GI Flashcards
What system defends against reduction of body fat?
Central circuit - involves leptin
Weight gain causes ____ in sympathetic nervous activity, ___ in energy expenditure. This prompts weight ____. The reverse is also true for weight loss.
Increase
Increase
Loss
___ is an altered microbiota composition. It represents when ____ start producing bacterial metabolites and toxins.These can cause systemic diseases, intestinal, liver, lung and brain conditions and problems with adipose tissue.
dysbiosis
pathobionts
what are the cause of non-infectious diarrhoea
- Antibiotics side effect
- post infectious irritable bowel syndrome
- IBD
- microscopic colitis
- ischeamic colitis
- coeliac disease
how do you determine esophageal motility?
Manometry (pressure measurements)
Describe and name the sign seen in cholecystitis
Murphy’s sign - inspiratory arrest on RUQ palpation due to pain
How do osmoreceptors bring about ADH release?
- Cells shrink when plasma more concentrated
- Proportion of cation channels increases -> membrane depolarises
- Signals sent to ADH producing cells to increase ADH
- Fluid retention, invokes drinking
State the two types of peptides released from Arcuate nucleus in hypothalamus . what are their functions?
Orexigenic - appetite stimulant
Anorectic - appetite suppressive
Describe the mechanism involved in the development of IBD.
impaired mucosal immune response to the gut microbiota in a genetically susceptible host. Dysbiosis present
What do diagnostic tests show in esophageal perforation?
CXR and CT - shows pneumomediastinum
- OGD - blood
- Gastrograffin Swallow (it is water soluble)
A patient with severe acute pancreatitis and duodenal stenosis is being fed with NJT. Develops increased bowel frequency. Type 7 stool that is yellow in colour. Dietician adds pancreatic enzymes to the feed to support absorption but minimal improvement in bowel frequency . How do we continue to feed our patient?
Start parenteral nutrition, reduce the NJT feeding to a ‘trophic’ rate
Describe how naproxen can be used to treat knee pain
Target = COX enzymes (naproxen is non-selective i.e. inhibits COX1 and COX2).
Location = peripheral nociceptive nerve endings
Effect - COX produces PGs. PGs mediate inflammation by sensitising peripheral nociceptors mediators like bradykinin, histamine
State 2 sources of Immunological defense in GI tract
MALT
GALT
how do you manage/prevent RFS
Provide 10-20 kcal energy. CHO 40-50%. Micronutrients from onset
Monitor and correct electrolytes daily
Administer thiamine from onset of feeding
Monitor fluid shifts and minimise risk of fluid and Na+ overload
The ventromedial hypothalamus is associated with which food related feeling?
satiety
What is the most abundant circulating protein in human plasma?
albumin
What is the effect of body fat on leptin?
Low when low body fat
High when high body fat
state 4 risk factors for GERD
- Smoking (reduces buffering capacity of saliva - decrease ph)
- Alcohol - damages mucosa
- Hiatus hernia - sliding UP vs Rolling
- Conditions that decrease LES tone
- Obesity, fatty foods
How do you diagnose and treat a norovirus infection?
PCR diagnosis
Treatment not usually required
___ bowel obstruction Xray shows ladder pattern of dilated loops with striations that pass completely across the width
small
The main cause of ulcers is __ infection
H. pylori
State two things that cause microbiota cell reduction
Chemical digestive factors -> lysis
Peristalsis, contraction, defecation
The adipostat mechanism states that hormone is produced by __. The hypothalamus senses the concentration of hormone then alters __ to increase or decrease food intake.
fat
neuropeptides
what are the complications associated with enteral feeding?
Mechanical - misplacement, blockage, buried bumper
Metabolic - hyperglycemia, deranged electrolytes
GI - aspiration, nasopharyngeal pain, laryngeal ulceration, vomiting, diarrhoea
diabetes mellitus, gallstones and steatorrhea are clinical features of which NET?
somatostatinoma
What is choledocholithiasis?
Gallstones in common bile duct.
Effect of congenital leptin deficiency?
obesity
How many types of Adipsia are there? Which is most common?
4
Type A most common
Is albumin a valid marker of malnutrition in the acute hospital setting?
no- as it decreases in response to inflammation
Describe how naproxen (NSAID) can cause an adverse effect within the stomach
Target - COX I enzyme
Location - gastric mucosal cells
Effect - inhibition of PG so inhibition of PG mediated protection of gastric mucosa. PGs increase mucus production, blood flow, bicarb release
What is a major cause of C.diff dysbiosis?
long term antibiotic use
What conditions can cause a strangulating bowel obstruction instead of simple?
Strangulated hernia, volvulus, intussusception
What urinary sodium value indicates dehydration?
<20 mmol/L
Causes of primary polydipsia?
- Mental illness - schizophrenia, mood disorders, anorexia, drug use - can be psychogenic or acquired
- Brain injuries
- Organic brain damage
What do diagnostic tests show in esophageal scleroderma?
Manometry
- decreased LES resting pressure
- absent peristalsis
In which type of IBD is there mucosal and submucosal inflammation only, ulcers and pseudopolyps and loss of haustra on gross morphology and crypts abscesses on microscopic morphology?
ulcerative colitis
what groups are at highest risk of malnutrition?
Elderly Cancer patients Patients with dementia Patients with chronic illness Patients who abuse drugs or alcohol
what are the signs and symptoms of bowel obstruction?
- Abdominal pain - colicky or constant
- nausea/Vomiting
- Absolute constipation
- Abdominal distention
(Dehydration, increased tinkling bowel sounds or absent bowel sounds, diffuse abdominal tenderness)
what are the causes of IDA in order of frequency?
Aspirin/NSAID use Colonic adenocarcinoma Gastric carcinoma Benign gastric ulcer Angiodysplasia Coeliac disease Gastrectomy (decreased absorption) H.pylori
In peyers patches, B-cells class switch from __ to IgA
IgM
What are the 3 areas of anatomical constriction in the esophagus?
