Scott-Brown Chapter 50: Functional Investigations of the Upper Gastrointestinal Tract

ENT PG Exam-Oriented Notes

1. OVERVIEW AND ENT RELEVANCE

• Laryngopharyngeal reflux (LPR) is the commonest UGI disorder seen by ENT surgeons
• Dysphagia is a key ENT symptom requiring UGI evaluation
• Globus pharyngeus, chronic cough, dysphonia, and post-nasal drip may all have UGI origin
• ENT surgeons must understand and interpret UGI functional tests

2. ANATOMY RELEVANT TO UGI FUNCTION

• Formed by: cricopharyngeus muscle (main), inferior pharyngeal constrictor, proximal cervical oesophagus
• Resting pressure: 40-80 mmHg
• Relaxes during swallowing, belching, vomiting
• Acts as the last barrier protecting the laryngopharynx from gastric contents

3. SYMPTOMS SUGGESTING UGI DYSFUNCTION (ENT PERSPECTIVE)

• 9-item questionnaire (each item scored 0-5)
• Score >10 = possible LPR
• Score >20 = moderate LPR
• Score >30 = severe LPR
• Fairly sensitive but limited specificity (other causes of laryngeal inflammation also raise RSI)

1. Hoarseness/voice problems
2. Throat clearing
3. Excess throat mucus/post-nasal drip
4. Difficulty swallowing
5. Coughing after eating/lying down
6. Breathing difficulties/choking
7. Troublesome cough
8. Lump in throat/globus sensation
9. Heartburn/chest pain/indigestion

• Dysphonia
• Swallowing difficulty ("pseudodysphagia")
• Globus / FLIT (feeling of lump in throat) / FOSIT
• Throat clearing / tickle in throat
• Sore throat
• Cough / choking
• Thick mucus in throat, post-nasal drip, "catarrh"
• Laryngospasm / cough syncope

• Reflux disease
• Smoking / inhaled irritants
• Alcohol
• Allergy
• Viral infections
• Voice abuse

4. ENDOSCOPIC INVESTIGATION

A. Reflux Finding Score (RFS) - High Yield

• Total score: 0-26
• Score >7 is abnormal (suggests LPR)
• Pseudosulcus (subglottic oedema below vocal fold) is the most specific finding for LPR

B. Transnasal Oesophagoscopy (TNO) - Very Important

• ENT surgeons increasingly using TNO as office procedure
• Avoids hospital admission and sedation (unlike traditional endoscopy)
• Endoscope diameter: 3.1-5.3 mm outer diameter
• Working channel: 2 mm (for suction, biopsy forceps, injection, laser fibre)
• Alternative: sheath technique (endoscope doesn't need full sterilisation between patients)

• Laryngopharyngeal reflux
• Dysphagia evaluation
• Monitoring of Barrett's oesophagus
• Oesophageal foreign body
• Surveillance of head and neck cancer patients
• Post-treatment assessment

• Office/outpatient setting
• No sedation required
• No hospital admission
• Cheaper
• Transnasal route = familiar to ENT surgeons
• Patient can speak during procedure (functional assessment during swallowing)

5. pH MONITORING

A. Standard pH Monitoring (single sensor)

• Probe placed 5 cm above LOS
• Records pH over 24 hours
• Normal: pH <4 for <4.2% of total time (DeMeester score)
• DeMeester score >14.72 = abnormal

B. Dual-channel pH Monitoring

• Two sensors: one 5 cm above LOS (oesophageal) + one in hypopharynx (4-5 cm above UOS)
• Detects extra-oesophageal/pharyngeal reflux events
• Pharyngeal pH <4 on hypopharyngeal probe = extra-oesophageal reflux event

C. Wireless pH Capsule (Bravo)

• Capsule attached to oesophageal mucosa
• 48-96 hour recording (longer than catheter)
• More comfortable for patient (no transnasal catheter)
• Transmits data via radiofrequency to external recorder

