Cystic Fibrosis and the Gastrointestinal tract Flashcards
What is the cystic fibrosis transmembrane conductance regulator (CFTR)?
- a membrane protein and chloride channel
- encoded by the CFTR gene
- this is mutated in cystic fibrosis
What type of mutation, in terms of how affected genes are is cycstic fibrosis?
- point mutation
- a single nucleotide is affected
What is the most common genetic mutation in cycstic fibrosis?
- deltaF508
In cystic fibrosis are the mutations in the CFTR that patients have on their 2 different alleles homozygous or heterozygous?
- can be both
- homozygous (2 of the same gene)
- heterozygous (2 different genes) - RARER
In cystic fibrosis mutations in the CFTR affect the membrane proteins ability to pump chloride (Cl-). In the body this specifically affects something that is produced by epithelial cells, and therefore affects very specific tissues. What is it that is affected in cystic fibrosis?
- mucous]
- lungs, pancreas, GIT
In cystic fibrosis mutations in the CFTR affect the membrane proteins ability to pump chloride (Cl-). In the body this specifically affects mucous that is produced by epithelial cells, and therefore affects very specific tissues. How can this affected the GIT?
- affects bicarbonate and fluid levels in GIT
In cystic fibrosis mutations in the CFTR affect the membrane proteins ability to pump chloride (Cl-). In the body this specifically affects mucous that is produced by epithelial cells, and therefore affects very specific tissues. How can this affected the pancreas?
- exocrine and endocrine secretions are sticky
- leads to pabcreatic insufficiency
In cystic fibrosis mutations in the CFTR affect the membrane proteins ability to pump chloride (Cl-). In the body this specifically affects mucous that is produced by epithelial cells, and therefore affects very specific tissues. How can this affected failure to develop?
- canalisation, which is tube formation is impaired if mucous is affected
- the intestine in utero (causing neonatal meconium (dark stricky mucous) ileus)
- essentially blocking of GIT
Can cystic fibrosis present as acute or chronic only?
- both
Does cystic fibrosis present at any specific age?
- any age
- generally diagnosed early though
As the GIT and pancreas are affected, what can this lead to?
- malabsotpion of nutrients
If a patient presents at A&E with cystic fibrosis and acute abdomianl pain, what could be some other differential diagnosis that are associated with cystic fibrosis?
- pancreatitis (inflammation of pancreas)
- distal intestinal obstructive syndrome (DIOS)
- cholecystitis (gallbladder inflammation)
- gastro-oesophageal reflux disease (GORD)
- Cystic Fibrosis Liver Disease (CFLD)
- colorectal cancer
If a patient presents at A&E with cystic fibrosis and acute abdomianl pain, what could be some other differential diagnosis that are NOT associated with cystic fibrosis?
- IBS
- appendicitis
- gastritis
- gastroenteritis
How can cystic fibrosis be inherited?
- autosomal recessive (no sex chromosomes)
- patients need a mutated gene from both parents
- if only one gene they are a carrier
If a patient presents at A&E with cystic fibrosis and acute abdomianl pain, what could be some of the tests run that could help identify the problem?
- bloods
- chest X-ray
- abdominal CT scan
What is distal intestinal obstruction syndrome (DIOS)
- a complication of cystic fibrosis
- bowel becomes partially or completely blocked
- generallty occurs where the small bowel joins the large bowel.
Distal intestinal obstruction syndrome (DIOS) is a complete or partial blockage of the GIT that is a complication of cystic fibrosis. What is the main cause of this?
- thick “stool” blocks intestinal tube
Distal intestinal obstruction syndrome (DIOS) is a complete or partial blockage of the GIT that is a complication of cystic fibrosis that is caused by thick “stool” blocking the intestinal tube. Why does thick stool form in cystic fibrosis?
- lack of enzymes (exocrine – amylase, lipase, protease)
- dehydration
- narrow of GIT, ileocaecal area particularly affected
- terminal ileum leads to vitamin B12 absorption
- valve dysfunction leads to “dumping” syndrome from ileum to colon
- can present like an appendicitis
Distal intestinal obstruction syndrome (DIOS) is a complete or partial blockage of the GIT that is a complication of cystic fibrosis that is caused by thick “stool” blocking the intestinal tube. Another cause of obstruction, but less common is intussusception. What is intussusception?
- part of the intestine slides into an adjacent part of the intestine
- very dangerous
How can we treat distal intestinal obstruction syndrome and/or intussusception?
- rehydration
- laxatives
- enzyme (Creon)
- surgery
How can cystic fibrosis cause Cholecystitis?
- CFTR is highliy expressed in liver and biliary tree
- can lead to narrowing bilary tree or mini gall bladder
- bile scretions will be thick and sticky
Cystic fibrosis can cause Cholecystitis due to the high expression of the CFTR in the liver and biliary tree. This can lead to narrowing of the bilary tree or a mini gall bladder. What can CF due to bile secretions and increase the risk of?