Cricopharyngeal constriction
Aortic and bronchial constriction
diaphragmatic/LES constriction
how does inflammatory pain present?
Constant pain, made worse by movement, persists until inflammation subsides
What is the mechanism of Histamine (H2) receptor antagonists in treating PUD? Give an example.
inhibit the stimulatory action of histamine released from enterochromaffin-like (ECL) cells on the gastric parietal cells. So inhibit gastric acid secretion
E.g. Ranitidine
a patient is suspected of gallstone pancreatitis, what is your first investigation?
if after treatment for gallstone pancretitis, their LFTs remain deranged after 5 days, what would be your next investigation?
following this next investigation, if the patient is found to have stones in bile duct, what is the next investigation?
Following an ERCP, if a patient is still unwell days later, what is the next investigation and treatment?
USS abdomen
MRCP - check for stones in bile duct
ERCP
CT abdomen/pelvis
If only changes associated with pancreatitis on CT -> laparoscopic cholecystectomy
state 2 risks of a hellers myotomy
Esophageal and gastric perforation - most common
Division of vagus nerve
Splenic injury
State 3 functional disorders of GI tract when there is an absence of stricture (at least initially)
- Hypermotility - Achalasia
- Hypomotility - Scleroderma
- Disordered contraction -Diffuse esophageal spasm (corkscrew esophagus)
- GORD
what 3 things stimulate gastric acid secretion?
Gastrin
Acetylcholine - via vagus nerve
Histamine
differentiate between the common causes of bowel obstruction in small intestine vs large intestine
SBO: more common A - adhesions (60%) B - bulge (hernia) C - cancer/ neoplasia chrons disease, intussusception, intraluminal (foreign body, bezoar)
LBO:
colorectal carcinoma, volvulus, diverticulitis, hirschsprung disease, feacal impaction
What are the 4 methods of stomach protection from ulcers?
Mucus film
HCO3- secretion
Mucosal blood perfusion
Epithelial barrier
what investigation is ordered if acute mesenteric ischemia is suspected?
CT abdomen and pelvis with contrast
which part of stomach secretes HCL?
body and fundus
___ bowel obstruction Xray shows distended bowel with haustrations of taenia coli
large
what are the symptoms of achalasia?
Progressive dysphagia to solids then liquids
(also, weight loss, pain, aspiration pneumonia, esophagitis)
Increased esophageal cancer risk
What are the symptoms and lab results in acute pancreatitis?
Acute EPIGASTRIC pain often radiating to back
Increase in serum amylase or lipase
What is the mechanism of paracetamol/acetaminophen? What is the main side effect?
possibly involving interaction with a COX-3 isoform (inhibition of PG synthesis), cannabinoid receptors or the endogenous opioids
Overdose -> hepatotoxicity
what are the symptoms of gastric adenocarcinoma?
A nemia L oss of weight or appetite A abdominal mass on examination R ecent onset of progressive symptoms M alaena or haematemesis S wallowing difficulty 55 years or > * dyspepsia most common
what bloods are done to investigate GI perforation?
FBC - neutophilic leukocytosis
Possible elevation of urea, creatinine
VBG: lactic acidosis
What is acute pancreatitis?
Autodigestion of pancreas by pancreatic enzymes
What is the most common cause of diarrhoea in infants and young children worldwide?
rotavirus
what imaging is carried out for appendicitis?
CT
Side effect of PPIs?
The use of these drugs may mask the symptoms of gastric cancer.
Omeprazole is an inhibitor of cytochrome P2C19 and has been reported to reduce the activity of e.g. clopidogrel, when platelet function is monitored.
Decrease in calcium absorption -> fracture risk
pain on swallowing is ___
Odynophagia
What human CNS mutations affect appetite?
POMC deficiency and MC4-R mutations cause morbid obesity
No NPY or Agrp mutations associated with humans
what is the function of secretory IgA?
Binds luminal antigen -> prevents its adhesion and invasion
state 4 anatomical contributions to LOS
- Angle of his
- Phrenoesophageal ligament
- Diaphragm surrounds LOS
- Distal oesophagus within abdomen
How does the epithelium repair itself after ulcers?
Epithelial migration
Cell division to close gap
State 4 eating disorders
Binge eating disorder
Anorexia nervosa
Bulimia nervosa
Pica
Rumination syndrome - regurgitate food deliberately and swallow again
Avoidant/restrictive food intake disorder
Which two regions are osmoreceptors found in?
Organum vasculosum of the lamina terminalis (OVLT) Subfornical organ (SFO)
what are the clinical features of a VIPoma ?
VM syndrome= watery diarrhea, hypokalemia, achlorhydria
What is the main treatment for gallstones when they cause complications?
cholecystectomy
State 2 indications for surgery in a patient with toxic megacolon
Colonic perforation
Necrosis or full-thickness ischaemia
Intra-abdominal hypertension or abdominal compartment syndrome
Which hormone regulates plasma osmolality?
ADH
osmoreceptors
what are some lab values that may indicate a severe c. difficile case?
WCC>15, Creat >150
__ is made by adipocytes and enterocytes. It acts on the hypothalamus to regulate appetite and thermogenesis.
leptin
What do diagnostic tests show in diffuse esophageal spasm?
Manometry - intermittent high pressures associated with peristalsis (400-500). Normal LES pressure
Barium swallow - corkscrew esophagus
Whenever you are managing a gI perforation surgically, you always lavage and do a __
MC&S
what is oesophageal scleroderma?
An autoimmune disease
Neuronal defects -> smooth muscle ATROPHY of oesophagus -> hypomotility
26F, otherwise healthy. 3 months history of diarrhoea (4x / day) with rectal bleeding.
Associated urgency and mucous secretion.
no recent travel.
