MGH PM - Gastroenterology III

Question 1

Nutrition in hospitalized patients - Pathophysiology:

Answer 1

1. When acutely ill, catabolism > anabolism ==> Carbs preferred due to decr. fat metab.
2. When recovering, anabolism > catabolism ==> Body restores protein and muscle loss.

Question 2

Nutrition in hospitalized patients - Critical illness (JPEN 2009):

Answer 2

Goals not well validated but 18-30 kcal/kg/d and 1.2-1.5g/kg/d protein.

Question 3

Nutrition in hospitalized patients - Critical illness - Enteral:

Answer 3

Start w/in 24-48hrs of admission, trend toward decr. infxns and mortality in early (<48h) feeding in critically ill Pts who are adequately nourished at presentation.

Question 4

Nutrition in hospitalized patients - Critical illness - Enteral - Contraindic:

Answer 4

1. Inadequate volume resusc.
2. Intestinal obstruction.
3. Major GIB.
4. Severe vomiting.
5. Ischemic bowel.

Question 5

Nutrition in hospitalized patients - Critical illness - Parenteral:

Answer 5

Start if unable to tolerate enteral w/in 7d or evidence of protein/cal malnutrition on admission.

==> May be beneficial in those below calorie goal w/ enteral (Lancet 2013).

Question 6

Nutrition in hospitalized patients - Critical illness - Parental - Contraindic:

Answer 6

1. Hyperosmolality.
2. Severe electrolyte disturbances.
3. Severe hyperglycemia.

==> Sepsis is a RELATIVE contraindic.

Question 7

Nutrition in hospitalized patients - End-stage liver disease (Clin Gastro & Hep 2012) - Nutrition status …?

Answer 7

Predicts morbidity/mortality malnutrition in 50-90% of cirrhotics.

Question 8

Nutrition in hospitalized patients - End-stage liver disease (Clin Gastro & Hep 2012) - Protein req …?

Answer 8

HIGHER than healthy adults (1-1.5g/kg/d vs 0.8g/kg/d).

==> Restrict ONLY if acute hep encephalopathy.

Question 9

Nutrition in hospitalized patients - End-stage liver disease (Clin Gastro & Hep 2012) - Supplements:

Answer 9

Vit ADEK + Zinc, Selenium.

==> Do NOT carb restrict.

Question 10

Nutrition in hospitalized patients - Refeeding syndrome (BMJ 2008):

Answer 10

Fluid/electrolyte shifts in malnourished Pts receiving artificial nutrition.

==> Hypophosphatemia is HALLMARK, but also decr. K and Mg, hyperglycemia, decr. thiamine, hypervolemia.

Question 11

Nutrition in hospitalized patients - Refeeding syndrome (BMJ 2008) - Prevention:

Answer 11

1. Thiamine 300mg PO qd.
2. Vit B complex tid.
3. MVI.
4. Start feeding at 10kcal/kg/d (or 25% of estim goal) and incr. over 3-5days.

==> Advance only when electrolytes are w/in nl range.

==> Follow electrolytes and volume status, rehydrating and repleting.

Question 12

Diverticular disease - Diverticulosis (Lancet 2004) - Definition:

Answer 12

Acquired herniation of colonic mucosa and submucosa through the colonic wall.

Question 13

Diverticular disease - Diverticulosis (Lancet 2004) - Pathobiology - Existing dogma:

Answer 13

Low-fiber diet ==> Incr. stool transit time and decr. stool volume ==> Incr. intraluminal pressure ==> Herniation where vasa recta penetrate, but now ?’d (Gastro 2012).

Question 14

Diverticular disease - Diverticulosis - Epidemiology:

Answer 14

Prevalence higher w/ incr. age (10% if <40y; 50-66% if >80y).

==> “Westernized” societies.

==> Left side (90%, mostly sigmoid) > Right side of colon (EXCEPT in Asia, where R>L).

Question 15

Diverticular disease - Diverticulosis - Clinical manifestations:

Answer 15

1. Usually asx, but 5-15% develop diverticular hemorrhage and <5% diverticulitis.
2. Nuts, etc. intake in asx diverticulosis does NOT incr. risk of diverticulitis (JAMA 2008).

Question 16

Diverticulitis - Pathophysio (NEJM 2007):

Answer 16

Retention of undigested food and bacteria in diverticulum ==> Fecalith formation ==> Obstruction ==> Compromise of diverticulum’s blood supply, infection, perforation.

Question 17

Diverticulitis - Pathophysio (NEJM 2007) - Uncomplicates and complicated:

Answer 17

Uncomplicated ==> Microperforation ==> Localized infection.

Complicated (25%) ==> Macroperforation ==> Abscess, peritonitis, fistula (65% w/ bladder), obstruction, stricture.

Question 18

Diverticulitis - Clinical manifestations:

Answer 18

LLQ abd pain, fever, N/V, constipation.

Question 19

Diverticulitis - PEx:

Answer 19

Ranges from LLQ tenderness +/- palpable mass to peritoneal signs and septic shock.

Question 20

Diverticulitis - Ddx:

Answer 20

1. IBD.
2. Infectious colitis.
3. PID.
4. Tubal pregnancy.
5. Cystitis.
6. CRC.

Question 21

Diverticulitis - Diagnostic studies:

Answer 21

1. Plain abd radiographs to r/o free air, ileus or obstruction.
2. Abdominal CT (I+O+): >95% Se and Sp ==> Assess complicated disease (abscess, fistula).
3. Colono contraindicated acutely ==> Incr. risk of perforation ==> Do 6wk after to r/o neoplasm.

