CSI 17 - Acute Abdomen Flashcards
in what demographics can a pain free acute abdomen occur in?
Old people
Children
Immunocompromised
Last trimester of pregnancy
After the initial diagnostic procedures (Hx, Exams Ixs, labs, etc), what other pathways or methods may you use to help determine cause of an acute abdomen IF the symptoms doesn’t neccesitate immediate surgery
Further abdo exams by a physician with more xp
Diagnostic laparoscopy
what conditions can laparascopy be used therapeutically
- Appendicitis
- Cholecystitis
- Lysis of adhesions
- Hernia repair
- many gynaecological causes of an acute abdo
what diagnostic algorithms or tools can help to further stratify risk of appendicitis
Appendicitis Inflammatory Response (AIR) score
Novel Pediatric Appendicitis Risk Calculator (pARC)
Need further prospective studies to evaluate clinical use
How has the attitude of narcotic analgesia changed over time regarding it’s use in patient’s with an acute abdomen
Before: it was discouraged as they thought it would mask the symptoms or exam findings and hence miss diagnosis
Now: evidence shows it doesn’t hinder management and improves pt comfort.
Fentanyl or one of it’s analouges is a useful agent used due to it’s potency and short half life
Give reasons as to why old people present atypically with abdo pain
They have long standing co-morbidiites hence cannot mount the appropriate physiological response (due to comorbidities or meds treat it).
Deteriorating CNS or PNS
- CNS- dementia and hence can’t communcate symptoms effectively
- PNS - alter perception of pain/temperature
Give reasons as to why pregnant people present atypically with abdo pain.
Explain any response needed?
Pregnancy have different physiology and hence making diagnosis very difficult.
Enlarged uterus compress abdo organs and there’s laxity of abdo walls: makes it difficult to localise pain and can blunt peritoneal signs
Pregnant people mauy have mild physiological leukocytosis (this finiding is non-specific in women with acute abdo).
Concerns about imaging (CT or Xrays)
what is the amount/threshold of radiation that hasn’t been linked to maternal or foetal defects?
less than 5 rads
what are the abdominal sources/causes of an acute abdomen?
From most common to least common
Intestinal Obstruction
Peritonitis secondary to infection
Inflammatory conditions that present with peritonism
Haemorrhage (e.g. ectopic pregnancy)
Ischaemia (Mesenteric ischaemia or ovarian torsion)
Processes associated with contamination of GI contents (e.g. perforated duodenal ro gastric ulcer)
What should you do if you see a pt with peritonitis secondary to infection?
what is needed?
Surgical emergency- LAPARATOMY
Don’t wait for diagnostic studies
what are the causes of obstruction (leading to an acute abdomen)
Adhesions (most common)
Incarceration of hernia (2nd msot common) and most common in people without prior abdo surgery
Volvulus, Gallstones, Intussuception
Congential anatomical abnormalities
Cancer
IBD
Inflammation may be an aetiology for an acute abdomen.
Give causes of inflammtion
Cholecystitis,etc
Diverticulitis
Meckel’s diverticulitis
IBD- pain due to inflammation itself or secondary obstruction
Perforation may be an aetiology for an acute abdomen.
Give causes of perforation
Gasstric or duodenal ulcers
Boerhaave’s syndrome and
Mallory weiss tear
Can lead to oesophageal laceration and GI haemorrhage
what are the gynacological causes of an acute abdomen
Ectopic pregnancy hence always do a pregnancy test for women in child bearing age
Others are:
- Ruptured overian cyst
- Ovarian torsion
- Pelvic inflammatory diseases
- Endometriosis
what are the vascular causes of an acute abdomen.