D. pH Parameters Measured:

• % total time pH <4
• % upright time pH <4
• % supine time pH <4
• Number of reflux episodes
• Number of episodes >5 minutes
• Longest reflux episode
• DeMeester composite score

6. IMPEDANCE-pH MONITORING (MOST IMPORTANT CURRENT TEST)

• Multi-channel intraluminal impedance (MII) combined with pH = MII-pH
• Gold standard for detecting all types of reflux (acid, weakly acid, alkaline/non-acid)
• Dual pH-impedance manometry (combined) = most helpful relatively objective test for extra-oesophageal reflux

• Many LPR patients have normal pH studies but symptomatic
• Weakly acidic or non-acid reflux causes laryngeal damage (pepsin is active even at mildly acidic pH)
• Detects gas (belching patterns) and liquid reflux

7. OESOPHAGEAL MANOMETRY

A. Conventional/Standard Manometry

• Measures pressure at multiple points along oesophagus
• 8-channel water-perfused catheter (traditional)
• Evaluates: LOS pressure, oesophageal body peristalsis, UOS pressure

• LOS resting pressure: 10-45 mmHg
• LOS relaxation: >90% during swallowing
• UOS resting pressure: 40-80 mmHg
• Oesophageal peristaltic amplitude: 30-180 mmHg

B. High-Resolution Manometry (HRM) - Modern Standard

• Type I (Classic): Failed LOS relaxation, absent peristalsis, no pressurisation
• Type II: Failed LOS relaxation, pan-oesophageal pressurisation (>30 mmHg in >20% swallows) - best prognosis
• Type III (Spastic): Failed LOS relaxation, premature/spastic contractions - worst prognosis

• Key HRM metric
• Measures LOS relaxation during swallowing
• Normal IRP: <15 mmHg (with Medtronic/Sierra) or <10 mmHg (depending on system)
• Elevated IRP = outflow obstruction (as in achalasia, EGJ outflow obstruction)

C. Pharyngeal Manometry / High-Resolution Pharyngeal Manometry

• Pharyngeal contraction amplitude (velopharynx, mesopharynx, hypopharynx)
• UOS resting pressure
• UOS relaxation (nadir pressure, duration)
• Pharyngo-UOS coordination
• Hypopharyngeal intrabolus pressure

8. VIDEOFLUOROSCOPY / BARIUM SWALLOW

Modified Barium Swallow (MBS):

• Gold standard for oropharyngeal dysphagia assessment
• Done by speech therapist + radiologist
• Assesses all 4 phases of swallowing in real-time
• Detects: aspiration, penetration, residue, vallecular pooling, pyriform sinus overflow

Key Findings:

• Cricopharyngeal bar: Posterior indentation at C5-C6 = cricopharyngeal dysfunction
• Zenker's diverticulum: Posterior pharyngeal pouch above cricopharyngeus (Killian's triangle)
• Aspiration: Barium below vocal fold level during swallow
• Penetration: Barium entering laryngeal vestibule but not below cords

• 1 = No penetration
• 2-5 = Laryngeal penetration (various depths)
• 6-8 = Aspiration (6 = ejected, 7 = not ejected but responds, 8 = silent aspiration)

9. FIBRE-OPTIC ENDOSCOPIC EVALUATION OF SWALLOWING (FEES)

• Performed by ENT surgeon or speech therapist
• Flexible nasendoscope positioned above larynx
• No radiation (unlike videofluoroscopy)
• Can use coloured food/liquid (no barium)
• Portable - can be done at bedside or ICU

• No radiation
• Portable
• Shows anatomy directly
• Can assess sensory function (FEESST - with air pulse)
• Demonstrates laryngopharyngeal secretion pooling

FEESST (FEES with Sensory Testing):

• Air pulses delivered to aryepiglottic fold
• Tests laryngeal adductor reflex (LAR)
• Normal threshold: <4 mmHg
• Elevated threshold = laryngeal sensory deficit, aspiration risk

