Alimentary disease Flashcards
Economics; Signs and symptoms; Abdominal pain; Obesity; Jaundice; Alcohol; Gastrointestinal cancer; Clinical nutrition; Malnutrition
What are the features of jaundice?
Yellow discolouration of sclerae and skin
What causes jaundice?
Raised bilirubin ( serum bilirubin >40μmol/L)
What are the 3 major categories of jaundice?
Haemolytic
Congenital
Cholestatic
What causes prehepatic jaundice?
Haemolysis
What causes hepatic jaundice?
Viral hepatitis Drugs Alcoholic hepatitis Cirrhosis Pregnancy Reccurent ideopathic cholestasis Congenital disorders Infiltrations
What causes post-hepatic jaundice?
Common duct stones Carcinoma in: -bile duct -Head of pancreas -Ampulla Biliary stricture Sclerosing cholangitis Pancreatitis Pseudocyst
What is haemolytic jaundice?
Haemolytic anemias cause increased breakdown of RBC→increased production of bilirubin→jaundice
Unconjugated bilirubin ∴ not water soluble and doesn’t pass into urine
Increased serum urobilinogen
Otherwise normal liver biochemistry
What is hyperbilirubinaemia?
Impaired conjugation of bilirubin with glucuronic acid or impaired bilirubin handling by the liver
Raised bilirubin but normal biochemistry otherwise
What is the most common congenital hyperbilirubinaemia?
Gilbert’s syndrome
-autosomal recessive
-mutation in gene coding for UDP-glucuronyl transferase = decreased enzyme activity = decreased conjugation of bilirubin
asymptomatic, slightly raised serum bilirubin
Must be triggered to lead to jaundice
What triggers Gilbert’s syndrome to lead to jaundice?
Dehydration
fasting
viral illness
How is Gilbert’s syndrome diagnosed?
Raised unconjugated hyperbilirubin
Otherwise normal liver biochemistry
Normal full blood count, smear and reticulocyte count (excludes haemolysis)
Absence of signs of liver disease
What causes cholestatic jaundice?
Failure of bile secretion by the liver OR bile duct obstruction
Divided into hepatic and post hepatic cholestasis:
-Hepatic - hepatocellular swelling or abnormalities at cellular level of bile excretion
-Post-hepatic - obstruction of bile flow at any point distal to bile canaliculi
What characterises cholestatic jaundice?
Conjugated bilirubin
Pale stool
Dark urine
Abnormal liver biochemistry
What are healthy eating reccommendations in the UK based on?
Dietary reference values
series of estimates for different population subgroups for the essential macros and micros to prevent nutritional deficiencies
What are the healthy eating guidelines in the UK?
Eat at least 5 portions of fruit and veg a day
Base meals on starchy carbohydrates, wholegrain versions where possible
Have dairy or dairy alternatives - lower fat and lower sugar alternatives
Eat some beans, pulses, fish, eggs, meat and other proteins (2 portions of fish per week, one oily)
Choose unsaturated oils and spreads and eat in small amounts
6-8 cups of fluid daily
How is nutritional status evaluated?
National diet and nutrition survey
Look at what factors influence dietary choices
NHS apps
Nutrition screening
What are the two strategies use when patients are not able to eat for themselves?
Enteral feeding - delivery of nutritious fluid past upper GI tract and into stomach/small intestine
Paraneteral feeding - Bypasses GI tract all together via delivery of nutrients into the blood
What type of patient normally receives enteral nutrition?
Patient with upper GI problem e.g. dysphagia/trauma
Cannot chew/swallow food normally
What are complications associated with enteral nutrition?
V low risk of
Nausea
Vomition
Aspiration
What are technical requirements of enteral nutrition?
Basic training to administer and maintain
What are the effects of enteral nutrition on the GI tract?
No effect
Maintains internal structure and function of GI tract
What is the cost of enteral compared to parenteral nutrition?
Parenteral expensive and 5x more expensive than enteral
What type of patient receives parenteral nutrition?