Explain any relevant details
Haemorrhage caused by
- ruptured AAA
- Abdo aortic dissection
- ruptured splenic artery aneurysm
Ischeamic:
- AMI or ischeamic colitis
- splenic infarct
- Vaso-occlusive episoded of sickle cell crisis
Budd chiari syndrome - stop hepatic venous outflow and hence lead to hepatomegaly and ascites
Abdo wall haemtoma
- occur spontaneously or
- secondary to trauma , coughong, exercise or procedure
State and explain the infective causes of an acute abdomen
Psoas abscess- due to tuberculosis abcess spreading from lumbar vertebrae to psoa
Hepatitis/hepatic abcess
gastroenterirtis, infectious colitis
Typhilitis (neutropenic enterocolitis)
Fitz-Hugh syndrome: complication of pelvic inflammatory disease
- you hsve RUQ pain associated with perihepatitis
what are the metabolic causes of acute abdomen
Uraemia
Diabetic ketoacidosis
Addisonian crisis
Hypercalcaemia
Genetic:
- Acute intermittent porphyria
- Hereditary Meditteranean fever
state what toxic substances can cause an acute abdomen
Heavy metal poisoning - caused by medical/environmental/occupational exposure to, mercury, lead, or arsenic.
Narcotic withdrawal from opioids may result in abdominal cramping pain.
what are the urological and other causes of acute abdomen
Urology
- In men, testicular torsion should be considered.
- In both men and women: kidney stones and pyelonephritis
Other
Radiation enteritis and spider bites
what are the general urgent considerations for pt with an acute abdoment
Whilst waiting for routine labs, consult a surgeon; it’s more efficient
IV access should be obtained and monitor vital signs
Correct any abnormalities (with fluids or blood products)
what should you consider for a pt exhibiting evidence of hypovolaemic shock with a known or suspected haemoperitoneum
Get to surgery ASAP (with limited pre-op evaluation)
Those with ongoing haemorrhage:
- Give 2 large bore IV lines
- Urgent typing and cross-mathcing of blood is needed
- Fluid resuscitation
Initial resuscitation involves:
- 2L of isotonic fluids
- O negative uncross-matched blood can be given until cross-matched blood can be given
- Maybe give antifibrinolytic like tranexamic acid
what should you consider regarding FLUIDs for a pt exhibiting evidence of aortic dissection or ruptured AAA?
Explain why
Careful fluid management (aim SBP to bebetween 80 and 90) or even lower if mentation is intact
This is becauses aggressive fluid replacment can lead to more bleeding via:
- hypothermic and dilutional coagulopathy
- Lowering blood viscosity
- Increased perfusion pressure FROM FLUID expands volume and lead to sendoary clot disruption
what should you consider APART FROM FLUIDs for a pt exhibiting evidence of aortic dissection or ruptured AAA?
Explain why
O2
multiple peripheral or centraL venous access
Urgent blood typing and cross-matching
Routing labs tests
Vascular surgery consultation
Prophylactic Abx
what should you consider if a perforated viscus, appendicitis or cholecystitis is suspected
i.e what measures should you take quickly?
Give Broad spectrum Abx: contents of GI can lead to sepsis
Urine MCS and dip stick
Blood tests
what should you consider for a pt that is female of childbearing age.
what should you do now?
Preg test - exclude ectopic preg
if ectopic is suspected give 2 large bore IV cannulae (incase it ruptures)
Blood type and cross matching should be considered
Urgent gynaecological consultation is needed
what should you consider If a patient reports abdominal pain disproportionate to the signs on physical examination,
what disgnois should you think of and what should you offer
Consider mesenteric ischeamia esp in old ppl with Hx of:
- Smoking
- Peripheral vascular diseases
- A-fib
Offer:
- O2
- Fluid resuscitation
- Broad spectrum Abx
- Urgent surgical and Interventional radiologist consultation needed
what are the common differentials for an acute abdomen?
*The list is not exhaustive but you should already the know the ones not listed*
Gastrointestinal malignancy
Hepatic abscess
Fitz-Hugh Curtis syndrome
Mallory-Weiss tear
Abdominal wall haematoma
Hereditary Mediterranean fever
Typhlitis (neutropenic enterocolitis
Narcotic withdrawal
Infectious colitis
what are the uncommon causes of an acute abdomen.
*Again list is not exhausitve, the others are too niche that you would guess them in the SBA*
- Volvulus
- Intussusception
- Duodenal ulcer
- Ruptured ovarian cyst
- Ovarian torsion
- AMI/ ishcameic colitis
- Hypercalcaemia
- Aortic dissection
- Ruptured AAA
- DKA
what does long standing epigastric pain suggest?
