GI Lab diagnostics questions Flashcards
1) A 60 year-old man complains of weight loss, diarrhea alternating with constipation. The patient is pale (anemic). What tests would you perform?
Age, weight loss, diarrhea, and anemia are suggestive of colorectal cancer.
The diarrhea alternating with constipation is a particular sign associated with late stage crc, due to iron-deficient anemia caused by the carcinoma induced bleeding.
Perform digital rectal exam, and then colonoscopy to check for polyps or crc.
Fecal occult blood test to look for bleeding in stool
and
Fecal DNA test for oncogenes and tumor associated genes. APC mutation, Wnt dysregulation genes.
2) A patient with symptoms of chronic alcoholism complains of recurrent abdominal pain, meteorism. He has lost weight in the past few months, his stools are voluminous, difficult to flush.
serum Ca: 2.1 mmol/l
prothrombin time INR: 2.6; normalized after vitamin K administration
serum glucose (fasting): 12 mmol/l
ALP: 264 U/l
albumin: 40 g/l
fecal elastase: decreased
abdominal ultrasound: enlarged pancreas
What is your diagnosis? What other tests would you do?
meteorism: bloating, abdominal swelling due to gas.
Calcium is low. Range 2.2-2.8mM. This is due to ADEK absorption def. and Low Vitamin D
PT INR is high, Range is 0.8-1.2 min Normalized after K administration - malabsorption of fats.
Fasting blood glucose is diabetic range
ALP is increased, obstructive. or bone disorder. in this case due to vitamin d deficiency and hypo calcemia.
Albumin is normal 35-50 g/L, so not a synthesis defect.
Decreased fecal elastase indicates a decrease in pancreatic enzymes (it is secreted in equal amounts as other digestive enzymes, but is not degraded in the colon).
Chronic alcoholic that has lost weight, bloated, and with large fatty stools that are hard to flush.
Liver cirrhosis is causing lack of bile secretion and malabsorption of food.
Chronic Pancreatitis, or less likely pancreatic cancer but we didn’t see cancer on the US.
Further tests:
Lindt test: Stimulate pancrease with CCK, then collect the pancreas exretions with an endoscope.
ERCP to confirm it is not a bile obstruction (although I have in my notes NOT to do this test but I don’t know why not to).
- Pancreolauryl test: Fluorecein-dileurate is given, and it is cleaved by the pancreatic esterases.
When cleaved fluorescein is released, and it is possible to measure in the urine. If there is no fluorescein in the urine, it would reflect no exocrine pancreas secretion/enzyme activity.
3) A patient complains of intense periumbilical pain of sudden onset. His blood pressure is low, the pulse is fast, he is sweating and has nausea. There is no defense on physical examination of the abdomen.
Laboratory results:
ESR: 42 mm/h
WBC: 11 G/l
serum α-amylase: 1800 U/l
urine α-amylase: increased
serum lipase: increased
serum urea: 10 mmol/l
serum creatinine: 90 μmol/l
serum Ca: 1.9 mmol/l
serum albumin: 30 g/l
fasting blood glucose: 6.5 mmol/l.
What is your diagnosis? What other tests would you perform?
ESR: is increased Erythrocyte sedimentation rate range < 20 mm/h
WBC: is increased white blood cell count range is 4-10 G/L
Serum alpha-amylase: should not be present
Urine alpha-amyase: increased.
Serum lipase: increased. Serum LIPASE is a specific indicator of ACUTE pancreatitis and not chronic pancreatitis.
Serum urea: 10 mM increased, range is : 3 - 7 mM, which indicates kidney malfunciton/failure.
Serum Creatinine: is Normal range 40-130 - kidney failure hasn’t completely occured yet, good!
Fasting blood glucose is impaired, due to pancreatitis and increased glucose release from sympathetic/cortisol activation.
The increased sedimentation rate and WBC count indicate an inflammation. The increased serum pancreatic enzymes and pain in the periumbilical region indicate acute pancreatitis.
