Critical Care Gi Tract

Front 1

1. What is the cutoff point for the thickening of the gallbladder in acalculous cholecystitis on ultrasound?

Back 1

3- 3.5 mm. Thickening of the gallbladder wall is the most reliable feature seen in patients with acalculous cholecystitis. Using a cutoff of 3.5mm ultrasonography has a sensitivity of 80% and a specificity of 99% for detecting acalculous cholecystitis.

Front 2

2. What is the accordion sign on CT scan?

Back 2

This refers to the similarity between the thickened edematous walls of pseudomembranous colitis to that of an accordion. Oral contrast is trapped between edematous haustral folds and pseudomembranes, which are formed on the surface of the colon.

Front 3

3. What are the few clues to diagnose D lactic Acidosis?

Back 3

D- Lactic acidosis can occur in patients with short bowel syndrome, jejunoileal bypasses or small bowel resections. Bacteria in the gut are responsible for metabolizing glucose and carbohydrate to D lactic acid, which is then systemically absorbed.

Treatment: Fluid resuscitation

Restriction of simple sugars

Sodium bicarbonate administration and careful use of antibiotics such as Metronidazole.

Front 4

4. What is a Curling ulcer?

Back 4

This is an acute peptic ulcer, which results as a complication of a severe burn. It occurs when reduced plasma volume leads to sloughing of f of the gastric mucosa. They are more often seen in pediatric patients with burns compared with adults.

Front 5

5. How do PPIs work?

Back 5

PPIs inhibit the stimulated parietal cells with active proton pumps and rapid administration of I/V PPI bolus can rapidly achieve this

Front 6

6. How do H2 blocking drugs work?

Back 6

The letter H in their name stands for histamine. Histamine is a chemical naturally produced by certain cells in the body, including cells in the lining of the stomach, called the enterochromaffin-like cells (ECL cells). Histamine released from ECL cells then stimulates the acid-making cells (parietal cells) in the lining of the stomach to release acid. What H2 blockers do is stop the acid-making cells in the stomach lining from responding to histamine. This reduces the amount of acid produced by your stomach.

Front 7

7. In treating excess acidity, what is meant by the term " Green Goddess"?

Back 7

This is a GI cocktail consisting of:

10-30 ml of Mylanta

10 ml of Donnatal

10ml of viscous Lidocaine.

It is considered effective for the treatment of dyspepsia.

Front 8

8. Which commonly used drug for GI prophylaxis in critical care units may decrease the efficacy of Plavix (Clopidogrel)?

Back 8

Omeprazole (Prilosec).

PPIs inhibit the enzyme CYP2C19- the main enzyme that converts Plavix (prodrug) to its active metabolite.

Front 9

9. Which electrolyte abnormality may prevent Neostigmine from resolving Oglivies syndrome (Acute colonic pseudo obstruction)?

Back 9

Potassium. here there is large bowel obstruction with no evidence of mechanical colonic obstruction. It is secondary to invasion and destruction of the splanchic nerves, superior mesenteric ganglion and celiac nerve plexus.

Neostigmine is an acetyl cholinesterase inhibitor, which increases the acetylcholine concentrations of the enteric neuromuscular junctions in the nervous system which assists in smooth muscle contraction.

Front 10

10. What are some possible side effects of Neostigmine?

Back 10

Excessive sweating, salivation, bradycardia, and bronchospasm and hypotension. Atropine should be readily available.

Neostigmine use in renal failure should be used with caution.

Front 11

11. What is Mackler's triad?

Back 11

1. Lower chest pain

2. Vomiting

3. Subcutaneous emphysema

This is a classic presentation of esophageal rupture (Boorhaave's syndrome, but presents in only a few paptients.

Front 12

12. How much blood is needed to turn guaiac based fecal occult blood test positive?

Back 12

About 10ml over 24 hours.

Normally, there is only about 1-2 ml of blood a day that escapes blood vessels into the stool per day. The guaiac based fecal occult blood teat usually picks up a daily blood loss of about 10ml.

Front 13

13. It is said that insertion of a chest tube in hydrothorax is a bad idea. Why is this?

Back 13

This may result in uncontrollable fluid loss and has a high mortality secondary to hypovolemic shock.

Therapeutic thoracocentesis with albumin replacement may provide temporary relief, but it may fill again.

Front 14

14. What is Asterixix?

Back 14

asterixis is a motor disturbance marked by intermittent lapses of an assumed posture as a result of intermittency of sustained contraction of groups of muscles; called liver flap because of its occurrence in coma associated with liver disease, but also observed in other conditions.

