CHI335 GI System Lecture 1 PDF

CHI335 Diagnosis I Lecture I Briefly review the anatomy & physiology of the GI system Identify the general functions of the digestive system and the liver Explain the phases of digestion, different nutrients included in the diet and the definition and presentation of malnutrition Understan...

CHI335 Diagnosis I Lecture I Briefly review the anatomy & physiology of the GI system Identify the general functions of the digestive system and the liver Explain the phases of digestion, different nutrients included in the diet and the definition and presentation of malnutrition Understand S&S of some common GI disorders, including the role of laboratory investigations in hepatic diseases PV is the vessel that drains the blood from the gastrointestinal tract, gallbladder, pancreas, and spleen to the liver This blood is rich in nutrients absorbed from the GI tract Ingestion Secretion Mixing and propulsion Digestion Mechanical Chemical Absorption Defecation  19- 10 1.Cephalic phase (Thought, sight, or smell of food as well as the taste of it) Facial and glossopharyngeal nerves stimulate saliva secretion  The vagus nerve stimulates acid secretion in the stomach 2.Gastric phase Increased gastric secretions and peristalsis and emptying of the stomach 3.Intestinal phase It slows down gastric emptying to allow the small intestine time to absorb the nutrients that enter it It inhibits more acid secretion Ingestion and use of nutrients for homeostasis and energy Water Macronutrients Protein Carbohydrates Lipids Micronutrients Vitamins Minerals Recommended daily intake (RDI) is determined based on Age Gender Activity level Current weight Pregnancy/lactation Micronutrients (μg or mg per day) Macronutrients (cal/kg) Carbs: 45% to 65% Protein: 10% to 35% Fats: 20% to 35% Adipocytes Lipids Liver Vitamins A, B12, D, E, K Iron Copper Glycogen Deficiencies, excesses or imbalances in a person’s intake of energy and/or nutrients Excessive intake Excessive caloric intake Vitamin/mineral toxicity Inadequate intake Low caloric or vitamin/mineral intake Starvation (marasmus) vs. protein deprivation (kwashiorkor) Excessive nutrient losses Malabsorption syndromes Genetic defects Phenylketonuria (PKU) Tay-Sachs disease Weight loss or gain Muscle wasting Fatigue and weakness Delayed wound healing, recurrent infections Diarrhea, abdominal pain/cramps Changes in skin and mucous membranes Immune-mediated adverse reactions to foods Eggs Nuts (Peanut, Tree nut, etc.) Milk (lactose) Soy Fish and shellfish Wheat Dietary interventions Increasing or decreasing the overall caloric intake of particular macronutrients Taking vitamin and mineral supplements Avoiding specific foods Pharmacologic interventions e.g. in hyperlipidaemia e.g. digestive enzymes in CF Signs & Symptoms GI Gastroduodenal Intestinal Hepatobiliary Pancreatic Splenic Urinary tract Gynaecological Vascular Medical causes Referred pain Gastroduodenal PUD, gastritis, malignancies, gastric volvulus Intestinal Appendicitis, Obstruction, Diverticulitis, Gastroenteritis, Mesenteric adenitis, Strangulated hernia, IBD, IBS, Intussusception, Volvulus Hepatobiliary Acute/chronic cholecystitis, cholangitis, hepatitis Pancreatic Acute/chronic pancreatitis, malignancy Splenic Rupture (spontaneous/traumatic), infarction Urinary tract Pyelonephritis, Cystitis, Nephrolithiasis, Hydronephrosis (due to retention of urine), Tumours Gynaecological Ruptured ectopic pregnancy, Ruptured/Torsion of ovarian cyst, Severe dysmenorrhoea, Mittelschmerz, Endometriosis, Salpingitis Vascular AAA dissection, Ischaemic colitis, Mesenteric embolus, Mesenteric venous thrombosis Medical causes Hypercalcaemia, Uraemia, Diabetic ketoacidosis, Sickle cell disease, Addison’s disease, Tabes dorsalis Myocardial infarction Pericarditis Lobar pneumonia Pleurisy Herpes zoster Thoracic spine disease, e.g. disc, tumour Testicular torsion Heartburn & Regurgitation Dysphagia Diarrhoea Constipation Bleeding (haematemesis, melaena, or haematochezia) Jaundice Pruritus The gastrointestinal tract and the skin have a common origin from the embryoblast. Therefore, some GI disorders can present with skin involvement: Dermatitis herpetiformis (coeliac disease) Acanthosis nigricans (DM, malignancy) Porphyria cutanea tarda (alcoholic liver disease) Generalised pigmentations (haemochromatosis) Brown-black lesions of the