length of
2.5 mm and consisting of 12 circumferentially
dispersed smaller sensing elements.
 The pressure recorded at each axial location is the
mean pressure measured from the 12 elements.

77. 77
 Computer technology allows the large data set
acquired by HRM to be analysed and presented
in realtime.
 Concurrent video fluoroscopy images displayed in
the same record as HRM allow simultaneous
analysis,
 HRM detects segmental abnormalities of
oesophageal function and predicts the success of
bolus transport more accurately than
conventional oesophageal manometry, and
identifies clinically important abnormalities not
detected by other investigations

78. High-resolution manometry video
78

79. 79

80. Manofluoroscopy
80
 Pharyngeal manometry is rarely the first or sole
study used to evaluate swallowing function,
because of the limitations , particularly when using
conventional manometry.
 More information is provided when it is performed
simultaneously with videofluoroscopy, termed
manofluoroscopy or videomanometry.
 Shows a simultaneous image with pressure
readings so that clinicians gain information about
bolus flow relative to anatomical movements.
 Radio-opaque metal housing around each pressure
sensor gives accurate information about the
placement and position of the sensors during
movement to ensure.

81. Advantages
81
 Manofluoroscopy aids clinical decisions about
the need for medical procedures:
 It provides information to distinguish between
UOS opening with and without relaxation of
the cricopharyngeal musculature.
 Where adequate UOS relaxation is occurring,
manofluoroscopy can help to differentiate
between poor opening of the UOS secondary
to weak pharyngeal and tongue forces; poor
elevation of the hyoid; and decreased
elasticity of the cricopharyngeus muscle.
 Videofluoroscopy alone without manometry
cannot make the above distinctions.

82. Procedure
82
 Standard methodology for oropharyngeal
manometry is needed because of the technical and
subject variables.
 To date, Normal and dysphagic results are not
directly or numerically comparable because of
different equipment and procedures.
 Salassa et al. have proposed catheter standards for
pharyngeal manofluoroscopy, which aim to enable
comparison of the same patient over time; to
establish normal ranges for all parameters; and to
evaluate abnormal results in relation to the
diagnosis, treatment, outcome and effectiveness of
treatments.

83. Equipment
83
Sensor type
 Catheters with miniature strain gauge pressure
transducer sensors are required for pharyngeal and
UOS measurements for the following reasons.
 Striated muscle contractions are quicker in the
oropharyngeal area, producing altering pressures of
higher frequency and amplitude, compared with the
slower smooth muscle contractions in the
oesophagus.
 The pharyngeal pressure 'wave' travels at a speed of
9-25 cm per second (requiring a recording frequency
of over 50 Hz), whereas the slower oesophageal wave
travels at 4 cm per second (requiring a recording
frequency of 5 Hz).

84.  Patients can be tested
in a normal upright
position, unlike the
supine position with
water perfused
catheters.
 Although less
expensive, water
perfused catheters
are usually slower to
set up and use, and
they also introduce
water into the
pharynx, so causing
unwanted swallows
and poor tolerance.
84

85. 85
Catheter
 The diameter should be small (3 mm or less) both
for comfort and to avoid the reactive increase in
UOS tonic pressure.
 Catheters with fibreoptical 'sensors' are available,
and these provide circumferential readings without
increasing the catheter diameter.
 An ovoid shaped catheter helps to maintain correct
orientation, (as UOS radial pressures are
asymmetrical).
 Clear markings in centimetres, with the distal
sensor marked at 0 cm, indicates anterior and
posterior orientation, and helps with the inter-subject
variation in pharyngeal length and UOS
high pressure zone length.

86. 86
 Catheters need to be 100 cm long for oseophageal
manometry.
 A short (4 cm) malleable section of the catheter
should extend past the most distal sensor to enable
easier naso-pharyngeal insertion
 Also to allow some of the catheter to pass into the
oesophagus to provide catheter stability laterally and
horizontally during manometry recordings

87. 87
Sensor spacing and placement in conventional
manometry
 One sensor each should be placed in three (or four)
locations, which are level with
 the tongue base,
 hypopharynx,
 UOS (and upper cervical oesophagus);
(with 2 and 3 cm between the sensors in the order
stated above)
 Unidirectional in-line sensors, orientated posteriorly,
capture readings of maximum amplitude.
 The advantage of circumferential sensors is that
radial asymmetries can be averaged, and readings
are not affected by unwanted changes in the
orientation of the catheter.

88.  Correct placement of the UOS sensor can be seen
during swallowing by production of a waveform that
has a negative nadir, preceded and followed by an
elevated pressure wave and clearing wave.
 A pressure transducer too high in the nasopharynx
should be avoided in case the readings record the
soft palate against the posterior pharyngeal wall.
88

89. 89
 The techniques of station pull through (SPT) or rapid
pull through (RPT) are used to position the catheters
accurately. Each sensor passes the DOS in Turn.
 In HRM, the above procedural difficulties are
overcome by the large number of circumferentially
placed and closely spaced sensors.