Gastric ulcer
A sudden worsening suggests perforation
what does sudden epigastric pain following vomiting and/or OGD suggests?
Oesophageal perforation
what does it suggest for areas of the pain in the diagram that present gradually or more progressively
If a pt has similar pain before but now it’s come back, what does it suggest?
This may suggest a recurrent condition, such as cholecystitis, pancreatitis or diverticulitis, with increasing frequency and severity indicating disease progression.
what does RUQ pain signify
Cholelithiasis, cholecystitis, hepatitis, hepatic abscess,
Fitz-Hugh Curtis syndrome,
Perforation or malignancy of the colon,
Pyelonephritis, or kidney stones.
Acute appendicitis in a pregnant woman due to displacement by the enlarging uterus.
what does LLQ pain indicate?
Sigmoid volvulus (typically older patients), diverticulitis, IBD kidney stones, gastrointestinal malignancy,
Psoas abscess,
incarcerated / strangulated hernia,
gynaecological concerns,:
- ovarian torsion or cyst rupture,
- ectopic pregnancy, or pelvic inflammatory disease (PID).
what are the causes of periumbilical pain?
Appendicitis before radiating
Acute mesenteric ischeamia
Leaking or ruptured AAA
Small bowel obstruction
What does persistent lateralised pain indicate?
condition associated with ascending or descending colon, kidney, gallbladder or ovary.
what does the diagram show about radiation
what does referred pain to the follwoing indicate?
Right scapula
Left scapula
Scrotal/Testicular pain
Right scapula:
- Gallbladder disease, liver disease,
- irritation of right hemidiaphragm (e.g., right lower lobe pneumonia)
Left scapula:
Cardiac disease, gastric disease, pancreatic disease, splenic disease, or irritation of left hemidiaphragm.
Scrotal or testicular pain:
- Usually from loin to groin: kidney stones or ureteral disease
*
what are other important information to consider when a pt presents with abdominal pain
Character: Aortic diseection is a sharp, tearing pain.
Other associated symptoms like fever, chills, N&Vomiting shows:
- Cholecystitis , etc
- spider bites, abdominal wall haematoma
Time of last bowel movement: important for construction
Nature of recent stool
Time and type of last meal or oral intake
Presence of anorexia:
- Appendicitis
- radiation enteritis
- hepatic abscess
PMHx, FHx, SHx, DHx
last menstrual period
why is it important to ask about history of cardiac disease for a pt with an acute abdo
CVD predispose to AAA
History of A-fib can lead to acute mesenteric ischaemia
why is travel history important?
whether the patient has visited an area endemic for amoebiasis (hepatic abscess),
or areas that have insanitary conditions (gastroenteritis and infectious colitis).
what does it signify if a pt is still and relunctant to move?
More typical for peritonitis
Apart from patients with marked obstruction, in what patients would you see absent bowel sounds
perforated viscus,
haemoperitoneum, or other conditions with peritoneal inflammation.
On palpation, what does it signify if a pt has peritonitis with reflex involuntary guarding?
what about rebound tenderness?
Peptic ulcer disease
Rebound tenderness:
- appendicitis, diverticulitis
- any condition that causes inflammation of the parietal peritoneum
what does it signify if you palpate the following on a pt?
- Irreducible hernia
- Palpable masses
Irreducible hernia signify incarcerated hernia
Palpable masses:
- cholecystitis
- appendix mass
- intussusception
- aortic aneurysm
what should you consider (although uncommon) if a pt presents with left sided abdominal pain?
Situs invertus and/or mid-gut malrotation
what should you consider for a pelvic examiantion?
what signs should you look for?
For most women with lower abdo pain
Can help to exclude or diagnose ectopic pregnancy, PID, ovarain torsion.