Question 22

Diverticulitis - Tx (Am J Gastro 2008) - Mild:

Answer 22

OutPt Rx indicated if Pt has few comorbidities and can tolerate POs.

==> PO abx: (MNZ + FQ) or amox/clav for 7-10d.

==> Liquid diet until clinical improvement, though recent evidence suggest abx may be unnecessary (Br J Surg 2012).

Question 23

Diverticulitis - Tx (Am J Gastro 2008) - Severe:

Answer 23

1. InPt Rx if cannot take POs.
2. Narcotics needed for pain, or complications.
3. NPO, IV fluids, NGT (if ileus).
4. IV abx (GNR and anaerobic coverage): amp/gent/MNZ or pip/taz.

Question 24

Diverticulitis - Tx (Am J Gastro 2008) - Abscess:

Answer 24

> 4cm should be drained percutaneously or surgically.

Question 25

Diverticulitis - Tx (Am J Gastro 2008) - Surgery:

Answer 25

If progression despite med Rx, undrainable abscess, free perforation or possibly recurrent disease (>2severe episodes).

Question 26

Diverticulitis - Tx (Am J Gastro 2008) - Colonic stricture:

Answer 26

Late complication of diverticulitis. ==> Rx w/ endoscopic dilation vs. resection. ==> Colono after 6wk to exclude neoplasm.

Question 27

Diverticulitis - Prevention:

Answer 27

1. LOW-fiber diet immediately after acute episode. 2. HIGH fiber diet when >6wk w/o sx. ==> Consider mesalamine +/- rifaximin if multiple episodes.

Question 28

Diverticulitis - Risk fo recurrence:

Answer 28

10-30% w/in 10y of 1st episode. ==> More likely 2nd episode complicated.

Question 29

Diverticular hemorrhage - Pathophysio:

Answer 29

Intimal thickening and medial thinning of vasa recta as they course over dome of diverticulum ==> weaking of vascular wall ==> Arterial rupture.

Question 30

Diverticular hemorrhage - Diverticular hemorrhage:

Answer 30

Diverticula MORE COMMON in left colon. ==> But BLEEDING diverticula more often in RIGHT colon.

Question 31

Diverticular hemorrhage - Clinical manifestations:

Answer 31

1. Painless hematochezia/ BRBPR; can have abdominal cramping. 2. Usually stops spontaneously (-75%) but resolution may occur over hrs-days. 20% recur.

Question 32

Diverticular hemorrhage - Diagnostic studies:

Answer 32

1. Colono ==> Rapid prep w/ PEG-based solution via NGT. | 2. Arteriography +/- tagged RBC scan if severe bleeding.

Question 33

Diverticular hemorrhage - Tx:

Answer 33

1. Colono: epinephrine inj +/- electrocautery (NEJM 2000), hemoclip, banding. 2. Arteriography: Intra-arterial vasopressin infusion or embolization. 3. Surgery: If above modalities fail and bleeding is persistent and hemodynamically significant.

Question 34

IBD - Definition:

Answer 34

UC ==> Idiopathic inflammation of the colonic MUCOSA. CD ==> Idiopathic TRANSMURAL inflammation of the GI tract, skip areas. Indeterminate colitis ==> In 5-10% of chronic colitis, cannot distinguish UC vs CD even w/ bx.

Question 35

IBD - Epidemiology and pathophysiology (NEJM 2009, Gastro 2011):

Answer 35

1. 1.4million people in US. 2. Prev 1/1000 UC and 1/3000 CD. 3. Incr. incidence in Caucasians, Jews. 4. Age of onset 15-30y in UC and CD; CD is BIMODAL and has a 2nd peak at 50-70y. 5. Smokers incr. risk for CD, whereas nonsmokers + former smokers at incr. risk for UC. Genetic predisposition + disruption of intestinal barrier (epithelial or decr. defenses) +/- Δ in gut microbiota ==> Acute inflam w/o immune downregulation or tolerance ==> Chronic inflam.

Question 36

UC (NEJM 2011, Lancet 2012) - Clinical manifestations:

Answer 36

1. Grossly bloody diarrhea, lower abd cramps, urgency, tenesmus. 2. Severe colitis (15%). 3. Extracolonic manifestations (>25%).

Question 37

UC (NEJM 2011, Lancet 2012) - Clinical manifestations - Severe colitis (15%):

Answer 37

1. Progresses rapidly over 1-2wk with decr. Ht. 2. Incr. ESR. 3. Fever. 4. Hypotension. 5. >6 bloody BMs per day. 6. Distended abdomen with absent bowel sounds.

Question 38

UC (NEJM 2011, Lancet 2012) - Clinical manifestations - Extracolonic (>25%):

Answer 38

1. Erythema nodosum. 2. Pyoderma gangrenosum. 3. Aphthous ulcers. 4. Uveitis. 5. Episcleritis. 6. Thromboembolic events. (esp. during a flare; Lancet 2010). 7. AIHA. 8. Seroneg arthritis. 9. Chronic hep. 10. Cirrhosis. 11. PSC (incr. risk for cholangio CA, CRC).