90. METHODOLOGY
90
Salassa et al. also suggest that methodology
guidelines are still needed in order to
standardize:
 Bolus volumes, consistencies and
temperatures;
 Duration of swallow intervals;
 Single or multiple swallow analysis;
 Methods to obtain and values of pressure
recordings to analyse;
 Comparable software analysis systems.

91. Recordings
91
 A computerized
mulitchannel recording
device is used to collect
store and display the
pressure readings.
 A channel is needed for
each transducer pressure
reading, and these are
displayed in graph form
with amplitude (x axis)
against time (Y axis).

92. 92
 Computer recordings are accurate, quick and
unbiased.
 Automatic data collation into a database gives
faster analysis and interpretation.
 The frequency by which pressure reading data is
recorded needs to be standardized.
 Each laboratory needs to decide whether to
average all the readings taken at the UOS) and for
this to be a constant in recorded values over time
and between patients.

93. Calibration
93
 Regular calibration of the equipment is necessary
before the equipment is used.
 The measurement of UOS pressure is usually
expressed relative to intrapharyngeal zero
baseline, (equivalent to atmospheric pressure).
 Sensors are zeroed to an accurate baseline of
atmospheric pressure) then a known pressure
(e.g. 200 mmHg) is applied to calibrate) before
readings are taken.

94. 94
CONTRAINDICATIONS
 Patients suspected of having a perforated
gastrointestinal tract.
 Same as Endoscopy.

95. Analysis
95
 UOS tonic (resting) pressures, and variations
in pressure in the pharynx, UOS and
oesophagus during swallowing are the main
measurements. Large numbers of swallows
per subject are needed due to intra-subject
variability.
 Two types of pressure can be analysed, and
both are seen within one pressure wave
shape :
1. Bolus pressure on the sensors as they are
surrounded by fluid, also called intra-bolus
or luminal or cavity pressure, and usually
small in amplitude.
2. Contact pressure from contraction of the
lumen walls on the sensors during

96. 96
 Measurements made include:
1. maximum and minimum pressures;
2. duration of contraction with the sequence, and
relative timing of contractions and relaxations.

97. OTHER INVESTIGATIONS
97
Respiration
 The oropharyngeal tract is the same anatomical
channel for swallowing and breathing, resulting in
the need for deglutition apnoea and the potential
risk of aspiration.
 Respiratory recordings can measure the duration
and timing of deglutition apnoea, direction and rate
of airflow and thus a more complete picture of the
physiology of swallowing.
 Continuous recordings of oxygen saturation by
pulse oximetry have also been investigated as a
possible marker of aspiration with conflicting
results.

98. Ultrasound
98
 The ultrasound transducer with high frequency
sounds ( > 2 MHz) is placed sub mentally to
produce dynamic images of the soft tissue in the
oral cavity and parts of the oropharynx, and the
motion of the hyoid can be tracked.
 It is noninvasive and risk free.
 Quality of the tongue image, for measuring tongue
movements, is not easy to interpret.
 The pharyngeal stage of swallowing cannot be
viewed.

99. Oesophageal pH monitoring
99
 Prolonged (24-hour ambulatory) pH monitoring is
the most reliable method of diagnosing gastro-oesophageal
reflux, especially atypical
presentations.
 The distal oesophageal pH probe is placed 5 cm
above the LOS (position determined by
manometry) and the proximal one below the
UOS, thus any reflux is measured along the
entire length of the oesophagus.
 However, the invasive technique prevents some
patients from undertaking activities that provoke
reflux during the investigation, so underestimating
their problems?

100. Scintigraphy
100
 This procedure tracks movement of the bolus
over time, and quantifies the residual bolus in the
oropharynx, larynx and trachea, using radio
nuclide material with liquid or food, and a gamma
camera.
 Although it detects aspiration and reflux, it does
not have a significant advantage over other
functional investigations as it does not image
anatomy and physiology, nor does it image the
biomechanics of swallowing, and the cause of
aspiration cannot be determined.

101. Lingual pressure recording
101
 Recently, three-bulb linear manometric sensor
arrays (Kay Elemetrics Workstation) have been
used to evaluate the timing and pressure patterns
of the tongue during the oral phase of swallowing.
 The small strain gauge pressure sensors are
attached to the palate).

102. Electromyography
 Surface electromyography (sEMG) measures the
amplitude (voltage) of swallowing muscle activity
(from the submental muscle group) from electrodes
placed on the throat, and is a method for identifying
the onset of swallowing only.
 Activity is recorded from any or all of the submental
muscles during swallowing, and they are variable in
their order of activation both within and between
subjects.
102

103. Thank You
103

104. 104

105. Double contrast image of
pharynx
105

106. Examination of oesophagus
106

107. Dc image of gastro oesophageal
junction
107

108. asymmetry
108

109. Stasis
109

110. Cricopharyngeal dysfunction
110

111. 111

112. 112

113. 113

114. 114

115. 115

116. 116

117. Aspiration
117

118. Web
118

119. 119
THANK YOU