Dysfunctional GI tract that is unable to digest, absorb or excrete appropriately
Can take more than 12 hours to administer so has serious consequences on quality of life
What are complications of parenteral nutrition?
High risk of
Blood clots
infection
liver failure
What are technical requirements of parenteral nutrition?
Requires specialist training and support throughout feeding period
What is the effect of parenteral nutrition on the GI tract?
Atrophy of GI structures due to underuse
What is short bowel syndrome and why is it sometimes necessary?
Characterised by significant removal of bowel, leaving patient with less than 100cm of functional intestinal tract
Sometimes needed due to problems such as Crohn’s, cancer, isachemia, ulcerative colitis, irradiation
What does short bowel syndrome result in?
Dehydration, malnutrition, malabsorption of nutrients
What are the consequences of short bowel syndrome?
reduction in absorptive sfa
loss of tissue interrupts control of gut function via hormones and the enteric NS
Loss of large intestine tissue is associated with increased risk of infection
What are the 3 main aims for management of short bowel syndrome?
Provide adequate nutrition for patients
ensure adequate water and electrolytes to maintain homeostasis
correction and prevention of acid base imbalance
What can reduce reliance on parenteral nutrition?
Anastamosis of the small intestine to the colon
How is alcohol metabolised?
Three separate pathways
1) ethanol → acetaldehyde in peroxisomes via H2O2
2) Ethanol → acetaldehyde in microsomes using NADPH, H+ and O2 = NADP+ and H2O
3) Ethanol → acetaldehyde in cytosol by ADH, reversible reduction of NAD+
What factors affect the metabolism of alcohol?
Diet, gender, body habitus, racial and genetic influences
appreciation of these factors can lead to greater understanding of why some individuals are more susceptible to effects of alcohol
What are the physical effects of alcohol?
Effects large number of end organs CNA CVS GIT GUT LMS Endocrine and reproduction
What are the psychological effects of alcohol?
Alcohol is a drug of addiction
Frequently used in conjunction with other recreational drugs of abuse
Used as a bad coping mechanism for a number of psychological conditions
What is obesity?
High accumulation of body fat or adipose tissue in relation to lean body mass
Individuals usually at high clinical risk because of excess body fat
What are the main causes of obesity?
Occurs when energy intake exceeds energy expenditure for a long period of time
- as a result of increased availability of labour saving devices
- less physical activity, more sedentary lifestyle
Small genetic contribution but only explains 5% obesity
What are the major components of daily energy expenditure in humans?
Resting Metabolic Rate - sum of sleeping metabolic rate and energy cost of arousal - 50-70% EE
Thermic effect of food - 5-15% EE
Physical activity - spontaneous and also voluntary - 20-40% EE
Basal metabolic rate - correlates with body weight ∴ total EE is higher in obese persons
How is BMI calculated?
Weight in kg/ Height² in m
What are the main complications associated with obesity?
Cost of treating obesity very high and still increasing
Chronic and severe medical problems
What are the health risks of obesity?
Isachemic heart disease - hypertension, coronary thrombosis, congestive heart failure, angina, myocardial infarction T2D Cancers - due to effect on hormones Gallstones Osteoarthritis Mental health Stroke Sleep apnoea Gout Infertility
What is the difference between android and gynoid obesity?
Android - fat is more around middle
Gynoid - fat more around hips and buttocks
Android associated with worse health complications and higher risk of complications
What are the NICE recommendations regarding clinical management of obesity?
Diet Exercise Behavioural therapy Drug treatment Surgery if BMI>40
What is the main difference between signs and symptoms?
Signs are externally visible and detectable to someone other than the patient
Symptoms internally experienced by patients and impossible to detect by others
What are the signs and symptoms of general GI tract disease?
Unintentional and uncontrollable rapid weight loss due to reduced energy intake and increased bowel motility
Anaemia - reduced ability to carry O2
Malaise - generally feeling unwell
Anorexia
What are the signs and symptoms of upper GI tract disease?