PID:
- cervical motion tenderness
- adnexal tenderness
- Bimanual exam or USS may show tibo-ovarian abscess
Ectopic preganancy:
- Palpable adnexal mass with/wtihout tenderness
- vaginal beleding on speculum examination
Ovarian torsion:
- severe, unilateral adnexal tenderness that is often palpable
- Urgent gynae review is needed
what should you bear in mind for a scrotal or testicular exam?
Tenderness can suggest epidydimitis or testicular torsion
Testicular torsion :
- Need doppler ultrasound quickly (to check perfusion) and urgent urology review
- Surgical detorsion is recommended less than 6 hrs from presentation
USS can help seperate hydrocoeele (due to patent process vaginalis) and identify testicular masses
Check inguinal canals on BOTH sides for hernias
what does hypoCL or HypoK+ occur in ?
what about glucose?
urea
latter stages of intesitnal obstruction
Glucose: pancreatitis if insulin is compromised
Urea:
- Aortic dissection
- AAA
- renal srteries are compromised
If diagnosis is not definitive from the physical examination, laboratory analysis, or radiographic evaluation, why are the following tests helpful?
e.g
- LFT
- Coagulation studies
- Serum amylase
- Lactic acid
LFTs (and basic comprehensive panel)
Coagulation studies:
- For all pts with suspected vascular causes like AAA, AMI etc
- Unstable pts esp if surgery is indicated.
Serum amylase and lipase:
- Pancreatitis (3 times mroe than normal)
- Lipase is better indicator as it last longer in blood (2wks compared to 5 days)
- Have a low threshold for admitting as it can be missed
Consider other conditions that need surgery even if tests are normal
Serum lactic acid (VBG):
- if mesenteric ischaemia is suspected
- serial measurements should be used for resuscitation
what are the other conditions that can also mildly elevate amylase
Ectopic pregnancy, intestinal obstruction, and perforated duodenal ulcer.
Although amylase levels are not used to diagnose or monitor these condition
What can a plain AXR show?
Show obstruction and dilation
Radio-opaque stones indicative of cholecystitis , pancreatitis or kidney or ureteric stones.
AAA:
- aortic wall calcification on kidney, ureters or bladder
- loss of psoas shadow: shows a ruptured AAA
these findings with the clinical picture is sufficient to proceed to surgery
when shoukd you perform an Erect CXR and what can it show?
if perforation is suspected
- rule out pneumopeitoneum
- if pneumoperitoneum is visible - need surgical consult immediately
may also be a useful pre-op tests for anaesthetists and id often performed in conjuction with plain AXRs
what is the indication of CT?
what about pregnant women?
Any surgically related causes of an acute abdomen : e.g. cholecystitis, etc
If pt with ruputre AAA is too uinstable to be moved, use an USS
Can be used in pregnant women but need obs&gynae consult first to check fetal viability (24 wks)
describe the usefulness of ultraosound ,
what will it show for the following dieases?
- Cholecyctitis
- Pelvic - ectopic pregnancy
- Ovarian torsion
what else can it show?
For cholecystitis , can show :
- gallstones
- thickened gall bladder wall (more than 4 mm)
- pericholecystic fluid.
Pelvic utraosund for ectopic pregnancy:
- show blood or pseudogestational sac in utero
- ectopic pregnancy
- complex mass in adnexa
ovarian torsion:
- doppler USS may show reduced or absent blood flow to torsed ovary
Can also show presence and size of AAA and presnece of fluid or blood within the peritoneum (esp for unstable pts)
what is the significance of Focused Assessment with Sonography for Trauma (FAST)
A limited ultrasound examination directed solely at identifying the presence of free intraperitoneal or pericardial fluid and is used principally in trauma situations.i
in what pts may a laparoscopy be considered?
- Clinically stable
- No indication for therapeutic surgical intervention
- No apparent cause for their abdominal pain after non-invasive procedures
- No relative or absolute contraindication to surgery.