High WCC, Platelets, CRP. What are the differential diagnoses? What investigation(s) should be ordered next?
infectious - C.difficile, shigella, etc
Non-infectious - IBD, haemorrhoids, post-infectious irritable bowel syndrome etc
INVESTIGATIONS: Stool culture, calprotectin & FIT
when is parenteral nutrition indicated?
Inadequate or unsafe oral and/or enteral nutritional intake
A non-functioning, inaccessible or perforated GI tract
is enteral or parenteral nutrition better?
enteral
diabetes mellitus and necrolytic migratory erythema are clinical features of which NET?
glucagonoma
A patient is being treated with vancomycin for C.difficile. Despite this she has ongoing diarrhoea, blood in stool, WCC and creatinine and CRP increased further. Low blood pressure. Abdominal X-ray now shows dilation of bowel. What is the most likely diagnosis? What is the treatment?
Fulminant colitis with Toxic megacolon
First line = antibiotics
Then ITU monitoring -> IV fluid resuscitation & inotropic support
After improvement, discharge with extended course of oral vancomycin
What are the symptoms of inflammatory bowel disease?
Abdominal pain, bloody diarrhea (may not be bloody in Chrons)
Fistulas in Crohn’s disease can cause perianal disease
state 4 medical consequences of re-feeding syndrome
Arrhythmia, tachycardia, CHF -> Cardiac arrest, sudden death
Respiratory depression
Encephalopathy, coma, seizures, rhabdomyolysis
Wernicke’s encephalopathy
__ ___ is an infection of the biliary tree due to obstruction that leads to stasis/bacterial overgrowth
acute cholangitis
Lateral hypothalamus only produces __ peptides
orixogenic
How do you manage acute pancreatitis?
IV fluids
NPO - pancreatic rest
Analgesia
Determine underlying cause
If severe pancreatitis scoring -> HDU
what are the causes of infectious diarrhoea
C.difficile
klebsiella oxytoca
salmonella
clostridium perfringens
___ nutrition is the delivery of nutrients, electrolytes and fluids directly into the ____.
Parental
Blood - central venous catheter with tip in SVC
What screening tests are there for colorectal cancer?
FIT which detects haemoglobin ages 60-74
One off sigmoidoscopy >55 to remove polyps
state 3 sources of antigen load to the gut
Dietary antigens
Exposure to pathogens
Resident microbiota
What is the most common cause of food poisoning in the UK?
campylobacter
Return of oesophageal contents from above an obstruction is ____
regurgitation
ghrelin function?
stimulates appetite, increases gastric emptying
What happens if there is a loss of cation influx in osmoreceptors?
Hyperpolarization -> inhibition of firing
What are the symptoms and lab results with acute cholangitis?
Charcot’s triad: RUQ pain, fever, jaundice
State 3 signs/symptoms in anorexia
Low BMI/ continuous weight loss Amenorrhea Halitosis mood swings dry hair, skin & hair thinning
state 3 effects of malnutrition on hospitalised patients
Increased mortality
Increased septic risk and post-surgical complications
Increased length of hospital stays/re-admissions
Decreased wound healing & response to treatment
State 4 clinical outcomes of H pylori infection
asymptomatic/chronic gastritis
Chronic atrophic gastritis (intestinal metaplasia)
Gastric or duodenal ulcer
Gastric adenocarcinoma
MALT lymphoma
how do steroids treat IBD?
Increase anti-inflammatory gene products. Block pro-inflammatory genes.
What questions do you ask to narrow down the causes of Iron deficiency aneamia?
Any overt bleeding noticed?- Blood in stool, Haematuria, Epistaxis, Haemoptysis
Generic symptoms of malignancy? - Weight loss, anorexia, malaise
Symptoms that might suggest colorectal cancer?- Change in bowel habit, Blood or mucus in stool, Faecal incontinence, Feeling of incomplete emptying of bowels (tenesmus)
Symptoms that might suggest an upper GI cancer? - Dysphagia, Dyspepsia
Is there blood in the stool or urine that the patient has not noticed?- Perform a digital rectal examination.- Dip the urine to check for blood.
How does blood control thirst?
- Blood pressure drops -> juxtaglomerular cells of renal afferent arteriole secrete renin
- Renin cleaves angiotensinogen from liver to angiotensin 1
- Angiotensin I converted to II bye ACE in lungs
- Angiotensin II causes thirst, aldosterone secretion, and activates the sympathetic nervous system leading to vasoconstriction/increase in sympathetic activity
how do you treat H. Pylori infection?
Triple therapy - PPI + amoxicillin + clarithromycin
State 3 extraintestinal manifestations seen in both types of IBD.
- Arthritis (axial like Ankylosing Spondylitis or Peripheral)
- Skin rash (Erythema nodosum, Pyoderma gangrenosum)
- Eye inflammation (Anterior uveitis, Episcleritis/Iritis)
- Liver (Primary Sclerosing Cholangitis (PSC) associated with ulcerative colitis only - causes jaundice) and (autoimmune hepatitis)
Mrs smith 84. Had several coronal angiplasties. SOB which doctor prescribed medication for. very forgetful. Lips always dry despite drinking a large amount of water. What could be causing this?
diuretic
what do diagnostic tests show in achalasia?
Manometry:
- HIGH LES resting pressure
- Uncoordinated or absent peristalsis (receptive relaxation sets in late during pharyngeal phase. Swallowed food collects in oesophagus causing dilation)
Barium swallow:
“Birds beak esophagus”
What are the symptoms of diffuse esophageal spasm?
Dysphagia and ANGINA-LIKE chest pain
how do you treat a non severe C.diff?
Isolate patient
Metronidazole and oral Vancomycin
FMT
What screening tests are there for hepatocellular cancer?
Regular ultrasound & AFP - for individuals with cirrhosis as a result of viral or alcoholic hepatitis
In a patient with a jejunostomy, what is the target stoma output 6 weeks after surgery?