Belching Acid regurgitation Heartburn Epigastric pain Chest pain Dysphagia - difficulty swallowing Odynophagia - pain when swallowing Vomiting - may be haematemesis Melaena - black tarry stool Haemoptysis - coughing up blood
What are general signs over the whole body of GI tract disease?
Cachexia - muscle wasting
Obesity
Jaundice
Lymphadenopathy - disease of lymph nodes
What are signs and symptoms of hepatobiliary disease?
Right upper quadrant pain esp when palpated
Biliary colic - sudden pain caused by gallbladder contraction against downstream obstruction
Jaundice - increase in bilirubin not processable by hepatobiliary system
Dark urine - XS bilirubin
Pale stool - lack of bilirubin in gut
Ascites - oedema in abdominal cavity
What are signs and symptoms of mid GI tract disease?
Abdominal pain superficial to abdominal cavity
Steatorrhoea - sloppy, oily faeces due to XS fats in stool
Diarrhoea - watery poo
Abdominal distension
What are the signs and symptoms of lower GI tract disease?
Abdominal pain Flatulence Incontinence Diarrhoea Constipation Red rectal bleeding
What are signs on the hands of GI tract disease?
Koilonychia - spoon nails Tremours Leuconychia - whitening of nails Nail clubbing Dupytrens contracture Tachycardia
What are signs in the anus and rectum of GI tract disease?
Haemorrhoids
Fistula
Fissure
Proctitis
What two things should be considered when describing and interpreting descriptions of abdominal pain?
Subjectivity
-location and severity of pain may be perceived differently between different people
Interpretability
-Pain may not always be where it is perceived
What are typical causes of right hypochondriac area pain?
Gall stones Gall bladder infection Pulled muscle Hepatitis Kidney stone Pneumonia
What are the regions of the abdomen?
Right hypochondriac epigastric left hypochondriac
right lumbar/flank umbilical left lumbar/flank
right iliac/inguinal hypogastric/suprapubic left iliac/inguinal
What are typical causes of epigastric area pain?
acid reflux heartburn heart attack gastritis stomach ulcer duodenal ulcer pancreatitis epigastric hernia
What are typical causes of left hypochondriac area pain?
Pneumonia Spleen infection Splenomegaly Hepatitis Kidney stone Constipation Trapped wind
What are typical causes of right lumbar/flank area pain?
Kidney stone kidney infection trapped wind constipation pulled muscle appendicitis
What are typical causes of umbilical area pain?
Stomach ulcer Bowel obstruction Constipation Worms Crohns Food poisoning trapped wind umbilical hernia
What are typical causes of left lumbar/flank pain?
Constipation Trapped wind Diverticulitis IBS Kidney stone Kidney infection Crohns Ulcerative colitis
What are typical causes of right iliac/inguinal area pain?
Appendicitis Urine infection Constipation Ectopic pregnancy Menstrual pain Pelvic infection Endometriosis Ovarian cyst Trapped wind Hernia
What are typical causes of hypogastric/suprapubic area pain?
Trapped wind Constipation Blaster infection Urinary retention Menstrual cramps Endometriosis Pelvic infection Fibroids Miscarriage
What are typical causes of left iliac/inguinal area pain?
IBS Crohns Ulcerative colitis Diverticulitis Constipation Trapped wind Menstrual pain Endometriosis Pelvic infection Ovarian cysts Ectopic pregnancy hernia
What is the diagnostic approach for abdominal pain?
History of problem and family history
Examination - visual, auditory, smell and tactile inputs
Investigations - confirm or exclude diagnoses
How is pain investigated and reported?
SOCRATES Site - specific area or diffuse Onset - when and how Character of pain Radiation of pain elsewhere Associated symptoms Timing of pain - any changes over time Exacerbating/relieving factors Severity - 1-10 pain
What is cancer?
Disease called by uncontrollable divison of abnormal cells in a part of the body
How do primary cancers arise?
Directly from cells in an organ
How do secondary cancers arise?
Spread from another organ, directly or by other means e.g. blood or lymph
What locations does the branch term gastrointestinal cancer include?