Also for childbearing women with non-specific abdo pain and suspected appendicitis: (better prognosis and diagnosis)
what are the features of a laparoscopy? (diagnostically AND therapeutically)
can be diagnostic and therapeutic for:
- acute cholecystitis
- perforated ulcer
- appendicitis
- lysis of adhesions
if procedure can’t be done laparoscopically or the pt cannot tolerate insufflation pressure then the case is converted to a laparotomy
from F2F session
what are the systemic causes of epigastric pain, what shoudl you try to exclude in a pt with epigastric pain first
- DKA
- Addisonian crisis
- Lead poisioning
- Hypercalcaemia
Always try to exclude gastroenteritis for this patient (food poisoning)
- Features are febrile, too much diarrhoea and vomiting
- If suspected to have it secondary to takeaway ; report to public health England
Physiologically speaking, when are ALP and AST raised?
ALP more likely to raised when there’s obstruction of the liver (esp bile)
AST raised when hepatocyte dies
How are the overwhelming majority of gallstones found?
iNCIDENTALLY and they are asymptomatic
what are the clinical features/cause of biliary colic
Dull RUQ pain
Symptoms last for LESS than 6 hrs (more likely to be constant)
No inflammation: blood tests is normal
Trigger by fatty food; stimulate CCK causes contraction of gall bladder
Nausea and vomiting
Normally caused by blockage of gallstones in the cystic duct or neck of gallbladder causing muscular contraction
what are the clinical features/cause of acute cholecystitis
Severe constant RUQ pain or maybe epigastric
Murphy sign positive (do the same on the left hand side and confirm there’s no pain)
Pyrexia and tachycardia
Raised WCC, CRP
Sometimes, have a slightly raised ALP
Bilirubin is normal
Nausea and vomiting
what are the clinical features/cause of acute cholangitis
Biliary outflow obstruction and infection of bile ducts (bacterial)
Gallstones may be found in CBD
CLINICAL SIGNS:
- Jaundice
- Severe pain
- Rigors and fever
- Tachycardic, febrlle and hypotensive
- Raised WCC, CRP, ALP
- Raised LFTs (raised BR and others)
Charcot’s triad (Jaundice, rigors/fever and RUQ pain)
Very high mortality
Reynold’s Pentad: if they have shock and altered mental status
Obstruction of bile from liver or gallbladder and infection (bacterial)
what are the risk factors for gallstones
- Forty
- Female
- Fat
- Fertile
- Fair (caucasian)
- (High fat diet, maybe native American)
- Haemolytic anaemia
- Crohn’s disease (affect absorption of bile products in terminal ileum)
- Oestrogen increase biliary cholesterol production and OCP can increase risk
what investigation is used to see gallstones?
what will you see
USS
99% of gallstones don’t show up on AXR and CTs aren’t used
Features seen on USS:
- Hyperechoic echoing and posterior acoustic shadowing
what is the composition of bile and how does gallstones form?
what are the types of gallstones
Bile mainly made of water (98%). Others are BR, Cholesterol, bile salts and electrolytes
Gallstones result from supersaturation of bile, can differ in sizes.
The composition differs from age, diet and ethnicity.
Gallstone Crystallisation could be either from cholesterol (majority) or bilirubin (pigment) or both
what are the features of cholesterol stones and give relavant risk factors
Cholesterol gallstones normally found alone, and can be yellow or dark green or brown colour.
They are large.
RF are:
- poor diet and
- obesity due to excess cholesterol
what are the features and RF of pigment stones and mixed stones
Pigment stone:
- made up of bilirubin breakdown products.
- They are small, darker and numerous.
- It can be from excess bile pigment production.
- Can be black or brown
Black pigment: made up of calcium bilirubinate and more likely seen on X-ray
Brown: occur secondary to infectiojn
RF: haemolytic anaemia (for black pigment stones esp)
Mixed stones: combo of pigment and cholesterol , and bile salts
what are the different locations of gallstones that can cause
- Acute cholecystitis
- Bilairy colic
- Ascending cholangitis
- Pancreatitis
Gallstones in neck of gallbladder or cystic duct you get cholecystitis
Hartman’s pouch can also cause it
Impacted stone with inflammation gives you cholecystitis
Gallstone found in CBD with infection causes ascending cholangitis
Gallstone in the neck of gallbladder or cystic duct can also cause bilary colic
Gallstone in pancreatic duct causes acute pancreatitis
what are the complications of cholecystitis
Pancreatitis – block flow from MPD
Gallstone Ileus- rare
Gallstone cancer (cholangicarnicoma) due to long standing inflammation.
