GIT Flashcards
Discuss formation of cholesterol stones
Usually occur as a consequence of an elevated concentration of cholesterol in bile relative to the other principle constituents. Bile acids and lecithin act in conert to solubilze cholesterol as cholesterol levels rise bile acids and lecithin reduced increasing the tendenecy of cholesterol to form crystals. - These crystals particulary in a non complete emptying gallbladder serve as a nidus for stone formation.
Risk factors for cholesterol stone formation include
- increased age
- female gender
- massive obesity
- rapid weight loss
- CF
- parity
- Drugs
- Family history
Discuss the fomration of pigment stones
Two varients black and brown. Black stones occur exlcusively in the gallbladder contain a large amount of calcium bilirubinate. Seen in older adults and those with haemolytic disease
Brown stones are associated with infection and can form in the fallbladder and intra and extrahepatic duct systems. Bacteria are usually the cause but parasites ( ascaris lubricoides, clonorchis sinensis)
Discuss the clinical finding in bilary colic
Patient usually report steady pain rather than colic. Is associated with passage of stone through the cystic duct into the common bile duct.
RUQ pain cramping associated with nausea and vomting which can be severe and lead to electrolyte imbalances.
Usually have had self limited episdoes in the past and can be associated with oral intake
Discuss investigations for choliethiasis
Raised ALP, alk phos, bilirubin, ALT and AST can be raised due to hepatitis
Ultrasound diagnositic test of choice can be performed bedside
Discuss management of bilary colic and complications it can give rise
Supportive care with correction of fluid balance and electrolyte
Pain relief - antispasmodics, NSAIDS and opiates if needed.
Defomotove treatment is cholecystectomy
Complications
- dehydration
- electrolyte imbalance
- malloryweis tear
- infection
Bilary colic is uncommon in children and usually associated with an underlying haemolytic disease (sickle cell, spherocytosis)
Discuss disposition bliary colic
Patient with uncontrolled pain, vomiting, severe dehydration or electrolyte imbalance should be admitted for monitoring and supportive care
Otherwise if symptoms can be controlled discharge home with surgical OPD
Define cholecystitis
Sudden inflammation of the gallbladder. Risk factors are generally those for cholethiasis
Obstruction fo the cystic duct appears to be the critical factor in the development of gallbladder inflammation. Stones are identified in approxmiatly 95% of patients and may be located in the CBD in many cases of äcalculous cholecystitis
The ensuring inflammatory response may eb related to mucosal ischaemia from increased hydrostatic pressure or to the action of cytotoxi procts of bile metabolism
Bacteria is isolated from the gallbladder in most cases of cholecystitis however the role of infection is not completly understood
Choleforms are the most common isolates (e.coli, klebsiella, citrobacter) - anaerobes have been identified in as many as 40% of cases
Discuss causes of cystic duct obstruction not related to choleliathisis
- Tumor
- firbosis
- parasites
- lymphadenopathy
- kinking of the duct
Discuss clinical finding in Cholecystitis
Similar to bilary colic –
severe right upper qaudrant pain to palpation murpheys +ve
Fever and tachycardia are oftn absent in cholecystitis
Discuss DDX cholecyctitis
Bilary cholic cholangitis hepatits right lower lobe pathology pancreatitis PUD appendicitis
Discuss ultrasound finding of cholecystitis
Most commonly impacted stone seen
Gall bladder wall >3mm
pericholecysitic fluid
PPV of >90% with the above findings
Discuss CT in cholecytistis
Not modality of choice as ultrasound less complicatiosn and readily available with high spec and sens
It is particularly valuable in ephysematous or haemorrhagic cholecystitis
Discuss management of cholecystitis
Supportive care as per bilary cholic
Antibiotics – Triples
Discuss acalculos cholecystitis
More common inelderly patient and patients who are recovering from non bilary tract surgery.
Commonly seen in advanced immunodefiency syndrome usually secondary to CMV or cryptosporidium
Has a more acute and malignant course than calculus cholecystitis
In patients with acalculous cholecystitis, endothelial injury, gallbladder ischemia, and stasis, lead to concentration of bile salts, gallbladder distension, and eventually necrosis of the gallbladder tissue
Discuss Epmhysematous cholecystits
This is an uncommon variant characterized by the presence of gas in the gall bladder wall presumable due to invasion of gas forming organisms (e.coli, klebsiella, C perfringens)
More common in diabeteics has a male preponderance and is acalculis in 50
% of cases. Due to high rates of gangrene and perf surgery is indicated immediatly
Discuss disposition of cholecysitis
Admission for supportive care and ABs
Surgery is indicated in most cases – timing usually occurs when symptoms are resolving and the patient is still in hospital.