It can sometimes be observed in renal failure and azotemia
Hyperbaric respiratory failure
Those addicted to narcotics.

Front 15

15. List three mechanisms by which lactulose improves hepatic encephalopathy.

Back 15

1. The conversion of lactulose to lactic acid results in acidification of the gut lumen. This encourages conversion of NH4 to NH3 and the passage of NH3 from tissues into the lumen.

2. Gut acicdification inhibits ammoniagenic coliform bacteria, leading to increased levels of nonammoniagenic lactobacilli.

3. Lactulose also works as a cathartic, reducing the colonic bacterial load.

Front 16

16. Digitalis has been to cause vasoconstriction of both arterial and venous smooth muscle cells in the mesenteric vasculature. True/False

Back 16

True. This is potentially a dangerous situation. It is difficult to diagnose.

Front 17

17. What medication may transiently reverse hepatic encephalopathy?

Back 17

Flumazenil. The GI tract produces gamma amino butyric acid (GABA). which is a neuro-inhibitory substance.

GABA is the key cerebral nerve endings component. App. 25-45% of cerebral nerve endings are GABAergic.

Front 18

18. What occurs with GABA in cirrhotic patients when it crosses the extra permeable blood brain barrier?

Back 18

It tends to interact with very sensitive postsynaptic GABA receptors.The chloride ionophore is regulated by GABA receptor, in conjunction with receptors for benzodiazepines and barbitutaes. Binding of GABA to its receptor permits an influx of chloride ions into the post-synaptic neuron, which leads to the generation of an inhibitory post synaptic potential.

Front 19

19. A patient reports allergy to albumin. The patient is a Jehovah witness, but requires large volume paracentesis. Is there another option?

Back 19

Terlipressin in a dose of 1 mg every 4 hours for 48 hours may be used as an alternative to albumin for the prevention of circulatory collapse after large volumes of paracentesis.

Front 20

20. What is the V sign of Naclerio?

Back 20

This is noticed in about 25% of patients that have esophageal perforation. These are radiolucent streaks of air, which dissects the facial planes behind the heart to create the shape of the letter V.

Front 21

21. Why are non selective beta blockers preferred in portal hypertension instead of selective beta blockers?

Back 21

The non-selective beta blockers (propranolol, timolol and nadalol) are preferred because they cause decrease in both cardiac output via beta 1 blockade action and splanchnic blood flow, by blocking vasodilating beta 2 receptors at splanchnic vasculature.

Front 22

22. If lipase level is about 2.5-3 times that of amylase it is a strong indication of alcoholic pancreatitis. True/False

Back 22

True.

Front 23

23. What is the rule of thumb for I/V resuscitation in GI bleed?

Back 23

Replace each ml of blood loss with 3 ml of crystalloid fluid.

Front 24

24. If the ratio of BUN/Cr ratio is greater than 30, the source of GI bleed is more likely from the upper GI tract. True/False

Back 24

True.

Front 25

25. What is the disadvantage of using steroids in acute pericarditis?

Back 25

Steroids increase the chance of recurrent pericarditis. Colchicine on the other hand, is an effective treatment. If aspirin and NSAIDS are not sufficient, colchicine is an effective treatment.

Front 26

26. In patients with Cirrhotic ascites, the first line diuretic therapy is the combined use of spironolactone and furosemide. Both drugs can be titrated up as needed. True/False

Back 26

True. The use of 100:40 mg ratio of spironolactone to furosemide is generally recommended.

The accepted dosage range is 400 and 160 mg/day of spironolactone and furosemide respectively.

Front 27

27. What is the Chilaiditi sign?

Back 27

This is a condition where transposition of the loop of the large intestine (transverse segment) occurs in between the diaphragm and the liver. On X ray, it raises the suspicion of perforated viscus. It is usually benign, but may cause pain.

Front 28

28. Which antipsychotic drug has shown efficacy in preventing severe nausea and vomiting?

Back 28

Olanzapine (Zyprexa). Off label it is used as an anti-emetic.

Front 29

29. How would one distinguish between traumatic bloody ascitic tap and non traumatic bloody ascitic fluid?

Back 29

Bloody ascitic fluid from a traumatic tap will be heterogenously bloody, and tend to clot. Non traumatic bloody fluid is usually homogenously red and does not clot because the blood has already been lysed after clotting within the sac.

Front 30

30. What is the Mayo-Robson point?

Back 30

This is a point just above and to the right of the umbilicus. At this point, the tail of the pancreas is projected on the abdominal wall. Tenderness on pressure exists in diseases of the pancreas, and it is a critical sign seen in acute pancreatits.