Oesophageal Stomach BIliary system Pancreatic Colorectal- small and large intestine, colon, anus
What are the two types of oesophageal cancer?
Adenocarcinoma
Squamous cell carcinoma
What is oesophageal adenocarcinoma?
Occurs in the columnar epithelium that lines the lower 1/3 of the oesophagus
Related to acid reflux - repetitive damage to the epithelium
Associated with obesity, tobacco smoking and alcohol consumption
What are the stages of development of an adenocarcinoma?
Normal epithelium Hyperplasia - abnormal proliferation of epithelial cells Development of adenomatous polyps Development of adenocarcinoma Metastasis
Where does squamous cell carinoma occur?
In the squamous epithelium that lines the upper 2/3 of the oesophagus
What are the main causes of squamous cell carcinoma?
Tobacco smoking and chewing
Alcohol consumption
Ingestion of caustic substances
How does alcohol increase the risk of squamous cell carcinoma ?
Acetaldehyde metabolite in alcohol damages epithelial cells
Why is alcohol related squamous cell carcinoma more common in the Asian population?
Mutations in acetaldehyde dehydrogenase enzyme that leads to a build up of acetaldehyde which increases the risk of cancer
What are the stages of development of squamous cell carcinoma?
Normal epithelium
Metaplasia - development of abnormal squamous cell
Dysplasia - proliferation of abnormal cells
Severe dysplasia - almost all cells abnormal
Development of squamous cell carcinoma
Metastasis
What are symptoms of oesophageal cancer and when do they appear?
Appear after >50% of circumference of oesophagus is cancerous, due to tumour narrowing tube
Difficulty and pain when swallowing
Weight loss - lack of nutrition
Pain in breast bone and stomach or a feeling of reflux
Later stages = nausea, vomiting, regurgitation of food, vomiting blood due to trauma to the tumour
How are oesophageal cancers investigated?
Endoscopy - oesophagogastroduodenoscopy - camera and biopsy
CT scan - check for metastasis
Endoscopic ultrasound to determine level of invasion
What is the available treatment for oesophageal cancers?
Surgery
-Remove tumour from oesophageal wall
-Oesophagectomy - removal of part of the oesophagus
Chemotherapy and radiotherapy
Where does colorectal cancer occur?
colon or rectum
What are the main causes of colorectal cancer?
Old age lifestyle factors including: -diet -alcohol -obesity -tobacco smoking -lack of physical activity
What is the UK screening program for colorectal cancer?
faecal sample every two years tested for the presence of blood
Offered for those over 60 years old
What are risk factors for colon cancer?
Family history IBS Specific inherited conditions -familial adenomatous polyposis -hereditary non-polposis colon cancer -Lynch syndrome Uncontrolled ulerative colitis Age Previous polyps
What are the symptoms of colorectal cancer?
Worsening constipation Blood in stool Loss of appetite Loss of weight Nausea and vomiting Rectal bleeding Anemia
How is colorectal cancer investigated?
Abdominal radiography Plain CT Barium enema Colonoscopy CT virtual colonoscopy
What is the available treatment for colorectal cancer?
Surgery
-removal of the tumour via colonoscopy or laparotomy
-Removal of large parts of the colon = colostomy
Chemotherapy and radiotherapy
What is refeeding syndrome?
Metabolic disturbances occuring as a result of reinstitution of nutrition to patients who are starved or severely malnourished
usually when starved for 5 days or more
What is the mechanism of refeeding syndrome?
Insulin falls and cortisol/glucagon increased to cause protein catabolism and gluconeogenesis
Feeding leads to insulin secretion, causing an uptake of phosphorus, magnesium, potassium and glucose
This causes all their levels to drop rapidly - hypophosphatemia/kalemia/magnesaemia and sodium retention
What are the consequences of refeeding syndrome?
Arrhythmias Respiratory distress/depression Weakness Paralysis Confusion
How can refeeding syndrom be managed?
Daily biochemistry
Vitamin supplementation
Slow reintroduction of nutrition support