- bile scretions will be thick and sticky
- increased risk of gall stones and blockage of bilary tree
Cystic fibrosis can cause Cholecystitis due to the high expression of the CFTR in the liver and biliary tree. This can lead to narrowing of the bilary tree or a mini gall bladder. The bile scretions can be thick and sticky, increasing the risk of gall stones and blockage of bilary tree. What can this then increase the risk of?
- increased risk from bacterial endotoxins
Cystic fibrosis can cause Cholecystitis due to the high expression of the CFTR in the liver and biliary tree. This can lead to narrowing of the bilary tree or a mini gall bladder. The bile scretions can be thick and sticky, increasing the risk of gall stones and blockage of bilary tree and increase the risk of bacterial infections. What else can happen to bile once it has been pumped into the GIT?
- lost in stool as cannot be absorbed
- causes fat/bile acid diarrhoea
Cystic fibrosis can cause Cholecystitis due to the high expression of the CFTR in the liver and biliary tree. This can lead to narrowing of the bilary tree or a mini gall bladder. The bile scretions can be thick and sticky, increasing the risk of gall stones and blockage of bilary tree and increase the risk of bacterial infections. What can patients with CF present with?
- jaundice due to blocking of bile ducts
Gastro-oesophageal reflux disease (GORD) is common in CF, affecting around 35-80%. Although GORD has a number of nasty symptoms, it can also affect the lungs. How can this occur?
- gastric contents may enter the trachea
- increases risk of infections
Gastro-oesophageal reflux disease (GORD) is common in CF, affecting around 35-80%. Although GORD has a number of nasty symptoms including dyspepsia (indigestion), reflux, early satiety and regurgitation, it can also affect the lungs. Gastric contents may enter the trachea and can increases risk of infections. Surgery is the the extreme treatment via a nissen fundoplication, but physiotherapy can also help, how is this possible?
- CF patients have a physiological spincter
- body position can affect this and reduce GORD symptoms
Gastro-oesophageal reflux disease (GORD) is common in CF, affecting around 35-80%. Although GORD has a number of nasty symptoms including dyspepsia (indigestion), reflux, early satiety and regurgitation, it can also affect the lungs. Gastric contents may enter the trachea and can increases risk of infections. What drug has been increased in the prescription to CF patients?
- proton pump inhibitors
Pancreatitis, which is inflammation of the liver is rare but can occur in VF patients. The pancreas can be pancreatic sufficient (PS) and pancreatic insufficient (PI). Which of these causes pancreatitis and why?
- usually caused by PS
- PS means secretions can be secreted
- BUT these secretions are thick and stick and block pancreatic ducts
How can pancreatic sufficiency cause pancreatic insufficiency?
- pancrease pumps exocrine secretions which are thick and sticky
- secretions block the ducts
- chronic blockage and inflammation lead to scarring and atrophy of pancreatic tissue
If a patient did present with acute pancreatitis, how would thet generally present?
- acute epigastric pain that radiates to the back
- raised amylase (4x normal)
- raised WBC
- steatorrhea
- may develop nfection type 1 diabetes
How can cystic fibrosis cause cystic fibrosis associated liver disease (CFLD)?
- bile acids are thick and highly concentrated
- acidification damages the liver
- affects around 30% of patients, more in women than men
How can cystic fibrosis lead to colorectal cancer?
- chronic inflammation of the GIT
- secretions and mucous barrier is impaired
The risk of colrectal cancer is increased in cystic fibrosis by 5-10%. What symptoms might CF patients present with?
- blood in stool
- weight loss
- anaemia
- change in bowel habit
The risk of colrectal cancer is increased in cystic fibrosis by 5-10%. What investigations should be considered in CF patients?
- faecal immune test (qFIT)
- colonoscopy (polyps)
- capsule enterography
In patients with CF they may experience GIT symptoms that require surgery. What are the 2 key anaesthetic risks that must be considered prior to surgery?
- lung function status
- medication doses
In patients with CF they may experience GIT symptoms may require surgery. What are the most common procedures that are conducted?
- nasal polypectomy
- gastrostomy insertion (nutrition)
- central line insertion (Portacath, Hickman)
- appendicectomy
- rectal prolapse repair
In patients with CF they may experience GIT symptoms and may require surgery. In the instance where they need nutritional support what is the most common approach if they cannot take in caloires orally?
- gastrostomy insertion (nutrition) as longer term and more comfortable than a nadogastronomy
- percutaneous endoscopic gastrostomy (PEG) button
Why is nutritional support is important in CF patients in terms of calories required?
- increased metabolic load due to CF
- body essentially has to work harder
Although nutritional support is important in CF patients in terms of calories required due to the increased metabolic load, why can this cause a problem in CF?
- lack of pancreatic enzymes (CREON given)
- impaired intestinal absorption
- fat cannot be absorbed so fat soluble vitamins (A,D,E,K) are low
- if stomach is affected there is low intrinsic factor and therefore low B12 absorbed in the terminal ileum