10. SCINTIGRAPHY (RADIONUCLIDE STUDIES)

Oesophageal transit scintigraphy:

• Technetium-99m sulphur colloid in semi-solid bolus
• Measures oesophageal transit time
• Normal oesophageal transit: <10 seconds in upright position

Gastric emptying scintigraphy:

• Tc-99m labelled solid meal
• Diagnoses gastroparesis (delayed gastric emptying)
• Relevant in LPR: gastroparesis → increased gastric pressure → promotes reflux
• Normal: >50% gastric emptying at 2 hours

Salivagram:

• Radiolabelled saline administered orally
• Detects aspiration of saliva (chronic aspiration)
• Useful in neurologically impaired patients/children

11. SALIVARY PEPSIN ASSAY

• Peptest (Biocartis): non-invasive lateral flow device
• Detects pepsin in saliva (or laryngeal secretions, middle ear fluid)
• Pepsin is produced only by stomach - its presence in pharynx/larynx = reflux
• Sensitivity ~89%, specificity ~68% for LPR
• Advantage: non-invasive, point-of-care, cheap
• 2 saliva samples (morning/on-waking) + 1 after symptom provocation

• Pepsin detected even with non-acid reflux (active below pH 7)
• pH studies miss non-acid reflux
• Pepsin assay gaining popularity as first-line screening tool

12. OESOPHAGEAL MUCOSAL IMPEDANCE

• Assesses mucosal integrity directly
• Damaged/inflamed mucosa (from acid exposure) = lower impedance
• Pan-oesophageal baseline impedance <2292 Ω/cm = abnormal (GORD marker)
• Complements pH-impedance monitoring

13. PROTON PUMP INHIBITOR (PPI) TRIAL

• 2x daily PPI for 2-3 months (e.g., omeprazole 20-40 mg BD or lansoprazole 30 mg BD)
• Morning dose: 30-60 minutes before breakfast
• Evening dose: 30-60 minutes before evening meal
• Response to PPI = positive = LPR likely
• Limitation: Placebo response rate ~20-40%; specificity poor
• Non-response does not rule out LPR (non-acid reflux, inadequate compliance, pepsin damage persists)

• LPR has both upright (daytime) and supine (nocturnal) reflux events
• Nocturnal acid breakthrough occurs with once-daily PPI

14. INVESTIGATIONS SUMMARY TABLE (High-Yield MCQ)

15. KEY EXAM POINTS (Likely MCQ/Short Answer Topics)

1. RSI >10 = possible LPR; RFS >7 = abnormal laryngoscopy for LPR
2. Pseudosulcus (subglottic oedema) = most specific laryngoscopic sign of LPR
3. Dual pH-impedance manometry = most helpful objective test for extra-oesophageal reflux (Scott-Brown statement)
4. No gold standard exists for LPR diagnosis
5. Pepsin is produced only by the stomach - its presence in pharynx confirms reflux even if pH normal
6. MII-pH detects acid, weakly-acidic AND non-acid reflux - superior to pH alone
7. FEES vs videofluoroscopy: FEES no radiation/portable but "white-out" at swallow moment
8. FEESST: Air pulse to aryepiglottic fold tests laryngeal adductor reflex; threshold >4 mmHg = sensory deficit
9. Achalasia type II = best response to treatment; type III = worst
10. Chicago Classification uses IRP as key metric (normal <15 mmHg)
11. UOS = cricopharyngeus (main) + inferior constrictor + proximal cervical oesophagus
12. TNO (transnasal oesophagoscopy) = office procedure, no sedation needed; outer diameter 3.1-5.3 mm; 2 mm working channel
13. Silent aspiration = aspiration without cough reflex (score 8 on Rosenbek scale)
14. Cricopharyngeal bar on barium swallow = at C5-C6 = cricopharyngeal dysfunction
15. Zenker's diverticulum = posterior pouch above cricopharyngeus at Killian's triangle

16. CLINICAL SCENARIOS FOR VIVA