Gallbladder empyema : gallbladder gets blocked and lead to build up of pus
Explain the pathophysiology of Gallstone Ileus
Gallbladder lies adjacent to duodenum
It is small bowel obstruction secondary to gallstones.
Overtime wall of gallbladder is eroded due to chronic inflammation and lead to fistula formation b/w gallbladder and duodenum (this occurs over a long time)
It occurs when gallstone enters duodenum and causes the blockage of small bowel.
Gallstone enters ileocaceal valve and cause small bowel obstruction
It takes TIME
what is Mirrizi syndrome?
Stone in cystic duct or gall bladder neck that causes pressure on the hepatic ducts
You get obstructive jaundice. But imaging shows no gallstones in hepatic ducts
what are the treatment guidelines for :
- Asymptomatic gallstones
- Biliary colic
- Acute cholecystitis
Asymptomatic gallstones- no treatment
Biliary colic: avoid fatty food and other conservative treatment.
Cholecystitis: laparoscopic cholecystectomy
what are the complications of laparoscopic cholecystectomy
- General
- Speciifc
- Early
- Late
General: Inherent to any op
- Incision:
- Bleeding, scarring
- Infection at incision site
- Chronic pain (Post -op pain may not subside, ie. post-cholecysectomy syndrome)
- DVT and PE (due to inactivity of muscle as it’s paralysed, more time increases risk)
- Anaesthetic risk : depends on comorbidity , age
Specific :
- Vessel (cystic artery or hepatic artery) damage
- Damage surrounding structures (bowel, bladder, ureter, liver) that can lead to haemorrhage
- Bile duct injury- devastating
- Bowel leakage/perforation
- Laparascopic may be converted to open op and hence make bigger cuts
Early risk):
- Straight after op, wound can get infected
Late:
- Wound not heal properly and lead to hernia
Explain and outline the procedure for a laparoscopic chiolecystectomy
You must have knowledge of the procedure to obtain valid consent
Explain diagnosis to them and all the effects
Make sure they have capacity. Give them time
Treatment options:
- Include do nothing
- Tell them all available
- You cam recommend to pt but don’t force it
Purpose of treatment- needs to be written on consent form.
Tell risk:
- Different people have varying tolerance for risk
- Different risk are different for different people
what are the components of brown and black pigment gallstones?
what diseases are they associated with?
Brown:
- Infection of biliary tract (bacterial and helminth deconjugation of bilirubin glucoronides)
- Found in asia
Black:
- Consists of calcium bilirubinate
- Found in haemolytic aneamia or
- Pts with ineffective haematopoesis
- Pts with cystic fibrosis
what 3 mechanisms are important in the formation of cholesterol gall bladder stones
Cholesterol supersaturation
Gallbladder hypomotility
Kinetic, pro-nulceating protein factors
what are the components of the majority of gallstones
Cholesterol (70%) in a matrix of bile pigments, calcium salts and glycoproteins.
Explain the mechanism behind cholesterol supersaturation in the formation of cholesterol gallstones
Cholesterol is slightly soluble in water but bile makes it solubele via mixed micelles (containing bile salts and lecithin)
Precipitation of cholesterol occurs when it’s solubilty exceeds its saturation index of 1 (shown by Gibbs Triangle)
Hence it crystallises at:
- low phospholipid: cholesterol ratio
- low phospholipid and high bile salt concentration
The multilammellar vesicles then fuse and may aggregate as solid crystals
what does Gibbs triangle/ternary phase diagrams show regarding cholesterol supersaturation
Ternary phase diagrams shows molar bile salt-cholesterolphospholipid percentages
Explain the mechanism behind Gallbladder hypomotilty regarding gallstones formation
what are the at risk groups
Those with cholesterol gall stones have gallbladder hypomotility
Incomplete emptying lead to increased total lipid concentrations
impaired emptying seen in:
- diabetes
- those with rapid weight loss
Regarding gallbladder hypomotility, how does it relate to developing symptomatic disease when the stone has already formed
Risk of symptomatic disease higher for those that has higher/efficient gallbladder emptying
Explain the mechanism of how kinetic factors can lead to formation of cholesterol gallstones
Formation of microcrystals in supersaturated bile is modulated by kinetic protein factors.
