Session 11 Flashcards
What is a vagotomy and when is it commonly used?
a surgical operation in which one or more branches of the vagus nerve are cut, typically to reduce the rate of gastric secretion (e.g. in treating peptic ulcers)
What is a highly selective vagotomy?
refers to denervation of only those branches supplying the lower esophagus and stomach (leaving the nerve of Latarjet in place to ensure the emptying function of the stomach remains intact). It is one of the treatments of peptic ulcer.
Why is a vagotomy less commonly used for PUD?
- acid secretion control with H2 receptor antagonists, such as cimetidine, ranitidine, and famotidine
- proton pump inhibitors (PPIs), such as pantoprazole, rabeprazole, omeprazole
Highly selective vagotomy includes:
- denervation of only the fundus and body (parietal cell-containing areas) of the stomach (also called parietal cell vagotomy)
- preserves the nerve supply of the antrum and pylorus; a pyloric drainage procedure is not needed. It does not denervate the liver, biliary tree, pancreas, or small and large bowel. This procedure is also called proximal gastric vagotomy.
- What is Gastro-oesophageal reflux disease (GORD)?
- Symptoms include:
- Complications include:
- Risk factors include:
- Cause:
- Treatment
- Long-term condition where stomach contents come back up into the esophagus
- the taste of acid in the back of the mouth, heartburn, bad breath, chest pain, vomiting, breathing problems, and wearing away of the teeth.
- esophagitis, esophageal strictures, and Barrett’s esophagus
- obesity, pregnancy, smoking, hiatus hernia, and taking certain medicines (antihistamines, calcium channel blockers, antidepressants, and sleeping medication)
- poor closure of the lower esophageal sphincter
- Lifestyle changes - not lying down for three hours after eating, losing weight, avoiding certain foods, and stopping smoking
Medications - antacids, H2receptor blockers, proton pump inhibitors, and prokinetics
Surgery - Anti-reflux surgery
Gastric mucosa
- Defensive factors:
- Aggressive factors:
- Epithelial integrity
- Cell replication & restitution
- Mucous membrane barrier
- Vascular supply
- Epithelial integrity
- Acid
- Helicobacter pylori
- Drugs
- Acid
What does hyperemia mean?
an excess of blood in the vessels supplying an organ or other part of the body.
Parietal [oxyntic] cell
- Targets: Stimulatory receptors of the baso-lateral membrane
Medication which binds to this target?
- Target: Baso-lateral membrane receptors
Medication which binds to this target?
- Proton pump [canalicular membrane]
- Acetylcholine, Cholecystokinine B [CCK-B], Histamine 2 receptor [H2]
What is this image showing?
HK ATPase exchanges H for K
PPI action?
- Delayed as not all pumps active all of the time
- Max efficacy after 2-3 days
- Restoration of acid secretion requires de novo synthesis
H2 receptor antagonists
- Short half life
- bd dosage
State the targets for Neuro-endocrine regulation for acid control
- Cholecstokinine B [CCK B]
- Enterochromaffine like cells [ECL]
- Gastrin [G]
- Gastrin releasing protein [GRP]
- Somatostatin 2 receptor [SSTR2]
Which bacteria causes peptic ulcer disease & state its pathology
State the no. Of patients with a duodenal & gastric ulcer infected with H.pylori
- Describe the Helicobacter pylori pathogen
- Symptoms
- Causes
- Diagnostic method
- Medication:
- gram-negative
- microaerophilic (low o2 conc)
- helix
- contains a hydrogenase that can produce energy by oxidizing molecular hydrogen (H2) made by intestinal bacteria. It produces oxidase, catalase, and urease.
- gram-negative
- Asymptomatic
- Helicobacter pylorispread by fecal oral route
- Urea breath test, fecal antigen assay, tissue biopsy
- Proton pump inhibitor, clarithromycin, amoxicillin, metronidazole (triple therapy)
‘Drugs for peptic disorders’
Antacids
Alginates (mops up excess acid and forms a pH-neutral barrier that reduces reflux episodes)
- H2RA e.g.
- PPI e.g.
- Cimetidine, Ranitidine,
- Nizatidine, Famotidine [‘safe, interactions and SE minimal]
- Cimetidine, Ranitidine,
- Omeprazole,Lansoprazole,
- Rabeprazole,Pantoprazole,
- Esomeprazole [possibly safe (intermittend scares), diarrhoea]
- Omeprazole,Lansoprazole,
GORD treatment [principles]
- Symptom control
- Healing of oesophagitis
GORD symptom control
- Step up:
- Step down:
- Lifestyle
- Antacids? Alginates
- H2 RA
- PPI
- Lifestyle
- PPI
- H2RA
- Anacids/ alginates
- lifestyle
- PPI
Subtypes of oesophagitis
- reflux
- infectious ( Candida (Esophageal candidiasis), Herpes simplex (Herpes esophagitis), CMV)
- drug induced (NSAIDs, quinidine)
- chrons
Treatment for oesophagitis
reflux esophagitis - H-2 receptor blockers, proton pump inhibitors, and prokinetics, which help with the emptying of the stomach
infectious esophagitis - antibiotics
Peptic ulceration treatment:
- Stop NSAIDS
- H2RA/ PPI 6/52
- H pylori eradication -> 2 antibiotics and full acid blockade with PPI e.g. Clarithromycin 500 mg bd, Amoxycillin 1g bd, lansoprazole 30mg bd
Asthma Pathophysiology
Treatment for asthma
Why is asthma a heterogeneous disease
- Pathologically e.g. eosinophilic versus neutrophilic inflammation
- Symptom patterns and triggers of exacerbations
- Response to treatment
Stepwise management of asthma in adults
Asthma control
- Asthma control means:
- Before initiating a new drug therapy:
- • minimal symptoms during day and night
- minimal need for reliever medication
- no exacerbations
- no limitation of physical activity
- normal lung function (FEV1 and/or PEF >80% predicted or best)
Aim for early control, with stepping up or down as required
- • check compliance with existing therapies
- check inhaler technique
- eliminate trigger factors
Give a summary of asthma management in adults
Step 1
Mild intermittent asthma
- Treatment given?
- Mechanism of action?
- Used?
- B2 -agonist site of action when considering symptom relief
- Short-acting B2- agonist (salbutamol, terbutaline)
- Used for symptom relief through reversal of bronchoconstriction
* *Prevention of bronchoconstriction i.e. on exercise** - Agonists should only be used on an as-required basis
If used regularly, they reduce asthma control - • Predominant action is on airway smooth muscle
• Potentially inhibit mast cell degranulation if only used intermittently
• On regular use of B2 degranulation in response to allergen increases
What is the B2 receptor function in airway smooth muscle?
Using the graph state which lines are likely to be
Formoterol 12 µg
Formoterol 6 µg
Salbutamol 200 µg
Salbutamol 100 µg
Placebo
Salmeterol*
State which line is Formoterol Turbuhaler® 6 mg and Terbutaline Turbuhaler® 0.5 mg
B2-agonist side-effects?
Adrenergic i.e. tachycardia, palpitations, tremor……
Step 2
Regular preventer therapy
Medication given?
Start when?
Inhaled corticosteroids
- Using B2 agonist ≥3 times/week
- Symptoms ≥3 times/week
- Waking ≥1 time/week
- Exacerbation requiring oral steroids in last 2 years (consider)
- How does corticosteroids affect the asthma pathophysiology?
- Other than it’s effects on the bronchioles what are the benefits of inhaled corticosteroids
- Image
- • Improve symptoms
- Improve lung function
- Reduce exacerbations
- Prevent death