phmetría de 24 hrs

1. ESOPHAGEAL pH STUDIES IN
ESOPHAGEAL DISEASE
General Thoracic Surgery
Chapter 119

2. Gastroesophageal reflux
disease （ GERD ）
• Continues to be a challenge to diagnosis.
• Classic symptoms– Only 60 %-- Heart-burn
and regurgitation.
• Achalasia, cholelithiasis, gastritis, peptic
ulcer, coronary artery disease – All mimic
typical symptoms with GERD.

3. Gastroesophageal reflux
disease （ GERD ）
• Atypical symptoms include chest pain,
hoarseness, recurrent sorethroat, dental
caries, bronchospasm, wheezing, chronic
cough, recurrent chest infection.
• Diagnosis include scintiscanning, barium
radiography, acid-perfusion or Bernstein
test, panendoscopy, present esophagitis.

4. Gastroesophageal reflux
disease （ GERD ）
• The introduction of 24-hour esophageal pH
monitoring provided a method to quantitate
esophageal acid exposure.
• Greatest sensitivity and specificity for
diagnosis of gastroesophageal reflux – As
the gold standard test.

6. Gastroesophageal reflux
disease （ GERD ）
• Three main cause of increase exposure of
esophagus to refluxed gastric contents—
(1) LES defective– Most.
(2) Inefficient esophageal clearance as low
peristaltic amplitudes or increase ineffective
contractions.
(3)Gastric abnormal– Decrease gastric
empting.

7. Gastroesophageal reflux
disease （ GERD ）
• In early disease, the reflux episode occurred
in upright position.
• Bipositional reflux suggests more advanced
disease and LES is severely impaired.
• Pure supine reflux is rare.
• Prolong reflux episodes suggest delayed
esophageal clearance.

8. Bernstein test
• Acid-perfusion test — Patient sitting with N-G
tube 30 cm from nares, infusion normal saline
15 min, 0.1 N HCL at rate of 6 ml/min until
symptoms produced.
• The test is positive in two successive infusion
periods acid induces pain and saline induces
relief.
• Specificity 89%, sensitivity is low because the
pain induced by acid infusion does not correlate
with the severity of esophagitis present.

9. Acid emptying test
• Measeure the esophageal emptying capacity.
• A bolus 15 ml of 0.1N HCl is introduced into
esophagus 10 cm above the pH probe, patient
repeat dry-swallows at 30-second intervals.
• In normal– Distal esophagus is cleared of acid
within 10 swallows.
• Prolonged clearance test indicates an impaired
capacity of the esophagus to clear the irritant
material.
• Lacks sensitivity.

10. 24-hour esophageal pH monitoring
• Importance of—to detect an increased
esophageal exposure to refluxed acidic
gastric contents.
• patient with severe symptoms are found
mild degree esophagitis in endoscope
frequently.

11. 24-hour esophageal pH monitoring
• Mucosa injury was greatest in the exposure
of pH 0-2.
• Normal– The gastric pH is 1-2, esophageal
pH 4-7.
• Continuously measured esophageal pH
below 4– Became the commonly used
threshold of determing a reflux episode.

12. 24-hour esophageal pH monitoring
• False negative—duodenogastric reflux.
• Alkaline secretions neutralize gastric acid.
• If suspected, a probe measures bilirubin.
• Food in stomach can also neutralized gastric
acid.
• Probe malfunction or misplacement.
• Medication use-- particularly proton pump
inhibitors.

14. Analysis of data
• Analysis of pH tracing allowed calculation
of the time that esophageal pH less than 4.
• This value dose not reflect how the
exposure occurred, fig 119-3.
• It is necessary to know the number of times
that esophageal drops below 4 and the
duration of each episode.

16. Analysis of data
• Esophagel pH can fluctuate just above and
below 4 after a reflux episode fig 119-4.
• Six components of 24-hour pH record, table
119-1,2.
• Graphically displayed, fig 119-5.

20. Performance of the study
• All medication affect the pH should be
stopped.
• PPI — 2 week.
• H2-blocker — 2 day.
• Antacid — 12 hour.
• Promote gastrointestinal motility
medication — 2 days.

21. Performance of the study
• Keep accurate diary.
• Document meal periods, any symptoms.
• Only water is allowed between meal.
• Eat normal-size meal.
• Avoid much carbonated beverages –
Because they have acidic pH and cause
belching.

22. Performance of the study
• Sleep only at night.
• Avoid vigorous exercise.
• Avoid alcohol drinking, cigarette smoking.

23. Performance of the study
• Ideal probe to measure 24-hour pH—Small,
firm, rapid response, minimally affect by
temperature, no hysteresis effect, exhibit no
drift, inexpensive, simple to calibrate,
disposable or sterilizable – Not exist.
• Two probes—glass or antimony, fig 119-6,
• The probe should be calibrated in standard
solutions at pH 1,4,7;

25. Performance of the study
• Placement of probe — Proper positioning of
pH electrodes requires prior manometry.
• The probe must be placed 5 cm proximal to
the upper border of LES, trans-nasally.

27. Esophageal pH monitoring in
specific circumstances
• Unexplained chest pain.
• Recurrent pulmonary infection.
• Adult-onset asthma.
• Heartburn symptoms.

28. Unexplained chest pain
• 10% GERD with chest pain as the only
symptoms (esophageal claudication).
• Exercise can induce reflux then exercise-induced
chest pain.
• 24-hour pH monitoring is more sensitive.
• Ambulatory 24-hour esophageal manometry and
pH monitoring.
• Occurred in nutcracker esophagus or diffuse
esophageal spasm.

29. Recurrent or persistent
respiratory symptoms
• Asthma, recurrent pneumonia especially in
mid-lung field, severe bronchopulmonary
disease in nonsmoker without obvious
allergic triggers, onset bronchial asthma in
late childhood or adult life.
• Endoscopic esophagitis appear less
common.

30. Recurrent or persistent
respiratory symptoms
• 45% of patient with reflux-induced
respiratory disorder were found
abnormalities in esophageal contractility

35. Achalasia
• Some with heart-burn symptoms.
• When regurgitate, they usually describe the
material as bland tasting.
• No significant reflux of gastric contents up
into the esophagus.

36. Achalasia
• 24-hour pH monitoring— Fermentation of
retained food material in esophageal can
produce a slow decline in esophageal pH to
less than 4.
• Distinguish between fermentation and
reflux– The percentage of time that pH less
than 3– Fermentation never produced a pH
less than 3.

38. Bile
• Duodenogastric reflux is rare.
• Increase alkalinity in esophagus.
• Cannot distinguish between the effect of
swallowed saliva.
• Second probe can positioned in stomach,
acid reflux— Drop in esophageal pH less
than 4 and gastric pH remain less than 4.

39. Mixed reflux
• Esophageal pH decrease from 6 to 4-5 but
gastric pH risen above 4.
• Alkaline reflux – rise in esophageal pH
above 7 and gastric pH greater than 4