Immediate surgery is reserved for those in shock or preforation/gangrene
Discuss cholangitis
Acute cholangitis is a clinical syndrome characterized by fever, jaundice, and abdominal pain that develops as a result of stasis and infection in the biliary tract.
The key factors contributing to cholangitis are a obsturction, elevated intraluminal pressure and bacterial infection INcomplete obstuction occurs more commonly than a complete obsturction
Bacteria may gain acccess to the obstructed CBD in a retrograde manne from the duodenum or by way of the lyphatics or from the portal vein
Organisms are similar to those of other biliary tract disease - e.coli, klebsiella, enterococcus and bacteroids
Discuss clinical features of cholangitis
Most patient experience fevers, chills nausea and vomiting and abdominal pain
The class finding described by Charcto consists of RUQ pain, fever and jaundice . These finding are not only compatable with chalngitis but with hepatitis and cholecystitis
Sepsis is common with chalangitis evidenced by hypotension, tachycardia, tachypnoea and frank hypotension,
The presence of Charcot triad with clinical signs of sepsis, hypotnesiona and altered sensorium is reffered to as Reynolds Pentad.
DDX of cholangitis
Although patient with cholangitis generally have a higher fever than those with cholecysitis there is considerable overlap between the two condition
The presence of jaundice however is common in chlangitis and uncommon in cholecysitis
Ultrasound evidence of dialted common and intrahepatic ducts usually is required to differentiate the two.
Discuss diagnosis of cholangitis
Bloods – left shift leukocytosis, hyperbilirbuinaemia, elevated alkaline phosphatase and moderately increased aminotransferase levels. ABG to identify base excess as an early sign of abcess
US as above can show stones, intrahepatic or CBD dilatation
CT percutaneous transhepatic cholangiography and ERCP (endoscopic retrograde cholangiopancreatography) – THese offer the benefit of being able to offer therapeutics including sampling and culture of the bile, removal of impacted stones and decompression of the bilary tree.
TOKYO GUIDELINES can be used as a guide for the diagnosis of acute cholangitis : Guidlines include
- Part A(systemic inflammation) - fever and or chilld, + labs CRP and WBC
- Part B (cholestasis) Jaundice and abnormal liver enzymes
- Parct C (imaging) bilary dilation or evidence of the eitology
- Grading -system dysfucntion
Discuss management and disposition of cholangitis
Resus – with fluid and vasopressors as needed (ABC)
Broad spectrum coverage
Prompt decompression of the bilary tree is key for success
Disposition
Hospitalization
Discussing primary sclerosing cholangitis
idiopathic inflammatory disorder affecting the bilary tree characterised by diffus fibrosis and narrowing of the intrahepatic and extrahepatic bile duccts.
Commonly associated with IBD and particularly ulcerative collitits - is an isolated condition only 25% of the time
Patient report weight loss, lethargy, jaundice and pruritus
ERCP is often needed for diagnosis
Discuss AIDS cholangiopathy
Manifestation of sever HIV with CD4 counts under 200. AIDS cholangiopathy include bile duct stricutre, papillary stenosis and sclerosing cholangitis
Primary pathology is not well understood but infection with CMV, cryptosporidum, microsporidia or mycobacterium avium are related
Describe pancreatitis
Pancreatitis is an inflammatory condition that occurs with enzymatic autodigestation and inflammatory cascade that results in desctruction of pancreatic tissue.