<1.5L/day
What are the symptoms of carcinoid syndrome? What causes this?
vasodilation -> flushing
Bronchoconstriction -> wheezing
diarrhea
Right sided heart disease - PR & TR
Could present with abdominal pain if in GI tracts
Release of serotonin from tumours such as in lungs as hormones released directly into systemic circulation
how is IBD treated?
5 ASA
Steroids -E.g prednisolone short term in acutely unwell patients - adverse effects e.g cushings disease.
Immunosuppressants - Azathioprine, Methotrexate
Diet (e.g. liquid therapy diet), antibiotics, probiotics, FMT
Biologics - e.g. Anti-TNFα (infliximab, adalimumab)
What is the LES resting pressure? And peristaltic wave value on manometry?
LES = 20 mmHg
Peristaltic wave = 40
Other than cholera, name 3 other causes of infectious diarrhoea
Viral - rotavirus, norovirus
Protozoa parasitic
Other bacteria - campylobacter jejuni, e coli, salmonella, shigella, C diff.
what are some things in a history that can make you think of a diagnosis of acute mesenteric ischemia?
ex-smoker – ↑ed risk of cardiovascular disease
Short history
Central pain with guarding
No previous abdominal scar or hernia
No bowel sounds
Poor general condition
↑ed serum lactate - ischemic metabolic acidosis sign
what are the risk factors for RFS?
- low BMI
- very little/no nutrition over a couple days
- unintentional weight loss
- PMHx alcohol drug abuse
- Low K+, Mg2+, PO4 prior to refeeding
*check notes/NICE guidelines for specific number of criteria or values you need.
Which membrane protein plays a pivotal role in cholera enterotoxin induced diarrhoea?
Cystic Fibrosis Transmembrane conductance regulator
CFTCR
State 3 parts of the epithelial barrier that provide protection
Mucus layer
Tight junctions of epithelial monolayer
Paneth cells (small intestine - secrete defensins & lysozyme)
what is the difference between visceral and parietal pain?
Visceral:
- autonomic
- embryological
- dull, crampy, burning
parietal:
- somatic
- well-localised
- sharp ache
What bloods are ordered for bowel ischaemia and what do they show?
FBC - neutrophilic leukocytosis
VBG - lactic acidosis possible
What is the effect of starvation on electrolytes and how can this lead to re-feeding syndrome?
Increase in extracellular water, total body water and sodium. During refeeding carbohydrate reduces sodium and fluid excretion causing oedema
Decrease in K+, Mg2+, and phosphate. Serum concentrations maintained whilst intracellular stores depleted. Shift into cells upon refeeding causing low levels
Thiamine deficiency can occur upon refeeding if patient had low Vitamin B levels
treatment for acute peritonitis?
Pre-operative -NGT NBM & IV fluids. Antibiotics
Operative:
identification of cause of peritonitis, eradication of contamination source, peritoneal lavage and drainage.
Treatment of the perforated ulcer present
what are the indications for surgical management of bowel ischemia?
Small bowel ischaemia Signs of peritonitis or sepsis Hemodynamic instability Massive bleeding Fulminant colitis with toxic megacolon
What are the lab results and symptoms in choledocholithiasis?
Elevated ALP (»_space; elevation of AST or ALT)
Elevated direct/conjugated bilirubin ->JAUNDICE
Elevated GGT
Abdominal pain
how do you ensure an NGT is not misplaced and is in the stomach?
aspirate must be obtained from NGTs which indicates a pH < or equal to 5.5 showing that it is in the stomach
What type of virus are Rotaviruses? How many types are there and which is most common?
RNA
They replicate in enterocytes
5 types - A to E
A most common
What is erosive & hemorrhagic gastritis?
causes?
Gastritis resulting in acute ulcer -> gastric bleeding, perforation
-> Alcohol, NSAIDs, burns, brain injury, ischemia
what are the complications associated with parenteral nutrition?
Catheter related infections
Mechanical - pneumothorax, hemothorax, thrombosis, cardiac arrhythmias, catheter occlusions, thrombophlebitis, extravasion
Metabolic - deranged electrolytes, hyperglycemia, abnormal liver enzymes, oedema, hypertriglyceridemia
risk factors for bowel ischemia?
>65 Cardiac arrhythmias (mainly AF), atherosclerosis Hypercoagulation Vasculitis Sickle cell Shock causing hypotension
peptide YY function?
inhibits food intake
state 3 conditions that can develop as a result of GERD
- Reflux esophagitis
- Epithelial metaplasia (barretts) -> esophageal cancer
(Ulcers which heal and form) - peptic strictures
what bacteria causes cholera?
Vibrio cholerae serogroups 01 & 0139
State 3 protective mechanisms in body following reflux.
Volume clearance-esophageal peristalsis reflex
pH clearance - saliva
Epithelium - barrier properties
State 2 examples of clinical signs elicited for acute appendicitis
McBurney’s point
obturator sign
What is the role of a radiologist in cancer?
Reviews scans
Provides radiological tumour STAGE
Provides re-staging after treatment
Interventional radiology
15 year old girl, gingival bleeding. Wanted to see a dentist but parents did not allow her to. Lost weight, often hungry and would like to eat more, under some pressure at school. What is the likely cause of lost weight and bleeding?
child neglect and scurvy
How is a campylobacter infection spread?
Undercooked meat especially poultry, untreated water, unpasterised millk
__ is inappropriate lack of thirst
adipsia
what part of the stomach secretes gastrin?
antrum
What covers peyers patches?
Follicle associated epithelium
hypoglycemia and whipples triad are clinical features of which NET?
insulinoma
what are the symptoms in oesophageal scleroderma?
Dysphagia
Acid reflux (GERD)
Associated with CREST syndrome
How does the body prevent reflux?