A number of inhibitory or promoting proteins have been described.
Mucin, a glycoprotein mixture that is secreted by biliary epithelial cells is the crystallization promoting protein in gallbladder sludge.
Apart from emulsifying fat, what are the other functions of bile and where is the location of the gall bladder
essential for digesting fats, excreting cholesterol, and even possesses antimicrobial activity.
Gallbladder is found in the gallbladder fossa of the live rin the RUQ and is part of the extrahepatic biliary system
As part of the hepatic lobule, what structure helps in drainig bile into the biliary tree?
what cells lines them
small channels known as the Canals of Hering.
They are lined by simple cuboidal epithelium and ultimately drain the bile into the bile ductule of the portal triad, which will go on to drain into the bile duct.
Extensively describe the layetrs of the gallbladder and the function
The innermost mucosal layer is made up of columnar epithelium with microvilli.
The microvilli increase surface area which is useful for concentrating bile.
Beneath the mucosa is a lamina propria, a smooth muscle layer, and an outer serosal layer due to its intraperitoneal location.
what are the functions off CCK
they are released by I cells in duodenum and jejunum in response to fatty aicds and amino acids
It causes contraction of gallbladder
It relaxes sphinxter of Oddi
It increases pancreatic exocrine secretion
what enzyme catalyses the rate limiting step for the production of bile acids
cholesterol 7α—hydroxylase. (bile acid is made from cholesterol)
Explain how bile acids aid in absorption of fats
Bile acids are amphipathic and hence emulsify fats into micells
The hydrophilic part is negatively charg and hence repel other bile acids
Micelles are then formed (containing cholesterol and phospholipids)
Bile salts then reabsorbed in terminal ileum to enterohepatic circulation
What enzyme catalyses conjugation of Bilirubin and explain what occurs when BR cannot enter the duodenum
Enzyme is : glucuronate via the enzyme UDP-glucuronosyltransferase
You get Jaundice (yellowin of eyes, mucus membranes, etc) and pale stool (no stercobilinogen or urobilin made)
Although a USS is the inital test of choice for looking at gallbladder disease, what test is most specific and sensitive diagnostic test for cholecystitis?
Explain why and when is it used?
hepatobiliary iminodiacetic acid (HIDA) scan, also known as cholescintigraphy.
IV nucleotide tracer that can go up to the gallbladder, it concentrates in gallbaldder if the cystic duct is patent.
It is typically performed in the setting of an ambiguous abdominal ultrasound with clinical suspicion of gallbladder pathology.
How can aCCK be used a s a diagnositc test for gallbladdewr disease
CCK can be administered to test for the ejection fraction (EF) of the gallbladder.
An EF below 35% is considered abnormal and indicative of functional gallbladder disorder.
what are the names of the enzyme for LFTs you can measure
AST
ALT
ALP
GGT- likely to be raised as it’s made by hepatocyte and epithelial cells lining the gallbladder
BR
what is Choledocholithiasis ?
Choledocholithiasis occurs when a gallstone becomes lodged in the common bile duct..
This can affect LFTs and or pancreatic enzymes and may even lead to ascending cholangitis
Apart from gallstones what are other causes of cholecystits seen in ill pts (Acalculous cholecystiits)
infection, low perfusion, or biliary stasis
what drugs and conditions can increase risk of gallstones formation and explain why
OCP containing estrogen causes increased levels of cholesterol.
Somatostatin analogs such as octreotide block the release of CCK and lead to the formation of biliary sludge (gallbladder hypomotility)
Fibrates block the rate-limiting enzyme 7-alpha-hydroxylase causing increased cholesterol and decreased bile acid production.
Conditions:
- Fasting- less CCK made
- Those under parenteral nutrition- less CCK made
