GERD Flashcards
1
Q
Dfine GORD
A
- actionable GORD requires conclusive evidence of reflux-related pathology on endoscopy and/or abnormal reflux monitoring in the presence of compatible troublesome symptoms
2
Q
Describe the epidemiology of GORD
A
- 20% of western populations
- 3792 per 100000
- slight female skew
- increasing prevalence in developing countries
- stable or falling prevalence in western countries
3
Q
List the four factors that contribute to pathophysiology
A
- Lower (o)esophageal sphincter – LOS/LES tone
- Anatomical disruption on LOS
- Oesophageal mucosal defences
- Motility
4
Q
Describe the sphincter
A
- 3-4 cm, tonically contracted, smooth muscle
- crural diaphragm provides an extra layer of protection
- LOS and crural diaphragm together constitute the barrier
- most of the time LOS is closed and opens in response to food in the oesophagus
- transient LOS relaxations account for 50-70% of reflux events
5
Q
Describe how TLOSR occurs and factors that decrease LOS tone
A
- where teh LOS relaxes and intragastric pressure exceeds that of LOS, allowing for reflux of gastric contents into oesophagus
- many factors decrease LOS tone
- gastric distention e.g. large meal size
- chocolate
- caffeine
- smoking
- pregnancy
- meds: nitrates, CCBs
6
Q
Describe anatomical disruptions to sphincter
A
- hiatus hernia is most common - pulls above diaphragm
- LOS is shorter and weaker due to loss of support of crural diaphragm, leading to increased TLOSR
- makes reflux more likely
- can increase severity of erosive disease due to nocturnal reflux
- volume reflux
7
Q
Describe mucosal defences
A
- pre-epithelial:
- thin water layer with limited buffering capacity due to salivary bicarbonate
- secretions from oesophageal submucosal glands
- epithelial defences
- cell membranes and the intercellular junctional complex limit the rate of hydrogen ion penetration into the intracellular space or cell cytosol
- cellular and intracellular buffers (HCO3, proteins, phos) that neutralise back-diffusing luminal acid
- cell membrane ion transports remove acid from the cytosol when intracellular pH falls to acidic levels
8
Q
Describe how breach of mucosal defences occurs
A
- high luminal acidity, alcohol , heat causing caustic injury, smoke derived chemicals
- acid attacks and damages intracellular junctions
- increased paracellular permeability ie non-erosive reflux
- acidification of intracellular space by back diffusion of luminal acid
- cell oedema and necrosis
- poor epithelial repair due to reduced salivary epidermal GFs
- erosive reflux disease
9
Q
Describe the effect of altered motility
A
- reduced acid clearance by impaired oesophageal peristalsis
- ineffective oesophageal motility present in about 50% of cases of acid reflux referred for manometry and pH studies - direction of causality unknown
- swallowing of saliva which contains bicarbonate is essential to clear oesophageal acid and restoring oesophageal pH
- primary oesophageal peristalsis is initiated by swallowing ~60/h
- secondary peristalsis is not initiated by swallowing and can be triggered by luminal content and acid
- re-reflux can occur when refluxate is cleared but trapped in a hernia sack increases oesophageal acid exposure time
10
Q
Breakdown the symptoms
A
- oesophageal
- heartburn
- retrosternal burning pain, can radiate into neck, typically after meals or laying down
- heartburn
- regurgitation
- retrograde movement of acidic gastric contents into the mouth or pharynx
- chest pain
- extraoesophageal
- cough
- asthma
- laryngitis
- hoarse voice
- dental erosions
- globus sensation - feeling of something stuck in throat around sternal notch
11
Q
What is the significance of oesophageal vs extra-oesophageal symptoms?
A
- extra- symptoms not as responsive to therapeutics
- heartburn 50-70% will experience symptom relief from PPI
- chest pain if positive pH study up to 80%
- chronic cough, asthma, hoarse voice and pH negative chest pain , less than 25% will improve, some may get worse
12
Q
Provide an overview of the diagnosis of GERD
A
- troublesome suspicious GERD symptoms
- if no alarm symptoms, empiric trial of anti-secretory therpay
- oesophageal physiologic evaluation i.e.
- endoscopy (structural overview of oesophageal and stomach - see LA grades)
- ambulatory pH monitoring
- adjunctive approach
13
Q
Describe wireless ambulatory monitoring
A
- wireless - Bravo capsule
- attached endoscopically 3-5 cm above GOJ
- wireless pH recording for up to 48h
- capsule detaches spontaneously
- attachment can cause chest pain and discomfort in some people
- advantages: wireless, 48h
- disadvantages: requires endoscopic insertion, possibility of chest pain post attachment, early capsule detachment, acid exposure time only (nothing else measured - look to see if pH dips below 4)
14
Q
Describe wired ambulatory monitoring
A
- wired - 24 h pH
- catheter based system
- inserted while patient is awake therefore no anaesthetic risk
- multiple catheter options
- impedance capacity
- advantages: multiple catheter option (Single or dual pH sensor +/- impedance i.e. flow across oesophagus- helps to assess response to treatment, disringuish GERD from NERD), inserted in clinic setting i.e. no endoscopy, simple reinsertion if catheter dislodged, no pain
- disadvantages: unable to pass catheter nasally e.g. due to previous ENT surgery or anatomical abnormalities, if unable to tolerate catheter insertion, attached to box for 24h -can’t have shower
15
Q
Describe the LA classificaiton
A
- A – mucosal break < 5mm ie linear erosion
- B – mucosal break > 5mm
- C – Mucosal break which extends between folds ie ulcer
- D – Mucosal break > 75% circumference