LES closure
Increased LES pressure
If initial treatment for ulcers doesn’t work, what do you do?
- Measure serum gastrin - check for antral G-cell hyperplasia or zollinger ellison syndrome.
- OGD - biopsy for malignant ulcer
If after upper GI surgery, a patient develops SOB and bibasal creps on auscultation and white region on CXR. The most likely diagnosis is _____
pneumonia
Malnutrition results from a lack of __ or intake of nutrition
uptake
what does a nutritional assessment by a dietician use/consider?
Anthropometry - mid arm muscle circumference, scale, CTs, handgrip strength etc
Biochemistry
Clinical - PHx, signs, symptoms, medications
Dietary - allergies, dietary restrictions, aversions, cultural etc
Social + physical - should include disabilities, smoking and alcohol use
Nutrition requirements - estimate the patients resting metabolic requirement
what is the management of esophageal perforation?
Primary - NBM, IV fluids, broad spectrum antibiotics and antifungals, bloods (including G&S/group and save)
Definite - surgery:
- Esophagectomy with reconstruction
- Esophagostomy & delayed reconstruction
No surgery if small contained perforation or unfit
State important planes of the abdomen and structures they are associated with
Transpyloric plane - L1
Subcostal plane - L3 - origin of inferior mesenteric artery
Supracristal plane - L4 - bifurcation of the aorta
Intertubercular plane
Interspinous plane
state causes of acute pancreatitis
I - diopathic G - ALLSTONES - obstruct common bile duct - cause back-up of enzymes - common. LFTs affected. E - thanol - common T - rauma S - teroids M - umps (infections) A - utoimmune disease (AIP) S - corpion sting (toxins from some arachnids and reptiles) H -ypercalcemia/hypertroglyceridemia E - RCP D - rugs
where do NETs arise from?
GEP tract or bronchopulmonary system
Where long term enteral tube feeding is required (>3months), what is inserted?
gastrostomy/jejunostomy feeding tube
which type of IBD involves continuous inflammation always with rectal involvement?
ulcerative colitis
What are the two neuronal populations in the arcuate nucleus? how does leptin act on them?
Stimulatory - NPY/Agrp neuron
Inhibitory - POMC neuron - decreases neuron
Leptin act on them. Stimulates POMC, inhibits NPY
And both neuronal populations go through paraventricular nucleus
Without the consumption of water, what in the body can help to relieve thirst?
Receptors in mouth, pharynx, oesophagus
Differentiate between acute mesenteric ischemia and ischaemic colitis
Acute mesenteric ischemia: - Small bowel - Usually occlusive due to thromboemboli - Sudden onset Abdominal pain out of proportion of clinical signs
Ischeamic colitis:
- Large bowel
- Usually due to non-occlusive low flow states or atherosclerosis
- Mild and gradual onset
- Moderate pain and tenderness
state 3 causes of malnutrition in hospitals
Depression
Inactivity
Inflexibility of meal times
Quality of food
what causes achalasia?
Primary - unknown Secondary: - CHAgas disease can cause aCHAlasia!! - (Protozoa infection) - (Amyloid/Sarcoma/Eosinophilic Oesophagitis)
What are the side effects of NSAIDS?
gastric ulcers and bleeding, perforation; reduced creatinine clearance, acute interstitial nephritis; bronchoconstriction in susceptible individuals (contraindicated in asthma)
Prolonged use -> risk of Adverse cardiovascular effects, chronic renal failure
Aspirin linked with post-viral encephalitis (Reye’s syndrome) in children
In a patient suffering from
osteoporosis alongside osteoarthritis and developed PUD from NSAID use, the GP would have chosen a histamine (H2) receptor antagonist instead of a proton pump inhibitor. Why?
Acid imbalance causes osteoporosis and H2 receptor antagonists are less effective/ cause a smaller acid imbalance than PPIs. PPIs increase risk of fracture which is more likely if a patient has osteoporosis
what things decrease LES pressure?
Smoking, fat, NO
What do diagnostic tests show in a perforated viscus?
CXR - free subdiaphragmatic air
AXR - Rigler’s sign - free intraperitoneal air
MALT are found in the ____. They are surrounded by __ ___ ___ allowing passages of lymphocytes. The ___ cavity is rich in immunological tissue. In particular palatine and lingual tonsils.
Submucosa
HEV postcapillary venules
Oral
One cause of ____ _______ is as a result of a perforation such as a perforated ulcer. CT scan may show free fluid around the liver.
acute peritonitis
What is Achalasia?
Failure of LES to relax due to degeneration of inhibitory neurons (containing NO and VIP) of myenteric plexus
What are the potential effects on polydipsia on the body?
Kidney and bone damage, Headache
Nausea, Cramps, Slow reflexes, Slurred speech
Low energy, Confusion, Seizures
State 4 physical barriers in the GI tract
Anatomical
- epithelial barrier
- persitalsis
Chemical
- Enzymes
- Acidic pH
_ is a microorganism that benefits from an association with a host but has no effects on host. __ live with host without any benefits or harm either way. __ are symbionts that have the potential to elicit inflammation
Commensals
Symbionts
Pathobionts
what is artificial nutrition support?
Provision of enteral or parenteral nutrients to treat or prevent malnutrition
how does obstruction of a muscular tube present?
Colicky pain, fluctuates in severity, move to try and get comfortable
Prolonged obstruction can cause distension - > constant stretching pain -> when colicky pain becomes constant you worry about ischemia
most NETs are __
Asymptomatic
How do you treat a perforated ulcer?
Laparoscopic omental patch
Radical surgery - vagotomy, gastrectomy
Conservative treatment - Taylors approach
State 2 cancers of GI tract resulting from connective tissue
Leiomyoma & liposarcomas
state 3 roles of gut microbiota
Provide nutrients
Digest compounds
Defence against opportunistic pathogens
Contribute to intestinal architecture
What is the mechanism of PPIs in treating PUD?