It can range from a mild selflimiting disease to sepsis, to MOF
Overall mortality is 4-10% although in severe cases can be as high as 30%
Discuss causes of pancreatitis and list the three most common
Three most common
1) Gall stones (40-70%) - more common in females
2) ETOH 25-35% ( more common in men)
3) ERCP
Toxic-metabolic
- ALcohol
- drugs
- hyperlipidaemia
- hypercalcaemia
- Uremia
- Scorpian venom
Mechanical or obstuctive
- Bilary stones
- Congenital - pancreas divisum, annula pancreas
- Tumors- umpullary, neuroendorcrine, pancreatic carcinoma
- Post ERCP
- Ampullary dysfunction or stenosis
- Duodenal diverticulum
- Trauma
Infection
- Viral (CMV, mumps, coxsackie, HIV, EBV, varicella)
- Bacterial - TB, salonella, Campylobacter legionella, mycoplasma,
- Parasitic - ascaris
Vascular
- Vasculitis
- embolic
- hypoperfusion
- hypercoagulability
Other
- idiopathic
- herediatry
- DM-DKA
- Autoimmune
Describe the pathophysiology of pancreatitis
Begins with an exciting event wether that be toxic or metabolic such as ETOH, hyperlipidaemia or obstruction from gall stones
Cellular injury disrupts usual trafficking of enzymes and leads to activtion of trypsinogen and other digestive enymes
This in turn leads to autodigestion of the pancreatic tissue initiating both local and systemic inflammatory cascades
Locally cytockines cause increased vascular permeability which can results in complications such as oedema, haemorrhage and necrosis
Systemic inflammation may lead to SIRS, shock and sepsis.
Discuss disease classification in pancreatitis
Cna be classifed by type (interstitial odematous or necrotic) and be local complictions
Most patient will have interstial odematous disease which usually resolves within a week
About 5-10% of patient will develop necrotising pancreatitis which can involve pancreatic parenchyma and surrounding tissues,
Local complications as defined by the revised 2012 Atlanta Clssification are categorised based on which type of pancreatitis has occured
Discuss local complications of pancreatitis
Interstitial oedematous type
- Acute peripancreatic fluid collection – within 4 weeks of infection no wall
- psuedocyst formation more than 4 weeks after infection – well formed wall
Necrotic pancreatitis
- Acute necrotic collection – heterogenous collection of fluid and necrosis: intrapancreatic and/or extrapancreatic
- walled off necrosis- heterogenous collection of fluid and necrosis with well defined wall: intra or extrapancreatic seen > 4 weeks from symptom onset
Other local complications
- bowel necrosis
- splenic or portal vein thrombosis
- GIT bleed
- Gastric outlet obstruction
Discuss systemic complciations of pancreatitis
Related to progression of local inflammation. If persistant can lead to fluminant sepsis, shock and organ failure.
Pulmonary
- ARDS - due to microvascular damage and increase permeability, also can have direct surfactant degradating affect
- Atelectasis
- Pleural effusion in up to 50% of cases usually on the left
CVS
- hypovolaemic shock secondary to fluid shift
Coagulopathy
- DIC
- Thrombocytopenia
Metaboic
- hyperglycaemia
- hypocalcaemia from low albuin and magnesium levels
Discuss clinical features of pancreatitis
Rapid onset of contant epigastric or left upper quadrant pain.
Usually moderate to severe in nature having nil correlation to severity of disease
Vitals reflect patient discomfort and inflammation with tachycardia, tachypnoea and hihg temp
Respiration can be shallow due to splinting
jaundice if obstruction present
Abdomen can be distended
Cullens and gray turners are rare but in cases of necrotic haemorrhagic pancreatitis are signs of poor prognosis
Tender epigastrium with gaurding and rebound
Discuss DDX of pancreatitis
Abdominal
- GUD
- Bilary colic
- cholecysitis
- cholangitis
- Gastroenteritis
- ureteral stone
- bowel obsturction
- mesenteric ischaemia
- AAA
- ectopic pregnancy
- perf
Cardiopulonmary -ACS -Pneumonia pericarditis -pleural effusion
Systemic disorders
- DKA
- SIckle cell disease
Discuss amylase vs lipase
Lipase more specific and sensitive 96%,99%
Amylase less sensitivity with 78 and 99% respectively
Amylase is produced in both pancreas and salivary and is raised for a range of resions including
- malignancy,
- trauma, burns , salivary and liver disease, cholecystitis, renal failure, HIV and pregnancy
Discuss use of CT in pancreatitis
Rarlely needed as a routine investigation in pancreatitis
Reasons for CT include
1) diagnostic uncertainty
2) to excude other suscpected DDX
3)to assess for complications in patient who fail to respond to treatment within 48 hours
The evaluation of complications with CT is best performed 3-7 days after onset of illness. DUring the first few days it doe not accuratley identify the degree of pancreatic necrosis. Complications such as abcess or pseudocust do not occur for several weeks
Ct finding include
- enlargement of the gland
- loss of typical texture and borders
- surrounding fluid and fat straning
- areas demonstrating nil enhancing with contrast are likley necrotic