The low blood pressure and tachycardia are indiciative of shock, usually hypovolemic shock, which is commonly associated with severe acute pancreatitis, from fluid loss to the abdominal cavity as the pancreas necrotizes, or if a pancreatic vessel ruptures causing hemorrhagic shock, which is highly lethal.
Tests to perform: Ultrasound and CT scan.
Further tests: We don’t really need further tests to establish diagnosis.
- Ultrasound to determine severity (size) and to check for bile obstructions
- [CRP] serum
- CT to asses extent of inflammation
Look for:
- Cullens sign: periumbilical discolorization and edema due to bleeding
- Gray-Turner sign: discolorization of the flanks due to intraperitoneal / retroperitoneal bleeding
- Blumberg test: rebound tenderness; progression to peritonitis
4) A 35 year-old man complains of heartburn and occasional regurgitation of sour material in his mouth, mostly in the morning especially if leaning down.
These symptoms were provoked by drinking beer the evening before. Findings of an esophago-gastro-duodenoscopy: the proxymal part of the esophagus is normal, but the distal part is hyperemic with erosions. The cardia is loose, the antrum is hyperemic in patches. The bulbus and the postbulbar duodenum is normal.
What is your diagnosis? What further test and treatment should be considered?
GERD, with Barret Esophagus
Esophageal pH monitoring is the current gold standard for diagnosis of GERD.
Also test for H. Pylori infection.
Should be treated.
PPI inhibitors, antacids for acute attacks, and lifestyle change.
Manage obesity, don’t eat acidic foods, alcohol
Could test for an H. Pylori infection as it could be the early stages.
5) A 45 year old patient complains of maldigestion, increasing abdominal pain and weakness. Abdominal discomfort occurs shortly after meals or alcohol ingestion. Laboratory results:
Haemoccult: positive
anemia
What tests would you do, what are the treatment options?
Peptic ulcer because the pain is shortly after meals (if it was colitis, it is not associated with pain after the meal because this is too far away)
Hemocult positive so it is causing some bleeding which is causing anemia.
Also malabsorption of B12 may be causing anemia
Test for H. Pylori,
Perform endoscopy of duodenum to check for other possiblities of blood in the stool, especially for colorectal cancer
- PCR of stool with a focus on genetic translocations in APC gene and TP53
- CT to check for gastrinomas: Zollinger-Ellison syndrome: gastrin secreting adenoma, HCL secretion increase
Treatments: eleminate H. pylori withe OmeClaMox
Omeprazol, the PPI,
Clarithromicin, anaerobic.
Amoxicillin, aerobic
6) What tests would you perform if you suspect your patient has an autoimmune inflammatory bowel disease?
IBD:
Symptoms: fever, abdominal pain, diarrhea, weight loss, blood in stool, diseases:
- Crohn’s disease: effects areas in patches, especially the terminal ileum; check with colonoscopy
- Ulcerative colitis: do colonoscopy; usually a whole section of the colon from the rectum is affected
- *Tests: - Inflammatory markers
- Contrast X-ray to look for stenosis/spasms.
- Colonoscopy with biopsy
- Stool for occult bleeding
- Video-capsule endoscopy
- Autoantibodies**
7) A 30 year-old man complains of recurrent abdominal pain usually accompanied with diarrhea. These symptoms occur after the ingestion of fresh dairy products or alcohol.
What may be the cause of these complaints? What tests would you do?
Lactose intolerance, insignificant.
- Hydrogen breath test: after overnight fasting, 25g of lactose are ingested. If there is no lactase enzyme, bacteria will break down the lactose, producing hydrogen and methane gas. These gases can be detected in the patients breath (gas chromatograph).
- Blood test: after fasting, lactose is given. Blood is drawn every 30 minutes, and if there is no elevation in blood sugar, it will indicate the body cannot utilize lactose.
- Stool acitidy test: breakdown of lactose by bacteria creates acidic stool (pH < 5.5)
- Blood test with alcohol: alcohol is known to inhibit lactase activity
- Genetic test
Therapy: avoid fresh dairy products and alcohol, or take lactate tablets with food