Give an example
Irreversible inhibitors of H+/K+ ATPase in gastric parietal cells. They are weak bases and accumulate in the acid environment
Omeprazole, lansoprazole
What causes non-erosive chronic active gastritis?
H Pylori infection of antrum of stomach.
__ is excessive thirst or excessive drinking
polydipsia
What is a side effect of H2 receptor blockers in treating PUD?
Confusion, dizziness
Cimetidine (but not other H2 antagonists) inhibits cytochrome P450 and may retard the metabolism and potentiate the effects of a range of drugs
Other than through m-cells, what other way do bacteria invade the GI epithelium?
Dendritic cells open up tight-junctions and collect bacteria from outside epithelium.
Bacteria then transported to mesenteric lymph nodes.
zollinger-ellison syndrome is a clinical feature of which NET?
gastrinoma
What hormonal changes occur after bariatric surgery?
- Ghrelin reduces - reduction of appetite
- GLP1 and GLP2 increased - insulin release stimulated, glucagon release inhibited
- PYY increased - increase in satiety
State 2 cancers of GI tract resulting from epithelial cells
Squamous cell carcinoma & adenocarcinoma
What 3 triggers control thirst?
Body fluid osmolality
Blood volume reduction
Blood pressure reduction
A patient taking naproxen is diagnosed with PUD. There is no active bleeding and he is Helicobacter pylori negative.
What treatment would you initiate and what is the mechanism?
1st line - treat underlying cause plus PPI (4-8 weeks, e.g 20mg omeprazole)
Mechanism - Irreversible inhibitors of H+/K+ ATPase in gastric parietal cells. Reduce acid production. Allows ulcer to heal
Naproxen - stop if possible
Describe the mechanism for vibrio cholerae invasion and damage
Bacteria releases enterotoxin in SI which enters enterocyte
Increased adenylate cyclase activity -> increased cAMP -> salt excretion causing water excretion -> diarrhea
What type of drug is diclofenac?
NSAID
What happens when plasma ADH is low? What is this called?
Large volume of urine is excreted
Diuresis
which people should be considered for nutrition support?
- malnourished
- BMI <18.5
- unintentional weight loss > 10% past 3-6 months
- BMI <20 + unintentional weight loss > 5% in past 3-6 months - At risk of malnutrition
- Eaten little or nothing for >5 days or likely to
- Have poor absorptive capacity and or high nutrient losses and/or increased nutritional needs from causes such as catabolism
Intra abdominal collection may occur following surgery if patient is not lavaged properly Some signs include:
Abdominal pain, soft and tender - with guarding
Very high CRP
High WCC, fever
confirmed by CT
what are the symptoms of GERD?
HEARTBURN
Regurgitation
Dysphagia
Can be associated with asthma
State 3 reasons why H.pylori is so virulent
- urease :
Converts uric acid to ammonia - neutralises stomach acid
- Ammonia chloride formation - gastric injury - VacA exotoxin - gastric mucosal injury
- Secretory enzymes e.g protease, lipase - gastric mucosal injury
What is calculous cholecystitis?
Gallstone impaction in cystic duct -> inflammation and gallbladder wall thickening
describe 2 locations where you can experience dysphagia
UES or LES
what features suggest strangulation in bowel obstruction?
Change in pain from colicky to continuous
Tachycardia, pyrexia, peritonism
Bowel sounds absent or reduced
Leucocytosis, increased CRP
How do you assess the severity of acute pancreatitis?
Glasgow criteria
- specific criteria in notes/online
how do you treat scleroderma?
Exclude organic obstruction
Improve peristalsis using prokinetics (cisapride)
treatment for achalasia?
Pneumatic dilatation
Surgery:
- Hellers Myotomy (cutting of esophageal sphincter muscle). Often combined with Dor fundoplication to prevent GERD development
- Peroral endoscopic myotomy (POEM)
Inflammation causes _ levels of albumin and this is associated with poor prognosis
low
What is the criteria for short bowel syndrome?
2m or less from duodenojejunal flexure
How do you diagnose and stage gastric adenocarcinomas?
Endoscopy + biopsy
Staging:
- CT of the chest, abdomen & pelvis
- PET-CT
- Diagnostic laparoscopy - peritoneal & liver metastases
- Endoscopic ultrasound - local invasion & node involvement
Diagnosis and Treatment for cholera?
Diagnosis - bacterial culture of stool
Main = oral rehydration
Vaccines- dukoral
state 2 differences in symptoms and signs in large bowel obstruction vs small
constipation is early rather than late sign in LBO
vomiting is late sign in LBO. initially bilious and progresses to faecal vomiting
In an examination for bowel obstruction, you should always search for ___ ___ and abdominal scars. You should also determine if obstruction is single or strangulating.
inguinal hernia
Ulcer perforations are usually of the __ and occur more commonly on the __ surface
Duodenum
Anterior
What are the Non-GI causes of IDA in order of frequency?
- Menstruation
- Blood donation
- Haematuria (1% of iron deficiency anaemias)
- Epistaxis
what is the first-line approach for enteral feeding?
NGT
If gastric feeding is impossible e.g. in gastric outlet obstruction - NDT/NJT used
With IBD, ___ ___ can affect any part of the GI tract, but __ __ is limited to colon.
Crohn’s disease
Ulcerative
State different causes of upper abdominal pain
Cardiac GI MSK Diabetes Dermatological
How do Bcells and Tcells circulate once they are formed?
Peyers Patch -> lymphocyte proliferation in lymph node -> thoracic duct -> circulation -> entering peripheral immune system (skin, tonsils, BALT)
OR exit back into intestinal mucosa/lamina propria (HEVs express MAdCAM1 - an adhesion molecule, and lymphocytes express alpha4beta7 to enable this)
constant RUQ pain. Bilirubin and LFTS are fine. Sweats and rigors present. most likely diagnosis?
cholecystitis
Which abdominal organs usually cause colicky pain and which usually cause constant?
