GI bleeding

Question 1

Diff b/t upper and lower GI bleeds?

Answer 1

• ligament of trietz (LoT) is at duodenojejunal jxn
• upper GI bleed is from a source above the LoT
• lower GI bleed from a source below the LoT

Question 2

Presentation of an upper GI bleed?

Answer 2

• hematemesis
• blood or coffee grounds (blood oxidized in acid)detected during nasogastric lavage
• melena
• BUN to serum creatinine ratio greater than 30

Question 3

Presentation of lower GI bleed?

Answer 3

• blood clots in the stool
• red blood that is mixed with solid brown stool
• dripping of blood into toilet after a BM

Question 4

How may hematemesis present?

Answer 4

• red or brown flakes like coffee grounds

Question 5

When does melena occur?

Answer 5

• may occur with just 50-100 mL of blood loss in upper GI tract

Question 6

What is hematochezia, source?

Answer 6

• red or maroon colored stool

- generally from lower GI source but can occur with loss of more than 1000 ml of blood in the upper GI tract

Question 7

What causes coffee-ground emesis?

Answer 7

• blood sitting in stomach acid causes iron to oxidize resulting in appearance of coffee ground like flakes

Question 8

All the main characteristics of an upper GI bleed?

Answer 8

• 2/3 of cases of GIB
• severity: more likely to have sig bleeding (may present with shock if sig blood loss)
• site: above LoT
• presentation: hematemesis, melena, hematochezia if massive UGI of more than 1000 ml
• NG lavage: blood
• bowel sounds: hyperactive
• BUN:creat ratio: greater than 30:1

Question 9

All the maincharacteristics of a lower GI bleed?

Answer 9

• severity: less likely to present with shock or reqr transfusion
• site: below the LoT
• present: hematochezia
• NG lavage: clear fluid
• bowel sounds: normal
• BUN:Creat: normal (could be diff with renal failure)

Question 10

Where does BUN come from?

Answer 10

• when protein is used for energy the carbon is cleaved from the aa and leaves behind a N, the N takes up 3 H+ to form NH3+ which is ammonia
• the ammonia is then processed through the liver to become urea, when urea enters the blood stream it is called blood urea nitrogen, this is then excreted by the kidney

Question 11

WHen does BUN increase?

Answer 11

• when protein is broken down and more ammonia is formed
• burns
• tetracyclines
• fever
• steroids
• catabolic state
• upper GI bleeding (breakdown of hemoglobin protein by stomach acid and enzymes)

Question 12

Epidemiology of upper GI bleeds?

Answer 12

• 250,000 hosp. a year in US for acute UGI
• mortality rate of 4-10%
• more than half of pts are older than 60

Question 13

Most common etiologies of upper GI bleeds?

Answer 13

• PUD 50% - hx should screen for RFs (h pylori, NSAIDs, ZES, smokers)
• portal HTN 20% - most common cause is cirrhosis, results in formation of esophageal, gastric and duodenal varices that can rupture (clotting enzymes also effected in liver)
• M-W tears 10%: laceration of gastroesophageal jxn, often report a hx of retching which may be due to heavy drinking
  seizure, childbirth, straining, defectation, wt lifting
• vascular anomalies 7%: angiodysplasia: small AV malformations (leaky), telangectasis: assoc with CT disease like CREST or HHT
• gastric neoplasm
• erosive gastritis: susually superficial bleeding that doesn’t lead to acute sig blood loss
• erosive esophagitis: secondary to chronic reflux

Question 14

Other causes of UGI bleeds?

Answer 14

• aortoenteric fistula: complication post AAA (initial presentation or post graft placement)
• hepatic tumor
• angioma
• penetrating trauma
• pancreatic malignancy

Question 15

Etiology of LGI bleeding depending on age?

Answer 15

- age younger than 50: infectious colitis
anorectal disease
IBD
- older than 50:
diverticulitis
agioectasis
malignancy
ischemia 

• LGI: more common bleed in pts older than 50

Question 16

Etiology of LGI bleeding - diverticulosis presentation

Answer 16

• cause of 50% of LGIs
• ASA and NSAIDs increase risk of bleeding for diverticulosis
• acute, painless, large volume maroon or bright red hematochezia

Question 17

Etiology of LGI bleeding - angioectasis presentation?

Answer 17

• painless bleeding in upper or LGI tract

- most common in pts older than 70

Question 18

etiology of LGI bleed - IBD cause?

Answer 18

• primarily will be UC

Question 19

etiology of LGI bleed - anorectal disease presentation?

Answer 19

• hemorrhoids and fissures

- bright red blood noted on tp, blood streaked stool or blood dripping into toliet

Question 20

etiology of LGI bleed - ischemic colitis presentation?

Answer 20

• most often in older pts with atherosclerotic disease
• can be complication of aortic surgery
• can be seen in younger pts post long distance running (blood is being diverted away from colon - prolonged shunting)

Question 21

When would a LGI bleed caused by radiation induced proctitis present?

Answer 21

• months to years post pelvic radiation

Question 22

Initial management of GI bleed?

Answer 22

• stabilization
• blood replacement
• GI consult for upper or lower endoscopy

Question 23

Assessment of the degree of bleeding:

Answer 23

- severe: 
SBP of less than 100 mmHg
HR or more than 100
- moderate:
SBP greater than 100 mmHG
HR of more than 100
- minor:
normal HR and BP

Question 24

Labs for GI bleeds?

Answer 24

• CBC: may take 24 hrs to reflect degree of blood loss
• PT/INR
• CMP
• blood type and screening

Question 25

If your pt has chronic GI blood loss, what will they probably have?

Answer 25

- microcytic, hypochromic anemia | - Fe deficient

Question 26

How do you stabilize pt with GI bleed?

Answer 26

- 2 large bore IVs - NS or lactated ringer soln - NG tube +/- can lavage with saline and aspirate contents looking for blood to confirm upper source - IV PPI for UGI - if due to varices from portal HTN then give IV ocreotide or somatostatin to reduce splanchnic blood flow and portal pressures

Question 27

Transfusion guidelines?

Answer 27

- usually target to maintain a Hgb of 7-10 g/dL - Hgb should increase 1 g/dL for each unit transfused - give 1 unit of FFP for each 5 units of packed RBCs (need to replace clotting factors) - transfuse platelets if less than 50K and actively bleeding - FFP if INR is greater than 1.8 - uremic pts may benefit from DDAVP (activates VW factor - works on platelets -- improve platelet fxn

Question 28

Endoscopy indications?

Answer 28

- unless very unstable usually prefer to do bowel prep if colonoscopy is needed - upper endoscopy: can help enhance stomach emptying by administration of IV erythromycin - endoscopy can be dx as well as therapeutic: sclerosis or banding of varices, cautery of bleeding vessels

Question 29

Tx of GI bleed?

Answer 29

- depends on underlying cause of bleed: - may reqr surgical repair - intra-arterial embolization (done percutaneously) - decompression of portal vein with shunt placement if varices not manageable

Question 30

What should you consider if there is abdominal pain and peritoneal signs?

Answer 30

- bowel or esophageal perforation

Question 31

How long may it take HCT to reflect current state of blood volume?

Answer 31

- 24 hrs or more

Question 32

If blood loss is acute RBCs should be? If chronic?

Answer 32

- acute: normocytic anemia | - chronic: microcytic hypochromic anemia

Question 33

The higher the BUN:creat ratio the more likely bleeding is from what source?

Answer 33

- UGI source