lips (Peutz-Jeghers syndrome) Pallor (IDA) Ecchymoses (liver failure) Malabsorption Malignancies Anorexia nervosa Other metabolic/endocrine conditions Terry’s nail (type of leukonychia) Chronic liver disease Clubbing Cirrhosis, IBD, Coeliac disease,… Palmar erythema Chronic liver disease,…  Pallor on palmar creases IDA Dupuytren’s contracture Alcoholism,… Jaundice Hyperbilirubinaemia Anaemia Kayser-Fleischer rings Wilson disease Iritis IBD Xanthelasmata Elevated serum cholesterol, cholestasis Periorbital purpura Amyloidosis Glossitis & Angular stomatitis Iron, folate and vitamin B12 deficiencies Gynaecomastia Chronic liver disease,…  Generalised abdominal distension fat, fluid (ascites), foetus, flatus, faeces, big tumour (e.g. ovarian tumour or hydatid cyst) Prominent abdominal veins (Caput Medusae, very rare) Severe portal HTN (a venous hum might be heard over the liver) Pulsation  could be normal or Might indicate AAA Skin discolouration or lesions Herpes zoster Cullen’s sign Acute pancreatitis Grey-Turner’s sign Acute pancreatitis Spider naevus Alcoholic liver disease, Hepatitis B and C, Pregnancy Hepatomegaly Infection, infiltrative, neoplastic, metabolic, vascular  Acute liver disease (e.g. acute hepatitis) Generalised symptoms of malaise, anorexia and fever (viral) Jaundice appears as the illness progresses Chronic liver disease Asymptomatic or nonspecific symptoms i.e. fatigue Right hypochondria pain Abdominal distension (liver distension & ascites) Ankles swelling (oedema) Haematemesis and melaena (GI bleeding – variceal) Jaundice and pruritus Gynaecomastia, loss of libido and amenorrhoea Confusion and drowsiness, neuropsychiatric complications (hepatic encephalopathy) Alanine aminotransferase (ALT) More specific to the liver (a rise only occurs with liver disease) Aspartate aminotransferase (AST) Rises in hepatic necrosis, MI, muscle injury and CHF Gamma Glutamyl transpeptidase (GGT) Rises in Obstruction (cholestasis) and also with meds and alcohol Alkaline phosphatase (ALP) Rises in liver, bone and intestine diseases Serum Bilirubin Rises in hepatocyte impairment/destruction/overload (jaundice) Prothrombin time (PT) - INR Increases in liver damage (Vit K def. must be ruled out) Protein (serum albumin) A falling serum albumin is a bad prognostic sign http://youtu.be/dJ_dasmimE4 Patterns of hyperbilirubinaemia (jaundice) Pre-hepatic: increased bilirubin production (unconjugated) Haemolysis and dyserythropoiesis Normal urine and stool colour (the liver still conjugating as normal) Hepatic: liver dysfunction (no conjugation by the liver) Also seen an increase in AST, ALT, ALP Pale stool, normal urine colour Post-hepatic (cholestatic) e.g. duct obstruction (conjugated) Also seen an increase in ALP and GGT Pale stool, dark urine https://emedicine.medscape.com/article/178841-overview https://emedicine.medscape.com/article/178757-overview  Tests Positive tests and explanations HBV DNA / HBe Ag Active Hepatitis B infection (or the patient's degree of infectiousness) Order of events Current infection with Hepatitis B Infection HBs Ag If present for >6mths then chronic Surface antigen (HBs Ag) and HBe Ag HBV + ve Core antibodies (Anti HBc) + ve Anti HBs (HBs Ab) Recovery / immunity Surface antigen (HBs Ag) – ve Surface antibodies (Anti HBs) + ve Acute infection if in conjunction Therefore with HBs Ag or Natural immunity to HBV Anti HBc Previous infection if found in o Core antibodies +ve conjunction with Anti HBs but, o Surface antibodies +ve Not found in a vaccinated person Vaccination o Surface antibodies +ve (ONLY) A recent HAV infection. Presents for 3 months after onset of an acute infection Anti HAV (IgM) raises first and anti HAV (IgG) will develop later HAV Ab (IgM) Anti HAV (IgG) test is not normally done and is not needed unless checking the immunity Not Examinable Blood tests Endoscopy FBE, ESR, CRP etc. Oesophagogastroduodenoscopy UE ERCP LFTs, amylase/lipase Sigmoidoscopy Imaging Colonoscopy X-ray & CT scan Other With/without contrast Stool examination MRI FOBT Ultrasound Biopsy Breath test 13C urea A FOBT is a simple, non-invasive test that can be completed in your own home. The test detects tiny amounts of blood, often released from bowel cancers or their precursors (polyps or adenomas) into the bowel lumen http://goo.gl/ht3fzH https://goo.gl/Gu3KFH GI bleeding, common causes Upper GI Lower GI