Flashcards in GI bleeding Deck (33)
Diff b/t upper and lower GI bleeds?
- 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
Presentation of an upper GI bleed?
- blood or coffee grounds (blood oxidized in acid)detected during nasogastric lavage
- BUN to serum creatinine ratio greater than 30
Presentation of lower GI bleed?
- blood clots in the stool
- red blood that is mixed with solid brown stool
- dripping of blood into toilet after a BM
How may hematemesis present?
- red or brown flakes like coffee grounds
When does melena occur?
- may occur with just 50-100 mL of blood loss in upper GI tract
What is hematochezia, source?
- 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
What causes coffee-ground emesis?
- blood sitting in stomach acid causes iron to oxidize resulting in appearance of coffee ground like flakes
All the main characteristics of an upper GI bleed?
- 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
All the maincharacteristics of a lower GI bleed?
- 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)
Where does BUN come from?
- 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
WHen does BUN increase?
- when protein is broken down and more ammonia is formed
- catabolic state
- upper GI bleeding (breakdown of hemoglobin protein by stomach acid and enzymes)
Epidemiology of upper GI bleeds?
- 250,000 hosp. a year in US for acute UGI
- mortality rate of 4-10%
- more than half of pts are older than 60
Most common etiologies of upper GI bleeds?
- 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
Other causes of UGI bleeds?
- aortoenteric fistula: complication post AAA (initial presentation or post graft placement)
- hepatic tumor
- penetrating trauma
- pancreatic malignancy
Etiology of LGI bleeding depending on age?
- age younger than 50: infectious colitis
- older than 50:
- LGI: more common bleed in pts older than 50
Etiology of LGI bleeding - diverticulosis presentation
- cause of 50% of LGIs
- ASA and NSAIDs increase risk of bleeding for diverticulosis
- acute, painless, large volume maroon or bright red hematochezia
Etiology of LGI bleeding - angioectasis presentation?
- painless bleeding in upper or LGI tract
- most common in pts older than 70
etiology of LGI bleed - IBD cause?
- primarily will be UC
etiology of LGI bleed - anorectal disease presentation?
- hemorrhoids and fissures
- bright red blood noted on tp, blood streaked stool or blood dripping into toliet
etiology of LGI bleed - ischemic colitis presentation?
- 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)
When would a LGI bleed caused by radiation induced proctitis present?
- months to years post pelvic radiation
Initial management of GI bleed?
- blood replacement
- GI consult for upper or lower endoscopy
Assessment of the degree of bleeding:
SBP of less than 100 mmHg
HR or more than 100
SBP greater than 100 mmHG
HR of more than 100
normal HR and BP
Labs for GI bleeds?
- CBC: may take 24 hrs to reflect degree of blood loss
- blood type and screening
If your pt has chronic GI blood loss, what will they probably have?
- microcytic, hypochromic anemia
- Fe deficient
How do you stabilize pt with GI bleed?
- 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
- 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
- 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
Tx of GI bleed?
- 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
What should you consider if there is abdominal pain and peritoneal signs?
- bowel or esophageal perforation
How long may it take HCT to reflect current state of blood volume?
- 24 hrs or more
If blood loss is acute RBCs should be? If chronic?
- acute: normocytic anemia
- chronic: microcytic hypochromic anemia