Constant - liver, spleen, kidney
Colicky - ureteric, biliary, bowel
State 4 examples of organised GALT
Peyers patches - SI
Caecal patches - LI
Isolated lymphoid follicles
Mesenteric lymph nodes
State 4 things to consider in a medical history for obesity
- Dietary and physical activity patterns
- psychosocial factors
- weight-gaining medications
- familial traits
State 2 cancers of GI tract resulting from neuroendocrine tumours
NETs and GISTs
n which type of IBD is there transmural inflammation (->fistulas), cobblestone mucosa, creeping fat and “string sign” on gross morphology with granulomas on microscopic morphology?
chrons disease
Ecoli has __ pathotypes associated with diarrhoea. ____ causes bloody diarrhoea. ___ causes hemolytic uraemic syndrome.
6
EIEC
EHEC/STEC
what is biliary colic?
Stone in gallbladder causing intermittent RUQ pain
What are peyers patches composed of?
Naive Tcells and Bcells - development requires microbiota exposure
what are the symptoms and signs of bowel ischemia?
Sudden onset crampy abdominal pain
Bloody, loose stool (currant jelly)
Fever, signs of septic shock
what investigations can be ordered for dysphagia?
Bedside: ECG (are there signs of cardiac ischaemia?)
Blood tests: Full blood count (iron deficiency anaemia from chronic GI bleed?), urea and electrolytes (dehydration from poor oral intake?)
Imaging: CXR (if basal crepitations present )
Microbiology: if infective cause suspected
Special/invasive: urgent upper GI endoscopy if cancer suspected
What are the two main groups of bowel obstruction?
paralytic ileus
mechanical
What bloods are ordered for acute appendicitis and what do they show?
FBC - neutrophilic leukocytosis
Increased CRP
Urinalysis - possible mild pyuria/hematuria
What cells are found within follicle associated epithelium? What are their function?
M (microfold) cells
Transfer IgA-bacteria complex into Peyers patches!!
What can you use to measure improvement in nutrition?
Increase in lean body mass
Increase in mid-arm circumference
What treatment is given in severe c.difficile infection where there is fulminant colitis (hypotension, fever, -> can cause ileus, toxic megacolon)
Antibiotic therapy, supportive care and close monitoring
Early surgical consultation
What diagnostic test is used for gallstones?
ultrasound
State 3 causes of esophageal perforation.
- Iatrogenic - MOST COMMON - usually at OGD
- Borehaave’s Syndrome
- Foreign body(can include acid/alkali ingestion), Malignant, Trauma(blunt force to thorax, penetrating injury), spontaneous
- Intraoperative causes such as hellers myotomy
Effect of PYY release in terminal ileum and colon?
Stimulates POMC neurons
Inhibits NPY release
what are the symptoms of biliary colic?
intermittent RUQ pain that may radiate to the shoulder blade.
Nausea, vomiting
Pain especially after eating (gallbladder contraction). Especially fatty foods (CCK release triggers gallbladder contraction)
What imaging is carried out to diagnose bowel ischemia?
CT angiogram - can show vascular stenosis, pneumatosis intestinalis, thumbprint sign for ischaemic colitis
treatment for GERD?
Lifestyle - no smoking, weight loss
PPIs
Surgical:
- Dilatation of peptic strictures
- Refractory GERD - Nissens fundoplication
What are the symptoms in esophageal perforation?
Pain Fever Dysphagia Subcutaneous emphysema (blood in saliva and haematemesis if trauma)
what are the 3 types of tumours associated with MEN1
- Pituitary tumours
- Pancreatic tumours
- Parathyroid tumours
How does 5 ASA treat IBD?
Inhibition of pro-inflammatory cytokines (IL-1 and TNF-a )
What are the causes of secondary polydipsia?
- Chronic medical conditions: Diabetes insipidus & mellitus, Kidney failure, Conn’s syndrome, Addison’s disease, Sickle cell anaemia
- Medications: Diuretics, Laxatives, Antidepressants
- Dehydration: Acute illness, Sweating, Fevers, Vomiting, Diarrhoea, Underhydration
what are the symptoms and signs of GI perforation?
sudden severe abdominal pain with distention
Diffuse abdominal guarding, rigidity and rebound tenderness!!
(Pain aggravated by movement
Nausea, vomiting, absolute constipation
Fever, tachycardia, tachypnoea, hypotension
Decreased or absent bowel sounds (due to ileus))
what are the two structures that need to be identified and divided during a laparoscopic cholecystectomy?
Cystic duct and cystic artery
what is atrophic gastritis?
Antibodies attack parietal cells:
- parietal cell atrophy
- Decrease in acid and IF secretion(pernicious anemia risk)
- Occurs in fundus
How do you diagnose NETs?
Biochemical assessment
- screen for gut hormones like insulin, somatostatin, PPY
- screen for calcium PTH, prolactin, GH
- 24 hr urinary 5-HIAA!!!
Imaging - somatostatin receptor scintigraphy, CT/MRI etc
What does an endoscopy show in bowel ischaemia?
Oedema, cyanosis and ulceration of mucosa
how do you treat a rotavirus infection?
Oral rehydration
Vaccine
what is the cost of malnutrition in england per year?
£19.6 billion - 15% health budget
what are the causes of bowel obstruction?
Causes in the lumen - faecal impaction, gallstone ‘ileus’
causes in the wall - Crohn’s disease, tumours, diverticulitis of colon
Causes outside the wall - strangulated hernia, volvulus, obstruction due to adhesions or bands
__ hernias can cause dead bowel without proper obstruction
Richter’s
How do you treat a campylobacter infection?
Not usually required
Can use azithromycin
what are the different types of dysphagia you can get?
For solids or fluids. Intermittent or progressive. Precise or vague in appreciation.
what is diffuse esophageal spasm?
Uncoordinated contractions of the esophagus with NORMAL LES pressure
what screening tool is used for malnutrition? what 3 things does it consider?
- MUST
- BMI score, weight loss score, presence of acute disease
- Score may result in referral to dietician for assessment
what investigation do you carry out for suspected GERD?
OGD
- +ve findings include peptic stricture, barretts, esophagitis
- look to see if cancer is present or not.
A patient is found to have microcytic aneamia. Patient states weight loss and loose stools, no palpable masses in rectum, rectal exam shows blood in stool. What is the most likely diagnosis? What investigations are required?
What will the lower GI MDT need to consider when deciding the treatment approach?
Colon cancer
Bedside: Urine dipstick (haematuria?)
Blood tests: Iron studies (needed to confirm iron deficiency as the cause of microcytic anaemia), anti-TTG (a screening test for coeliac disease)
Imaging: Unlikely to order any from the GP clinic.
Microbiology: None required.
Special/invasive: She qualifies for an urgent colonoscopy. If this is negative, an upper GI endoscopy will be organised
staging CT CAP
What is a characteristic imaging finding in acute pancreatitis?
CT of abdomen shows pancreas surrounded by edema. Enlarged pancreas
What oral fluid advice would you give to prevent further dehydration and electrolyte imbalance if these issues are present in a patient with a duodenal jejunostomy?
Restrict oral fluid intake - hypotonic fluids may drag Na+ into gut lumen
Give electrolyte mix to patient (glucose-saline solution)
Passive return of gastroduodenal content to mouth is ____
reflux
What is boerhaave’s syndrome?
Severe vomiting against a closed glottis. Causes sudden increase in esophageal pressure and transmural rupture of esophagus.
What is the primary treatment for ulcers?
Triple therapy for H pylori
Then PPI or H2 blocker
State and describe 2 vascular anomalies causing dysphagia
Dysphagia lusoria - vascular compression of the esophagus by an aberrant right subclavian artery
Double aortic arch
What is the role of a pathologist in cancer?
Confirms diagnosis using biopsy
Provides histologic typing
Provides molecular typing
Provides tumor grade
in an elderly patient on antibiotics with new onset diarrhea, what are the important investigations?
- stool sample to check for C.difficile
2. followed by AXR
___ is responsible for both adaptive and innate immune responses. It can be non-organised such as ______ lymphocytes and ___ ___ lymphocytes or it can be organised.
GALT
Intra-epithelial (in intestines)
Lamina propria
State 5 comorbidities associated with obesity
Stroke, MI, Hypertension Diabetes Depression Sleep apnoea Bowel cancer Osteoarthritis Gout PVD
State 4 things that decrease gastric acid secretion
Prostaglandins
Somatostatin
Secretin
GIP
how do you treat gastric cancer?
Neoadjuvant chemotherapy
Tumor at oesophago-gastric junction = oesophago-gastrectomy
<5cm from OG junction = total gastrectomy
> 5cm = subtotal
Adjuvant chemotherapy
describe how a sigmoid volvulus is managed conservatively
A sigmoidoscope is passed with the patient lying in the left lateral position.
flatus tube passed along the sigmoidoscope.
if that fails -> Flexible sigmoidoscopy
If that fails -> Exploratory Laparotomy & Sigmoid Colectomy with end colostomy (Hartmann’s Procedure)
____ combines endoscopy and fluoroscopy. It is used for imaging and therapy of biliary disorders.
ERCP
76-yr-old gentleman presents to GP complains of discomfort behind his sternum every time he eats, starts seconds after swallowing. He noticed this 3 months ago and it’s getting worse.
As a result, he has been eating less and less. His wife, who comes to the clinic with him, says he has lost a lot of weight, although he has not noticed.
He denies any other symptoms.
what would be your starting list of differential diagnoses?
Abdominal: Causes of dysphagia:
Upper dysphagia:
- Structural causes: Pharyngeal cancer, pharyngeal pouch
- Neurological causes: Parkinson’s, stroke, motor neuron disease
Lower dysphagia:
- Structural causes: Inside (mural and luminal): oesophageal or gastric cancer, stricture, Schatzki ring. Outside (extrinsic compression): lung cancer
- Neurological causes: Achalasia, diffuse oesophageal spasm
Cardiac: Post-prandial angina
Other: Globus sensation/anxiety
State some complications of ulcers? (surgical indication)
Hemorrhage
Obstruction
Perforation
What blood investigations are carried out in bowel obstruction and what do they show?
WCC/CRP - only elevated in strangulation/perforation
U&E electrolyte imbalance if vomiting
VBG - metabolic acidosis (lactate) if strangulation
What causes gastric adenocarcinoma?
Major driver is chronic gastritis and things that cause it like:
- H. pylori infection
- Pernicious anaemia
- Patients who have had a partial gastrectomy (leads to bile reflux to stomach)
- epstein-Barr virus infection
Hereditary diffuse-type gastric adenocarcinoma (due to E-cadherin mutations)
what causes NETs?
75% sporadic
25% associated with a genetic syndrome e.g. MEN1
What conditions are associated with each region of the abdomen?
NB: always consider cardiac causes and lung causes in the foregut
- picture in notes, can also look online
State 4 causes of dysbiosis
Infection, inflammation Diet Xenobiotics Hygiene Genetics
what causes relaxation of the LES?
Inhibitory NCNA neurons of myenteric plexus of esophageal wall mediated by vagus nerve
Give 2 differential diagnosis for GI perforation
MI, acute pancreatitis
What complication can develop from BOTH atrophic and chronic gastritis?
gastric adenocarcinoma
What is pseudomembranous colitis?
Characteristic yellow-white plaques that form on pseudomembranes of colonic mucosa
Often associated with c.difficile infection
When severe = fulminant colitis
